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la Fontaine LA, Bruijnes JE, Smulders FH, Gorissen-Brouwers C, Karnebeek IE, Braakman HM, Klinkenberg S, Mul K, 't Hoen PBA, van Kuijk SM, van Engelen BG, Merkies IS, Faber CG. Comprehensive four-year disease progression assessment of myotonic dystrophy type 1. Neuromuscul Disord 2024; 43:44-52. [PMID: 39216342 DOI: 10.1016/j.nmd.2024.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2024] [Accepted: 08/15/2024] [Indexed: 09/04/2024]
Abstract
Myotonic dystrophy type 1 (DM1) is a heterogeneous neuromuscular disorder characterized by progressive muscle weakness and myotonia. This study investigates the progression of muscular strength and function over a four-year period. Patients with DM1 were examined at baseline and four years later. The following metrics were assessed over time: muscle strength (Medical Research Council-sumscore), hand-grip strength (Martin-Vigorimeter), hand-grip relaxation time (myotonia), and limitations in activities of daily living and (DM1ActivC questionnaire). A total of 648 patients entered the registry. Recruitment and follow-up is ongoing. In our manuscript, we focus on, 187 patients who were followed for 4 years. A significant decline in MRC sum score was observed, with distal muscles showing more deterioration. Hand-grip strength decreased significantly, with notable differences between sex and phenotype classified by disease onset. Surprisingly, an improvement of myotonia was observed. Follow-up analysis revealed a significant interaction between myotonia and grip-strength over time. Thus, the improvement in myotonia is likely explained by decreased in grip strength. Finally, there was a significant reduction in DM1ActivC score, indicating decreased activity and social participation. This study demonstrated variability in disease progression depending on sex, phenotype and disease status. This research demonstrates a nuanced pattern of disease progression, highlighting the need to combine different outcome measures to fully understand the complexity of DM1.
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Affiliation(s)
- Leandre A la Fontaine
- Department of Neurology, Maastricht University Medical Centre+, P. Debyelaan 25, Maastricht 6229 HX, the Netherlands; Mental Health and Neuroscience Research Institute, Maastricht University, Universiteitssingel 40, Maastricht 6229 ER, the Netherlands.
| | - Johanna E Bruijnes
- Department of Neurology, Maastricht University Medical Centre+, P. Debyelaan 25, Maastricht 6229 HX, the Netherlands; Mental Health and Neuroscience Research Institute, Maastricht University, Universiteitssingel 40, Maastricht 6229 ER, the Netherlands.
| | - Fran Hp Smulders
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Thomas van Aquinostraat 4, Nijmegen 6525 GD, the Netherlands.
| | - Carla Gorissen-Brouwers
- Department of Neurology, Maastricht University Medical Centre+, P. Debyelaan 25, Maastricht 6229 HX, the Netherlands.
| | - Ilse Ea Karnebeek
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Thomas van Aquinostraat 4, Nijmegen 6525 GD, the Netherlands.
| | - Hilde Mh Braakman
- Department of Pediatric Neurology, Radboud University Medical Center, Amalia Children's Hospital, Geert Grooteplein Zuid 32, Nijmegen 6525 GA, the Netherlands.
| | - Sylvia Klinkenberg
- Department of Neurology, Maastricht University Medical Centre+, P. Debyelaan 25, Maastricht 6229 HX, the Netherlands; Mental Health and Neuroscience Research Institute, Maastricht University, Universiteitssingel 40, Maastricht 6229 ER, the Netherlands.
| | - Karlien Mul
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Thomas van Aquinostraat 4, Nijmegen 6525 GD, the Netherlands.
| | - Peter-Bram Ac 't Hoen
- Department of Medical BioSciences, Radboud University Medical Centre, Geert Grooteplein Zuid 10, Nijmegen 6525 GA, the Netherlands.
| | - Sander Mj van Kuijk
- Department of Clinical Epidemiology and Medical Technology Assessment, P. Debyelaan 25, Maastricht 6229 HX, the Netherlands.
| | - Baziel Gm van Engelen
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Thomas van Aquinostraat 4, Nijmegen 6525 GD, the Netherlands.
| | - Ingemar Sj Merkies
- Department of Neurology, Maastricht University Medical Centre+, P. Debyelaan 25, Maastricht 6229 HX, the Netherlands; Department of Neurology, Curaçao Medