Outcomes of Research or Clinical Trials Activity Levels Acute Flaccid Paralysis Ageing Anaerobic Threshold Anaesthesia Assistive Technology Brain Cardiorespiratory Cardiovascular Clinical Evaluation Cold Intolerance Complementary Therapies Continence Coping Styles and Strategies Cultural Context Diagnosis and Management Differential Diagnosis Drugs Dysphagia Dysphonia Epidemiology Exercise Falls Fatigue Fractures Gender Differences Immune Response Inflammation Late Effects of Polio Muscle Strength Muscular Atrophy Orthoses Pain Polio Immunisation Post-Polio Motor Unit Psychology Quality of Life Renal Complications Respiratory Complications and Management Restless Legs Syndrome Sleep Analaysis Surgery Vitality Vocational Implications

Title order Author order Journal order Date order
Category: Post-Polio Motor Unit

Title: A long-term follow-up study of patients with post-poliomyelitis neuromuscular symptoms
Author: Dalakas MC, Elder G, Hallett M, Ravits J, Baker M, Papadopoulos N, Albrecht P, Sever J
Affiliation: Not stated
Journal: The New England Journal of Medicine
Citation: N Engl J Med. 1986 Apr 10; 314(15):959-63
Publication Year and Month: 1986 04

Abstract: A “post-polio” syndrome characterized by new neuromuscular symptoms, including muscle weakness, may develop years after recovery from acute paralytic poliomyelitis. We studied 27 patients (mean age, 50.6 years) in whom new muscle weakness developed a mean of 28.8 years after recovery from acute polio. We reevaluated these patients during a mean follow-up period of 8.2 years (range, 4.5 to 20) after they were originally studied at the National Institutes of Health. The total mean follow-up period after the onset of new weakness was 12.2 years (range, 6 to 29). The patients were assessed with quantitative muscle testing, muscle biopsy, electromyography, and virologic and immunologic examination of the cerebrospinal fluid. Muscle strength had declined in all patients. The rate of decline averaged 1 percent per year. The decrease was irregular, with subjective plateau periods that ranged from 1 to 10 years. None of the patients had amyotrophic lateral sclerosis. Oligoclonal bands (IgG) were found in the cerebrospinal fluid of 7 of 13 patients studied, but no specific elevation of antibodies to poliovirus was observed in the cerebrospinal fluid. The newly affected muscles that were evaluated longitudinally with follow-up muscle biopsies and electromyography showed signs of chronic and new denervation. Groups of atrophic muscle fibers (group atrophy) and "neurogenic jitter" were not present. New post-polio muscle weakness is not a life-threatening form of motor-neuron deterioration. It appears that this weakness is not due to a loss of whole motor neurons, as in amyotrophic lateral sclerosis, but that it is due to a dysfunction of the surviving motor neurons that causes a slow disintegration of the terminals of individual nerve axons.

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Category: Post-Polio Motor Unit

Title: A rat model of the post-polio motor unit
Author: Pachter BR, Eberstein A
Affiliation: Department of Rehabilitation Medicine, New York University Medical Center, NY 10016
Journal: Orthopedics
Citation: Orthopedics. 1991 Dec; 14(12):1367-73
Publication Year and Month: 1991 12

Abstract: We examined the long-term effects of muscle usage on a rat model of the post-polio motor unit. Isometric tensions, type I and type II muscle fiber areas, the incidence of collateral sprouting, and motor endplate morphology were examined following 1, 3, 6, and 9 months of partial denervation in rat plantaris muscle. Full morphologic and functional stability of the expanded motor units occurred at 6 months post-partial denervation. Fiber hypertrophy was observed, possibly the result of compensatory work hypertrophy due to muscle overuse. Following 9 months of partial denervation and muscle overuse, the twitch and tetanic tensions and type I and type II muscle fiber areas were significantly reduced as compared to sham controls; angulated myofibers and group atrophy also were seen. The percent collateral sprouting, the number of terminal branches per endplate, and the endplate area were all increased, possibly a compensatory response to a decreased synthesis of neurotrophic factor(s) and/or transmitter-related components. These aging-like changes seem to occur earlier in chronically stressed, overenlarged, and overworked motor units.

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Category: Post-Polio Motor Unit

Title: Acute and latent effect of poliomyelitis on the motor unit as revealed by electromyography
Author: Wiechers DO
Affiliation: Not stated
Journal: Orthopedics
Citation: Orthopedics. 1985 Jul; 8(7):870-2
Publication Year and Month: 1985 07

Abstract: When polio virus attacks the motor neuron it may be completely destroyed, damaged, or unaffected. Muscle fibers of a destroyed motor neuron are orphaned or reinnervated. Nearby functioning motor units will then send terminal axon sprouts to reinnervate the orphaned muscle fibers. If there are too many orphaned muscle fibers and not enough surviving motor units to reinnervate them, the orphaned muscle fibers will continue to fibrillate until they atrophy and die. The resultant effect of poliomyelitis upon the affected muscle is an overall loss of motor units with the remaining units innervating many more muscle fibers than they originally did. There appears to be a late effect of polio upon these larger reinnervated motor units. After approximately 20 to 30 years, impulse transmission to the muscle fibers of the large reinnervated motor unit begins to fail. These transmission difficulties increase with age and time from recovery. These late onset transmission abnormalities may be factors in patient complaints of fatigue and progressive weakness.

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Category: Post-Polio Motor Unit

Title: An algorithm for automatic detection of repeater F-waves and MUNE studies
Author: N. TuğrulArtuğ, N. Görkem Şirin, Emel Oğuz Akarsu, M. Baris Baslo, A. EmreÖge
Affiliation: Electrical and Electronics Engineering, Istanbul Arel University, Tepekent, Buyukcekmece, Istanbul, Turkey

Istanbul Medical Faculty, Istanbul University, Fatih, Capa, Istanbul, Turkey
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Biomedical Signal Processing and Control
Volume 51, May 2019, Pages 264-276
Publication Year and Month: 2019 05

Abstract: The present study aims to develop an algorithm and software that automatically detects repeater F-waves which are very difficult to analyze when elicited as high number of recordings in motor unit number estimation studies. The main strategy of the study was to take the repeater F waves discriminated by the neurologist, from limited number of recordings, as the gold standard and to test the conformity of the results of the new automated method.

Ten patients with ALS and ten healthy controls were evaluated. 90 F-waves with supramaximal stimuli and 300 F-waves with submaximal stimuli were recorded. Supramaximal recordings were evaluated both manually by an expert neurologist and automatically by the developed software to test the performance of the algorithm. The results both acquired from the neurologist and from the software were found compatible. Therefore, the main expected impact of the present study is to make the analysis of repeater F waves easier primarily in motor unit number estimation studies, since there is currently a continuing need for such automated programs in clinical neurophysiology.

Submaximal recordings were examined only by the developed software. The extracted features were: maximum M response amplitude, mean power of M response, mean of sMUP values, MUNE value, number of baskets, persistence of F-waves, persistence of repeater F-waves, mean of F-waves’ powers, median of F-waves’ powers. Feature selection methods were also applied to determine the most valuable features. Various classifiers such as multi-layer perceptron (MLP), radial basis function network (RBF), support vector machines (SVM) and k nearest neighbors (k-NN) were tested to differentiate two classes. Initially all features, then decreased numbers of features after feature selection process were applied to the aforementioned classifiers. The classification performance usually increased when decreased features were applied to intelligent systems. Ulnar recordings under submaximal stimulation showed better performance when compared with supramaximal equivalents or median nerve equivalents. The highest performance was obtained as 90% with k-NN algorithm which was a committee decision based classifier. This result was achieved with only two features, namely mean of sMUP amplitude and MUNE value.

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Outcome of Research: More research required

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Category: Muscular Atrophy, Post-Polio Motor Unit

Title: An autopsy case of progressive generalized muscle atrophy over 14 years due to post-polio syndrome
Author: Oki R (1), Uchino A, Izumi Y, Ogawa H, Murayama S, Kaji R
Affiliation: (1) Department of Clinical Neuroscience, Institute of Health Bioscience, University of Tokushima Graduate School
Journal: Rinsho Shinkeigaku (Clinical Neurology)
Citation: Rinsho Shinkeigaku. 2015 Nov 30
Publication Year and Month: 2015 11

Abstract: We report the case of a 72-year-old man who had contracted acute paralytic poliomyelitis in his childhood. Thereafter, he had suffered from paresis involving the left lower limb, with no relapse or progression of the disease. He began noticing slowly progressive muscle weakness and atrophy in the upper and lower extremities in his 60s. At the age of 72, muscle weakness developed rapidly, and he demonstrated dyspnea on exertion and dysphagia. He died after about 14 years from the onset of muscle weakness symptoms. Autopsy findings demonstrated motoneuron loss and glial scars not only in the plaque-like lesions in the anterior horns, which were sequelae of old poliomyelitis, but also throughout the spine. No Bunina bodies, TDP-43, and ubiquitin inclusions were found. Post-polio syndrome is rarely fatal due to rapid progressive dyspnea and dysphagia. Thus, the pathological findings in the patient are considered to be related to the development of muscle weakness.

Conclusions:

Outcome of Research: Not applicable

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Comments (if any): The full paper is in Japanese.

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Category: Post-Polio Motor Unit

Title: Are the nonparalytic muscles of polio survivors free from the risk of post-polio syndrome?
Author: K.Sawada, M.Horii, D.Imoto, Y.Mikami, T.Kubo
Affiliation: Kyoto Prefectural University of Medicine, Department of Rehabilitation Medicine, Kyoto, Japan
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Volume 61, Supplement, July 2018, Page e263
Publication Year and Month: 2018 07

Abstract: Introduction/Background
The aim of this study was to reveal the relation between the neurogenetic change in the nonparalytic muscles in upper and lower limbs of Polio survivors and the later muscle strength decline.

Material and method
Retrospective study. We looked back the data of electromyography (EMG) of Polio survivors in our Polio clinic (average age: 58.9). Muscles whose strength at EMG had been normal were extracted. We looked up the muscle strength at EMG time and two years later from medical record.

Results
The subjects were 23 deltoid (middle strand), 40 biceps branchii, 36 triceps branchii, 24 vastus lateralis, 19 tibialis anterior, and gastrocnemius (medial head). The ratio of neurogenic change subject (giant spike or interference pattern reduction) was, 30.4%, 25.0%, 36.1%, 62.5%, 47.4%, and 73.7%, respectively. In neurogenic change group of Biceps, 50.0% showed decline in their muscle strength. In non-neurogenic change group of Deltoid, 25.0% showed decline in their muscle strength.

Conclusions: Conclusion
Present study suggested that some muscle strength decline may be caused by Post-polio syndrome (PPS), and that EMG might be the most useful tool for the risk detection of PPS, especially for Biceps branchii. On the other hand, the fact that 25% of Deltoid non-neurogenic change group showed muscle strength decline was not understood in this study. Pain or disuse from disorder in shoulder joint might possibly be as a cause.

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: Changes in macro electromyography over time in patients with a history of polio: a comparison of 2 muscles.
Author: Sandberg A, Stalberg E
Affiliation: Department of Clinical Neurophysiology, Uppsala University Hospital, ing 85, 3 tr., S-751 85 Uppsala, Sweden.
Journal: Archives of Physical Medicine and Rehabilitation
Citation: 2004 Jul;85(7):1174-82.
Publication Year and Month: 2004 07

Abstract: OBJECTIVE:
To investigate whether changes over time are different in a weight-bearing leg muscle than in a less heavily used arm muscle.

DESIGN:
Prospective study.

SETTING:
University hospital laboratory.

PARTICIPANTS:
Twenty-three patients with a history of poliomyelitis.

INTERVENTION:
Two investigations were performed 5 years apart, using macro electromyography and the patients' own assessments of symptoms in the tibial anterior and the biceps brachii muscles. Test-retest of macro electromyography was performed in controls and in patients with old polio.

MAIN OUTCOME MEASURES:
Macro motor unit potential (MUP) and symptoms in the tibial anterior and biceps brachii over time.

RESULTS:
The macro MUP amplitude increased by 24% (P<.05) in the tibial anterior but was unchanged in the biceps brachii muscle.

Conclusions: CONCLUSIONS:
An increase in the macro MUP amplitude of the tibial anterior muscle, but not of the biceps brachii, most likely indicates a more pronounced ongoing denervation-reinnervation process over time in the tibial anterior. This difference could be activity dependent, but other factors cannot be excluded.

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: CMAP scan and scanning EMG in the same muscle: Two cases with post-polio muscular atrophy
Author: Mehmet Baris Baslo, Nermin G.Sirin, EmelOguz-Akarsu, ElifKocasoy-Orhan, BaharErbas, ImranGoker, TugrulArtugAli EmreOge
Affiliation:
Journal: Clinical Neurophysiology
Citation: Volume 129, Supplement 1, May 2018, Page e32

Publication Year and Month: 2018 05

Abstract: Post-polio muscular atrophy (PPMA) is characterized by new onset or increased weakness in patients with prior poliomyelitis after a stable period of time. Loss of highly reinnervated motor units during ageing has been accused for the development of this syndrome which is also known as “unstable-polio”. These patients have less number of motor units that can be estimated by conventional electrophysiological methods. By showing the large steps, CMAP scan provides information about the amount of collateral reinnervation in the construction of total muscle response (CMAP). As well as the number of motor units, their territory is also an object of curiosity. It is possible to record bioelectrical activity of motor unit lengthwise by scanning EMG and depict the temporal and spatial features of motor unit action potential (MUAP). This presentation aims to combine the findings in CMAP scan with scanning EMG and draw attention to reinnervation status of 2 PPMA patients whose tibialis anterior (TA) muscles were affected in different degrees.

Methods
Two patients aged 39and 41 years were included. Patient 1 had PPMA for 8 years and his TA muscle strength was 3-/5, whereas Patient 2 showed PPMA findings for 1 year and his TA strength was 4/5. CMAP scan of TA muscle on recently affected side was performed with a commercially available software. In scanning EMG, MU territories were scanned with a concentric needle electrode (CNE) which is attached to a stepper motor. Another CNE is used for sweep triggering with the rate of selected motor units’ firing frequency. Acquired signals were processed by the dedicated software designed by the authors.

Results
CMAP scan of Patient 1 revealed a 1.65 mV CMAP constituting of 4 very large steps and Patient 2 revealed a 5.5 mV CMAP containing a few smaller steps. In scanning EMG, both patients’ motor units showed increased voltage in different parts corresponding to dense areas arisen from collateral reinnervation. Interestingly, the patient with more pronounced weakness for a longer period revealed both huge steps in his CMAP scan and also showed electrically silent areas in his scanned motor units. On the other hand, the patient with stronger TA muscle did not show very large steps or silent areas in his CMAP scan and MU scan, respectively.

Conclusions: Loss of dense motor units leads to PPMA. However, in PPMA patients with severe weakness which is depicted by less number of motor units and presence of huge steps in CMAP scan, loss of fractions in motor unit territory might be a principal contributing factor which can only be demonstrated by scanning EMG.

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: Correlation of Electrophysiology with Pathology, Pathogenesis, and Anticholinesterase Therapy in Post-Polio Syndrome
Author: Neil R. Cashman and Daria A. Trojan
Affiliation: Department of Neurology, Montreal Neurological Institute and Hospital, McGill University
Journal: Annals of the New York Academy of Sciences
Citation: Reprinted from The Post-Polio Syndrome: Advances in the Pathogenesis and Treatment
Volume 753 [pp 138-150] of the Annals of the New York Academy of Sciences
May 25, 1995
Publication Year and Month: 1995 05

Abstract:

Conclusions: A great deal of data has been generated on PPS, and a great deal more will be generated before we understand the pathophysiology of this common and disabling disorder. Perhaps now, to guide future work and direct therapeutic approaches, it is best to think of the symptoms of PPS as due to two lesions of the motor unit: a "progressive lesion" and a "fluctuating lesion." The progressive lesion gives rise to the symptom of slowly progressive weakness, and is due to the degeneration of terminal axons (and perhaps motor neurons) over the course of years. This lesion, best articulated by Wiechers and Hubble,[18] has been difficult to objectify because of its indolent nature. However, significant clinical weakening has indeed been quantified by several groups, including Munsat and colleagues,[7] and Sonies and Dalakas.[53] The best objective "proof" of the progressive lesion at present is the appearance of muscle fiber atrophy in biopsies, isolated and in groups, suggesting ongoing "permanent" denervation.[22] Diminution of motor unit size over time, as suggested by the macro-EMG studies of Lange et al.,[32] are also consistent with this hypothesis, albeit more controversial.

The other lesion of the PPS motor unit, hypothesized as a "fluctuating lesion," may be due to dysfunction of terminal axons, which gives rise to symptoms (muscle fatigability, generalized fatigue, and a component of weakness) that can change over the course of minutes to days. The underlying pathophysiology of these symptoms may be due to critical enlargement of motor units with limitations of distal components subserving axonal conduction and NMJ transmission, and/or the constant remodeling of the motor unit which appears to occur in virtually every individual after recovery from paralytic poliomyelitis. The best objective evidence for this ongoing lesion is provided by innumerable electrophysiologic studies demonstrating unstable motor unit action potentials and decrement on repetitive stimulation with conventional EMG, increased SFEMG jitter, and a host ofother studies.[54] In addition, the widespread expression of N-CAM in muscle biopsies of post-polio subjects (sometimes exceeding 10% of fibers)[22] strongly suggests that axono-myofiber interactions are distinctly unstable and/or immature. Clearly, agents that support the integrity or function of motor axonal sprouts may improve or delay patient symptoms in PPS.

Outcome of Research: Not applicable

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Category: Post-Polio Motor Unit

Title: Correlation of motor units with strength and spectral characteristics in polio survivors and controls
Author: Rodriguez AA, Agre JC
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin-Madison Medical School
Journal: Muscle & Nerve
Citation: 1991 May;14(5):429-34.
Publication Year and Month: 1991 05

Abstract: The purpose of this study was to determine whether quantitative motor unit analysis in postpolio individuals correlates with muscle strength, endurance, work capacity, or power spectral characteristics of surface EMG and to determine whether power spectrum differentiates postpolio from control subjects. This study was designed to compare these variables in 34 symptomatic postpolio, 16 asymptomatic postpolio, and 41 control subjects. Quantitative motor unit analysis of the quadriceps femoris muscle was performed using a concentric needle electrode. Isometric knee extension peak torque, endurance (time to exhaustion) at 40% of maximal torque, work capacity (tension time index), and recovery of force through 10 minutes post-exhaustion were determined. Median frequency of the surface power spectrum was determined during the above testing. Power spectrum histograms were compared at the onset and termination of endurance exercise. Motor unit action potential variables did not correlate with isometric peak torque, tension time index, endurance time, recovery of strength, or with median frequency. Surface power spectrum did not differentiate postpolio from control subjects.

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Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: Dynamic electromyography and muscle biopsy changes in a 4-year follow-up: study of patients with a history of polio
Author: Stålberg E, Grimby G
Affiliation: Department of Clinical Neurophysiology, University Hospital, Uppsala, Sweden
Journal: Muscle & Nerve
Citation: Muscle Nerve. 1995 Jul;18(7):699-707
Publication Year and Month: 1995 07

Abstract: Eighteen patients who had had polio 29-56 years prior to the first investigation were studied on two occasions, 4 years apart. Isokinetic and isometric strength measurements and Macro EMG were performed in 28 legs. Muscle biopsy specimens were obtained on both occasions from 11 legs. On average the muscle strength was 56% of control values at the first examination, and decreased by another 8% during the observation period. The muscle fiber area was increased compared to that of controls and did not change significantly. Macro EMG, comprising muscle fiber area and number of muscle fibers, and/or single fiber EMG showed clear signs of reinnervation in all legs. The motor units at the first examination were increased 11-fold, on average, compared with age-matched control values. During the observation period, reinnervation continued and the size of motor units increased by another 56% as a result of ongoing denervation, that is, loss of neurons. This compensation was particularly pronounced in patients with stable conditions. The parameters studied did not reveal any definite pattern predicting future development of new muscle weakness in individual subjects.

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Category: Post-Polio Motor Unit

Title: Electrodiagnostic Findings in 108 Consecutive Patients Referred to a Post-Polio Clinic – The Value of Routine Electrodiagnostic Studies
Author: Anne C. Gawne, Bao T. Pham, and Lauro S. Halstead

Affiliation:
Journal: Annals of the New York Academy of Sciences
Citation: The Post-Polio Syndrome: Advances in the Pathogenesis and Treatment Volume 753 pp 383-385 of the Annals of the New York Academy of Sciences May 25, 1995.
Publication Year and Month: 1995 05

Abstract: Many patients with a history of polio develop new symptoms including weakness, pain, fatigue, and changes in function, or post-polio syndrome (PPS).[1] Before a diagnosis of PPS is made, other diagnoses must first be ruled out. Assessment must be done in a comprehensive and coordinated manner.[2] Therefore, as part of our routine evaluation, we do an electromyogram/nerve conduction study (EMG/NCS) on every patient. During examinations on our clinic patients we began to notice (1) electrodiagnostic evidence of polio in limbs not previously felt to be involved; (2) a normal EMG, or evidence of another disease; and (3) EMG evidence consistent with additional neurological lesions, including compression neuropathies, peripheral neuropathies, and radiculopathies. A prospective study using a routine, standardized four-extremity electrodiagnostic protocol was done to quantify the frequency of these occurrences.

Conclusions: Our findings strongly support the value of a standardized four-extremity EMG/NCS as an adjuvant to a comprehensive history and physical examination. It helps to differentiate between old polio and other neurological diagnoses. There is a high prevalence of subclinical polio, which is important to know about in order to give proper recommendations regarding rest and activity. Given the frequency of risk factors for development of potentially treatable neurological lesions like CTS, early detection is valuable. We believe routine electrodiagnostic testing is essential for proper evaluation and management of the post-polio patient.

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Category: Post-Polio Motor Unit

Title: Electromyographic and morphological functional compensation in late poliomyelitis
Author: Einarsson G, Grimby G, Stålberg E
Affiliation: Department of Rehabilitation Medicine, Gothenburg University, Sweden
Journal: Muscle & Nerve
Citation: Muscle Nerve. 1990 Feb; 13(2):165-71
Publication Year and Month: 1990 02

Abstract: Patients with prior poliomyelitis may experience muscle function deterioration decades after onset of disease. The present study is aimed at describing electromyographic and morphometric evidence of muscular compensation and of on-going muscular instability. Ten subjects 42-62 years of age with onset of polio 25-52 years earlier were studied with macro EMG, single-fiber EMG (SFEMG), muscle strength measurement, and morphometrical analysis of muscle biopsies from the vastus lateralis muscle. SFEMG revealed increased fiber density (FD) and large macro-MUP potentials indicating pronounced reinnervation as compensation to loss of motor neurons. From electrophysiological data of motor unit size, morphometric measures of fiber size, and muscle strength data, the minimal degree of motor neuron loss was estimated to be greater than 70%.

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Category: Post-Polio Motor Unit

Title: Electrophysiology and Electrodiagnosis of the Post-Polio Motor Unit
Author: Daria A. Trojan, MD, Daniel Gendron, MD, Neil R. Cashman, MD
Affiliation:
Journal: Orthopedics
Citation: Orthopedics December 1991 Vol 14 No 12 1353-1361
Publication Year and Month: 1991 12

Abstract: Post-poliomyelitis syndrome refers to new symptoms that may occur years after recovery from poliomyelitis. The most common of these symptoms are new weakness, fatigue, and pain. This article describes electrodiagnostic studies -- conventional electromyography (EMG), single fiber electromyography (SFEMG), and macroelectromyography (macro-EMG) -- that have provided information on the post-polio motor unit and on the possible etiology of some post-polio syndrome symptoms. Muscular fatigue, and indirectly, general fatigue, may be due to neuromuscular junction transmission defects in some post-polio individuals, as suggested by reduction of the compound motor action potentials on repetitive stimulation, and increased jitter and blocking on SFEMG. Progressive weakness and atrophy in post-polio syndrome is probably due to a distal degeneration of post-polio motor units with resultant irreversible muscle fiber denervation. Electrodiagnostic evidence of ongoing denervation includes fibrillation and fasciculation potentials on conventional EMG, increased jitter and blocking on SFEMG, and smaller macro-EMG amplitudes in newly weakened postpolio muscles. However, even though electrodiagnostic studies have provided insight into the possible causes of some postpolio syndrome symptoms, no specific electrodiagnostic test for the syndrome is currently available.

Conclusions:

Outcome of Research: Not applicable

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Category: Post-Polio Motor Unit

Title: Functional recovery – a major risk factor for the development of postpoliomyelitis muscular atrophy
Author: Klingman J, Chui H, Corgiat M, Perry J
Affiliation: Department of Neurology, University of Southern California School of Medicine, Los Angeles
Journal: Archives of Neurology
Citation: Arch Neurol. 1988 Jun;45(6):645-7
Publication Year and Month: 1988 06

Abstract: A retrospective study was undertaken to identify potential risk factors for the development of progressive postpoliomyelitis muscular atrophy (PPMA). Patients with PPMA (n = 57) were compared with patients with a history of poliomyelitis but without a history of progressive weakness (n = 49). Patients who later developed PPMA had histories of more widespread acute paralysis, but relatively greater functional recovery. They were less disabled, and reported higher recent activity levels. Seventy-nine percent of the total variance between the PPMA and control groups could be accounted for by recovery alone (ie, severity minus disability). Functional recovery is generally attributed to reinnervation of sarcomeres by collateral sprouting from surviving lower motor neurons. Since degree of recovery predicts the risk of developing PPMA, our findings suggest that enlarged motor units may carry an increased susceptibility for dysfunction and/or degeneration.

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Category: Post-Polio Motor Unit

Title: How long does denervation take in poliomyelitis? Or is it a lifetime?
Author: Senol, M.G., Kaplan, C., Ozdağ, F., Saraçoğlu, M.
Affiliation: GATA Haydarpasa Training Hospital, Istanbul
Journal:
Citation: Journal of Neurosciences in rural practice
Senol, M.G., Kaplan, C., Ozdağ, F., Saraçoğlu, M. (2017) How long does denervation take in poliomyelitis? Or is it a lifetime? J Neurosci Rural Pract. 8:511-5
Publication Year and Month: 2017 11

Abstract: Background and Objective: This study aims to determine the period of reinnervation in patients with poliomyelitis. This research was conducted to identify the appearance of denervation potentials in patients with poliomyelitis as indicators for reinnervation.

Materials and Methods: A total of 246 male patients with poliomyelitis were assessed electrophysiologically between 1988 and 2007. The mean age was 22.8 (18–42). It has been an average of 19.9 ± 4.9 years since the beginning of complaints from the patients.

Results: The patients had no complaints of newly developing muscle weakness, fatigue, muscle and joint pain, and difficulties in breathing and swallowing. Neurological examinations revealed the absence of myotomal pain and sensory loss. Upon assessment of the patients' limbs, the following findings were revealed: two patients had left upper and lower limb involvement, two patients had left upper and right lower limb involvement, 6 patients had left upper limb involvement, 12 patients had both lower limb involvement, 105 patients had left lower limb involvement, 1 patient had both upper limb involvement, 2 patients had right lower and upper limb involvement, 12 patients had right upper limb involvement, 6 patients had both lower limb involvement, 95 patients had right lower limb involvement, and 3 had all the three extremities affected. The needle electromyography revealed the presence of denervation potentials in 25.2% (62) of the patients.

Conclusion: When poliovirus attacks the motor neuron, this neuron may be completely destroyed, damaged, or unaffected. Reinnervation occurs when nearby functioning motor units send out terminal axon sprouts to reinnervate the damaged muscle fibers. As a consequence of poliomyelitis, several muscle fibers become atrophic and fibrotic, but others continue to survive. This study showed that patients with a history of poliomyelitis experienced denervation with subsequent reinnervation for many years.

Conclusions: The electrophysiological evidences indicating denervation continuing in 25% of the patients are shown in this study.

Outcome of Research: More research required

Availability of Paper: The full text of this paper has been generously made available by the publisher.

Comments (if any): This study has great potential if there is regular monitoring of participants to see the effects of ageing and denervation.

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Category: Post-Polio Motor Unit

Title: Late denervation in patients with antecedent paralytic poliomyelitis
Author: Cashman NR, Maselli R, Wollmann RL, Roos R, Simon R, Antel JP
Affiliation: Not stated
Journal: The New England Journal of Medicine
Citation: N Engl J Med. 1987 Jul 2; 317(1):7-12
Publication Year and Month: 1987 07

Abstract: The development of new weakness, fatigue, and pain decades after acute paralytic poliomyelitis is a recognized syndrome. We conducted a controlled study of this syndrome by analyzing clinical, electromyographic, and muscle-biopsy features in 18 patients with a history of poliomyelitis--13 reporting 1 to 20 years of new weakness and 5 without new symptoms. The patients with new weakness also reported new muscle atrophy (9 of 13) and fatigue (10 of 13), symptoms not reported by the controls. The age at the time of acute poliomyelitis, severity of poliomyelitis, residual disability, number of years since acute poliomyelitis, and age at the time of study were comparable in the weakening and control groups. Evidence of remote denervation consistent with antecedent poliomyelitis was demonstrated in all patients by electromyography or muscle biopsy or both. In addition, active denervation (as evidenced by spontaneous activity on conventional electromyography, increased jitter on single-fiber electromyography, or atrophic myofibers) was found in 12 patients in the weakening group and in all 5 controls. Immunohistochemical detection of myofibers expressing the neural-cell adhesion molecule corroborated ongoing denervation in both patient groups. When muscle data from both groups were pooled, correlations were observed between the extent of past reinnervation and the degree of ongoing motor-unit instability. We conclude that the extensive reinnervation of denervated muscle that occurs in paralytic poliomyelitis may be followed by late denervation of the previously reinnervated muscle fibers. Electromyographic and muscle-biopsy evidence of ongoing denervation does not distinguish between stable patients with prior paralytic poliomyelitis and those with new weakness.

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Category: Post-Polio Motor Unit

Title: Late effects of polio: critical review of the literature on neuromuscular function
Author: Agre JC, Rodríquez AA, Tafel JA
Affiliation: University of Wisconsin - Madison Medical School
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1991 Oct; 72(11):923-31
Publication Year and Month: 1991 10

Abstract: Many individuals who have had poliomyelitis are now complaining of several new problems attributed to their former illness including muscle atrophy; fatigue; progressive weakness; and muscle, back, and joint pain. This paper critically examines the literature regarding the neuromuscular effects of poliomyelitis. Weakness resulting from poliomyelitis was due to destruction of anterior horn cells. After the illness, muscle strength was partially recovered as a result of several physiologic adaptive mechanisms including terminal sprouting and reinnervation, myofiber hypertrophy, and, possibly, myofiber type transformation. Several pathophysiologic and functional etiologies have been proposed for late neuromuscular deterioration, but none has been proven. In fact, to date, there is no objective evidence documenting progressive loss of strength in polio survivors. Studies attempting to differentiate polio survivors with and without symptoms of deterioration have resulted in conflicting results; however, it appears reasonable to conclude that symptomatic postpolio subjects had a more severe illness with greater loss of neuromuscular function. Exercise may be helpful for many postpolio patients, but the prescription must be tailored to the individual to avoid problems of overuse or excessive fatigue.

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Category: Post-Polio Motor Unit

Title: Loss of motor unit size and quadriceps strength over 10 years in post-polio syndrome
Author: Bickerstaffe A (1), van Dijk JP (2), Beelen A (3), Zwarts MJ (4), Nollet F (5)
Affiliation: (1) Department of Rehabilitation, Academic Medical Center (AMC), Postbus 22660, 1100 DD Amsterdam, The Netherlands. Electronic address: [email protected]; (2) Radboud University Nijmegen Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology/Clinical Neurophysiology, Postbus 910, 6500 HB Nijmegen, The Netherlands; Epilepsy Centre Kempenhaeghe, Postbus 61, 5590 AB Heeze, The Netherlands. Electronic address: [email protected]; (3) Department of Rehabilitation, Academic Medical Center (AMC), Postbus 22660, 1100 DD Amsterdam, The Netherlands. Electronic address: [email protected]; (4) Epilepsy Centre Kempenhaeghe, Postbus 61, 5590 AB Heeze, The Netherlands. Electronic address: [email protected]; (5) Department of Rehabilitation, Academic Medical Center (AMC), Postbus 22660, 1100 DD Amsterdam, The Netherlands. Electronic address: [email protected]
Journal: Clinical Neurophysiology
Citation: Clin Neurophysiol. 2014 Jun;125(6):1255-60. doi: 10.1016/j.clinph.2013.11.003
Publication Year and Month: 2014 06

Abstract: OBJECTIVE: To investigate whether strength decline in post-polio syndrome (PPS) results from excessive distal axonal degeneration of enlarged motor units.

METHODS: We assessed changes over 10 years in isometric quadriceps strength, mean motor unit action potential (MUAP) size, root mean squared (RMS) amplitude, and level of interference (LOI) in 47 patients with PPS and 12 healthy controls, using high density surface EMG. At baseline, all patients had symptomatic quadriceps dysfunction, evidenced by transmission defects on single-fibre EMG.

RESULTS: MU size and strength declined significantly by 20% and 15%, respectively in patients with PPS. Those with the largest initial MU sizes exhibited the greatest losses of mean MU size (27%) and proportional decreases in quadriceps strength (23%). Initial strength, change in LOI and change in RMS amplitude together explained 35% of the variability in strength changes in patients. MU size of controls did not change, although they lost 29% strength.

SIGNIFICANCE: This long term follow-up study provides evidence that size diminution of enlarged MUs combined with a reduced number of active MUs contributes to the gradual strength decline in PPS.

Conclusions: MU size and strength declined concomitantly in a homogeneous cohort of patients with PPS and quadriceps dysfunction.

Outcome of Research: Effective

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Category: Post-Polio Motor Unit

Title: Macro electromyography and motor unit number index in the tibialis anterior muscle: differences and similarities in characterizing motor unit properties in prior polio
Author: Sandberg A, Nandedkar SD, Stalberg E
Affiliation: Department of Neuroscience, Clinical Neurophysiology, Uppsala University, Uppsala SE-751 85, Sweden
Journal: Muscle & Nerve
Citation: 2011 Mar;43(3):335-41
Publication Year and Month: 2011 03

Abstract: Our objective was to establish the usefulness of the noninvasive method of the motor unit number index (MUNIX) in a large muscle and to study how macro electromyography (EMG) and MUNIX complement each other in describing the motor units (MUs) in prior polio. MUNIX and macro EMG were performed in 48 tibialis anterior muscles in 33 prior polio patients. In addition, the reproducibility of MUNIX was investigated. It is shown that MUNIX can be used to characterize MUs with high reproducibility, even in a large muscle. As judged by MUNIX values, the patients had a 25% reduction of motor neurons, whereas the macro EMG indicated a loss of 60% of the neurons. Macro EMG showed more pronounced changes compared with control material than the MUNIX. One of the reasons for this finding may be the difference in MU populations studied with the two methods.

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Category: Post-Polio Motor Unit

Title: Motor unit number estimation (MUNE)
Author: Clifton L Gooch, MD. Robert Henderson, MD.
Affiliation: Department of Neurology
University of South Florida, Royal Brisbane & Women's Hospital
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Clifton L Gooch, MDRobert Henderson, MDSection Editor:Jeremy M Shefner, MD, PhDDeputy Editor:April F Eichler, MD, MPH
Publication Year and Month: 2018

Abstract: Electrophysiologic testing of nerve and muscle function has played a critical role in the diagnosis of neuromuscular disease for over half a century. Advances in computer technology and technical refinements have enabled the development of more sophisticated electrodiagnostic methods, which are providing information on the motor nerve and its function in health and disease. Motor unit number estimation (MUNE) is a technique that can be used to determine the approximate number of motor neurons in a muscle or group of muscles. In addition, MUNE methods provide a means of measuring motor unit size, enabling tracking of both loss of motor units and the compensatory phenomenon of collateral reinnervation. MUNE is used most often in neuromuscular disorders such as amyotrophic lateral sclerosis and spinal muscular atrophy.
This topic will review the methodology and utility of MUNE.

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Category: Post-Polio Motor Unit

Title: Motor Unit Number Index (MUNIX) as a biomarker of motor unit loss in post-polio syndrome versus needle EMG
Author: Malgorzata Gawel, Ewa Zalewska, Elżbieta Szmidt-Salkowska, Marta Lipowska, Anna Lusakowska, Anna M.Kaminska, Anna Kostera-Pruszczyk
Affiliation: Department of Neurology, Medical University of Warsaw, 02-097 Warsaw, Banacha 1A str., Poland

Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, 02-109 Warsaw, Ks. Trojdena 4 str., Poland
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Journal of Electromyography and Kinesiology
Volume 46, June 2019, Pages 35-40
Publication Year and Month: 2019 06

Abstract: MUNIX method (Motor Unit Number Index) had been not used to assess number of motor neurons in post-polio syndrome in contrary to needle electromyography.

Objectives
To confirm if MUNIX reflects motor unit loss and clinical stage and to assess difference in MUNIX and EMG results between muscles in different stage.

Methods
132 Muscles (MUNIX) and 96 (EMG) in 12 patients were studied and divided into groups: with normal strength(N), stable weakness and atrophy(S), new weakness and atrophy(W).

Results
In PPS group MUNIX global was 561.36 ± 282.6 (right 6 muscles) and 561.27 ± 281.1 (left) significantly lower than in control group (six muscles 1139.6 ± 164.5) (p < 0.05). MUNIX global correlated with MRC global. MUNIX was greater in muscles with normal strength (95–100% of normal values) than in those with stable weakness (48%-0% of normal values) and new weakness (65%-0% of normal values). Respectively to clinical stage of muscle MUP (motor unit potential) amplitude increased to 350% of normal value, from 250% to 110%, and from 300% to 700%. No correlation was found between MUP parameters and MRC values.

Conclusions: MUNIX reflects motor dysfunction and could be a good biomarker for loss of motor neurons in PPS.

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Category: Post-Polio Motor Unit

Title: Muscle Function, Muscle Structure, and Electrophysiology in a Dynamic Perspective in Late Polio
Author: Gunnar Grimby, MD, PhD, Erik Stålberg, MD.
Affiliation:
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Gunnar Grimby, MD, PhD, Erik Stålberg, MD., Muscle Function, Muscle Structure, and Electrophysiology in a Dynamic Perspective in Late Polio, Chapter 2, pp 15-24.
Publication Year and Month: 1995

Abstract: The muscular impairment in patients with a history of polio varies from none to severe. The relationship between the degree of initial involvement and the effect of various compensatory mechanisms determines the clinical picture, which changes dynamically. Early and late recovery after poliomyelitis depend on a number of factors. Clinical improvement that appears within a few weeks after the acute phase is probably due to recovery in the excitability of functional, but not degenerated, motor neurons. Degeneration of neurons, causing peripheral denervation, is compensated by collateral sprouting, i.e., by nerve twigs branching off from surviving motor units overlapping with the denervated ones. This is most likely the main factor explaining recovery within the first 6-12 months. Another late compensatory process is the increase in size of the muscle fibers. As a result of these processes, normal muscle strength and presumably normal muscle volume can be seen despite a calculated loss exceeding 50% of the number of motor neurons.

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Category: Post-Polio Motor Unit

Title: Neurological manifestations of the post-polio syndrome
Author: Jubelt B, Cashman NR
Affiliation: Les Turner Amyotrophic Lateral Sclerosis Research Laboratory, Northwestern University Medical School, Chicago, Illinois
Journal: Critical Reviews in Neurobiology
Citation: Crit Rev Neurobiol. 1987;3(3):199-220
Publication Year and Month: 1987 03

Abstract: Patients with late effects of poliomyelitis, ie PPS, are being seen at an ever increasing frequency by general physicians, neurologists, and orthopedists. An appropriate time interval for the onset of late manifestations has elapsed since the major epidemics of poliomyelitis in the 1940s and 1950s. Post-polio neurological manifestations primarily include new weakness, atrophy, muscle pain, and fasciculations. Fortunately, the weakness is of a very slow, progressive nature. Abnormal laboratory studies include routine EMG, demonstrating chronic denervation; SFEMG, demonstrating increased fiber density, increased jitter, and blocking; and muscle biopsy most often revealing fiber-type grouping of chronic denervation and small isolated angular (or angulated) fibers and group atrophy in some series, both suggestive of active denervation. Unfortunately, both EMG and muscle biopsy studies suffer from a lack of specificity as they do not appear to distinguish asymptomatic from symptomatic (new weakness, PPMA) patients with prior poliomyelitis. Although the cause of PPMA is unknown, electrophysiological (SFEMG) and muscle biopsy studies suggest that the process involves a loss or dropout of axon terminals of reinnervated motor units. The axons terminal dropout could be due to dysfunction in the cell soma, the axon, or the terminals themselves. Whether motor neuron exhaustion, a persistent viral infection, or immune-mediated mechanisms play a role in the pathogenesis of the late weakness is unclear at present and will require further investigation. Treatment at this time is of a supportive nature. A major controversy involves the role of strengthening exercises in these patients since experimental animal studies suggest that excessive exercise of denervated muscles leads to increased weakness. Clearly, a better understanding of PPS and PPMA will allow more effective management of these patients’ problems and might also provide insight into other motor neuron and neuromuscular junction diseases.

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Category: Post-Polio Motor Unit

Title: Neuromuscular function in polio survivors at one-year follow-up.
Author: Agre JC, Rodriguez AA
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin Medical School, Madison
Journal: Archives of Physical Medicine and Rehabilitation
Citation: 1991 Jan;72(1):7-10.
Publication Year and Month: 1991 01

Abstract: Many polio survivors complain of progressive loss of strength, work capacity, endurance, and ability to recover from fatiguing activity. These variables were measured initially and one year later in the quadriceps muscles of 28 symptomatic and 16 asymptomatic persons who had polio and 38 control individuals. Peak knee extension torque was measured isokinetically and isometrically. Endurance, or the amount of time the subject could maintain isometric torque at 40% of maximal torque, was measured. Work capacity was determined as the product of isometric torque and endurance time. Recovery of strength was measured at regular intervals for ten minutes after the endurance test. Statistical analysis was done by repeated measures ANOVA. Although the initial measures showed significant deficits in mean peak torque, work capacity, and recovery of strength in symptomatic postpolio subjects, no significant changes were found one year later in any of the variables.

Conclusions: Symptomatic postpolio subjects do not lose significant neuromuscular function in one year.

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: P63-S Insidious neuromuscular deterioration in polio survivors demonstrated by CMAP scan analysis.
Author: Sirin NG, Erbas B, Akasu EO, et al.
Affiliation: Istanbul University Istanbul Medical Faculty, Neurology Department, Istanbul, Turkey

Istanbul University Istanbul Medical Faculty, Physical Therapy and Rehabilitation Department, Istanbul, Turkey
Journal: Clinical Neurophysiology
Citation: Volume 130, Issue 7, July 2019, Pages e110-e111

Publication Year and Month: 2019 07

Abstract: This study aimed to explore the subtle motor unit(MU) changes in asymptomatic muscles of poliomyelitis survivors (PS) using CMAP Scan analysis.

Material and method
Nineteen PS cases and 21 controls were recruited. CMAP Scan recordings were obtained from asymptomatic thenar and hypothenar muscles. CMAP Scan parameters indicating nerve excitability [stimulus intensities producing 50%, 95% and 5% of the CMAP amplitude (SI%5, SI%50, SI%95), absolute range width (ARW) (SI%95-SI%5), relative width (RW) (SI95 − SI5)/SI5], all step parameters and D50 which reflect the MU motor unit loss and reinnervation were analyzed. The new motor unit number estimation (MUNE) method, MscanFit was also calculated.

Results
There were no significant differences in ages, maximum CMAP amplitudes and MScanFit MUNE between the groups. PS group median and ulnar D50 values (46.76 ± 10.98, 46.19 ± 12.42 respectively) were lower than control group (37.21 ± 17.37, 36.44 ± 11.99) (p < 0.05). Median nerve,excitability parameters of patients (SI 5%; 14.81 ± 6.97, SI 50%; 19.07 ± 9.2, SI 95%; 24.06 ± 11.52), ARW (9.26 ± 5.79), RW (0.65 ± 0.31) were higher than those of the controls (SI 5%; 9.64 ± 2.57, SI 50%; 11.64 ± 3.27, SI 95%; 13.64 ± 3.66, ARW; 4.00 ± 1.56, RW; 0.42 ± 0.13) (p < 0.05). Median and ulnar nerve step size parameters, step number and step% in the patients were also significantly higher (p < 0.05).

Conclusions: CMAP Scan can show reduced axonal excitability and reveal insidious MU loss and reinnervation in presumably unaffected muscles of PS, regardless of the decrease in CMAP amplitudes or a significant reduction in MUNE values.

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Category: Post-Polio Motor Unit

Title: P66-S Corticospinal function in poliomyelitis survivors
Author: Nermin Gorkem Sirin, Bahar Erbas, Gulsah Gula, Emel Oguz-Akarsu, Hava Ozlem Dede, Elif Kocasoy-Orhan, Mehmet Baris Baslo, Aysegul Ketenci, Halil Atilla Idrisoglu, Ali Emre Oge
Affiliation: Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Istanbul, Turkey

Istanbul University, Istanbul Faculty of Medicine, Department of Physical Medicine and Rehabilitation, Istanbul, Turkey
Journal: Clinical Neurophysiology
Citation: Volume 130, Issue 7, July 2019, Pages e111-e112

Publication Year and Month: 2019 07

Abstract: Poliomyelitis survivors (PS) become candidates to post-polio syndrome (PPS) in their later lives. The mechanism of PPS has been suggested to be multifactorial involving cortical, spinal and peripheral mechanisThe aim of this study was to evaluate TMS parameters in PS and to compare them with those of amyotrophic lateral sclerosis (ALS) patients and controls.

Material and methods
Single and paired TMS, contralateral and ipsilateral silent period (SP) and triple stimulation technique (TST) were performed by recording from abductor digiti minimi (ADM) and abductor pollicis brevis (APB) muscles of 18 PS, 31 ALS patients and 21 controls. The results were compared with mixed ANOVA and nonparametric independent tests.

Results
No significant difference was present for within and between subject factors except those for the different interstimuli intervals. Resting motor threshold and MEP/M% in ADM, MEP amplitudes and latencies and TST% in both ADM and APB were significantly different. In posthoc analyses, MEP latencies were higher and TST% were lower in both ADM and APB in ALS group (20.7 ± 4.2 ms, 22.4 ± 5.0 ms, 83.1 ± 42.2, 72.3 ± 29.9) as compared to PS (18.3 ± 1.0 ms, 19.2 ± 2.0 ms, 101.6 ± 15.9, 98.1 ± 14.9), MEP/M% in ADM were lower in PS group (56.0 ± 13.4) as compared to controls (85.2 ± 23.9). SPs, TST, MEP amplitudes and latencies and MEP/M amplitudes did not show any significant difference between ADM and APB in both patient groups.

Conclusions: Our results revealed upper motor neuron dysfunction in ALS compared to PS and may provide limited evidence about presence of an abnormal cortical drive to mostly uninvolved upper extremity muscles in PS.

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Category: Post-Polio Motor Unit

Title: Polioencephalitis and the Brain Fatigue Generator Model of Post-Viral Fatigue Syndromes
Author: Richard L. Bruno, Ph.D., Nancy M. Frick, Lh.D., Susan Creange, M.A., Jerald R. Zimmerman, M.D., and Todd Lewis, Ph.D.


Affiliation: Post-Polio Rehabilitation and Research Service; Kessler Institute for Rehabilitation, Department of Physical Medicine and Rehabilitation; UMDNJ/New Jersey Medical School, Harvest Center; Hackensack, New Jersey
Journal:
Citation: Journal of Chronic Fatigue Syndrome, 1996; Department of Physical Medicine and Rehabilitation (in press)
Publication Year and Month: 1996

Abstract: Fatigue is the most commonly reported and most debilitating Post-Polio Sequelae (PPS) affecting millions of polio survivors world-wide. Post-polio fatigue is associated with: 1) subjective reports of difficulty with attention, cognition, word-finding and maintaining wakefulness; 2) clinically significant deficits on neuropsychological tests of information processing speed and attention; 3) gray and white matter hyperintensities in the reticular activating system on magnetic resonance imaging of the brain; 4) neuroendocrine evidence of impaired activation of the HPA axis. Many of these findings are identical to those documented following a variety of viral encephalitides, including acute poliovirus infection, lethargic encephalitis, Iceland Disease, myalgic encephalomyelitis, and, most recently, Chronic Fatigue Syndrome. The clinical, historic, neuropsychologic, neuroanatomic and physiologic parallels between poliovirus infection, post-polio fatigue and post-viral fatigue syndromes (PVFS) will be explored in an attempt to describe the pathophysiology of PVFS. The disinhibition of a putative Brain Fatigue Generator will be implicated as a cause of the subjective symptoms and objective signs that accompany PVFS. The results of a pilot placebo-controlled study of a dopamine 2 receptor agonist to treat post-polio fatigue will also be described.

Conclusions:

Outcome of Research: Not applicable

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Category: Post-Polio Motor Unit

Title: Repeater F-waves are signs of motor unit pathology in polio survivors
Author: Hachisuka A (1), Komori T, Abe T, Hachisuka K
Affiliation: (1) Department of Rehabilitation Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu, 807-8555, Japan
Journal: Muscle & Nerve
Citation: Muscle Nerve. 2015 May;51(5):680-5. doi: 10.1002/mus.24428
Publication Year and Month: 2015 05

Abstract: INTRODUCTION: The purpose of this study was to determine whether F-waves reveal electrophysiological features of anterior horn cells in polio survivors.

METHODS: Forty-three polio survivors and 20 healthy controls underwent motor nerve conduction studies of the median and tibial nerves bilaterally, including sampling of F-waves elicited by 100 stimuli and the determination of motor unit number estimation (MUNE).

RESULTS: A significant increase in abnormally stereotyped ("repeater") F-waves and a reduction of F-wave persistence were observed in both nerves in the polio group as compared with the control group. Repeater F-waves had a negative correlation with MUNE.

Conclusions: These trends in F-wave persistence and repeater F-waves after motor unit loss are characteristic findings in polio survivors. Repeater F-waves are a sign of motor unit pathology.

Outcome of Research: Not applicable

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Category: Post-Polio Motor Unit

Title: Stimulation frequency-dependent neuromuscular junction transmission defects in patients with prior poliomyelitis
Author: Daria A. Trojan, Daniel Gendron and Neil R. Cashman
Affiliation: Department of Neurology, McGill University, Montreal Neurological Institute and Hospital
Journal:
Citation: Journal of the Neurological Sciences, 118 (1993) 150-157
Publication Year and Month: 1993 03

Abstract: Generalized fatigue and muscle fatiguability are major symptoms of post-poliomyelitis syndrome (PPS), and may be due to neuromuscular junction transmission defects, as suggested by increased jitter on single fiber electromyography (SFEMG). To determine the etiology of this defect, we studied jitter at low (1, 5 Hz) and high (10, 15, 20 Hz) frequency stimulation with stimulation SFEMG in 17 post-polio patients with muscle fatiguability, and in 9 normal controls. In 5 of 17 PPS patients and in 1 of 9 controls, jitter was significantly higher (unpaired t-test, P < 0.05) at high frequency stimulation (HFS). In the remaining PPS patients and controls there was no significant difference in jitter at high and low stimulation frequencies. PPS patients with increased jitter at HFS had a significantly longer time interval since acute polio (mean 48.5 years) than PPS patients without increased jitter at HFS (mean 40 years; P < 0.05), but were not distinguished by other historical or clinical criteria. We conclude that the neuromuscular junction defect in post-polio patients is similar to that observed in amyotrophic lateral sclerosis, and is probably due to ineffective conduction along immature nerve sprouts and exhaustion of acetylcholine stores. The appearance of an increase in jitter with HFS in post-polio patients may be dependent upon time after acute polio.

Conclusions:

Outcome of Research: Not applicable

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Category: Post-Polio Motor Unit

Title: Vasomotor abnormalities as post-polio sequelae: functional and clinical implications
Author: Bruno RL, Johnson JC, Berman WS
Affiliation: Not stated
Journal: Orthopedics
Citation: Orthopedics. 1985 Jul; 8(7):865-9
Publication Year and Month: 1985 07

Abstract: Persons who had poliomyelitis report cold and discolored extremities and decreased muscle strength when exposed to mildly cool ambient temperatures. Bilateral digital cutaneous blood flow, skin temperature and median nerve latencies and amplitudes were measured at 30 degrees C, 25 degrees C and 20 degrees C in five post-polio subjects and age-matched controls. Cutaneous blood flow was lowest on the more affected side in the post-polio subjects but vasoconstriction with decreasing Ta was equal bilaterally in both groups. With decreasing Ta, median motor nerve latencies became clinically abnormal and “giant” sensory nerve potential amplitudes were seen in a majority of the post-polio subjects. It is concluded that an impairment of sympathetic vasoconstrictor outflow in post-polios allows passive dilatation and engorgement of the cutaneous venous capacitance beds. This promotes uncontrolled heat loss and causes cooling of nerve and muscle that is responsible for the impairment of muscle functioning and the abnormal electrophysiological findings.

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There are currently 31 papers in this category.

Category: Post-Polio Motor Unit

Title: Neuromuscular function in polio survivors at one-year follow-up.
Author: Agre JC, Rodriguez AA
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin Medical School, Madison
Journal: Archives of Physical Medicine and Rehabilitation
Citation: 1991 Jan;72(1):7-10.
Publication Year and Month: 1991 01

Abstract: Many polio survivors complain of progressive loss of strength, work capacity, endurance, and ability to recover from fatiguing activity. These variables were measured initially and one year later in the quadriceps muscles of 28 symptomatic and 16 asymptomatic persons who had polio and 38 control individuals. Peak knee extension torque was measured isokinetically and isometrically. Endurance, or the amount of time the subject could maintain isometric torque at 40% of maximal torque, was measured. Work capacity was determined as the product of isometric torque and endurance time. Recovery of strength was measured at regular intervals for ten minutes after the endurance test. Statistical analysis was done by repeated measures ANOVA. Although the initial measures showed significant deficits in mean peak torque, work capacity, and recovery of strength in symptomatic postpolio subjects, no significant changes were found one year later in any of the variables.

Conclusions: Symptomatic postpolio subjects do not lose significant neuromuscular function in one year.

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: Late effects of polio: critical review of the literature on neuromuscular function
Author: Agre JC, Rodríquez AA, Tafel JA
Affiliation: University of Wisconsin - Madison Medical School
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1991 Oct; 72(11):923-31
Publication Year and Month: 1991 10

Abstract: Many individuals who have had poliomyelitis are now complaining of several new problems attributed to their former illness including muscle atrophy; fatigue; progressive weakness; and muscle, back, and joint pain. This paper critically examines the literature regarding the neuromuscular effects of poliomyelitis. Weakness resulting from poliomyelitis was due to destruction of anterior horn cells. After the illness, muscle strength was partially recovered as a result of several physiologic adaptive mechanisms including terminal sprouting and reinnervation, myofiber hypertrophy, and, possibly, myofiber type transformation. Several pathophysiologic and functional etiologies have been proposed for late neuromuscular deterioration, but none has been proven. In fact, to date, there is no objective evidence documenting progressive loss of strength in polio survivors. Studies attempting to differentiate polio survivors with and without symptoms of deterioration have resulted in conflicting results; however, it appears reasonable to conclude that symptomatic postpolio subjects had a more severe illness with greater loss of neuromuscular function. Exercise may be helpful for many postpolio patients, but the prescription must be tailored to the individual to avoid problems of overuse or excessive fatigue.

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Category: Post-Polio Motor Unit

Title: Electrodiagnostic Findings in 108 Consecutive Patients Referred to a Post-Polio Clinic – The Value of Routine Electrodiagnostic Studies
Author: Anne C. Gawne, Bao T. Pham, and Lauro S. Halstead

Affiliation:
Journal: Annals of the New York Academy of Sciences
Citation: The Post-Polio Syndrome: Advances in the Pathogenesis and Treatment Volume 753 pp 383-385 of the Annals of the New York Academy of Sciences May 25, 1995.
Publication Year and Month: 1995 05

Abstract: Many patients with a history of polio develop new symptoms including weakness, pain, fatigue, and changes in function, or post-polio syndrome (PPS).[1] Before a diagnosis of PPS is made, other diagnoses must first be ruled out. Assessment must be done in a comprehensive and coordinated manner.[2] Therefore, as part of our routine evaluation, we do an electromyogram/nerve conduction study (EMG/NCS) on every patient. During examinations on our clinic patients we began to notice (1) electrodiagnostic evidence of polio in limbs not previously felt to be involved; (2) a normal EMG, or evidence of another disease; and (3) EMG evidence consistent with additional neurological lesions, including compression neuropathies, peripheral neuropathies, and radiculopathies. A prospective study using a routine, standardized four-extremity electrodiagnostic protocol was done to quantify the frequency of these occurrences.

Conclusions: Our findings strongly support the value of a standardized four-extremity EMG/NCS as an adjuvant to a comprehensive history and physical examination. It helps to differentiate between old polio and other neurological diagnoses. There is a high prevalence of subclinical polio, which is important to know about in order to give proper recommendations regarding rest and activity. Given the frequency of risk factors for development of potentially treatable neurological lesions like CTS, early detection is valuable. We believe routine electrodiagnostic testing is essential for proper evaluation and management of the post-polio patient.

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Category: Post-Polio Motor Unit

Title: Loss of motor unit size and quadriceps strength over 10 years in post-polio syndrome
Author: Bickerstaffe A (1), van Dijk JP (2), Beelen A (3), Zwarts MJ (4), Nollet F (5)
Affiliation: (1) Department of Rehabilitation, Academic Medical Center (AMC), Postbus 22660, 1100 DD Amsterdam, The Netherlands. Electronic address: [email protected]; (2) Radboud University Nijmegen Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology/Clinical Neurophysiology, Postbus 910, 6500 HB Nijmegen, The Netherlands; Epilepsy Centre Kempenhaeghe, Postbus 61, 5590 AB Heeze, The Netherlands. Electronic address: [email protected]; (3) Department of Rehabilitation, Academic Medical Center (AMC), Postbus 22660, 1100 DD Amsterdam, The Netherlands. Electronic address: [email protected]; (4) Epilepsy Centre Kempenhaeghe, Postbus 61, 5590 AB Heeze, The Netherlands. Electronic address: [email protected]; (5) Department of Rehabilitation, Academic Medical Center (AMC), Postbus 22660, 1100 DD Amsterdam, The Netherlands. Electronic address: [email protected]
Journal: Clinical Neurophysiology
Citation: Clin Neurophysiol. 2014 Jun;125(6):1255-60. doi: 10.1016/j.clinph.2013.11.003
Publication Year and Month: 2014 06

Abstract: OBJECTIVE: To investigate whether strength decline in post-polio syndrome (PPS) results from excessive distal axonal degeneration of enlarged motor units.

METHODS: We assessed changes over 10 years in isometric quadriceps strength, mean motor unit action potential (MUAP) size, root mean squared (RMS) amplitude, and level of interference (LOI) in 47 patients with PPS and 12 healthy controls, using high density surface EMG. At baseline, all patients had symptomatic quadriceps dysfunction, evidenced by transmission defects on single-fibre EMG.

RESULTS: MU size and strength declined significantly by 20% and 15%, respectively in patients with PPS. Those with the largest initial MU sizes exhibited the greatest losses of mean MU size (27%) and proportional decreases in quadriceps strength (23%). Initial strength, change in LOI and change in RMS amplitude together explained 35% of the variability in strength changes in patients. MU size of controls did not change, although they lost 29% strength.

SIGNIFICANCE: This long term follow-up study provides evidence that size diminution of enlarged MUs combined with a reduced number of active MUs contributes to the gradual strength decline in PPS.

Conclusions: MU size and strength declined concomitantly in a homogeneous cohort of patients with PPS and quadriceps dysfunction.

Outcome of Research: Effective

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Category: Post-Polio Motor Unit

Title: Vasomotor abnormalities as post-polio sequelae: functional and clinical implications
Author: Bruno RL, Johnson JC, Berman WS
Affiliation: Not stated
Journal: Orthopedics
Citation: Orthopedics. 1985 Jul; 8(7):865-9
Publication Year and Month: 1985 07

Abstract: Persons who had poliomyelitis report cold and discolored extremities and decreased muscle strength when exposed to mildly cool ambient temperatures. Bilateral digital cutaneous blood flow, skin temperature and median nerve latencies and amplitudes were measured at 30 degrees C, 25 degrees C and 20 degrees C in five post-polio subjects and age-matched controls. Cutaneous blood flow was lowest on the more affected side in the post-polio subjects but vasoconstriction with decreasing Ta was equal bilaterally in both groups. With decreasing Ta, median motor nerve latencies became clinically abnormal and “giant” sensory nerve potential amplitudes were seen in a majority of the post-polio subjects. It is concluded that an impairment of sympathetic vasoconstrictor outflow in post-polios allows passive dilatation and engorgement of the cutaneous venous capacitance beds. This promotes uncontrolled heat loss and causes cooling of nerve and muscle that is responsible for the impairment of muscle functioning and the abnormal electrophysiological findings.

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Category: Post-Polio Motor Unit

Title: Late denervation in patients with antecedent paralytic poliomyelitis
Author: Cashman NR, Maselli R, Wollmann RL, Roos R, Simon R, Antel JP
Affiliation: Not stated
Journal: The New England Journal of Medicine
Citation: N Engl J Med. 1987 Jul 2; 317(1):7-12
Publication Year and Month: 1987 07

Abstract: The development of new weakness, fatigue, and pain decades after acute paralytic poliomyelitis is a recognized syndrome. We conducted a controlled study of this syndrome by analyzing clinical, electromyographic, and muscle-biopsy features in 18 patients with a history of poliomyelitis--13 reporting 1 to 20 years of new weakness and 5 without new symptoms. The patients with new weakness also reported new muscle atrophy (9 of 13) and fatigue (10 of 13), symptoms not reported by the controls. The age at the time of acute poliomyelitis, severity of poliomyelitis, residual disability, number of years since acute poliomyelitis, and age at the time of study were comparable in the weakening and control groups. Evidence of remote denervation consistent with antecedent poliomyelitis was demonstrated in all patients by electromyography or muscle biopsy or both. In addition, active denervation (as evidenced by spontaneous activity on conventional electromyography, increased jitter on single-fiber electromyography, or atrophic myofibers) was found in 12 patients in the weakening group and in all 5 controls. Immunohistochemical detection of myofibers expressing the neural-cell adhesion molecule corroborated ongoing denervation in both patient groups. When muscle data from both groups were pooled, correlations were observed between the extent of past reinnervation and the degree of ongoing motor-unit instability. We conclude that the extensive reinnervation of denervated muscle that occurs in paralytic poliomyelitis may be followed by late denervation of the previously reinnervated muscle fibers. Electromyographic and muscle-biopsy evidence of ongoing denervation does not distinguish between stable patients with prior paralytic poliomyelitis and those with new weakness.

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Category: Post-Polio Motor Unit

Title: Motor unit number estimation (MUNE)
Author: Clifton L Gooch, MD. Robert Henderson, MD.
Affiliation: Department of Neurology
University of South Florida, Royal Brisbane & Women's Hospital
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Clifton L Gooch, MDRobert Henderson, MDSection Editor:Jeremy M Shefner, MD, PhDDeputy Editor:April F Eichler, MD, MPH
Publication Year and Month: 2018

Abstract: Electrophysiologic testing of nerve and muscle function has played a critical role in the diagnosis of neuromuscular disease for over half a century. Advances in computer technology and technical refinements have enabled the development of more sophisticated electrodiagnostic methods, which are providing information on the motor nerve and its function in health and disease. Motor unit number estimation (MUNE) is a technique that can be used to determine the approximate number of motor neurons in a muscle or group of muscles. In addition, MUNE methods provide a means of measuring motor unit size, enabling tracking of both loss of motor units and the compensatory phenomenon of collateral reinnervation. MUNE is used most often in neuromuscular disorders such as amyotrophic lateral sclerosis and spinal muscular atrophy.
This topic will review the methodology and utility of MUNE.

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Category: Post-Polio Motor Unit

Title: A long-term follow-up study of patients with post-poliomyelitis neuromuscular symptoms
Author: Dalakas MC, Elder G, Hallett M, Ravits J, Baker M, Papadopoulos N, Albrecht P, Sever J
Affiliation: Not stated
Journal: The New England Journal of Medicine
Citation: N Engl J Med. 1986 Apr 10; 314(15):959-63
Publication Year and Month: 1986 04

Abstract: A “post-polio” syndrome characterized by new neuromuscular symptoms, including muscle weakness, may develop years after recovery from acute paralytic poliomyelitis. We studied 27 patients (mean age, 50.6 years) in whom new muscle weakness developed a mean of 28.8 years after recovery from acute polio. We reevaluated these patients during a mean follow-up period of 8.2 years (range, 4.5 to 20) after they were originally studied at the National Institutes of Health. The total mean follow-up period after the onset of new weakness was 12.2 years (range, 6 to 29). The patients were assessed with quantitative muscle testing, muscle biopsy, electromyography, and virologic and immunologic examination of the cerebrospinal fluid. Muscle strength had declined in all patients. The rate of decline averaged 1 percent per year. The decrease was irregular, with subjective plateau periods that ranged from 1 to 10 years. None of the patients had amyotrophic lateral sclerosis. Oligoclonal bands (IgG) were found in the cerebrospinal fluid of 7 of 13 patients studied, but no specific elevation of antibodies to poliovirus was observed in the cerebrospinal fluid. The newly affected muscles that were evaluated longitudinally with follow-up muscle biopsies and electromyography showed signs of chronic and new denervation. Groups of atrophic muscle fibers (group atrophy) and "neurogenic jitter" were not present. New post-polio muscle weakness is not a life-threatening form of motor-neuron deterioration. It appears that this weakness is not due to a loss of whole motor neurons, as in amyotrophic lateral sclerosis, but that it is due to a dysfunction of the surviving motor neurons that causes a slow disintegration of the terminals of individual nerve axons.

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Category: Post-Polio Motor Unit

Title: Stimulation frequency-dependent neuromuscular junction transmission defects in patients with prior poliomyelitis
Author: Daria A. Trojan, Daniel Gendron and Neil R. Cashman
Affiliation: Department of Neurology, McGill University, Montreal Neurological Institute and Hospital
Journal:
Citation: Journal of the Neurological Sciences, 118 (1993) 150-157
Publication Year and Month: 1993 03

Abstract: Generalized fatigue and muscle fatiguability are major symptoms of post-poliomyelitis syndrome (PPS), and may be due to neuromuscular junction transmission defects, as suggested by increased jitter on single fiber electromyography (SFEMG). To determine the etiology of this defect, we studied jitter at low (1, 5 Hz) and high (10, 15, 20 Hz) frequency stimulation with stimulation SFEMG in 17 post-polio patients with muscle fatiguability, and in 9 normal controls. In 5 of 17 PPS patients and in 1 of 9 controls, jitter was significantly higher (unpaired t-test, P < 0.05) at high frequency stimulation (HFS). In the remaining PPS patients and controls there was no significant difference in jitter at high and low stimulation frequencies. PPS patients with increased jitter at HFS had a significantly longer time interval since acute polio (mean 48.5 years) than PPS patients without increased jitter at HFS (mean 40 years; P < 0.05), but were not distinguished by other historical or clinical criteria. We conclude that the neuromuscular junction defect in post-polio patients is similar to that observed in amyotrophic lateral sclerosis, and is probably due to ineffective conduction along immature nerve sprouts and exhaustion of acetylcholine stores. The appearance of an increase in jitter with HFS in post-polio patients may be dependent upon time after acute polio.

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Outcome of Research: Not applicable

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Category: Post-Polio Motor Unit

Title: Electrophysiology and Electrodiagnosis of the Post-Polio Motor Unit
Author: Daria A. Trojan, MD, Daniel Gendron, MD, Neil R. Cashman, MD
Affiliation:
Journal: Orthopedics
Citation: Orthopedics December 1991 Vol 14 No 12 1353-1361
Publication Year and Month: 1991 12

Abstract: Post-poliomyelitis syndrome refers to new symptoms that may occur years after recovery from poliomyelitis. The most common of these symptoms are new weakness, fatigue, and pain. This article describes electrodiagnostic studies -- conventional electromyography (EMG), single fiber electromyography (SFEMG), and macroelectromyography (macro-EMG) -- that have provided information on the post-polio motor unit and on the possible etiology of some post-polio syndrome symptoms. Muscular fatigue, and indirectly, general fatigue, may be due to neuromuscular junction transmission defects in some post-polio individuals, as suggested by reduction of the compound motor action potentials on repetitive stimulation, and increased jitter and blocking on SFEMG. Progressive weakness and atrophy in post-polio syndrome is probably due to a distal degeneration of post-polio motor units with resultant irreversible muscle fiber denervation. Electrodiagnostic evidence of ongoing denervation includes fibrillation and fasciculation potentials on conventional EMG, increased jitter and blocking on SFEMG, and smaller macro-EMG amplitudes in newly weakened postpolio muscles. However, even though electrodiagnostic studies have provided insight into the possible causes of some postpolio syndrome symptoms, no specific electrodiagnostic test for the syndrome is currently available.

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Outcome of Research: Not applicable

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Category: Post-Polio Motor Unit

Title: Electromyographic and morphological functional compensation in late poliomyelitis
Author: Einarsson G, Grimby G, Stålberg E
Affiliation: Department of Rehabilitation Medicine, Gothenburg University, Sweden
Journal: Muscle & Nerve
Citation: Muscle Nerve. 1990 Feb; 13(2):165-71
Publication Year and Month: 1990 02

Abstract: Patients with prior poliomyelitis may experience muscle function deterioration decades after onset of disease. The present study is aimed at describing electromyographic and morphometric evidence of muscular compensation and of on-going muscular instability. Ten subjects 42-62 years of age with onset of polio 25-52 years earlier were studied with macro EMG, single-fiber EMG (SFEMG), muscle strength measurement, and morphometrical analysis of muscle biopsies from the vastus lateralis muscle. SFEMG revealed increased fiber density (FD) and large macro-MUP potentials indicating pronounced reinnervation as compensation to loss of motor neurons. From electrophysiological data of motor unit size, morphometric measures of fiber size, and muscle strength data, the minimal degree of motor neuron loss was estimated to be greater than 70%.

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Category: Post-Polio Motor Unit

Title: Muscle Function, Muscle Structure, and Electrophysiology in a Dynamic Perspective in Late Polio
Author: Gunnar Grimby, MD, PhD, Erik Stålberg, MD.
Affiliation:
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Gunnar Grimby, MD, PhD, Erik Stålberg, MD., Muscle Function, Muscle Structure, and Electrophysiology in a Dynamic Perspective in Late Polio, Chapter 2, pp 15-24.
Publication Year and Month: 1995

Abstract: The muscular impairment in patients with a history of polio varies from none to severe. The relationship between the degree of initial involvement and the effect of various compensatory mechanisms determines the clinical picture, which changes dynamically. Early and late recovery after poliomyelitis depend on a number of factors. Clinical improvement that appears within a few weeks after the acute phase is probably due to recovery in the excitability of functional, but not degenerated, motor neurons. Degeneration of neurons, causing peripheral denervation, is compensated by collateral sprouting, i.e., by nerve twigs branching off from surviving motor units overlapping with the denervated ones. This is most likely the main factor explaining recovery within the first 6-12 months. Another late compensatory process is the increase in size of the muscle fibers. As a result of these processes, normal muscle strength and presumably normal muscle volume can be seen despite a calculated loss exceeding 50% of the number of motor neurons.

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Category: Post-Polio Motor Unit

Title: Repeater F-waves are signs of motor unit pathology in polio survivors
Author: Hachisuka A (1), Komori T, Abe T, Hachisuka K
Affiliation: (1) Department of Rehabilitation Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu, 807-8555, Japan
Journal: Muscle & Nerve
Citation: Muscle Nerve. 2015 May;51(5):680-5. doi: 10.1002/mus.24428
Publication Year and Month: 2015 05

Abstract: INTRODUCTION: The purpose of this study was to determine whether F-waves reveal electrophysiological features of anterior horn cells in polio survivors.

METHODS: Forty-three polio survivors and 20 healthy controls underwent motor nerve conduction studies of the median and tibial nerves bilaterally, including sampling of F-waves elicited by 100 stimuli and the determination of motor unit number estimation (MUNE).

RESULTS: A significant increase in abnormally stereotyped ("repeater") F-waves and a reduction of F-wave persistence were observed in both nerves in the polio group as compared with the control group. Repeater F-waves had a negative correlation with MUNE.

Conclusions: These trends in F-wave persistence and repeater F-waves after motor unit loss are characteristic findings in polio survivors. Repeater F-waves are a sign of motor unit pathology.

Outcome of Research: Not applicable

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Category: Post-Polio Motor Unit

Title: Neurological manifestations of the post-polio syndrome
Author: Jubelt B, Cashman NR
Affiliation: Les Turner Amyotrophic Lateral Sclerosis Research Laboratory, Northwestern University Medical School, Chicago, Illinois
Journal: Critical Reviews in Neurobiology
Citation: Crit Rev Neurobiol. 1987;3(3):199-220
Publication Year and Month: 1987 03

Abstract: Patients with late effects of poliomyelitis, ie PPS, are being seen at an ever increasing frequency by general physicians, neurologists, and orthopedists. An appropriate time interval for the onset of late manifestations has elapsed since the major epidemics of poliomyelitis in the 1940s and 1950s. Post-polio neurological manifestations primarily include new weakness, atrophy, muscle pain, and fasciculations. Fortunately, the weakness is of a very slow, progressive nature. Abnormal laboratory studies include routine EMG, demonstrating chronic denervation; SFEMG, demonstrating increased fiber density, increased jitter, and blocking; and muscle biopsy most often revealing fiber-type grouping of chronic denervation and small isolated angular (or angulated) fibers and group atrophy in some series, both suggestive of active denervation. Unfortunately, both EMG and muscle biopsy studies suffer from a lack of specificity as they do not appear to distinguish asymptomatic from symptomatic (new weakness, PPMA) patients with prior poliomyelitis. Although the cause of PPMA is unknown, electrophysiological (SFEMG) and muscle biopsy studies suggest that the process involves a loss or dropout of axon terminals of reinnervated motor units. The axons terminal dropout could be due to dysfunction in the cell soma, the axon, or the terminals themselves. Whether motor neuron exhaustion, a persistent viral infection, or immune-mediated mechanisms play a role in the pathogenesis of the late weakness is unclear at present and will require further investigation. Treatment at this time is of a supportive nature. A major controversy involves the role of strengthening exercises in these patients since experimental animal studies suggest that excessive exercise of denervated muscles leads to increased weakness. Clearly, a better understanding of PPS and PPMA will allow more effective management of these patients’ problems and might also provide insight into other motor neuron and neuromuscular junction diseases.

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Category: Post-Polio Motor Unit

Title: Are the nonparalytic muscles of polio survivors free from the risk of post-polio syndrome?
Author: K.Sawada, M.Horii, D.Imoto, Y.Mikami, T.Kubo
Affiliation: Kyoto Prefectural University of Medicine, Department of Rehabilitation Medicine, Kyoto, Japan
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Volume 61, Supplement, July 2018, Page e263
Publication Year and Month: 2018 07

Abstract: Introduction/Background
The aim of this study was to reveal the relation between the neurogenetic change in the nonparalytic muscles in upper and lower limbs of Polio survivors and the later muscle strength decline.

Material and method
Retrospective study. We looked back the data of electromyography (EMG) of Polio survivors in our Polio clinic (average age: 58.9). Muscles whose strength at EMG had been normal were extracted. We looked up the muscle strength at EMG time and two years later from medical record.

Results
The subjects were 23 deltoid (middle strand), 40 biceps branchii, 36 triceps branchii, 24 vastus lateralis, 19 tibialis anterior, and gastrocnemius (medial head). The ratio of neurogenic change subject (giant spike or interference pattern reduction) was, 30.4%, 25.0%, 36.1%, 62.5%, 47.4%, and 73.7%, respectively. In neurogenic change group of Biceps, 50.0% showed decline in their muscle strength. In non-neurogenic change group of Deltoid, 25.0% showed decline in their muscle strength.

Conclusions: Conclusion
Present study suggested that some muscle strength decline may be caused by Post-polio syndrome (PPS), and that EMG might be the most useful tool for the risk detection of PPS, especially for Biceps branchii. On the other hand, the fact that 25% of Deltoid non-neurogenic change group showed muscle strength decline was not understood in this study. Pain or disuse from disorder in shoulder joint might possibly be as a cause.

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Category: Post-Polio Motor Unit

Title: Functional recovery – a major risk factor for the development of postpoliomyelitis muscular atrophy
Author: Klingman J, Chui H, Corgiat M, Perry J
Affiliation: Department of Neurology, University of Southern California School of Medicine, Los Angeles
Journal: Archives of Neurology
Citation: Arch Neurol. 1988 Jun;45(6):645-7
Publication Year and Month: 1988 06

Abstract: A retrospective study was undertaken to identify potential risk factors for the development of progressive postpoliomyelitis muscular atrophy (PPMA). Patients with PPMA (n = 57) were compared with patients with a history of poliomyelitis but without a history of progressive weakness (n = 49). Patients who later developed PPMA had histories of more widespread acute paralysis, but relatively greater functional recovery. They were less disabled, and reported higher recent activity levels. Seventy-nine percent of the total variance between the PPMA and control groups could be accounted for by recovery alone (ie, severity minus disability). Functional recovery is generally attributed to reinnervation of sarcomeres by collateral sprouting from surviving lower motor neurons. Since degree of recovery predicts the risk of developing PPMA, our findings suggest that enlarged motor units may carry an increased susceptibility for dysfunction and/or degeneration.

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Category: Post-Polio Motor Unit

Title: Motor Unit Number Index (MUNIX) as a biomarker of motor unit loss in post-polio syndrome versus needle EMG
Author: Malgorzata Gawel, Ewa Zalewska, Elżbieta Szmidt-Salkowska, Marta Lipowska, Anna Lusakowska, Anna M.Kaminska, Anna Kostera-Pruszczyk
Affiliation: Department of Neurology, Medical University of Warsaw, 02-097 Warsaw, Banacha 1A str., Poland

Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, 02-109 Warsaw, Ks. Trojdena 4 str., Poland
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Journal of Electromyography and Kinesiology
Volume 46, June 2019, Pages 35-40
Publication Year and Month: 2019 06

Abstract: MUNIX method (Motor Unit Number Index) had been not used to assess number of motor neurons in post-polio syndrome in contrary to needle electromyography.

Objectives
To confirm if MUNIX reflects motor unit loss and clinical stage and to assess difference in MUNIX and EMG results between muscles in different stage.

Methods
132 Muscles (MUNIX) and 96 (EMG) in 12 patients were studied and divided into groups: with normal strength(N), stable weakness and atrophy(S), new weakness and atrophy(W).

Results
In PPS group MUNIX global was 561.36 ± 282.6 (right 6 muscles) and 561.27 ± 281.1 (left) significantly lower than in control group (six muscles 1139.6 ± 164.5) (p < 0.05). MUNIX global correlated with MRC global. MUNIX was greater in muscles with normal strength (95–100% of normal values) than in those with stable weakness (48%-0% of normal values) and new weakness (65%-0% of normal values). Respectively to clinical stage of muscle MUP (motor unit potential) amplitude increased to 350% of normal value, from 250% to 110%, and from 300% to 700%. No correlation was found between MUP parameters and MRC values.

Conclusions: MUNIX reflects motor dysfunction and could be a good biomarker for loss of motor neurons in PPS.

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Category: Post-Polio Motor Unit

Title: CMAP scan and scanning EMG in the same muscle: Two cases with post-polio muscular atrophy
Author: Mehmet Baris Baslo, Nermin G.Sirin, EmelOguz-Akarsu, ElifKocasoy-Orhan, BaharErbas, ImranGoker, TugrulArtugAli EmreOge
Affiliation:
Journal: Clinical Neurophysiology
Citation: Volume 129, Supplement 1, May 2018, Page e32

Publication Year and Month: 2018 05

Abstract: Post-polio muscular atrophy (PPMA) is characterized by new onset or increased weakness in patients with prior poliomyelitis after a stable period of time. Loss of highly reinnervated motor units during ageing has been accused for the development of this syndrome which is also known as “unstable-polio”. These patients have less number of motor units that can be estimated by conventional electrophysiological methods. By showing the large steps, CMAP scan provides information about the amount of collateral reinnervation in the construction of total muscle response (CMAP). As well as the number of motor units, their territory is also an object of curiosity. It is possible to record bioelectrical activity of motor unit lengthwise by scanning EMG and depict the temporal and spatial features of motor unit action potential (MUAP). This presentation aims to combine the findings in CMAP scan with scanning EMG and draw attention to reinnervation status of 2 PPMA patients whose tibialis anterior (TA) muscles were affected in different degrees.

Methods
Two patients aged 39and 41 years were included. Patient 1 had PPMA for 8 years and his TA muscle strength was 3-/5, whereas Patient 2 showed PPMA findings for 1 year and his TA strength was 4/5. CMAP scan of TA muscle on recently affected side was performed with a commercially available software. In scanning EMG, MU territories were scanned with a concentric needle electrode (CNE) which is attached to a stepper motor. Another CNE is used for sweep triggering with the rate of selected motor units’ firing frequency. Acquired signals were processed by the dedicated software designed by the authors.

Results
CMAP scan of Patient 1 revealed a 1.65 mV CMAP constituting of 4 very large steps and Patient 2 revealed a 5.5 mV CMAP containing a few smaller steps. In scanning EMG, both patients’ motor units showed increased voltage in different parts corresponding to dense areas arisen from collateral reinnervation. Interestingly, the patient with more pronounced weakness for a longer period revealed both huge steps in his CMAP scan and also showed electrically silent areas in his scanned motor units. On the other hand, the patient with stronger TA muscle did not show very large steps or silent areas in his CMAP scan and MU scan, respectively.

Conclusions: Loss of dense motor units leads to PPMA. However, in PPMA patients with severe weakness which is depicted by less number of motor units and presence of huge steps in CMAP scan, loss of fractions in motor unit territory might be a principal contributing factor which can only be demonstrated by scanning EMG.

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Category: Post-Polio Motor Unit

Title: An algorithm for automatic detection of repeater F-waves and MUNE studies
Author: N. TuğrulArtuğ, N. Görkem Şirin, Emel Oğuz Akarsu, M. Baris Baslo, A. EmreÖge
Affiliation: Electrical and Electronics Engineering, Istanbul Arel University, Tepekent, Buyukcekmece, Istanbul, Turkey

Istanbul Medical Faculty, Istanbul University, Fatih, Capa, Istanbul, Turkey
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Biomedical Signal Processing and Control
Volume 51, May 2019, Pages 264-276
Publication Year and Month: 2019 05

Abstract: The present study aims to develop an algorithm and software that automatically detects repeater F-waves which are very difficult to analyze when elicited as high number of recordings in motor unit number estimation studies. The main strategy of the study was to take the repeater F waves discriminated by the neurologist, from limited number of recordings, as the gold standard and to test the conformity of the results of the new automated method.

Ten patients with ALS and ten healthy controls were evaluated. 90 F-waves with supramaximal stimuli and 300 F-waves with submaximal stimuli were recorded. Supramaximal recordings were evaluated both manually by an expert neurologist and automatically by the developed software to test the performance of the algorithm. The results both acquired from the neurologist and from the software were found compatible. Therefore, the main expected impact of the present study is to make the analysis of repeater F waves easier primarily in motor unit number estimation studies, since there is currently a continuing need for such automated programs in clinical neurophysiology.

Submaximal recordings were examined only by the developed software. The extracted features were: maximum M response amplitude, mean power of M response, mean of sMUP values, MUNE value, number of baskets, persistence of F-waves, persistence of repeater F-waves, mean of F-waves’ powers, median of F-waves’ powers. Feature selection methods were also applied to determine the most valuable features. Various classifiers such as multi-layer perceptron (MLP), radial basis function network (RBF), support vector machines (SVM) and k nearest neighbors (k-NN) were tested to differentiate two classes. Initially all features, then decreased numbers of features after feature selection process were applied to the aforementioned classifiers. The classification performance usually increased when decreased features were applied to intelligent systems. Ulnar recordings under submaximal stimulation showed better performance when compared with supramaximal equivalents or median nerve equivalents. The highest performance was obtained as 90% with k-NN algorithm which was a committee decision based classifier. This result was achieved with only two features, namely mean of sMUP amplitude and MUNE value.

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Category: Post-Polio Motor Unit

Title: Correlation of Electrophysiology with Pathology, Pathogenesis, and Anticholinesterase Therapy in Post-Polio Syndrome
Author: Neil R. Cashman and Daria A. Trojan
Affiliation: Department of Neurology, Montreal Neurological Institute and Hospital, McGill University
Journal: Annals of the New York Academy of Sciences
Citation: Reprinted from The Post-Polio Syndrome: Advances in the Pathogenesis and Treatment
Volume 753 [pp 138-150] of the Annals of the New York Academy of Sciences
May 25, 1995
Publication Year and Month: 1995 05

Abstract:

Conclusions: A great deal of data has been generated on PPS, and a great deal more will be generated before we understand the pathophysiology of this common and disabling disorder. Perhaps now, to guide future work and direct therapeutic approaches, it is best to think of the symptoms of PPS as due to two lesions of the motor unit: a "progressive lesion" and a "fluctuating lesion." The progressive lesion gives rise to the symptom of slowly progressive weakness, and is due to the degeneration of terminal axons (and perhaps motor neurons) over the course of years. This lesion, best articulated by Wiechers and Hubble,[18] has been difficult to objectify because of its indolent nature. However, significant clinical weakening has indeed been quantified by several groups, including Munsat and colleagues,[7] and Sonies and Dalakas.[53] The best objective "proof" of the progressive lesion at present is the appearance of muscle fiber atrophy in biopsies, isolated and in groups, suggesting ongoing "permanent" denervation.[22] Diminution of motor unit size over time, as suggested by the macro-EMG studies of Lange et al.,[32] are also consistent with this hypothesis, albeit more controversial.

The other lesion of the PPS motor unit, hypothesized as a "fluctuating lesion," may be due to dysfunction of terminal axons, which gives rise to symptoms (muscle fatigability, generalized fatigue, and a component of weakness) that can change over the course of minutes to days. The underlying pathophysiology of these symptoms may be due to critical enlargement of motor units with limitations of distal components subserving axonal conduction and NMJ transmission, and/or the constant remodeling of the motor unit which appears to occur in virtually every individual after recovery from paralytic poliomyelitis. The best objective evidence for this ongoing lesion is provided by innumerable electrophysiologic studies demonstrating unstable motor unit action potentials and decrement on repetitive stimulation with conventional EMG, increased SFEMG jitter, and a host ofother studies.[54] In addition, the widespread expression of N-CAM in muscle biopsies of post-polio subjects (sometimes exceeding 10% of fibers)[22] strongly suggests that axono-myofiber interactions are distinctly unstable and/or immature. Clearly, agents that support the integrity or function of motor axonal sprouts may improve or delay patient symptoms in PPS.

Outcome of Research: Not applicable

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Category: Post-Polio Motor Unit

Title: P66-S Corticospinal function in poliomyelitis survivors
Author: Nermin Gorkem Sirin, Bahar Erbas, Gulsah Gula, Emel Oguz-Akarsu, Hava Ozlem Dede, Elif Kocasoy-Orhan, Mehmet Baris Baslo, Aysegul Ketenci, Halil Atilla Idrisoglu, Ali Emre Oge
Affiliation: Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Istanbul, Turkey

Istanbul University, Istanbul Faculty of Medicine, Department of Physical Medicine and Rehabilitation, Istanbul, Turkey
Journal: Clinical Neurophysiology
Citation: Volume 130, Issue 7, July 2019, Pages e111-e112

Publication Year and Month: 2019 07

Abstract: Poliomyelitis survivors (PS) become candidates to post-polio syndrome (PPS) in their later lives. The mechanism of PPS has been suggested to be multifactorial involving cortical, spinal and peripheral mechanisThe aim of this study was to evaluate TMS parameters in PS and to compare them with those of amyotrophic lateral sclerosis (ALS) patients and controls.

Material and methods
Single and paired TMS, contralateral and ipsilateral silent period (SP) and triple stimulation technique (TST) were performed by recording from abductor digiti minimi (ADM) and abductor pollicis brevis (APB) muscles of 18 PS, 31 ALS patients and 21 controls. The results were compared with mixed ANOVA and nonparametric independent tests.

Results
No significant difference was present for within and between subject factors except those for the different interstimuli intervals. Resting motor threshold and MEP/M% in ADM, MEP amplitudes and latencies and TST% in both ADM and APB were significantly different. In posthoc analyses, MEP latencies were higher and TST% were lower in both ADM and APB in ALS group (20.7 ± 4.2 ms, 22.4 ± 5.0 ms, 83.1 ± 42.2, 72.3 ± 29.9) as compared to PS (18.3 ± 1.0 ms, 19.2 ± 2.0 ms, 101.6 ± 15.9, 98.1 ± 14.9), MEP/M% in ADM were lower in PS group (56.0 ± 13.4) as compared to controls (85.2 ± 23.9). SPs, TST, MEP amplitudes and latencies and MEP/M amplitudes did not show any significant difference between ADM and APB in both patient groups.

Conclusions: Our results revealed upper motor neuron dysfunction in ALS compared to PS and may provide limited evidence about presence of an abnormal cortical drive to mostly uninvolved upper extremity muscles in PS.

Outcome of Research: More research required

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Category: Muscular Atrophy, Post-Polio Motor Unit

Title: An autopsy case of progressive generalized muscle atrophy over 14 years due to post-polio syndrome
Author: Oki R (1), Uchino A, Izumi Y, Ogawa H, Murayama S, Kaji R
Affiliation: (1) Department of Clinical Neuroscience, Institute of Health Bioscience, University of Tokushima Graduate School
Journal: Rinsho Shinkeigaku (Clinical Neurology)
Citation: Rinsho Shinkeigaku. 2015 Nov 30
Publication Year and Month: 2015 11

Abstract: We report the case of a 72-year-old man who had contracted acute paralytic poliomyelitis in his childhood. Thereafter, he had suffered from paresis involving the left lower limb, with no relapse or progression of the disease. He began noticing slowly progressive muscle weakness and atrophy in the upper and lower extremities in his 60s. At the age of 72, muscle weakness developed rapidly, and he demonstrated dyspnea on exertion and dysphagia. He died after about 14 years from the onset of muscle weakness symptoms. Autopsy findings demonstrated motoneuron loss and glial scars not only in the plaque-like lesions in the anterior horns, which were sequelae of old poliomyelitis, but also throughout the spine. No Bunina bodies, TDP-43, and ubiquitin inclusions were found. Post-polio syndrome is rarely fatal due to rapid progressive dyspnea and dysphagia. Thus, the pathological findings in the patient are considered to be related to the development of muscle weakness.

Conclusions:

Outcome of Research: Not applicable

Availability of Paper: The full text of this paper has been generously made available by the publisher.

Comments (if any): The full paper is in Japanese.

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Category: Post-Polio Motor Unit

Title: A rat model of the post-polio motor unit
Author: Pachter BR, Eberstein A
Affiliation: Department of Rehabilitation Medicine, New York University Medical Center, NY 10016
Journal: Orthopedics
Citation: Orthopedics. 1991 Dec; 14(12):1367-73
Publication Year and Month: 1991 12

Abstract: We examined the long-term effects of muscle usage on a rat model of the post-polio motor unit. Isometric tensions, type I and type II muscle fiber areas, the incidence of collateral sprouting, and motor endplate morphology were examined following 1, 3, 6, and 9 months of partial denervation in rat plantaris muscle. Full morphologic and functional stability of the expanded motor units occurred at 6 months post-partial denervation. Fiber hypertrophy was observed, possibly the result of compensatory work hypertrophy due to muscle overuse. Following 9 months of partial denervation and muscle overuse, the twitch and tetanic tensions and type I and type II muscle fiber areas were significantly reduced as compared to sham controls; angulated myofibers and group atrophy also were seen. The percent collateral sprouting, the number of terminal branches per endplate, and the endplate area were all increased, possibly a compensatory response to a decreased synthesis of neurotrophic factor(s) and/or transmitter-related components. These aging-like changes seem to occur earlier in chronically stressed, overenlarged, and overworked motor units.

Conclusions:

Outcome of Research:

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Category: Post-Polio Motor Unit

Title: Polioencephalitis and the Brain Fatigue Generator Model of Post-Viral Fatigue Syndromes
Author: Richard L. Bruno, Ph.D., Nancy M. Frick, Lh.D., Susan Creange, M.A., Jerald R. Zimmerman, M.D., and Todd Lewis, Ph.D.


Affiliation: Post-Polio Rehabilitation and Research Service; Kessler Institute for Rehabilitation, Department of Physical Medicine and Rehabilitation; UMDNJ/New Jersey Medical School, Harvest Center; Hackensack, New Jersey
Journal:
Citation: Journal of Chronic Fatigue Syndrome, 1996; Department of Physical Medicine and Rehabilitation (in press)
Publication Year and Month: 1996

Abstract: Fatigue is the most commonly reported and most debilitating Post-Polio Sequelae (PPS) affecting millions of polio survivors world-wide. Post-polio fatigue is associated with: 1) subjective reports of difficulty with attention, cognition, word-finding and maintaining wakefulness; 2) clinically significant deficits on neuropsychological tests of information processing speed and attention; 3) gray and white matter hyperintensities in the reticular activating system on magnetic resonance imaging of the brain; 4) neuroendocrine evidence of impaired activation of the HPA axis. Many of these findings are identical to those documented following a variety of viral encephalitides, including acute poliovirus infection, lethargic encephalitis, Iceland Disease, myalgic encephalomyelitis, and, most recently, Chronic Fatigue Syndrome. The clinical, historic, neuropsychologic, neuroanatomic and physiologic parallels between poliovirus infection, post-polio fatigue and post-viral fatigue syndromes (PVFS) will be explored in an attempt to describe the pathophysiology of PVFS. The disinhibition of a putative Brain Fatigue Generator will be implicated as a cause of the subjective symptoms and objective signs that accompany PVFS. The results of a pilot placebo-controlled study of a dopamine 2 receptor agonist to treat post-polio fatigue will also be described.

Conclusions:

Outcome of Research: Not applicable

Availability of Paper: The full text of this paper has been generously made available by the publisher.

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Category: Post-Polio Motor Unit

Title: Correlation of motor units with strength and spectral characteristics in polio survivors and controls
Author: Rodriguez AA, Agre JC
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin-Madison Medical School
Journal: Muscle & Nerve
Citation: 1991 May;14(5):429-34.
Publication Year and Month: 1991 05

Abstract: The purpose of this study was to determine whether quantitative motor unit analysis in postpolio individuals correlates with muscle strength, endurance, work capacity, or power spectral characteristics of surface EMG and to determine whether power spectrum differentiates postpolio from control subjects. This study was designed to compare these variables in 34 symptomatic postpolio, 16 asymptomatic postpolio, and 41 control subjects. Quantitative motor unit analysis of the quadriceps femoris muscle was performed using a concentric needle electrode. Isometric knee extension peak torque, endurance (time to exhaustion) at 40% of maximal torque, work capacity (tension time index), and recovery of force through 10 minutes post-exhaustion were determined. Median frequency of the surface power spectrum was determined during the above testing. Power spectrum histograms were compared at the onset and termination of endurance exercise. Motor unit action potential variables did not correlate with isometric peak torque, tension time index, endurance time, recovery of strength, or with median frequency. Surface power spectrum did not differentiate postpolio from control subjects.

Conclusions:

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: Macro electromyography and motor unit number index in the tibialis anterior muscle: differences and similarities in characterizing motor unit properties in prior polio
Author: Sandberg A, Nandedkar SD, Stalberg E
Affiliation: Department of Neuroscience, Clinical Neurophysiology, Uppsala University, Uppsala SE-751 85, Sweden
Journal: Muscle & Nerve
Citation: 2011 Mar;43(3):335-41
Publication Year and Month: 2011 03

Abstract: Our objective was to establish the usefulness of the noninvasive method of the motor unit number index (MUNIX) in a large muscle and to study how macro electromyography (EMG) and MUNIX complement each other in describing the motor units (MUs) in prior polio. MUNIX and macro EMG were performed in 48 tibialis anterior muscles in 33 prior polio patients. In addition, the reproducibility of MUNIX was investigated. It is shown that MUNIX can be used to characterize MUs with high reproducibility, even in a large muscle. As judged by MUNIX values, the patients had a 25% reduction of motor neurons, whereas the macro EMG indicated a loss of 60% of the neurons. Macro EMG showed more pronounced changes compared with control material than the MUNIX. One of the reasons for this finding may be the difference in MU populations studied with the two methods.

Conclusions:

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: Changes in macro electromyography over time in patients with a history of polio: a comparison of 2 muscles.
Author: Sandberg A, Stalberg E
Affiliation: Department of Clinical Neurophysiology, Uppsala University Hospital, ing 85, 3 tr., S-751 85 Uppsala, Sweden.
Journal: Archives of Physical Medicine and Rehabilitation
Citation: 2004 Jul;85(7):1174-82.
Publication Year and Month: 2004 07

Abstract: OBJECTIVE:
To investigate whether changes over time are different in a weight-bearing leg muscle than in a less heavily used arm muscle.

DESIGN:
Prospective study.

SETTING:
University hospital laboratory.

PARTICIPANTS:
Twenty-three patients with a history of poliomyelitis.

INTERVENTION:
Two investigations were performed 5 years apart, using macro electromyography and the patients' own assessments of symptoms in the tibial anterior and the biceps brachii muscles. Test-retest of macro electromyography was performed in controls and in patients with old polio.

MAIN OUTCOME MEASURES:
Macro motor unit potential (MUP) and symptoms in the tibial anterior and biceps brachii over time.

RESULTS:
The macro MUP amplitude increased by 24% (P<.05) in the tibial anterior but was unchanged in the biceps brachii muscle.

Conclusions: CONCLUSIONS:
An increase in the macro MUP amplitude of the tibial anterior muscle, but not of the biceps brachii, most likely indicates a more pronounced ongoing denervation-reinnervation process over time in the tibial anterior. This difference could be activity dependent, but other factors cannot be excluded.

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: How long does denervation take in poliomyelitis? Or is it a lifetime?
Author: Senol, M.G., Kaplan, C., Ozdağ, F., Saraçoğlu, M.
Affiliation: GATA Haydarpasa Training Hospital, Istanbul
Journal:
Citation: Journal of Neurosciences in rural practice
Senol, M.G., Kaplan, C., Ozdağ, F., Saraçoğlu, M. (2017) How long does denervation take in poliomyelitis? Or is it a lifetime? J Neurosci Rural Pract. 8:511-5
Publication Year and Month: 2017 11

Abstract: Background and Objective: This study aims to determine the period of reinnervation in patients with poliomyelitis. This research was conducted to identify the appearance of denervation potentials in patients with poliomyelitis as indicators for reinnervation.

Materials and Methods: A total of 246 male patients with poliomyelitis were assessed electrophysiologically between 1988 and 2007. The mean age was 22.8 (18–42). It has been an average of 19.9 ± 4.9 years since the beginning of complaints from the patients.

Results: The patients had no complaints of newly developing muscle weakness, fatigue, muscle and joint pain, and difficulties in breathing and swallowing. Neurological examinations revealed the absence of myotomal pain and sensory loss. Upon assessment of the patients' limbs, the following findings were revealed: two patients had left upper and lower limb involvement, two patients had left upper and right lower limb involvement, 6 patients had left upper limb involvement, 12 patients had both lower limb involvement, 105 patients had left lower limb involvement, 1 patient had both upper limb involvement, 2 patients had right lower and upper limb involvement, 12 patients had right upper limb involvement, 6 patients had both lower limb involvement, 95 patients had right lower limb involvement, and 3 had all the three extremities affected. The needle electromyography revealed the presence of denervation potentials in 25.2% (62) of the patients.

Conclusion: When poliovirus attacks the motor neuron, this neuron may be completely destroyed, damaged, or unaffected. Reinnervation occurs when nearby functioning motor units send out terminal axon sprouts to reinnervate the damaged muscle fibers. As a consequence of poliomyelitis, several muscle fibers become atrophic and fibrotic, but others continue to survive. This study showed that patients with a history of poliomyelitis experienced denervation with subsequent reinnervation for many years.

Conclusions: The electrophysiological evidences indicating denervation continuing in 25% of the patients are shown in this study.

Outcome of Research: More research required

Availability of Paper: The full text of this paper has been generously made available by the publisher.

Comments (if any): This study has great potential if there is regular monitoring of participants to see the effects of ageing and denervation.

Link to Paper (if available): Click here to view full text or to download


Category: Post-Polio Motor Unit

Title: P63-S Insidious neuromuscular deterioration in polio survivors demonstrated by CMAP scan analysis.
Author: Sirin NG, Erbas B, Akasu EO, et al.
Affiliation: Istanbul University Istanbul Medical Faculty, Neurology Department, Istanbul, Turkey

Istanbul University Istanbul Medical Faculty, Physical Therapy and Rehabilitation Department, Istanbul, Turkey
Journal: Clinical Neurophysiology
Citation: Volume 130, Issue 7, July 2019, Pages e110-e111

Publication Year and Month: 2019 07

Abstract: This study aimed to explore the subtle motor unit(MU) changes in asymptomatic muscles of poliomyelitis survivors (PS) using CMAP Scan analysis.

Material and method
Nineteen PS cases and 21 controls were recruited. CMAP Scan recordings were obtained from asymptomatic thenar and hypothenar muscles. CMAP Scan parameters indicating nerve excitability [stimulus intensities producing 50%, 95% and 5% of the CMAP amplitude (SI%5, SI%50, SI%95), absolute range width (ARW) (SI%95-SI%5), relative width (RW) (SI95 − SI5)/SI5], all step parameters and D50 which reflect the MU motor unit loss and reinnervation were analyzed. The new motor unit number estimation (MUNE) method, MscanFit was also calculated.

Results
There were no significant differences in ages, maximum CMAP amplitudes and MScanFit MUNE between the groups. PS group median and ulnar D50 values (46.76 ± 10.98, 46.19 ± 12.42 respectively) were lower than control group (37.21 ± 17.37, 36.44 ± 11.99) (p < 0.05). Median nerve,excitability parameters of patients (SI 5%; 14.81 ± 6.97, SI 50%; 19.07 ± 9.2, SI 95%; 24.06 ± 11.52), ARW (9.26 ± 5.79), RW (0.65 ± 0.31) were higher than those of the controls (SI 5%; 9.64 ± 2.57, SI 50%; 11.64 ± 3.27, SI 95%; 13.64 ± 3.66, ARW; 4.00 ± 1.56, RW; 0.42 ± 0.13) (p < 0.05). Median and ulnar nerve step size parameters, step number and step% in the patients were also significantly higher (p < 0.05).

Conclusions: CMAP Scan can show reduced axonal excitability and reveal insidious MU loss and reinnervation in presumably unaffected muscles of PS, regardless of the decrease in CMAP amplitudes or a significant reduction in MUNE values.

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: Dynamic electromyography and muscle biopsy changes in a 4-year follow-up: study of patients with a history of polio
Author: Stålberg E, Grimby G
Affiliation: Department of Clinical Neurophysiology, University Hospital, Uppsala, Sweden
Journal: Muscle & Nerve
Citation: Muscle Nerve. 1995 Jul;18(7):699-707
Publication Year and Month: 1995 07

Abstract: Eighteen patients who had had polio 29-56 years prior to the first investigation were studied on two occasions, 4 years apart. Isokinetic and isometric strength measurements and Macro EMG were performed in 28 legs. Muscle biopsy specimens were obtained on both occasions from 11 legs. On average the muscle strength was 56% of control values at the first examination, and decreased by another 8% during the observation period. The muscle fiber area was increased compared to that of controls and did not change significantly. Macro EMG, comprising muscle fiber area and number of muscle fibers, and/or single fiber EMG showed clear signs of reinnervation in all legs. The motor units at the first examination were increased 11-fold, on average, compared with age-matched control values. During the observation period, reinnervation continued and the size of motor units increased by another 56% as a result of ongoing denervation, that is, loss of neurons. This compensation was particularly pronounced in patients with stable conditions. The parameters studied did not reveal any definite pattern predicting future development of new muscle weakness in individual subjects.

Conclusions:

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Category: Post-Polio Motor Unit

Title: Acute and latent effect of poliomyelitis on the motor unit as revealed by electromyography
Author: Wiechers DO
Affiliation: Not stated
Journal: Orthopedics
Citation: Orthopedics. 1985 Jul; 8(7):870-2
Publication Year and Month: 1985 07

Abstract: When polio virus attacks the motor neuron it may be completely destroyed, damaged, or unaffected. Muscle fibers of a destroyed motor neuron are orphaned or reinnervated. Nearby functioning motor units will then send terminal axon sprouts to reinnervate the orphaned muscle fibers. If there are too many orphaned muscle fibers and not enough surviving motor units to reinnervate them, the orphaned muscle fibers will continue to fibrillate until they atrophy and die. The resultant effect of poliomyelitis upon the affected muscle is an overall loss of motor units with the remaining units innervating many more muscle fibers than they originally did. There appears to be a late effect of polio upon these larger reinnervated motor units. After approximately 20 to 30 years, impulse transmission to the muscle fibers of the large reinnervated motor unit begins to fail. These transmission difficulties increase with age and time from recovery. These late onset transmission abnormalities may be factors in patient complaints of fatigue and progressive weakness.

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There are currently 31 papers in this category.

Category: Post-Polio Motor Unit

Title: Polioencephalitis and the Brain Fatigue Generator Model of Post-Viral Fatigue Syndromes
Author: Richard L. Bruno, Ph.D., Nancy M. Frick, Lh.D., Susan Creange, M.A., Jerald R. Zimmerman, M.D., and Todd Lewis, Ph.D.


Affiliation: Post-Polio Rehabilitation and Research Service; Kessler Institute for Rehabilitation, Department of Physical Medicine and Rehabilitation; UMDNJ/New Jersey Medical School, Harvest Center; Hackensack, New Jersey
Journal:
Citation: Journal of Chronic Fatigue Syndrome, 1996; Department of Physical Medicine and Rehabilitation (in press)
Publication Year and Month: 1996

Abstract: Fatigue is the most commonly reported and most debilitating Post-Polio Sequelae (PPS) affecting millions of polio survivors world-wide. Post-polio fatigue is associated with: 1) subjective reports of difficulty with attention, cognition, word-finding and maintaining wakefulness; 2) clinically significant deficits on neuropsychological tests of information processing speed and attention; 3) gray and white matter hyperintensities in the reticular activating system on magnetic resonance imaging of the brain; 4) neuroendocrine evidence of impaired activation of the HPA axis. Many of these findings are identical to those documented following a variety of viral encephalitides, including acute poliovirus infection, lethargic encephalitis, Iceland Disease, myalgic encephalomyelitis, and, most recently, Chronic Fatigue Syndrome. The clinical, historic, neuropsychologic, neuroanatomic and physiologic parallels between poliovirus infection, post-polio fatigue and post-viral fatigue syndromes (PVFS) will be explored in an attempt to describe the pathophysiology of PVFS. The disinhibition of a putative Brain Fatigue Generator will be implicated as a cause of the subjective symptoms and objective signs that accompany PVFS. The results of a pilot placebo-controlled study of a dopamine 2 receptor agonist to treat post-polio fatigue will also be described.

Conclusions:

Outcome of Research: Not applicable

Availability of Paper: The full text of this paper has been generously made available by the publisher.

Comments (if any):

Link to Paper (if available): Click here to view full text or to download


Category: Post-Polio Motor Unit

Title: Stimulation frequency-dependent neuromuscular junction transmission defects in patients with prior poliomyelitis
Author: Daria A. Trojan, Daniel Gendron and Neil R. Cashman
Affiliation: Department of Neurology, McGill University, Montreal Neurological Institute and Hospital
Journal:
Citation: Journal of the Neurological Sciences, 118 (1993) 150-157
Publication Year and Month: 1993 03

Abstract: Generalized fatigue and muscle fatiguability are major symptoms of post-poliomyelitis syndrome (PPS), and may be due to neuromuscular junction transmission defects, as suggested by increased jitter on single fiber electromyography (SFEMG). To determine the etiology of this defect, we studied jitter at low (1, 5 Hz) and high (10, 15, 20 Hz) frequency stimulation with stimulation SFEMG in 17 post-polio patients with muscle fatiguability, and in 9 normal controls. In 5 of 17 PPS patients and in 1 of 9 controls, jitter was significantly higher (unpaired t-test, P < 0.05) at high frequency stimulation (HFS). In the remaining PPS patients and controls there was no significant difference in jitter at high and low stimulation frequencies. PPS patients with increased jitter at HFS had a significantly longer time interval since acute polio (mean 48.5 years) than PPS patients without increased jitter at HFS (mean 40 years; P < 0.05), but were not distinguished by other historical or clinical criteria. We conclude that the neuromuscular junction defect in post-polio patients is similar to that observed in amyotrophic lateral sclerosis, and is probably due to ineffective conduction along immature nerve sprouts and exhaustion of acetylcholine stores. The appearance of an increase in jitter with HFS in post-polio patients may be dependent upon time after acute polio.

Conclusions:

Outcome of Research: Not applicable

Availability of Paper: The full text of this paper has been generously made available by the publisher.

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Category: Post-Polio Motor Unit

Title: How long does denervation take in poliomyelitis? Or is it a lifetime?
Author: Senol, M.G., Kaplan, C., Ozdağ, F., Saraçoğlu, M.
Affiliation: GATA Haydarpasa Training Hospital, Istanbul
Journal:
Citation: Journal of Neurosciences in rural practice
Senol, M.G., Kaplan, C., Ozdağ, F., Saraçoğlu, M. (2017) How long does denervation take in poliomyelitis? Or is it a lifetime? J Neurosci Rural Pract. 8:511-5
Publication Year and Month: 2017 11

Abstract: Background and Objective: This study aims to determine the period of reinnervation in patients with poliomyelitis. This research was conducted to identify the appearance of denervation potentials in patients with poliomyelitis as indicators for reinnervation.

Materials and Methods: A total of 246 male patients with poliomyelitis were assessed electrophysiologically between 1988 and 2007. The mean age was 22.8 (18–42). It has been an average of 19.9 ± 4.9 years since the beginning of complaints from the patients.

Results: The patients had no complaints of newly developing muscle weakness, fatigue, muscle and joint pain, and difficulties in breathing and swallowing. Neurological examinations revealed the absence of myotomal pain and sensory loss. Upon assessment of the patients' limbs, the following findings were revealed: two patients had left upper and lower limb involvement, two patients had left upper and right lower limb involvement, 6 patients had left upper limb involvement, 12 patients had both lower limb involvement, 105 patients had left lower limb involvement, 1 patient had both upper limb involvement, 2 patients had right lower and upper limb involvement, 12 patients had right upper limb involvement, 6 patients had both lower limb involvement, 95 patients had right lower limb involvement, and 3 had all the three extremities affected. The needle electromyography revealed the presence of denervation potentials in 25.2% (62) of the patients.

Conclusion: When poliovirus attacks the motor neuron, this neuron may be completely destroyed, damaged, or unaffected. Reinnervation occurs when nearby functioning motor units send out terminal axon sprouts to reinnervate the damaged muscle fibers. As a consequence of poliomyelitis, several muscle fibers become atrophic and fibrotic, but others continue to survive. This study showed that patients with a history of poliomyelitis experienced denervation with subsequent reinnervation for many years.

Conclusions: The electrophysiological evidences indicating denervation continuing in 25% of the patients are shown in this study.

Outcome of Research: More research required

Availability of Paper: The full text of this paper has been generously made available by the publisher.

Comments (if any): This study has great potential if there is regular monitoring of participants to see the effects of ageing and denervation.

Link to Paper (if available): Click here to view full text or to download


Category: Post-Polio Motor Unit

Title: Correlation of Electrophysiology with Pathology, Pathogenesis, and Anticholinesterase Therapy in Post-Polio Syndrome
Author: Neil R. Cashman and Daria A. Trojan
Affiliation: Department of Neurology, Montreal Neurological Institute and Hospital, McGill University
Journal: Annals of the New York Academy of Sciences
Citation: Reprinted from The Post-Polio Syndrome: Advances in the Pathogenesis and Treatment
Volume 753 [pp 138-150] of the Annals of the New York Academy of Sciences
May 25, 1995
Publication Year and Month: 1995 05

Abstract:

Conclusions: A great deal of data has been generated on PPS, and a great deal more will be generated before we understand the pathophysiology of this common and disabling disorder. Perhaps now, to guide future work and direct therapeutic approaches, it is best to think of the symptoms of PPS as due to two lesions of the motor unit: a "progressive lesion" and a "fluctuating lesion." The progressive lesion gives rise to the symptom of slowly progressive weakness, and is due to the degeneration of terminal axons (and perhaps motor neurons) over the course of years. This lesion, best articulated by Wiechers and Hubble,[18] has been difficult to objectify because of its indolent nature. However, significant clinical weakening has indeed been quantified by several groups, including Munsat and colleagues,[7] and Sonies and Dalakas.[53] The best objective "proof" of the progressive lesion at present is the appearance of muscle fiber atrophy in biopsies, isolated and in groups, suggesting ongoing "permanent" denervation.[22] Diminution of motor unit size over time, as suggested by the macro-EMG studies of Lange et al.,[32] are also consistent with this hypothesis, albeit more controversial.

The other lesion of the PPS motor unit, hypothesized as a "fluctuating lesion," may be due to dysfunction of terminal axons, which gives rise to symptoms (muscle fatigability, generalized fatigue, and a component of weakness) that can change over the course of minutes to days. The underlying pathophysiology of these symptoms may be due to critical enlargement of motor units with limitations of distal components subserving axonal conduction and NMJ transmission, and/or the constant remodeling of the motor unit which appears to occur in virtually every individual after recovery from paralytic poliomyelitis. The best objective evidence for this ongoing lesion is provided by innumerable electrophysiologic studies demonstrating unstable motor unit action potentials and decrement on repetitive stimulation with conventional EMG, increased SFEMG jitter, and a host ofother studies.[54] In addition, the widespread expression of N-CAM in muscle biopsies of post-polio subjects (sometimes exceeding 10% of fibers)[22] strongly suggests that axono-myofiber interactions are distinctly unstable and/or immature. Clearly, agents that support the integrity or function of motor axonal sprouts may improve or delay patient symptoms in PPS.

Outcome of Research: Not applicable

Availability of Paper: The full text of this paper has been generously made available by the publisher.

Comments (if any):

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Category: Post-Polio Motor Unit

Title: Electrodiagnostic Findings in 108 Consecutive Patients Referred to a Post-Polio Clinic – The Value of Routine Electrodiagnostic Studies
Author: Anne C. Gawne, Bao T. Pham, and Lauro S. Halstead

Affiliation:
Journal: Annals of the New York Academy of Sciences
Citation: The Post-Polio Syndrome: Advances in the Pathogenesis and Treatment Volume 753 pp 383-385 of the Annals of the New York Academy of Sciences May 25, 1995.
Publication Year and Month: 1995 05

Abstract: Many patients with a history of polio develop new symptoms including weakness, pain, fatigue, and changes in function, or post-polio syndrome (PPS).[1] Before a diagnosis of PPS is made, other diagnoses must first be ruled out. Assessment must be done in a comprehensive and coordinated manner.[2] Therefore, as part of our routine evaluation, we do an electromyogram/nerve conduction study (EMG/NCS) on every patient. During examinations on our clinic patients we began to notice (1) electrodiagnostic evidence of polio in limbs not previously felt to be involved; (2) a normal EMG, or evidence of another disease; and (3) EMG evidence consistent with additional neurological lesions, including compression neuropathies, peripheral neuropathies, and radiculopathies. A prospective study using a routine, standardized four-extremity electrodiagnostic protocol was done to quantify the frequency of these occurrences.

Conclusions: Our findings strongly support the value of a standardized four-extremity EMG/NCS as an adjuvant to a comprehensive history and physical examination. It helps to differentiate between old polio and other neurological diagnoses. There is a high prevalence of subclinical polio, which is important to know about in order to give proper recommendations regarding rest and activity. Given the frequency of risk factors for development of potentially treatable neurological lesions like CTS, early detection is valuable. We believe routine electrodiagnostic testing is essential for proper evaluation and management of the post-polio patient.

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Category: Post-Polio Motor Unit

Title: Functional recovery – a major risk factor for the development of postpoliomyelitis muscular atrophy
Author: Klingman J, Chui H, Corgiat M, Perry J
Affiliation: Department of Neurology, University of Southern California School of Medicine, Los Angeles
Journal: Archives of Neurology
Citation: Arch Neurol. 1988 Jun;45(6):645-7
Publication Year and Month: 1988 06

Abstract: A retrospective study was undertaken to identify potential risk factors for the development of progressive postpoliomyelitis muscular atrophy (PPMA). Patients with PPMA (n = 57) were compared with patients with a history of poliomyelitis but without a history of progressive weakness (n = 49). Patients who later developed PPMA had histories of more widespread acute paralysis, but relatively greater functional recovery. They were less disabled, and reported higher recent activity levels. Seventy-nine percent of the total variance between the PPMA and control groups could be accounted for by recovery alone (ie, severity minus disability). Functional recovery is generally attributed to reinnervation of sarcomeres by collateral sprouting from surviving lower motor neurons. Since degree of recovery predicts the risk of developing PPMA, our findings suggest that enlarged motor units may carry an increased susceptibility for dysfunction and/or degeneration.

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Category: Post-Polio Motor Unit

Title: Late effects of polio: critical review of the literature on neuromuscular function
Author: Agre JC, Rodríquez AA, Tafel JA
Affiliation: University of Wisconsin - Madison Medical School
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1991 Oct; 72(11):923-31
Publication Year and Month: 1991 10

Abstract: Many individuals who have had poliomyelitis are now complaining of several new problems attributed to their former illness including muscle atrophy; fatigue; progressive weakness; and muscle, back, and joint pain. This paper critically examines the literature regarding the neuromuscular effects of poliomyelitis. Weakness resulting from poliomyelitis was due to destruction of anterior horn cells. After the illness, muscle strength was partially recovered as a result of several physiologic adaptive mechanisms including terminal sprouting and reinnervation, myofiber hypertrophy, and, possibly, myofiber type transformation. Several pathophysiologic and functional etiologies have been proposed for late neuromuscular deterioration, but none has been proven. In fact, to date, there is no objective evidence documenting progressive loss of strength in polio survivors. Studies attempting to differentiate polio survivors with and without symptoms of deterioration have resulted in conflicting results; however, it appears reasonable to conclude that symptomatic postpolio subjects had a more severe illness with greater loss of neuromuscular function. Exercise may be helpful for many postpolio patients, but the prescription must be tailored to the individual to avoid problems of overuse or excessive fatigue.

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Category: Post-Polio Motor Unit

Title: Neuromuscular function in polio survivors at one-year follow-up.
Author: Agre JC, Rodriguez AA
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin Medical School, Madison
Journal: Archives of Physical Medicine and Rehabilitation
Citation: 1991 Jan;72(1):7-10.
Publication Year and Month: 1991 01

Abstract: Many polio survivors complain of progressive loss of strength, work capacity, endurance, and ability to recover from fatiguing activity. These variables were measured initially and one year later in the quadriceps muscles of 28 symptomatic and 16 asymptomatic persons who had polio and 38 control individuals. Peak knee extension torque was measured isokinetically and isometrically. Endurance, or the amount of time the subject could maintain isometric torque at 40% of maximal torque, was measured. Work capacity was determined as the product of isometric torque and endurance time. Recovery of strength was measured at regular intervals for ten minutes after the endurance test. Statistical analysis was done by repeated measures ANOVA. Although the initial measures showed significant deficits in mean peak torque, work capacity, and recovery of strength in symptomatic postpolio subjects, no significant changes were found one year later in any of the variables.

Conclusions: Symptomatic postpolio subjects do not lose significant neuromuscular function in one year.

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Category: Post-Polio Motor Unit

Title: Changes in macro electromyography over time in patients with a history of polio: a comparison of 2 muscles.
Author: Sandberg A, Stalberg E
Affiliation: Department of Clinical Neurophysiology, Uppsala University Hospital, ing 85, 3 tr., S-751 85 Uppsala, Sweden.
Journal: Archives of Physical Medicine and Rehabilitation
Citation: 2004 Jul;85(7):1174-82.
Publication Year and Month: 2004 07

Abstract: OBJECTIVE:
To investigate whether changes over time are different in a weight-bearing leg muscle than in a less heavily used arm muscle.

DESIGN:
Prospective study.

SETTING:
University hospital laboratory.

PARTICIPANTS:
Twenty-three patients with a history of poliomyelitis.

INTERVENTION:
Two investigations were performed 5 years apart, using macro electromyography and the patients' own assessments of symptoms in the tibial anterior and the biceps brachii muscles. Test-retest of macro electromyography was performed in controls and in patients with old polio.

MAIN OUTCOME MEASURES:
Macro motor unit potential (MUP) and symptoms in the tibial anterior and biceps brachii over time.

RESULTS:
The macro MUP amplitude increased by 24% (P<.05) in the tibial anterior but was unchanged in the biceps brachii muscle.

Conclusions: CONCLUSIONS:
An increase in the macro MUP amplitude of the tibial anterior muscle, but not of the biceps brachii, most likely indicates a more pronounced ongoing denervation-reinnervation process over time in the tibial anterior. This difference could be activity dependent, but other factors cannot be excluded.

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Category: Post-Polio Motor Unit

Title: Are the nonparalytic muscles of polio survivors free from the risk of post-polio syndrome?
Author: K.Sawada, M.Horii, D.Imoto, Y.Mikami, T.Kubo
Affiliation: Kyoto Prefectural University of Medicine, Department of Rehabilitation Medicine, Kyoto, Japan
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Volume 61, Supplement, July 2018, Page e263
Publication Year and Month: 2018 07

Abstract: Introduction/Background
The aim of this study was to reveal the relation between the neurogenetic change in the nonparalytic muscles in upper and lower limbs of Polio survivors and the later muscle strength decline.

Material and method
Retrospective study. We looked back the data of electromyography (EMG) of Polio survivors in our Polio clinic (average age: 58.9). Muscles whose strength at EMG had been normal were extracted. We looked up the muscle strength at EMG time and two years later from medical record.

Results
The subjects were 23 deltoid (middle strand), 40 biceps branchii, 36 triceps branchii, 24 vastus lateralis, 19 tibialis anterior, and gastrocnemius (medial head). The ratio of neurogenic change subject (giant spike or interference pattern reduction) was, 30.4%, 25.0%, 36.1%, 62.5%, 47.4%, and 73.7%, respectively. In neurogenic change group of Biceps, 50.0% showed decline in their muscle strength. In non-neurogenic change group of Deltoid, 25.0% showed decline in their muscle strength.

Conclusions: Conclusion
Present study suggested that some muscle strength decline may be caused by Post-polio syndrome (PPS), and that EMG might be the most useful tool for the risk detection of PPS, especially for Biceps branchii. On the other hand, the fact that 25% of Deltoid non-neurogenic change group showed muscle strength decline was not understood in this study. Pain or disuse from disorder in shoulder joint might possibly be as a cause.

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Category: Post-Polio Motor Unit

Title: Loss of motor unit size and quadriceps strength over 10 years in post-polio syndrome
Author: Bickerstaffe A (1), van Dijk JP (2), Beelen A (3), Zwarts MJ (4), Nollet F (5)
Affiliation: (1) Department of Rehabilitation, Academic Medical Center (AMC), Postbus 22660, 1100 DD Amsterdam, The Netherlands. Electronic address: [email protected]; (2) Radboud University Nijmegen Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology/Clinical Neurophysiology, Postbus 910, 6500 HB Nijmegen, The Netherlands; Epilepsy Centre Kempenhaeghe, Postbus 61, 5590 AB Heeze, The Netherlands. Electronic address: [email protected]; (3) Department of Rehabilitation, Academic Medical Center (AMC), Postbus 22660, 1100 DD Amsterdam, The Netherlands. Electronic address: [email protected]; (4) Epilepsy Centre Kempenhaeghe, Postbus 61, 5590 AB Heeze, The Netherlands. Electronic address: [email protected]; (5) Department of Rehabilitation, Academic Medical Center (AMC), Postbus 22660, 1100 DD Amsterdam, The Netherlands. Electronic address: [email protected]
Journal: Clinical Neurophysiology
Citation: Clin Neurophysiol. 2014 Jun;125(6):1255-60. doi: 10.1016/j.clinph.2013.11.003
Publication Year and Month: 2014 06

Abstract: OBJECTIVE: To investigate whether strength decline in post-polio syndrome (PPS) results from excessive distal axonal degeneration of enlarged motor units.

METHODS: We assessed changes over 10 years in isometric quadriceps strength, mean motor unit action potential (MUAP) size, root mean squared (RMS) amplitude, and level of interference (LOI) in 47 patients with PPS and 12 healthy controls, using high density surface EMG. At baseline, all patients had symptomatic quadriceps dysfunction, evidenced by transmission defects on single-fibre EMG.

RESULTS: MU size and strength declined significantly by 20% and 15%, respectively in patients with PPS. Those with the largest initial MU sizes exhibited the greatest losses of mean MU size (27%) and proportional decreases in quadriceps strength (23%). Initial strength, change in LOI and change in RMS amplitude together explained 35% of the variability in strength changes in patients. MU size of controls did not change, although they lost 29% strength.

SIGNIFICANCE: This long term follow-up study provides evidence that size diminution of enlarged MUs combined with a reduced number of active MUs contributes to the gradual strength decline in PPS.

Conclusions: MU size and strength declined concomitantly in a homogeneous cohort of patients with PPS and quadriceps dysfunction.

Outcome of Research: Effective

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Category: Post-Polio Motor Unit

Title: CMAP scan and scanning EMG in the same muscle: Two cases with post-polio muscular atrophy
Author: Mehmet Baris Baslo, Nermin G.Sirin, EmelOguz-Akarsu, ElifKocasoy-Orhan, BaharErbas, ImranGoker, TugrulArtugAli EmreOge
Affiliation:
Journal: Clinical Neurophysiology
Citation: Volume 129, Supplement 1, May 2018, Page e32

Publication Year and Month: 2018 05

Abstract: Post-polio muscular atrophy (PPMA) is characterized by new onset or increased weakness in patients with prior poliomyelitis after a stable period of time. Loss of highly reinnervated motor units during ageing has been accused for the development of this syndrome which is also known as “unstable-polio”. These patients have less number of motor units that can be estimated by conventional electrophysiological methods. By showing the large steps, CMAP scan provides information about the amount of collateral reinnervation in the construction of total muscle response (CMAP). As well as the number of motor units, their territory is also an object of curiosity. It is possible to record bioelectrical activity of motor unit lengthwise by scanning EMG and depict the temporal and spatial features of motor unit action potential (MUAP). This presentation aims to combine the findings in CMAP scan with scanning EMG and draw attention to reinnervation status of 2 PPMA patients whose tibialis anterior (TA) muscles were affected in different degrees.

Methods
Two patients aged 39and 41 years were included. Patient 1 had PPMA for 8 years and his TA muscle strength was 3-/5, whereas Patient 2 showed PPMA findings for 1 year and his TA strength was 4/5. CMAP scan of TA muscle on recently affected side was performed with a commercially available software. In scanning EMG, MU territories were scanned with a concentric needle electrode (CNE) which is attached to a stepper motor. Another CNE is used for sweep triggering with the rate of selected motor units’ firing frequency. Acquired signals were processed by the dedicated software designed by the authors.

Results
CMAP scan of Patient 1 revealed a 1.65 mV CMAP constituting of 4 very large steps and Patient 2 revealed a 5.5 mV CMAP containing a few smaller steps. In scanning EMG, both patients’ motor units showed increased voltage in different parts corresponding to dense areas arisen from collateral reinnervation. Interestingly, the patient with more pronounced weakness for a longer period revealed both huge steps in his CMAP scan and also showed electrically silent areas in his scanned motor units. On the other hand, the patient with stronger TA muscle did not show very large steps or silent areas in his CMAP scan and MU scan, respectively.

Conclusions: Loss of dense motor units leads to PPMA. However, in PPMA patients with severe weakness which is depicted by less number of motor units and presence of huge steps in CMAP scan, loss of fractions in motor unit territory might be a principal contributing factor which can only be demonstrated by scanning EMG.

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Category: Post-Polio Motor Unit

Title: P66-S Corticospinal function in poliomyelitis survivors
Author: Nermin Gorkem Sirin, Bahar Erbas, Gulsah Gula, Emel Oguz-Akarsu, Hava Ozlem Dede, Elif Kocasoy-Orhan, Mehmet Baris Baslo, Aysegul Ketenci, Halil Atilla Idrisoglu, Ali Emre Oge
Affiliation: Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Istanbul, Turkey

Istanbul University, Istanbul Faculty of Medicine, Department of Physical Medicine and Rehabilitation, Istanbul, Turkey
Journal: Clinical Neurophysiology
Citation: Volume 130, Issue 7, July 2019, Pages e111-e112

Publication Year and Month: 2019 07

Abstract: Poliomyelitis survivors (PS) become candidates to post-polio syndrome (PPS) in their later lives. The mechanism of PPS has been suggested to be multifactorial involving cortical, spinal and peripheral mechanisThe aim of this study was to evaluate TMS parameters in PS and to compare them with those of amyotrophic lateral sclerosis (ALS) patients and controls.

Material and methods
Single and paired TMS, contralateral and ipsilateral silent period (SP) and triple stimulation technique (TST) were performed by recording from abductor digiti minimi (ADM) and abductor pollicis brevis (APB) muscles of 18 PS, 31 ALS patients and 21 controls. The results were compared with mixed ANOVA and nonparametric independent tests.

Results
No significant difference was present for within and between subject factors except those for the different interstimuli intervals. Resting motor threshold and MEP/M% in ADM, MEP amplitudes and latencies and TST% in both ADM and APB were significantly different. In posthoc analyses, MEP latencies were higher and TST% were lower in both ADM and APB in ALS group (20.7 ± 4.2 ms, 22.4 ± 5.0 ms, 83.1 ± 42.2, 72.3 ± 29.9) as compared to PS (18.3 ± 1.0 ms, 19.2 ± 2.0 ms, 101.6 ± 15.9, 98.1 ± 14.9), MEP/M% in ADM were lower in PS group (56.0 ± 13.4) as compared to controls (85.2 ± 23.9). SPs, TST, MEP amplitudes and latencies and MEP/M amplitudes did not show any significant difference between ADM and APB in both patient groups.

Conclusions: Our results revealed upper motor neuron dysfunction in ALS compared to PS and may provide limited evidence about presence of an abnormal cortical drive to mostly uninvolved upper extremity muscles in PS.

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Category: Post-Polio Motor Unit

Title: P63-S Insidious neuromuscular deterioration in polio survivors demonstrated by CMAP scan analysis.
Author: Sirin NG, Erbas B, Akasu EO, et al.
Affiliation: Istanbul University Istanbul Medical Faculty, Neurology Department, Istanbul, Turkey

Istanbul University Istanbul Medical Faculty, Physical Therapy and Rehabilitation Department, Istanbul, Turkey
Journal: Clinical Neurophysiology
Citation: Volume 130, Issue 7, July 2019, Pages e110-e111

Publication Year and Month: 2019 07

Abstract: This study aimed to explore the subtle motor unit(MU) changes in asymptomatic muscles of poliomyelitis survivors (PS) using CMAP Scan analysis.

Material and method
Nineteen PS cases and 21 controls were recruited. CMAP Scan recordings were obtained from asymptomatic thenar and hypothenar muscles. CMAP Scan parameters indicating nerve excitability [stimulus intensities producing 50%, 95% and 5% of the CMAP amplitude (SI%5, SI%50, SI%95), absolute range width (ARW) (SI%95-SI%5), relative width (RW) (SI95 − SI5)/SI5], all step parameters and D50 which reflect the MU motor unit loss and reinnervation were analyzed. The new motor unit number estimation (MUNE) method, MscanFit was also calculated.

Results
There were no significant differences in ages, maximum CMAP amplitudes and MScanFit MUNE between the groups. PS group median and ulnar D50 values (46.76 ± 10.98, 46.19 ± 12.42 respectively) were lower than control group (37.21 ± 17.37, 36.44 ± 11.99) (p < 0.05). Median nerve,excitability parameters of patients (SI 5%; 14.81 ± 6.97, SI 50%; 19.07 ± 9.2, SI 95%; 24.06 ± 11.52), ARW (9.26 ± 5.79), RW (0.65 ± 0.31) were higher than those of the controls (SI 5%; 9.64 ± 2.57, SI 50%; 11.64 ± 3.27, SI 95%; 13.64 ± 3.66, ARW; 4.00 ± 1.56, RW; 0.42 ± 0.13) (p < 0.05). Median and ulnar nerve step size parameters, step number and step% in the patients were also significantly higher (p < 0.05).

Conclusions: CMAP Scan can show reduced axonal excitability and reveal insidious MU loss and reinnervation in presumably unaffected muscles of PS, regardless of the decrease in CMAP amplitudes or a significant reduction in MUNE values.

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Category: Post-Polio Motor Unit

Title: Neurological manifestations of the post-polio syndrome
Author: Jubelt B, Cashman NR
Affiliation: Les Turner Amyotrophic Lateral Sclerosis Research Laboratory, Northwestern University Medical School, Chicago, Illinois
Journal: Critical Reviews in Neurobiology
Citation: Crit Rev Neurobiol. 1987;3(3):199-220
Publication Year and Month: 1987 03

Abstract: Patients with late effects of poliomyelitis, ie PPS, are being seen at an ever increasing frequency by general physicians, neurologists, and orthopedists. An appropriate time interval for the onset of late manifestations has elapsed since the major epidemics of poliomyelitis in the 1940s and 1950s. Post-polio neurological manifestations primarily include new weakness, atrophy, muscle pain, and fasciculations. Fortunately, the weakness is of a very slow, progressive nature. Abnormal laboratory studies include routine EMG, demonstrating chronic denervation; SFEMG, demonstrating increased fiber density, increased jitter, and blocking; and muscle biopsy most often revealing fiber-type grouping of chronic denervation and small isolated angular (or angulated) fibers and group atrophy in some series, both suggestive of active denervation. Unfortunately, both EMG and muscle biopsy studies suffer from a lack of specificity as they do not appear to distinguish asymptomatic from symptomatic (new weakness, PPMA) patients with prior poliomyelitis. Although the cause of PPMA is unknown, electrophysiological (SFEMG) and muscle biopsy studies suggest that the process involves a loss or dropout of axon terminals of reinnervated motor units. The axons terminal dropout could be due to dysfunction in the cell soma, the axon, or the terminals themselves. Whether motor neuron exhaustion, a persistent viral infection, or immune-mediated mechanisms play a role in the pathogenesis of the late weakness is unclear at present and will require further investigation. Treatment at this time is of a supportive nature. A major controversy involves the role of strengthening exercises in these patients since experimental animal studies suggest that excessive exercise of denervated muscles leads to increased weakness. Clearly, a better understanding of PPS and PPMA will allow more effective management of these patients’ problems and might also provide insight into other motor neuron and neuromuscular junction diseases.

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Category: Post-Polio Motor Unit

Title: Electromyographic and morphological functional compensation in late poliomyelitis
Author: Einarsson G, Grimby G, Stålberg E
Affiliation: Department of Rehabilitation Medicine, Gothenburg University, Sweden
Journal: Muscle & Nerve
Citation: Muscle Nerve. 1990 Feb; 13(2):165-71
Publication Year and Month: 1990 02

Abstract: Patients with prior poliomyelitis may experience muscle function deterioration decades after onset of disease. The present study is aimed at describing electromyographic and morphometric evidence of muscular compensation and of on-going muscular instability. Ten subjects 42-62 years of age with onset of polio 25-52 years earlier were studied with macro EMG, single-fiber EMG (SFEMG), muscle strength measurement, and morphometrical analysis of muscle biopsies from the vastus lateralis muscle. SFEMG revealed increased fiber density (FD) and large macro-MUP potentials indicating pronounced reinnervation as compensation to loss of motor neurons. From electrophysiological data of motor unit size, morphometric measures of fiber size, and muscle strength data, the minimal degree of motor neuron loss was estimated to be greater than 70%.

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Category: Post-Polio Motor Unit

Title: Dynamic electromyography and muscle biopsy changes in a 4-year follow-up: study of patients with a history of polio
Author: Stålberg E, Grimby G
Affiliation: Department of Clinical Neurophysiology, University Hospital, Uppsala, Sweden
Journal: Muscle & Nerve
Citation: Muscle Nerve. 1995 Jul;18(7):699-707
Publication Year and Month: 1995 07

Abstract: Eighteen patients who had had polio 29-56 years prior to the first investigation were studied on two occasions, 4 years apart. Isokinetic and isometric strength measurements and Macro EMG were performed in 28 legs. Muscle biopsy specimens were obtained on both occasions from 11 legs. On average the muscle strength was 56% of control values at the first examination, and decreased by another 8% during the observation period. The muscle fiber area was increased compared to that of controls and did not change significantly. Macro EMG, comprising muscle fiber area and number of muscle fibers, and/or single fiber EMG showed clear signs of reinnervation in all legs. The motor units at the first examination were increased 11-fold, on average, compared with age-matched control values. During the observation period, reinnervation continued and the size of motor units increased by another 56% as a result of ongoing denervation, that is, loss of neurons. This compensation was particularly pronounced in patients with stable conditions. The parameters studied did not reveal any definite pattern predicting future development of new muscle weakness in individual subjects.

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Category: Post-Polio Motor Unit

Title: Repeater F-waves are signs of motor unit pathology in polio survivors
Author: Hachisuka A (1), Komori T, Abe T, Hachisuka K
Affiliation: (1) Department of Rehabilitation Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu, 807-8555, Japan
Journal: Muscle & Nerve
Citation: Muscle Nerve. 2015 May;51(5):680-5. doi: 10.1002/mus.24428
Publication Year and Month: 2015 05

Abstract: INTRODUCTION: The purpose of this study was to determine whether F-waves reveal electrophysiological features of anterior horn cells in polio survivors.

METHODS: Forty-three polio survivors and 20 healthy controls underwent motor nerve conduction studies of the median and tibial nerves bilaterally, including sampling of F-waves elicited by 100 stimuli and the determination of motor unit number estimation (MUNE).

RESULTS: A significant increase in abnormally stereotyped ("repeater") F-waves and a reduction of F-wave persistence were observed in both nerves in the polio group as compared with the control group. Repeater F-waves had a negative correlation with MUNE.

Conclusions: These trends in F-wave persistence and repeater F-waves after motor unit loss are characteristic findings in polio survivors. Repeater F-waves are a sign of motor unit pathology.

Outcome of Research: Not applicable

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Category: Post-Polio Motor Unit

Title: Correlation of motor units with strength and spectral characteristics in polio survivors and controls
Author: Rodriguez AA, Agre JC
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin-Madison Medical School
Journal: Muscle & Nerve
Citation: 1991 May;14(5):429-34.
Publication Year and Month: 1991 05

Abstract: The purpose of this study was to determine whether quantitative motor unit analysis in postpolio individuals correlates with muscle strength, endurance, work capacity, or power spectral characteristics of surface EMG and to determine whether power spectrum differentiates postpolio from control subjects. This study was designed to compare these variables in 34 symptomatic postpolio, 16 asymptomatic postpolio, and 41 control subjects. Quantitative motor unit analysis of the quadriceps femoris muscle was performed using a concentric needle electrode. Isometric knee extension peak torque, endurance (time to exhaustion) at 40% of maximal torque, work capacity (tension time index), and recovery of force through 10 minutes post-exhaustion were determined. Median frequency of the surface power spectrum was determined during the above testing. Power spectrum histograms were compared at the onset and termination of endurance exercise. Motor unit action potential variables did not correlate with isometric peak torque, tension time index, endurance time, recovery of strength, or with median frequency. Surface power spectrum did not differentiate postpolio from control subjects.

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Category: Post-Polio Motor Unit

Title: Macro electromyography and motor unit number index in the tibialis anterior muscle: differences and similarities in characterizing motor unit properties in prior polio
Author: Sandberg A, Nandedkar SD, Stalberg E
Affiliation: Department of Neuroscience, Clinical Neurophysiology, Uppsala University, Uppsala SE-751 85, Sweden
Journal: Muscle & Nerve
Citation: 2011 Mar;43(3):335-41
Publication Year and Month: 2011 03

Abstract: Our objective was to establish the usefulness of the noninvasive method of the motor unit number index (MUNIX) in a large muscle and to study how macro electromyography (EMG) and MUNIX complement each other in describing the motor units (MUs) in prior polio. MUNIX and macro EMG were performed in 48 tibialis anterior muscles in 33 prior polio patients. In addition, the reproducibility of MUNIX was investigated. It is shown that MUNIX can be used to characterize MUs with high reproducibility, even in a large muscle. As judged by MUNIX values, the patients had a 25% reduction of motor neurons, whereas the macro EMG indicated a loss of 60% of the neurons. Macro EMG showed more pronounced changes compared with control material than the MUNIX. One of the reasons for this finding may be the difference in MU populations studied with the two methods.

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Category: Post-Polio Motor Unit

Title: Muscle Function, Muscle Structure, and Electrophysiology in a Dynamic Perspective in Late Polio
Author: Gunnar Grimby, MD, PhD, Erik Stålberg, MD.
Affiliation:
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Gunnar Grimby, MD, PhD, Erik Stålberg, MD., Muscle Function, Muscle Structure, and Electrophysiology in a Dynamic Perspective in Late Polio, Chapter 2, pp 15-24.
Publication Year and Month: 1995

Abstract: The muscular impairment in patients with a history of polio varies from none to severe. The relationship between the degree of initial involvement and the effect of various compensatory mechanisms determines the clinical picture, which changes dynamically. Early and late recovery after poliomyelitis depend on a number of factors. Clinical improvement that appears within a few weeks after the acute phase is probably due to recovery in the excitability of functional, but not degenerated, motor neurons. Degeneration of neurons, causing peripheral denervation, is compensated by collateral sprouting, i.e., by nerve twigs branching off from surviving motor units overlapping with the denervated ones. This is most likely the main factor explaining recovery within the first 6-12 months. Another late compensatory process is the increase in size of the muscle fibers. As a result of these processes, normal muscle strength and presumably normal muscle volume can be seen despite a calculated loss exceeding 50% of the number of motor neurons.

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Category: Post-Polio Motor Unit

Title: Motor unit number estimation (MUNE)
Author: Clifton L Gooch, MD. Robert Henderson, MD.
Affiliation: Department of Neurology
University of South Florida, Royal Brisbane & Women's Hospital
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Clifton L Gooch, MDRobert Henderson, MDSection Editor:Jeremy M Shefner, MD, PhDDeputy Editor:April F Eichler, MD, MPH
Publication Year and Month: 2018

Abstract: Electrophysiologic testing of nerve and muscle function has played a critical role in the diagnosis of neuromuscular disease for over half a century. Advances in computer technology and technical refinements have enabled the development of more sophisticated electrodiagnostic methods, which are providing information on the motor nerve and its function in health and disease. Motor unit number estimation (MUNE) is a technique that can be used to determine the approximate number of motor neurons in a muscle or group of muscles. In addition, MUNE methods provide a means of measuring motor unit size, enabling tracking of both loss of motor units and the compensatory phenomenon of collateral reinnervation. MUNE is used most often in neuromuscular disorders such as amyotrophic lateral sclerosis and spinal muscular atrophy.
This topic will review the methodology and utility of MUNE.

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Category: Post-Polio Motor Unit

Title: An algorithm for automatic detection of repeater F-waves and MUNE studies
Author: N. TuğrulArtuğ, N. Görkem Şirin, Emel Oğuz Akarsu, M. Baris Baslo, A. EmreÖge
Affiliation: Electrical and Electronics Engineering, Istanbul Arel University, Tepekent, Buyukcekmece, Istanbul, Turkey

Istanbul Medical Faculty, Istanbul University, Fatih, Capa, Istanbul, Turkey
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Biomedical Signal Processing and Control
Volume 51, May 2019, Pages 264-276
Publication Year and Month: 2019 05

Abstract: The present study aims to develop an algorithm and software that automatically detects repeater F-waves which are very difficult to analyze when elicited as high number of recordings in motor unit number estimation studies. The main strategy of the study was to take the repeater F waves discriminated by the neurologist, from limited number of recordings, as the gold standard and to test the conformity of the results of the new automated method.

Ten patients with ALS and ten healthy controls were evaluated. 90 F-waves with supramaximal stimuli and 300 F-waves with submaximal stimuli were recorded. Supramaximal recordings were evaluated both manually by an expert neurologist and automatically by the developed software to test the performance of the algorithm. The results both acquired from the neurologist and from the software were found compatible. Therefore, the main expected impact of the present study is to make the analysis of repeater F waves easier primarily in motor unit number estimation studies, since there is currently a continuing need for such automated programs in clinical neurophysiology.

Submaximal recordings were examined only by the developed software. The extracted features were: maximum M response amplitude, mean power of M response, mean of sMUP values, MUNE value, number of baskets, persistence of F-waves, persistence of repeater F-waves, mean of F-waves’ powers, median of F-waves’ powers. Feature selection methods were also applied to determine the most valuable features. Various classifiers such as multi-layer perceptron (MLP), radial basis function network (RBF), support vector machines (SVM) and k nearest neighbors (k-NN) were tested to differentiate two classes. Initially all features, then decreased numbers of features after feature selection process were applied to the aforementioned classifiers. The classification performance usually increased when decreased features were applied to intelligent systems. Ulnar recordings under submaximal stimulation showed better performance when compared with supramaximal equivalents or median nerve equivalents. The highest performance was obtained as 90% with k-NN algorithm which was a committee decision based classifier. This result was achieved with only two features, namely mean of sMUP amplitude and MUNE value.

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Category: Post-Polio Motor Unit

Title: Motor Unit Number Index (MUNIX) as a biomarker of motor unit loss in post-polio syndrome versus needle EMG
Author: Malgorzata Gawel, Ewa Zalewska, Elżbieta Szmidt-Salkowska, Marta Lipowska, Anna Lusakowska, Anna M.Kaminska, Anna Kostera-Pruszczyk
Affiliation: Department of Neurology, Medical University of Warsaw, 02-097 Warsaw, Banacha 1A str., Poland

Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, 02-109 Warsaw, Ks. Trojdena 4 str., Poland
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Journal of Electromyography and Kinesiology
Volume 46, June 2019, Pages 35-40
Publication Year and Month: 2019 06

Abstract: MUNIX method (Motor Unit Number Index) had been not used to assess number of motor neurons in post-polio syndrome in contrary to needle electromyography.

Objectives
To confirm if MUNIX reflects motor unit loss and clinical stage and to assess difference in MUNIX and EMG results between muscles in different stage.

Methods
132 Muscles (MUNIX) and 96 (EMG) in 12 patients were studied and divided into groups: with normal strength(N), stable weakness and atrophy(S), new weakness and atrophy(W).

Results
In PPS group MUNIX global was 561.36 ± 282.6 (right 6 muscles) and 561.27 ± 281.1 (left) significantly lower than in control group (six muscles 1139.6 ± 164.5) (p < 0.05). MUNIX global correlated with MRC global. MUNIX was greater in muscles with normal strength (95–100% of normal values) than in those with stable weakness (48%-0% of normal values) and new weakness (65%-0% of normal values). Respectively to clinical stage of muscle MUP (motor unit potential) amplitude increased to 350% of normal value, from 250% to 110%, and from 300% to 700%. No correlation was found between MUP parameters and MRC values.

Conclusions: MUNIX reflects motor dysfunction and could be a good biomarker for loss of motor neurons in PPS.

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: Vasomotor abnormalities as post-polio sequelae: functional and clinical implications
Author: Bruno RL, Johnson JC, Berman WS
Affiliation: Not stated
Journal: Orthopedics
Citation: Orthopedics. 1985 Jul; 8(7):865-9
Publication Year and Month: 1985 07

Abstract: Persons who had poliomyelitis report cold and discolored extremities and decreased muscle strength when exposed to mildly cool ambient temperatures. Bilateral digital cutaneous blood flow, skin temperature and median nerve latencies and amplitudes were measured at 30 degrees C, 25 degrees C and 20 degrees C in five post-polio subjects and age-matched controls. Cutaneous blood flow was lowest on the more affected side in the post-polio subjects but vasoconstriction with decreasing Ta was equal bilaterally in both groups. With decreasing Ta, median motor nerve latencies became clinically abnormal and “giant” sensory nerve potential amplitudes were seen in a majority of the post-polio subjects. It is concluded that an impairment of sympathetic vasoconstrictor outflow in post-polios allows passive dilatation and engorgement of the cutaneous venous capacitance beds. This promotes uncontrolled heat loss and causes cooling of nerve and muscle that is responsible for the impairment of muscle functioning and the abnormal electrophysiological findings.

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Category: Post-Polio Motor Unit

Title: Acute and latent effect of poliomyelitis on the motor unit as revealed by electromyography
Author: Wiechers DO
Affiliation: Not stated
Journal: Orthopedics
Citation: Orthopedics. 1985 Jul; 8(7):870-2
Publication Year and Month: 1985 07

Abstract: When polio virus attacks the motor neuron it may be completely destroyed, damaged, or unaffected. Muscle fibers of a destroyed motor neuron are orphaned or reinnervated. Nearby functioning motor units will then send terminal axon sprouts to reinnervate the orphaned muscle fibers. If there are too many orphaned muscle fibers and not enough surviving motor units to reinnervate them, the orphaned muscle fibers will continue to fibrillate until they atrophy and die. The resultant effect of poliomyelitis upon the affected muscle is an overall loss of motor units with the remaining units innervating many more muscle fibers than they originally did. There appears to be a late effect of polio upon these larger reinnervated motor units. After approximately 20 to 30 years, impulse transmission to the muscle fibers of the large reinnervated motor unit begins to fail. These transmission difficulties increase with age and time from recovery. These late onset transmission abnormalities may be factors in patient complaints of fatigue and progressive weakness.

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Category: Post-Polio Motor Unit

Title: A rat model of the post-polio motor unit
Author: Pachter BR, Eberstein A
Affiliation: Department of Rehabilitation Medicine, New York University Medical Center, NY 10016
Journal: Orthopedics
Citation: Orthopedics. 1991 Dec; 14(12):1367-73
Publication Year and Month: 1991 12

Abstract: We examined the long-term effects of muscle usage on a rat model of the post-polio motor unit. Isometric tensions, type I and type II muscle fiber areas, the incidence of collateral sprouting, and motor endplate morphology were examined following 1, 3, 6, and 9 months of partial denervation in rat plantaris muscle. Full morphologic and functional stability of the expanded motor units occurred at 6 months post-partial denervation. Fiber hypertrophy was observed, possibly the result of compensatory work hypertrophy due to muscle overuse. Following 9 months of partial denervation and muscle overuse, the twitch and tetanic tensions and type I and type II muscle fiber areas were significantly reduced as compared to sham controls; angulated myofibers and group atrophy also were seen. The percent collateral sprouting, the number of terminal branches per endplate, and the endplate area were all increased, possibly a compensatory response to a decreased synthesis of neurotrophic factor(s) and/or transmitter-related components. These aging-like changes seem to occur earlier in chronically stressed, overenlarged, and overworked motor units.

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Category: Post-Polio Motor Unit

Title: Electrophysiology and Electrodiagnosis of the Post-Polio Motor Unit
Author: Daria A. Trojan, MD, Daniel Gendron, MD, Neil R. Cashman, MD
Affiliation:
Journal: Orthopedics
Citation: Orthopedics December 1991 Vol 14 No 12 1353-1361
Publication Year and Month: 1991 12

Abstract: Post-poliomyelitis syndrome refers to new symptoms that may occur years after recovery from poliomyelitis. The most common of these symptoms are new weakness, fatigue, and pain. This article describes electrodiagnostic studies -- conventional electromyography (EMG), single fiber electromyography (SFEMG), and macroelectromyography (macro-EMG) -- that have provided information on the post-polio motor unit and on the possible etiology of some post-polio syndrome symptoms. Muscular fatigue, and indirectly, general fatigue, may be due to neuromuscular junction transmission defects in some post-polio individuals, as suggested by reduction of the compound motor action potentials on repetitive stimulation, and increased jitter and blocking on SFEMG. Progressive weakness and atrophy in post-polio syndrome is probably due to a distal degeneration of post-polio motor units with resultant irreversible muscle fiber denervation. Electrodiagnostic evidence of ongoing denervation includes fibrillation and fasciculation potentials on conventional EMG, increased jitter and blocking on SFEMG, and smaller macro-EMG amplitudes in newly weakened postpolio muscles. However, even though electrodiagnostic studies have provided insight into the possible causes of some postpolio syndrome symptoms, no specific electrodiagnostic test for the syndrome is currently available.

Conclusions:

Outcome of Research: Not applicable

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Category: Muscular Atrophy, Post-Polio Motor Unit

Title: An autopsy case of progressive generalized muscle atrophy over 14 years due to post-polio syndrome
Author: Oki R (1), Uchino A, Izumi Y, Ogawa H, Murayama S, Kaji R
Affiliation: (1) Department of Clinical Neuroscience, Institute of Health Bioscience, University of Tokushima Graduate School
Journal: Rinsho Shinkeigaku (Clinical Neurology)
Citation: Rinsho Shinkeigaku. 2015 Nov 30
Publication Year and Month: 2015 11

Abstract: We report the case of a 72-year-old man who had contracted acute paralytic poliomyelitis in his childhood. Thereafter, he had suffered from paresis involving the left lower limb, with no relapse or progression of the disease. He began noticing slowly progressive muscle weakness and atrophy in the upper and lower extremities in his 60s. At the age of 72, muscle weakness developed rapidly, and he demonstrated dyspnea on exertion and dysphagia. He died after about 14 years from the onset of muscle weakness symptoms. Autopsy findings demonstrated motoneuron loss and glial scars not only in the plaque-like lesions in the anterior horns, which were sequelae of old poliomyelitis, but also throughout the spine. No Bunina bodies, TDP-43, and ubiquitin inclusions were found. Post-polio syndrome is rarely fatal due to rapid progressive dyspnea and dysphagia. Thus, the pathological findings in the patient are considered to be related to the development of muscle weakness.

Conclusions:

Outcome of Research: Not applicable

Availability of Paper: The full text of this paper has been generously made available by the publisher.

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Category: Post-Polio Motor Unit

Title: Late denervation in patients with antecedent paralytic poliomyelitis
Author: Cashman NR, Maselli R, Wollmann RL, Roos R, Simon R, Antel JP
Affiliation: Not stated
Journal: The New England Journal of Medicine
Citation: N Engl J Med. 1987 Jul 2; 317(1):7-12
Publication Year and Month: 1987 07

Abstract: The development of new weakness, fatigue, and pain decades after acute paralytic poliomyelitis is a recognized syndrome. We conducted a controlled study of this syndrome by analyzing clinical, electromyographic, and muscle-biopsy features in 18 patients with a history of poliomyelitis--13 reporting 1 to 20 years of new weakness and 5 without new symptoms. The patients with new weakness also reported new muscle atrophy (9 of 13) and fatigue (10 of 13), symptoms not reported by the controls. The age at the time of acute poliomyelitis, severity of poliomyelitis, residual disability, number of years since acute poliomyelitis, and age at the time of study were comparable in the weakening and control groups. Evidence of remote denervation consistent with antecedent poliomyelitis was demonstrated in all patients by electromyography or muscle biopsy or both. In addition, active denervation (as evidenced by spontaneous activity on conventional electromyography, increased jitter on single-fiber electromyography, or atrophic myofibers) was found in 12 patients in the weakening group and in all 5 controls. Immunohistochemical detection of myofibers expressing the neural-cell adhesion molecule corroborated ongoing denervation in both patient groups. When muscle data from both groups were pooled, correlations were observed between the extent of past reinnervation and the degree of ongoing motor-unit instability. We conclude that the extensive reinnervation of denervated muscle that occurs in paralytic poliomyelitis may be followed by late denervation of the previously reinnervated muscle fibers. Electromyographic and muscle-biopsy evidence of ongoing denervation does not distinguish between stable patients with prior paralytic poliomyelitis and those with new weakness.

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Category: Post-Polio Motor Unit

Title: A long-term follow-up study of patients with post-poliomyelitis neuromuscular symptoms
Author: Dalakas MC, Elder G, Hallett M, Ravits J, Baker M, Papadopoulos N, Albrecht P, Sever J
Affiliation: Not stated
Journal: The New England Journal of Medicine
Citation: N Engl J Med. 1986 Apr 10; 314(15):959-63
Publication Year and Month: 1986 04

Abstract: A “post-polio” syndrome characterized by new neuromuscular symptoms, including muscle weakness, may develop years after recovery from acute paralytic poliomyelitis. We studied 27 patients (mean age, 50.6 years) in whom new muscle weakness developed a mean of 28.8 years after recovery from acute polio. We reevaluated these patients during a mean follow-up period of 8.2 years (range, 4.5 to 20) after they were originally studied at the National Institutes of Health. The total mean follow-up period after the onset of new weakness was 12.2 years (range, 6 to 29). The patients were assessed with quantitative muscle testing, muscle biopsy, electromyography, and virologic and immunologic examination of the cerebrospinal fluid. Muscle strength had declined in all patients. The rate of decline averaged 1 percent per year. The decrease was irregular, with subjective plateau periods that ranged from 1 to 10 years. None of the patients had amyotrophic lateral sclerosis. Oligoclonal bands (IgG) were found in the cerebrospinal fluid of 7 of 13 patients studied, but no specific elevation of antibodies to poliovirus was observed in the cerebrospinal fluid. The newly affected muscles that were evaluated longitudinally with follow-up muscle biopsies and electromyography showed signs of chronic and new denervation. Groups of atrophic muscle fibers (group atrophy) and "neurogenic jitter" were not present. New post-polio muscle weakness is not a life-threatening form of motor-neuron deterioration. It appears that this weakness is not due to a loss of whole motor neurons, as in amyotrophic lateral sclerosis, but that it is due to a dysfunction of the surviving motor neurons that causes a slow disintegration of the terminals of individual nerve axons.

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There are currently 31 papers in this category.

Category: Post-Polio Motor Unit

Title: P66-S Corticospinal function in poliomyelitis survivors
Author: Nermin Gorkem Sirin, Bahar Erbas, Gulsah Gula, Emel Oguz-Akarsu, Hava Ozlem Dede, Elif Kocasoy-Orhan, Mehmet Baris Baslo, Aysegul Ketenci, Halil Atilla Idrisoglu, Ali Emre Oge
Affiliation: Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Istanbul, Turkey

Istanbul University, Istanbul Faculty of Medicine, Department of Physical Medicine and Rehabilitation, Istanbul, Turkey
Journal: Clinical Neurophysiology
Citation: Volume 130, Issue 7, July 2019, Pages e111-e112

Publication Year and Month: 2019 07

Abstract: Poliomyelitis survivors (PS) become candidates to post-polio syndrome (PPS) in their later lives. The mechanism of PPS has been suggested to be multifactorial involving cortical, spinal and peripheral mechanisThe aim of this study was to evaluate TMS parameters in PS and to compare them with those of amyotrophic lateral sclerosis (ALS) patients and controls.

Material and methods
Single and paired TMS, contralateral and ipsilateral silent period (SP) and triple stimulation technique (TST) were performed by recording from abductor digiti minimi (ADM) and abductor pollicis brevis (APB) muscles of 18 PS, 31 ALS patients and 21 controls. The results were compared with mixed ANOVA and nonparametric independent tests.

Results
No significant difference was present for within and between subject factors except those for the different interstimuli intervals. Resting motor threshold and MEP/M% in ADM, MEP amplitudes and latencies and TST% in both ADM and APB were significantly different. In posthoc analyses, MEP latencies were higher and TST% were lower in both ADM and APB in ALS group (20.7 ± 4.2 ms, 22.4 ± 5.0 ms, 83.1 ± 42.2, 72.3 ± 29.9) as compared to PS (18.3 ± 1.0 ms, 19.2 ± 2.0 ms, 101.6 ± 15.9, 98.1 ± 14.9), MEP/M% in ADM were lower in PS group (56.0 ± 13.4) as compared to controls (85.2 ± 23.9). SPs, TST, MEP amplitudes and latencies and MEP/M amplitudes did not show any significant difference between ADM and APB in both patient groups.

Conclusions: Our results revealed upper motor neuron dysfunction in ALS compared to PS and may provide limited evidence about presence of an abnormal cortical drive to mostly uninvolved upper extremity muscles in PS.

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Category: Post-Polio Motor Unit

Title: P63-S Insidious neuromuscular deterioration in polio survivors demonstrated by CMAP scan analysis.
Author: Sirin NG, Erbas B, Akasu EO, et al.
Affiliation: Istanbul University Istanbul Medical Faculty, Neurology Department, Istanbul, Turkey

Istanbul University Istanbul Medical Faculty, Physical Therapy and Rehabilitation Department, Istanbul, Turkey
Journal: Clinical Neurophysiology
Citation: Volume 130, Issue 7, July 2019, Pages e110-e111

Publication Year and Month: 2019 07

Abstract: This study aimed to explore the subtle motor unit(MU) changes in asymptomatic muscles of poliomyelitis survivors (PS) using CMAP Scan analysis.

Material and method
Nineteen PS cases and 21 controls were recruited. CMAP Scan recordings were obtained from asymptomatic thenar and hypothenar muscles. CMAP Scan parameters indicating nerve excitability [stimulus intensities producing 50%, 95% and 5% of the CMAP amplitude (SI%5, SI%50, SI%95), absolute range width (ARW) (SI%95-SI%5), relative width (RW) (SI95 − SI5)/SI5], all step parameters and D50 which reflect the MU motor unit loss and reinnervation were analyzed. The new motor unit number estimation (MUNE) method, MscanFit was also calculated.

Results
There were no significant differences in ages, maximum CMAP amplitudes and MScanFit MUNE between the groups. PS group median and ulnar D50 values (46.76 ± 10.98, 46.19 ± 12.42 respectively) were lower than control group (37.21 ± 17.37, 36.44 ± 11.99) (p < 0.05). Median nerve,excitability parameters of patients (SI 5%; 14.81 ± 6.97, SI 50%; 19.07 ± 9.2, SI 95%; 24.06 ± 11.52), ARW (9.26 ± 5.79), RW (0.65 ± 0.31) were higher than those of the controls (SI 5%; 9.64 ± 2.57, SI 50%; 11.64 ± 3.27, SI 95%; 13.64 ± 3.66, ARW; 4.00 ± 1.56, RW; 0.42 ± 0.13) (p < 0.05). Median and ulnar nerve step size parameters, step number and step% in the patients were also significantly higher (p < 0.05).

Conclusions: CMAP Scan can show reduced axonal excitability and reveal insidious MU loss and reinnervation in presumably unaffected muscles of PS, regardless of the decrease in CMAP amplitudes or a significant reduction in MUNE values.

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Category: Post-Polio Motor Unit

Title: Motor Unit Number Index (MUNIX) as a biomarker of motor unit loss in post-polio syndrome versus needle EMG
Author: Malgorzata Gawel, Ewa Zalewska, Elżbieta Szmidt-Salkowska, Marta Lipowska, Anna Lusakowska, Anna M.Kaminska, Anna Kostera-Pruszczyk
Affiliation: Department of Neurology, Medical University of Warsaw, 02-097 Warsaw, Banacha 1A str., Poland

Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, 02-109 Warsaw, Ks. Trojdena 4 str., Poland
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Journal of Electromyography and Kinesiology
Volume 46, June 2019, Pages 35-40
Publication Year and Month: 2019 06

Abstract: MUNIX method (Motor Unit Number Index) had been not used to assess number of motor neurons in post-polio syndrome in contrary to needle electromyography.

Objectives
To confirm if MUNIX reflects motor unit loss and clinical stage and to assess difference in MUNIX and EMG results between muscles in different stage.

Methods
132 Muscles (MUNIX) and 96 (EMG) in 12 patients were studied and divided into groups: with normal strength(N), stable weakness and atrophy(S), new weakness and atrophy(W).

Results
In PPS group MUNIX global was 561.36 ± 282.6 (right 6 muscles) and 561.27 ± 281.1 (left) significantly lower than in control group (six muscles 1139.6 ± 164.5) (p < 0.05). MUNIX global correlated with MRC global. MUNIX was greater in muscles with normal strength (95–100% of normal values) than in those with stable weakness (48%-0% of normal values) and new weakness (65%-0% of normal values). Respectively to clinical stage of muscle MUP (motor unit potential) amplitude increased to 350% of normal value, from 250% to 110%, and from 300% to 700%. No correlation was found between MUP parameters and MRC values.

Conclusions: MUNIX reflects motor dysfunction and could be a good biomarker for loss of motor neurons in PPS.

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: An algorithm for automatic detection of repeater F-waves and MUNE studies
Author: N. TuğrulArtuğ, N. Görkem Şirin, Emel Oğuz Akarsu, M. Baris Baslo, A. EmreÖge
Affiliation: Electrical and Electronics Engineering, Istanbul Arel University, Tepekent, Buyukcekmece, Istanbul, Turkey

Istanbul Medical Faculty, Istanbul University, Fatih, Capa, Istanbul, Turkey
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Biomedical Signal Processing and Control
Volume 51, May 2019, Pages 264-276
Publication Year and Month: 2019 05

Abstract: The present study aims to develop an algorithm and software that automatically detects repeater F-waves which are very difficult to analyze when elicited as high number of recordings in motor unit number estimation studies. The main strategy of the study was to take the repeater F waves discriminated by the neurologist, from limited number of recordings, as the gold standard and to test the conformity of the results of the new automated method.

Ten patients with ALS and ten healthy controls were evaluated. 90 F-waves with supramaximal stimuli and 300 F-waves with submaximal stimuli were recorded. Supramaximal recordings were evaluated both manually by an expert neurologist and automatically by the developed software to test the performance of the algorithm. The results both acquired from the neurologist and from the software were found compatible. Therefore, the main expected impact of the present study is to make the analysis of repeater F waves easier primarily in motor unit number estimation studies, since there is currently a continuing need for such automated programs in clinical neurophysiology.

Submaximal recordings were examined only by the developed software. The extracted features were: maximum M response amplitude, mean power of M response, mean of sMUP values, MUNE value, number of baskets, persistence of F-waves, persistence of repeater F-waves, mean of F-waves’ powers, median of F-waves’ powers. Feature selection methods were also applied to determine the most valuable features. Various classifiers such as multi-layer perceptron (MLP), radial basis function network (RBF), support vector machines (SVM) and k nearest neighbors (k-NN) were tested to differentiate two classes. Initially all features, then decreased numbers of features after feature selection process were applied to the aforementioned classifiers. The classification performance usually increased when decreased features were applied to intelligent systems. Ulnar recordings under submaximal stimulation showed better performance when compared with supramaximal equivalents or median nerve equivalents. The highest performance was obtained as 90% with k-NN algorithm which was a committee decision based classifier. This result was achieved with only two features, namely mean of sMUP amplitude and MUNE value.

Conclusions:

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: Are the nonparalytic muscles of polio survivors free from the risk of post-polio syndrome?
Author: K.Sawada, M.Horii, D.Imoto, Y.Mikami, T.Kubo
Affiliation: Kyoto Prefectural University of Medicine, Department of Rehabilitation Medicine, Kyoto, Japan
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Volume 61, Supplement, July 2018, Page e263
Publication Year and Month: 2018 07

Abstract: Introduction/Background
The aim of this study was to reveal the relation between the neurogenetic change in the nonparalytic muscles in upper and lower limbs of Polio survivors and the later muscle strength decline.

Material and method
Retrospective study. We looked back the data of electromyography (EMG) of Polio survivors in our Polio clinic (average age: 58.9). Muscles whose strength at EMG had been normal were extracted. We looked up the muscle strength at EMG time and two years later from medical record.

Results
The subjects were 23 deltoid (middle strand), 40 biceps branchii, 36 triceps branchii, 24 vastus lateralis, 19 tibialis anterior, and gastrocnemius (medial head). The ratio of neurogenic change subject (giant spike or interference pattern reduction) was, 30.4%, 25.0%, 36.1%, 62.5%, 47.4%, and 73.7%, respectively. In neurogenic change group of Biceps, 50.0% showed decline in their muscle strength. In non-neurogenic change group of Deltoid, 25.0% showed decline in their muscle strength.

Conclusions: Conclusion
Present study suggested that some muscle strength decline may be caused by Post-polio syndrome (PPS), and that EMG might be the most useful tool for the risk detection of PPS, especially for Biceps branchii. On the other hand, the fact that 25% of Deltoid non-neurogenic change group showed muscle strength decline was not understood in this study. Pain or disuse from disorder in shoulder joint might possibly be as a cause.

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Category: Post-Polio Motor Unit

Title: CMAP scan and scanning EMG in the same muscle: Two cases with post-polio muscular atrophy
Author: Mehmet Baris Baslo, Nermin G.Sirin, EmelOguz-Akarsu, ElifKocasoy-Orhan, BaharErbas, ImranGoker, TugrulArtugAli EmreOge
Affiliation:
Journal: Clinical Neurophysiology
Citation: Volume 129, Supplement 1, May 2018, Page e32

Publication Year and Month: 2018 05

Abstract: Post-polio muscular atrophy (PPMA) is characterized by new onset or increased weakness in patients with prior poliomyelitis after a stable period of time. Loss of highly reinnervated motor units during ageing has been accused for the development of this syndrome which is also known as “unstable-polio”. These patients have less number of motor units that can be estimated by conventional electrophysiological methods. By showing the large steps, CMAP scan provides information about the amount of collateral reinnervation in the construction of total muscle response (CMAP). As well as the number of motor units, their territory is also an object of curiosity. It is possible to record bioelectrical activity of motor unit lengthwise by scanning EMG and depict the temporal and spatial features of motor unit action potential (MUAP). This presentation aims to combine the findings in CMAP scan with scanning EMG and draw attention to reinnervation status of 2 PPMA patients whose tibialis anterior (TA) muscles were affected in different degrees.

Methods
Two patients aged 39and 41 years were included. Patient 1 had PPMA for 8 years and his TA muscle strength was 3-/5, whereas Patient 2 showed PPMA findings for 1 year and his TA strength was 4/5. CMAP scan of TA muscle on recently affected side was performed with a commercially available software. In scanning EMG, MU territories were scanned with a concentric needle electrode (CNE) which is attached to a stepper motor. Another CNE is used for sweep triggering with the rate of selected motor units’ firing frequency. Acquired signals were processed by the dedicated software designed by the authors.

Results
CMAP scan of Patient 1 revealed a 1.65 mV CMAP constituting of 4 very large steps and Patient 2 revealed a 5.5 mV CMAP containing a few smaller steps. In scanning EMG, both patients’ motor units showed increased voltage in different parts corresponding to dense areas arisen from collateral reinnervation. Interestingly, the patient with more pronounced weakness for a longer period revealed both huge steps in his CMAP scan and also showed electrically silent areas in his scanned motor units. On the other hand, the patient with stronger TA muscle did not show very large steps or silent areas in his CMAP scan and MU scan, respectively.

Conclusions: Loss of dense motor units leads to PPMA. However, in PPMA patients with severe weakness which is depicted by less number of motor units and presence of huge steps in CMAP scan, loss of fractions in motor unit territory might be a principal contributing factor which can only be demonstrated by scanning EMG.

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: Motor unit number estimation (MUNE)
Author: Clifton L Gooch, MD. Robert Henderson, MD.
Affiliation: Department of Neurology
University of South Florida, Royal Brisbane & Women's Hospital
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Clifton L Gooch, MDRobert Henderson, MDSection Editor:Jeremy M Shefner, MD, PhDDeputy Editor:April F Eichler, MD, MPH
Publication Year and Month: 2018

Abstract: Electrophysiologic testing of nerve and muscle function has played a critical role in the diagnosis of neuromuscular disease for over half a century. Advances in computer technology and technical refinements have enabled the development of more sophisticated electrodiagnostic methods, which are providing information on the motor nerve and its function in health and disease. Motor unit number estimation (MUNE) is a technique that can be used to determine the approximate number of motor neurons in a muscle or group of muscles. In addition, MUNE methods provide a means of measuring motor unit size, enabling tracking of both loss of motor units and the compensatory phenomenon of collateral reinnervation. MUNE is used most often in neuromuscular disorders such as amyotrophic lateral sclerosis and spinal muscular atrophy.
This topic will review the methodology and utility of MUNE.

Conclusions:

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: How long does denervation take in poliomyelitis? Or is it a lifetime?
Author: Senol, M.G., Kaplan, C., Ozdağ, F., Saraçoğlu, M.
Affiliation: GATA Haydarpasa Training Hospital, Istanbul
Journal:
Citation: Journal of Neurosciences in rural practice
Senol, M.G., Kaplan, C., Ozdağ, F., Saraçoğlu, M. (2017) How long does denervation take in poliomyelitis? Or is it a lifetime? J Neurosci Rural Pract. 8:511-5
Publication Year and Month: 2017 11

Abstract: Background and Objective: This study aims to determine the period of reinnervation in patients with poliomyelitis. This research was conducted to identify the appearance of denervation potentials in patients with poliomyelitis as indicators for reinnervation.

Materials and Methods: A total of 246 male patients with poliomyelitis were assessed electrophysiologically between 1988 and 2007. The mean age was 22.8 (18–42). It has been an average of 19.9 ± 4.9 years since the beginning of complaints from the patients.

Results: The patients had no complaints of newly developing muscle weakness, fatigue, muscle and joint pain, and difficulties in breathing and swallowing. Neurological examinations revealed the absence of myotomal pain and sensory loss. Upon assessment of the patients' limbs, the following findings were revealed: two patients had left upper and lower limb involvement, two patients had left upper and right lower limb involvement, 6 patients had left upper limb involvement, 12 patients had both lower limb involvement, 105 patients had left lower limb involvement, 1 patient had both upper limb involvement, 2 patients had right lower and upper limb involvement, 12 patients had right upper limb involvement, 6 patients had both lower limb involvement, 95 patients had right lower limb involvement, and 3 had all the three extremities affected. The needle electromyography revealed the presence of denervation potentials in 25.2% (62) of the patients.

Conclusion: When poliovirus attacks the motor neuron, this neuron may be completely destroyed, damaged, or unaffected. Reinnervation occurs when nearby functioning motor units send out terminal axon sprouts to reinnervate the damaged muscle fibers. As a consequence of poliomyelitis, several muscle fibers become atrophic and fibrotic, but others continue to survive. This study showed that patients with a history of poliomyelitis experienced denervation with subsequent reinnervation for many years.

Conclusions: The electrophysiological evidences indicating denervation continuing in 25% of the patients are shown in this study.

Outcome of Research: More research required

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Comments (if any): This study has great potential if there is regular monitoring of participants to see the effects of ageing and denervation.

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Category: Muscular Atrophy, Post-Polio Motor Unit

Title: An autopsy case of progressive generalized muscle atrophy over 14 years due to post-polio syndrome
Author: Oki R (1), Uchino A, Izumi Y, Ogawa H, Murayama S, Kaji R
Affiliation: (1) Department of Clinical Neuroscience, Institute of Health Bioscience, University of Tokushima Graduate School
Journal: Rinsho Shinkeigaku (Clinical Neurology)
Citation: Rinsho Shinkeigaku. 2015 Nov 30
Publication Year and Month: 2015 11

Abstract: We report the case of a 72-year-old man who had contracted acute paralytic poliomyelitis in his childhood. Thereafter, he had suffered from paresis involving the left lower limb, with no relapse or progression of the disease. He began noticing slowly progressive muscle weakness and atrophy in the upper and lower extremities in his 60s. At the age of 72, muscle weakness developed rapidly, and he demonstrated dyspnea on exertion and dysphagia. He died after about 14 years from the onset of muscle weakness symptoms. Autopsy findings demonstrated motoneuron loss and glial scars not only in the plaque-like lesions in the anterior horns, which were sequelae of old poliomyelitis, but also throughout the spine. No Bunina bodies, TDP-43, and ubiquitin inclusions were found. Post-polio syndrome is rarely fatal due to rapid progressive dyspnea and dysphagia. Thus, the pathological findings in the patient are considered to be related to the development of muscle weakness.

Conclusions:

Outcome of Research: Not applicable

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Comments (if any): The full paper is in Japanese.

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Category: Post-Polio Motor Unit

Title: Repeater F-waves are signs of motor unit pathology in polio survivors
Author: Hachisuka A (1), Komori T, Abe T, Hachisuka K
Affiliation: (1) Department of Rehabilitation Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu, 807-8555, Japan
Journal: Muscle & Nerve
Citation: Muscle Nerve. 2015 May;51(5):680-5. doi: 10.1002/mus.24428
Publication Year and Month: 2015 05

Abstract: INTRODUCTION: The purpose of this study was to determine whether F-waves reveal electrophysiological features of anterior horn cells in polio survivors.

METHODS: Forty-three polio survivors and 20 healthy controls underwent motor nerve conduction studies of the median and tibial nerves bilaterally, including sampling of F-waves elicited by 100 stimuli and the determination of motor unit number estimation (MUNE).

RESULTS: A significant increase in abnormally stereotyped ("repeater") F-waves and a reduction of F-wave persistence were observed in both nerves in the polio group as compared with the control group. Repeater F-waves had a negative correlation with MUNE.

Conclusions: These trends in F-wave persistence and repeater F-waves after motor unit loss are characteristic findings in polio survivors. Repeater F-waves are a sign of motor unit pathology.

Outcome of Research: Not applicable

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Category: Post-Polio Motor Unit

Title: Loss of motor unit size and quadriceps strength over 10 years in post-polio syndrome
Author: Bickerstaffe A (1), van Dijk JP (2), Beelen A (3), Zwarts MJ (4), Nollet F (5)
Affiliation: (1) Department of Rehabilitation, Academic Medical Center (AMC), Postbus 22660, 1100 DD Amsterdam, The Netherlands. Electronic address: [email protected]; (2) Radboud University Nijmegen Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology/Clinical Neurophysiology, Postbus 910, 6500 HB Nijmegen, The Netherlands; Epilepsy Centre Kempenhaeghe, Postbus 61, 5590 AB Heeze, The Netherlands. Electronic address: [email protected]; (3) Department of Rehabilitation, Academic Medical Center (AMC), Postbus 22660, 1100 DD Amsterdam, The Netherlands. Electronic address: [email protected]; (4) Epilepsy Centre Kempenhaeghe, Postbus 61, 5590 AB Heeze, The Netherlands. Electronic address: [email protected]; (5) Department of Rehabilitation, Academic Medical Center (AMC), Postbus 22660, 1100 DD Amsterdam, The Netherlands. Electronic address: [email protected]
Journal: Clinical Neurophysiology
Citation: Clin Neurophysiol. 2014 Jun;125(6):1255-60. doi: 10.1016/j.clinph.2013.11.003
Publication Year and Month: 2014 06

Abstract: OBJECTIVE: To investigate whether strength decline in post-polio syndrome (PPS) results from excessive distal axonal degeneration of enlarged motor units.

METHODS: We assessed changes over 10 years in isometric quadriceps strength, mean motor unit action potential (MUAP) size, root mean squared (RMS) amplitude, and level of interference (LOI) in 47 patients with PPS and 12 healthy controls, using high density surface EMG. At baseline, all patients had symptomatic quadriceps dysfunction, evidenced by transmission defects on single-fibre EMG.

RESULTS: MU size and strength declined significantly by 20% and 15%, respectively in patients with PPS. Those with the largest initial MU sizes exhibited the greatest losses of mean MU size (27%) and proportional decreases in quadriceps strength (23%). Initial strength, change in LOI and change in RMS amplitude together explained 35% of the variability in strength changes in patients. MU size of controls did not change, although they lost 29% strength.

SIGNIFICANCE: This long term follow-up study provides evidence that size diminution of enlarged MUs combined with a reduced number of active MUs contributes to the gradual strength decline in PPS.

Conclusions: MU size and strength declined concomitantly in a homogeneous cohort of patients with PPS and quadriceps dysfunction.

Outcome of Research: Effective

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Category: Post-Polio Motor Unit

Title: Macro electromyography and motor unit number index in the tibialis anterior muscle: differences and similarities in characterizing motor unit properties in prior polio
Author: Sandberg A, Nandedkar SD, Stalberg E
Affiliation: Department of Neuroscience, Clinical Neurophysiology, Uppsala University, Uppsala SE-751 85, Sweden
Journal: Muscle & Nerve
Citation: 2011 Mar;43(3):335-41
Publication Year and Month: 2011 03

Abstract: Our objective was to establish the usefulness of the noninvasive method of the motor unit number index (MUNIX) in a large muscle and to study how macro electromyography (EMG) and MUNIX complement each other in describing the motor units (MUs) in prior polio. MUNIX and macro EMG were performed in 48 tibialis anterior muscles in 33 prior polio patients. In addition, the reproducibility of MUNIX was investigated. It is shown that MUNIX can be used to characterize MUs with high reproducibility, even in a large muscle. As judged by MUNIX values, the patients had a 25% reduction of motor neurons, whereas the macro EMG indicated a loss of 60% of the neurons. Macro EMG showed more pronounced changes compared with control material than the MUNIX. One of the reasons for this finding may be the difference in MU populations studied with the two methods.

Conclusions:

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: Changes in macro electromyography over time in patients with a history of polio: a comparison of 2 muscles.
Author: Sandberg A, Stalberg E
Affiliation: Department of Clinical Neurophysiology, Uppsala University Hospital, ing 85, 3 tr., S-751 85 Uppsala, Sweden.
Journal: Archives of Physical Medicine and Rehabilitation
Citation: 2004 Jul;85(7):1174-82.
Publication Year and Month: 2004 07

Abstract: OBJECTIVE:
To investigate whether changes over time are different in a weight-bearing leg muscle than in a less heavily used arm muscle.

DESIGN:
Prospective study.

SETTING:
University hospital laboratory.

PARTICIPANTS:
Twenty-three patients with a history of poliomyelitis.

INTERVENTION:
Two investigations were performed 5 years apart, using macro electromyography and the patients' own assessments of symptoms in the tibial anterior and the biceps brachii muscles. Test-retest of macro electromyography was performed in controls and in patients with old polio.

MAIN OUTCOME MEASURES:
Macro motor unit potential (MUP) and symptoms in the tibial anterior and biceps brachii over time.

RESULTS:
The macro MUP amplitude increased by 24% (P<.05) in the tibial anterior but was unchanged in the biceps brachii muscle.

Conclusions: CONCLUSIONS:
An increase in the macro MUP amplitude of the tibial anterior muscle, but not of the biceps brachii, most likely indicates a more pronounced ongoing denervation-reinnervation process over time in the tibial anterior. This difference could be activity dependent, but other factors cannot be excluded.

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: Polioencephalitis and the Brain Fatigue Generator Model of Post-Viral Fatigue Syndromes
Author: Richard L. Bruno, Ph.D., Nancy M. Frick, Lh.D., Susan Creange, M.A., Jerald R. Zimmerman, M.D., and Todd Lewis, Ph.D.


Affiliation: Post-Polio Rehabilitation and Research Service; Kessler Institute for Rehabilitation, Department of Physical Medicine and Rehabilitation; UMDNJ/New Jersey Medical School, Harvest Center; Hackensack, New Jersey
Journal:
Citation: Journal of Chronic Fatigue Syndrome, 1996; Department of Physical Medicine and Rehabilitation (in press)
Publication Year and Month: 1996

Abstract: Fatigue is the most commonly reported and most debilitating Post-Polio Sequelae (PPS) affecting millions of polio survivors world-wide. Post-polio fatigue is associated with: 1) subjective reports of difficulty with attention, cognition, word-finding and maintaining wakefulness; 2) clinically significant deficits on neuropsychological tests of information processing speed and attention; 3) gray and white matter hyperintensities in the reticular activating system on magnetic resonance imaging of the brain; 4) neuroendocrine evidence of impaired activation of the HPA axis. Many of these findings are identical to those documented following a variety of viral encephalitides, including acute poliovirus infection, lethargic encephalitis, Iceland Disease, myalgic encephalomyelitis, and, most recently, Chronic Fatigue Syndrome. The clinical, historic, neuropsychologic, neuroanatomic and physiologic parallels between poliovirus infection, post-polio fatigue and post-viral fatigue syndromes (PVFS) will be explored in an attempt to describe the pathophysiology of PVFS. The disinhibition of a putative Brain Fatigue Generator will be implicated as a cause of the subjective symptoms and objective signs that accompany PVFS. The results of a pilot placebo-controlled study of a dopamine 2 receptor agonist to treat post-polio fatigue will also be described.

Conclusions:

Outcome of Research: Not applicable

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Category: Post-Polio Motor Unit

Title: Dynamic electromyography and muscle biopsy changes in a 4-year follow-up: study of patients with a history of polio
Author: Stålberg E, Grimby G
Affiliation: Department of Clinical Neurophysiology, University Hospital, Uppsala, Sweden
Journal: Muscle & Nerve
Citation: Muscle Nerve. 1995 Jul;18(7):699-707
Publication Year and Month: 1995 07

Abstract: Eighteen patients who had had polio 29-56 years prior to the first investigation were studied on two occasions, 4 years apart. Isokinetic and isometric strength measurements and Macro EMG were performed in 28 legs. Muscle biopsy specimens were obtained on both occasions from 11 legs. On average the muscle strength was 56% of control values at the first examination, and decreased by another 8% during the observation period. The muscle fiber area was increased compared to that of controls and did not change significantly. Macro EMG, comprising muscle fiber area and number of muscle fibers, and/or single fiber EMG showed clear signs of reinnervation in all legs. The motor units at the first examination were increased 11-fold, on average, compared with age-matched control values. During the observation period, reinnervation continued and the size of motor units increased by another 56% as a result of ongoing denervation, that is, loss of neurons. This compensation was particularly pronounced in patients with stable conditions. The parameters studied did not reveal any definite pattern predicting future development of new muscle weakness in individual subjects.

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Category: Post-Polio Motor Unit

Title: Correlation of Electrophysiology with Pathology, Pathogenesis, and Anticholinesterase Therapy in Post-Polio Syndrome
Author: Neil R. Cashman and Daria A. Trojan
Affiliation: Department of Neurology, Montreal Neurological Institute and Hospital, McGill University
Journal: Annals of the New York Academy of Sciences
Citation: Reprinted from The Post-Polio Syndrome: Advances in the Pathogenesis and Treatment
Volume 753 [pp 138-150] of the Annals of the New York Academy of Sciences
May 25, 1995
Publication Year and Month: 1995 05

Abstract:

Conclusions: A great deal of data has been generated on PPS, and a great deal more will be generated before we understand the pathophysiology of this common and disabling disorder. Perhaps now, to guide future work and direct therapeutic approaches, it is best to think of the symptoms of PPS as due to two lesions of the motor unit: a "progressive lesion" and a "fluctuating lesion." The progressive lesion gives rise to the symptom of slowly progressive weakness, and is due to the degeneration of terminal axons (and perhaps motor neurons) over the course of years. This lesion, best articulated by Wiechers and Hubble,[18] has been difficult to objectify because of its indolent nature. However, significant clinical weakening has indeed been quantified by several groups, including Munsat and colleagues,[7] and Sonies and Dalakas.[53] The best objective "proof" of the progressive lesion at present is the appearance of muscle fiber atrophy in biopsies, isolated and in groups, suggesting ongoing "permanent" denervation.[22] Diminution of motor unit size over time, as suggested by the macro-EMG studies of Lange et al.,[32] are also consistent with this hypothesis, albeit more controversial.

The other lesion of the PPS motor unit, hypothesized as a "fluctuating lesion," may be due to dysfunction of terminal axons, which gives rise to symptoms (muscle fatigability, generalized fatigue, and a component of weakness) that can change over the course of minutes to days. The underlying pathophysiology of these symptoms may be due to critical enlargement of motor units with limitations of distal components subserving axonal conduction and NMJ transmission, and/or the constant remodeling of the motor unit which appears to occur in virtually every individual after recovery from paralytic poliomyelitis. The best objective evidence for this ongoing lesion is provided by innumerable electrophysiologic studies demonstrating unstable motor unit action potentials and decrement on repetitive stimulation with conventional EMG, increased SFEMG jitter, and a host ofother studies.[54] In addition, the widespread expression of N-CAM in muscle biopsies of post-polio subjects (sometimes exceeding 10% of fibers)[22] strongly suggests that axono-myofiber interactions are distinctly unstable and/or immature. Clearly, agents that support the integrity or function of motor axonal sprouts may improve or delay patient symptoms in PPS.

Outcome of Research: Not applicable

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Category: Post-Polio Motor Unit

Title: Electrodiagnostic Findings in 108 Consecutive Patients Referred to a Post-Polio Clinic – The Value of Routine Electrodiagnostic Studies
Author: Anne C. Gawne, Bao T. Pham, and Lauro S. Halstead

Affiliation:
Journal: Annals of the New York Academy of Sciences
Citation: The Post-Polio Syndrome: Advances in the Pathogenesis and Treatment Volume 753 pp 383-385 of the Annals of the New York Academy of Sciences May 25, 1995.
Publication Year and Month: 1995 05

Abstract: Many patients with a history of polio develop new symptoms including weakness, pain, fatigue, and changes in function, or post-polio syndrome (PPS).[1] Before a diagnosis of PPS is made, other diagnoses must first be ruled out. Assessment must be done in a comprehensive and coordinated manner.[2] Therefore, as part of our routine evaluation, we do an electromyogram/nerve conduction study (EMG/NCS) on every patient. During examinations on our clinic patients we began to notice (1) electrodiagnostic evidence of polio in limbs not previously felt to be involved; (2) a normal EMG, or evidence of another disease; and (3) EMG evidence consistent with additional neurological lesions, including compression neuropathies, peripheral neuropathies, and radiculopathies. A prospective study using a routine, standardized four-extremity electrodiagnostic protocol was done to quantify the frequency of these occurrences.

Conclusions: Our findings strongly support the value of a standardized four-extremity EMG/NCS as an adjuvant to a comprehensive history and physical examination. It helps to differentiate between old polio and other neurological diagnoses. There is a high prevalence of subclinical polio, which is important to know about in order to give proper recommendations regarding rest and activity. Given the frequency of risk factors for development of potentially treatable neurological lesions like CTS, early detection is valuable. We believe routine electrodiagnostic testing is essential for proper evaluation and management of the post-polio patient.

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Category: Post-Polio Motor Unit

Title: Muscle Function, Muscle Structure, and Electrophysiology in a Dynamic Perspective in Late Polio
Author: Gunnar Grimby, MD, PhD, Erik Stålberg, MD.
Affiliation:
Journal: NEW - PUT DETAILS IN CITATION FIELD
Citation: Gunnar Grimby, MD, PhD, Erik Stålberg, MD., Muscle Function, Muscle Structure, and Electrophysiology in a Dynamic Perspective in Late Polio, Chapter 2, pp 15-24.
Publication Year and Month: 1995

Abstract: The muscular impairment in patients with a history of polio varies from none to severe. The relationship between the degree of initial involvement and the effect of various compensatory mechanisms determines the clinical picture, which changes dynamically. Early and late recovery after poliomyelitis depend on a number of factors. Clinical improvement that appears within a few weeks after the acute phase is probably due to recovery in the excitability of functional, but not degenerated, motor neurons. Degeneration of neurons, causing peripheral denervation, is compensated by collateral sprouting, i.e., by nerve twigs branching off from surviving motor units overlapping with the denervated ones. This is most likely the main factor explaining recovery within the first 6-12 months. Another late compensatory process is the increase in size of the muscle fibers. As a result of these processes, normal muscle strength and presumably normal muscle volume can be seen despite a calculated loss exceeding 50% of the number of motor neurons.

Conclusions:

Outcome of Research:

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Category: Post-Polio Motor Unit

Title: Stimulation frequency-dependent neuromuscular junction transmission defects in patients with prior poliomyelitis
Author: Daria A. Trojan, Daniel Gendron and Neil R. Cashman
Affiliation: Department of Neurology, McGill University, Montreal Neurological Institute and Hospital
Journal:
Citation: Journal of the Neurological Sciences, 118 (1993) 150-157
Publication Year and Month: 1993 03

Abstract: Generalized fatigue and muscle fatiguability are major symptoms of post-poliomyelitis syndrome (PPS), and may be due to neuromuscular junction transmission defects, as suggested by increased jitter on single fiber electromyography (SFEMG). To determine the etiology of this defect, we studied jitter at low (1, 5 Hz) and high (10, 15, 20 Hz) frequency stimulation with stimulation SFEMG in 17 post-polio patients with muscle fatiguability, and in 9 normal controls. In 5 of 17 PPS patients and in 1 of 9 controls, jitter was significantly higher (unpaired t-test, P < 0.05) at high frequency stimulation (HFS). In the remaining PPS patients and controls there was no significant difference in jitter at high and low stimulation frequencies. PPS patients with increased jitter at HFS had a significantly longer time interval since acute polio (mean 48.5 years) than PPS patients without increased jitter at HFS (mean 40 years; P < 0.05), but were not distinguished by other historical or clinical criteria. We conclude that the neuromuscular junction defect in post-polio patients is similar to that observed in amyotrophic lateral sclerosis, and is probably due to ineffective conduction along immature nerve sprouts and exhaustion of acetylcholine stores. The appearance of an increase in jitter with HFS in post-polio patients may be dependent upon time after acute polio.

Conclusions:

Outcome of Research: Not applicable

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Category: Post-Polio Motor Unit

Title: A rat model of the post-polio motor unit
Author: Pachter BR, Eberstein A
Affiliation: Department of Rehabilitation Medicine, New York University Medical Center, NY 10016
Journal: Orthopedics
Citation: Orthopedics. 1991 Dec; 14(12):1367-73
Publication Year and Month: 1991 12

Abstract: We examined the long-term effects of muscle usage on a rat model of the post-polio motor unit. Isometric tensions, type I and type II muscle fiber areas, the incidence of collateral sprouting, and motor endplate morphology were examined following 1, 3, 6, and 9 months of partial denervation in rat plantaris muscle. Full morphologic and functional stability of the expanded motor units occurred at 6 months post-partial denervation. Fiber hypertrophy was observed, possibly the result of compensatory work hypertrophy due to muscle overuse. Following 9 months of partial denervation and muscle overuse, the twitch and tetanic tensions and type I and type II muscle fiber areas were significantly reduced as compared to sham controls; angulated myofibers and group atrophy also were seen. The percent collateral sprouting, the number of terminal branches per endplate, and the endplate area were all increased, possibly a compensatory response to a decreased synthesis of neurotrophic factor(s) and/or transmitter-related components. These aging-like changes seem to occur earlier in chronically stressed, overenlarged, and overworked motor units.

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Category: Post-Polio Motor Unit

Title: Electrophysiology and Electrodiagnosis of the Post-Polio Motor Unit
Author: Daria A. Trojan, MD, Daniel Gendron, MD, Neil R. Cashman, MD
Affiliation:
Journal: Orthopedics
Citation: Orthopedics December 1991 Vol 14 No 12 1353-1361
Publication Year and Month: 1991 12

Abstract: Post-poliomyelitis syndrome refers to new symptoms that may occur years after recovery from poliomyelitis. The most common of these symptoms are new weakness, fatigue, and pain. This article describes electrodiagnostic studies -- conventional electromyography (EMG), single fiber electromyography (SFEMG), and macroelectromyography (macro-EMG) -- that have provided information on the post-polio motor unit and on the possible etiology of some post-polio syndrome symptoms. Muscular fatigue, and indirectly, general fatigue, may be due to neuromuscular junction transmission defects in some post-polio individuals, as suggested by reduction of the compound motor action potentials on repetitive stimulation, and increased jitter and blocking on SFEMG. Progressive weakness and atrophy in post-polio syndrome is probably due to a distal degeneration of post-polio motor units with resultant irreversible muscle fiber denervation. Electrodiagnostic evidence of ongoing denervation includes fibrillation and fasciculation potentials on conventional EMG, increased jitter and blocking on SFEMG, and smaller macro-EMG amplitudes in newly weakened postpolio muscles. However, even though electrodiagnostic studies have provided insight into the possible causes of some postpolio syndrome symptoms, no specific electrodiagnostic test for the syndrome is currently available.

Conclusions:

Outcome of Research: Not applicable

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Category: Post-Polio Motor Unit

Title: Late effects of polio: critical review of the literature on neuromuscular function
Author: Agre JC, Rodríquez AA, Tafel JA
Affiliation: University of Wisconsin - Madison Medical School
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1991 Oct; 72(11):923-31
Publication Year and Month: 1991 10

Abstract: Many individuals who have had poliomyelitis are now complaining of several new problems attributed to their former illness including muscle atrophy; fatigue; progressive weakness; and muscle, back, and joint pain. This paper critically examines the literature regarding the neuromuscular effects of poliomyelitis. Weakness resulting from poliomyelitis was due to destruction of anterior horn cells. After the illness, muscle strength was partially recovered as a result of several physiologic adaptive mechanisms including terminal sprouting and reinnervation, myofiber hypertrophy, and, possibly, myofiber type transformation. Several pathophysiologic and functional etiologies have been proposed for late neuromuscular deterioration, but none has been proven. In fact, to date, there is no objective evidence documenting progressive loss of strength in polio survivors. Studies attempting to differentiate polio survivors with and without symptoms of deterioration have resulted in conflicting results; however, it appears reasonable to conclude that symptomatic postpolio subjects had a more severe illness with greater loss of neuromuscular function. Exercise may be helpful for many postpolio patients, but the prescription must be tailored to the individual to avoid problems of overuse or excessive fatigue.

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Category: Post-Polio Motor Unit

Title: Correlation of motor units with strength and spectral characteristics in polio survivors and controls
Author: Rodriguez AA, Agre JC
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin-Madison Medical School
Journal: Muscle & Nerve
Citation: 1991 May;14(5):429-34.
Publication Year and Month: 1991 05

Abstract: The purpose of this study was to determine whether quantitative motor unit analysis in postpolio individuals correlates with muscle strength, endurance, work capacity, or power spectral characteristics of surface EMG and to determine whether power spectrum differentiates postpolio from control subjects. This study was designed to compare these variables in 34 symptomatic postpolio, 16 asymptomatic postpolio, and 41 control subjects. Quantitative motor unit analysis of the quadriceps femoris muscle was performed using a concentric needle electrode. Isometric knee extension peak torque, endurance (time to exhaustion) at 40% of maximal torque, work capacity (tension time index), and recovery of force through 10 minutes post-exhaustion were determined. Median frequency of the surface power spectrum was determined during the above testing. Power spectrum histograms were compared at the onset and termination of endurance exercise. Motor unit action potential variables did not correlate with isometric peak torque, tension time index, endurance time, recovery of strength, or with median frequency. Surface power spectrum did not differentiate postpolio from control subjects.

Conclusions:

Outcome of Research: More research required

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Category: Post-Polio Motor Unit

Title: Neuromuscular function in polio survivors at one-year follow-up.
Author: Agre JC, Rodriguez AA
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin Medical School, Madison
Journal: Archives of Physical Medicine and Rehabilitation
Citation: 1991 Jan;72(1):7-10.
Publication Year and Month: 1991 01

Abstract: Many polio survivors complain of progressive loss of strength, work capacity, endurance, and ability to recover from fatiguing activity. These variables were measured initially and one year later in the quadriceps muscles of 28 symptomatic and 16 asymptomatic persons who had polio and 38 control individuals. Peak knee extension torque was measured isokinetically and isometrically. Endurance, or the amount of time the subject could maintain isometric torque at 40% of maximal torque, was measured. Work capacity was determined as the product of isometric torque and endurance time. Recovery of strength was measured at regular intervals for ten minutes after the endurance test. Statistical analysis was done by repeated measures ANOVA. Although the initial measures showed significant deficits in mean peak torque, work capacity, and recovery of strength in symptomatic postpolio subjects, no significant changes were found one year later in any of the variables.

Conclusions: Symptomatic postpolio subjects do not lose significant neuromuscular function in one year.

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Category: Post-Polio Motor Unit

Title: Electromyographic and morphological functional compensation in late poliomyelitis
Author: Einarsson G, Grimby G, Stålberg E
Affiliation: Department of Rehabilitation Medicine, Gothenburg University, Sweden
Journal: Muscle & Nerve
Citation: Muscle Nerve. 1990 Feb; 13(2):165-71
Publication Year and Month: 1990 02

Abstract: Patients with prior poliomyelitis may experience muscle function deterioration decades after onset of disease. The present study is aimed at describing electromyographic and morphometric evidence of muscular compensation and of on-going muscular instability. Ten subjects 42-62 years of age with onset of polio 25-52 years earlier were studied with macro EMG, single-fiber EMG (SFEMG), muscle strength measurement, and morphometrical analysis of muscle biopsies from the vastus lateralis muscle. SFEMG revealed increased fiber density (FD) and large macro-MUP potentials indicating pronounced reinnervation as compensation to loss of motor neurons. From electrophysiological data of motor unit size, morphometric measures of fiber size, and muscle strength data, the minimal degree of motor neuron loss was estimated to be greater than 70%.

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Category: Post-Polio Motor Unit

Title: Functional recovery – a major risk factor for the development of postpoliomyelitis muscular atrophy
Author: Klingman J, Chui H, Corgiat M, Perry J
Affiliation: Department of Neurology, University of Southern California School of Medicine, Los Angeles
Journal: Archives of Neurology
Citation: Arch Neurol. 1988 Jun;45(6):645-7
Publication Year and Month: 1988 06

Abstract: A retrospective study was undertaken to identify potential risk factors for the development of progressive postpoliomyelitis muscular atrophy (PPMA). Patients with PPMA (n = 57) were compared with patients with a history of poliomyelitis but without a history of progressive weakness (n = 49). Patients who later developed PPMA had histories of more widespread acute paralysis, but relatively greater functional recovery. They were less disabled, and reported higher recent activity levels. Seventy-nine percent of the total variance between the PPMA and control groups could be accounted for by recovery alone (ie, severity minus disability). Functional recovery is generally attributed to reinnervation of sarcomeres by collateral sprouting from surviving lower motor neurons. Since degree of recovery predicts the risk of developing PPMA, our findings suggest that enlarged motor units may carry an increased susceptibility for dysfunction and/or degeneration.

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Category: Post-Polio Motor Unit

Title: Late denervation in patients with antecedent paralytic poliomyelitis
Author: Cashman NR, Maselli R, Wollmann RL, Roos R, Simon R, Antel JP
Affiliation: Not stated
Journal: The New England Journal of Medicine
Citation: N Engl J Med. 1987 Jul 2; 317(1):7-12
Publication Year and Month: 1987 07

Abstract: The development of new weakness, fatigue, and pain decades after acute paralytic poliomyelitis is a recognized syndrome. We conducted a controlled study of this syndrome by analyzing clinical, electromyographic, and muscle-biopsy features in 18 patients with a history of poliomyelitis--13 reporting 1 to 20 years of new weakness and 5 without new symptoms. The patients with new weakness also reported new muscle atrophy (9 of 13) and fatigue (10 of 13), symptoms not reported by the controls. The age at the time of acute poliomyelitis, severity of poliomyelitis, residual disability, number of years since acute poliomyelitis, and age at the time of study were comparable in the weakening and control groups. Evidence of remote denervation consistent with antecedent poliomyelitis was demonstrated in all patients by electromyography or muscle biopsy or both. In addition, active denervation (as evidenced by spontaneous activity on conventional electromyography, increased jitter on single-fiber electromyography, or atrophic myofibers) was found in 12 patients in the weakening group and in all 5 controls. Immunohistochemical detection of myofibers expressing the neural-cell adhesion molecule corroborated ongoing denervation in both patient groups. When muscle data from both groups were pooled, correlations were observed between the extent of past reinnervation and the degree of ongoing motor-unit instability. We conclude that the extensive reinnervation of denervated muscle that occurs in paralytic poliomyelitis may be followed by late denervation of the previously reinnervated muscle fibers. Electromyographic and muscle-biopsy evidence of ongoing denervation does not distinguish between stable patients with prior paralytic poliomyelitis and those with new weakness.

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Category: Post-Polio Motor Unit

Title: Neurological manifestations of the post-polio syndrome
Author: Jubelt B, Cashman NR
Affiliation: Les Turner Amyotrophic Lateral Sclerosis Research Laboratory, Northwestern University Medical School, Chicago, Illinois
Journal: Critical Reviews in Neurobiology
Citation: Crit Rev Neurobiol. 1987;3(3):199-220
Publication Year and Month: 1987 03

Abstract: Patients with late effects of poliomyelitis, ie PPS, are being seen at an ever increasing frequency by general physicians, neurologists, and orthopedists. An appropriate time interval for the onset of late manifestations has elapsed since the major epidemics of poliomyelitis in the 1940s and 1950s. Post-polio neurological manifestations primarily include new weakness, atrophy, muscle pain, and fasciculations. Fortunately, the weakness is of a very slow, progressive nature. Abnormal laboratory studies include routine EMG, demonstrating chronic denervation; SFEMG, demonstrating increased fiber density, increased jitter, and blocking; and muscle biopsy most often revealing fiber-type grouping of chronic denervation and small isolated angular (or angulated) fibers and group atrophy in some series, both suggestive of active denervation. Unfortunately, both EMG and muscle biopsy studies suffer from a lack of specificity as they do not appear to distinguish asymptomatic from symptomatic (new weakness, PPMA) patients with prior poliomyelitis. Although the cause of PPMA is unknown, electrophysiological (SFEMG) and muscle biopsy studies suggest that the process involves a loss or dropout of axon terminals of reinnervated motor units. The axons terminal dropout could be due to dysfunction in the cell soma, the axon, or the terminals themselves. Whether motor neuron exhaustion, a persistent viral infection, or immune-mediated mechanisms play a role in the pathogenesis of the late weakness is unclear at present and will require further investigation. Treatment at this time is of a supportive nature. A major controversy involves the role of strengthening exercises in these patients since experimental animal studies suggest that excessive exercise of denervated muscles leads to increased weakness. Clearly, a better understanding of PPS and PPMA will allow more effective management of these patients’ problems and might also provide insight into other motor neuron and neuromuscular junction diseases.

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Category: Post-Polio Motor Unit

Title: A long-term follow-up study of patients with post-poliomyelitis neuromuscular symptoms
Author: Dalakas MC, Elder G, Hallett M, Ravits J, Baker M, Papadopoulos N, Albrecht P, Sever J
Affiliation: Not stated
Journal: The New England Journal of Medicine
Citation: N Engl J Med. 1986 Apr 10; 314(15):959-63
Publication Year and Month: 1986 04

Abstract: A “post-polio” syndrome characterized by new neuromuscular symptoms, including muscle weakness, may develop years after recovery from acute paralytic poliomyelitis. We studied 27 patients (mean age, 50.6 years) in whom new muscle weakness developed a mean of 28.8 years after recovery from acute polio. We reevaluated these patients during a mean follow-up period of 8.2 years (range, 4.5 to 20) after they were originally studied at the National Institutes of Health. The total mean follow-up period after the onset of new weakness was 12.2 years (range, 6 to 29). The patients were assessed with quantitative muscle testing, muscle biopsy, electromyography, and virologic and immunologic examination of the cerebrospinal fluid. Muscle strength had declined in all patients. The rate of decline averaged 1 percent per year. The decrease was irregular, with subjective plateau periods that ranged from 1 to 10 years. None of the patients had amyotrophic lateral sclerosis. Oligoclonal bands (IgG) were found in the cerebrospinal fluid of 7 of 13 patients studied, but no specific elevation of antibodies to poliovirus was observed in the cerebrospinal fluid. The newly affected muscles that were evaluated longitudinally with follow-up muscle biopsies and electromyography showed signs of chronic and new denervation. Groups of atrophic muscle fibers (group atrophy) and "neurogenic jitter" were not present. New post-polio muscle weakness is not a life-threatening form of motor-neuron deterioration. It appears that this weakness is not due to a loss of whole motor neurons, as in amyotrophic lateral sclerosis, but that it is due to a dysfunction of the surviving motor neurons that causes a slow disintegration of the terminals of individual nerve axons.

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Category: Post-Polio Motor Unit

Title: Vasomotor abnormalities as post-polio sequelae: functional and clinical implications
Author: Bruno RL, Johnson JC, Berman WS
Affiliation: Not stated
Journal: Orthopedics
Citation: Orthopedics. 1985 Jul; 8(7):865-9
Publication Year and Month: 1985 07

Abstract: Persons who had poliomyelitis report cold and discolored extremities and decreased muscle strength when exposed to mildly cool ambient temperatures. Bilateral digital cutaneous blood flow, skin temperature and median nerve latencies and amplitudes were measured at 30 degrees C, 25 degrees C and 20 degrees C in five post-polio subjects and age-matched controls. Cutaneous blood flow was lowest on the more affected side in the post-polio subjects but vasoconstriction with decreasing Ta was equal bilaterally in both groups. With decreasing Ta, median motor nerve latencies became clinically abnormal and “giant” sensory nerve potential amplitudes were seen in a majority of the post-polio subjects. It is concluded that an impairment of sympathetic vasoconstrictor outflow in post-polios allows passive dilatation and engorgement of the cutaneous venous capacitance beds. This promotes uncontrolled heat loss and causes cooling of nerve and muscle that is responsible for the impairment of muscle functioning and the abnormal electrophysiological findings.

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Category: Post-Polio Motor Unit

Title: Acute and latent effect of poliomyelitis on the motor unit as revealed by electromyography
Author: Wiechers DO
Affiliation: Not stated
Journal: Orthopedics
Citation: Orthopedics. 1985 Jul; 8(7):870-2
Publication Year and Month: 1985 07

Abstract: When polio virus attacks the motor neuron it may be completely destroyed, damaged, or unaffected. Muscle fibers of a destroyed motor neuron are orphaned or reinnervated. Nearby functioning motor units will then send terminal axon sprouts to reinnervate the orphaned muscle fibers. If there are too many orphaned muscle fibers and not enough surviving motor units to reinnervate them, the orphaned muscle fibers will continue to fibrillate until they atrophy and die. The resultant effect of poliomyelitis upon the affected muscle is an overall loss of motor units with the remaining units innervating many more muscle fibers than they originally did. There appears to be a late effect of polio upon these larger reinnervated motor units. After approximately 20 to 30 years, impulse transmission to the muscle fibers of the large reinnervated motor unit begins to fail. These transmission difficulties increase with age and time from recovery. These late onset transmission abnormalities may be factors in patient complaints of fatigue and progressive weakness.

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There are currently 31 papers in this category.

Outcomes of Research or Clinical Trials Activity Levels Acute Flaccid Paralysis Ageing Anaerobic Threshold Anaesthesia Assistive Technology Brain Cardiorespiratory Cardiovascular Clinical Evaluation Cold Intolerance Complementary Therapies Continence Coping Styles and Strategies Cultural Context Diagnosis and Management Differential Diagnosis Drugs Dysphagia Dysphonia Epidemiology Exercise Falls Fatigue Fractures Gender Differences Immune Response Inflammation Late Effects of Polio Muscle Strength Muscular Atrophy Orthoses Pain Polio Immunisation Post-Polio Motor Unit Psychology Quality of Life Renal Complications Respiratory Complications and Management Restless Legs Syndrome Sleep Analaysis Surgery Vitality Vocational Implications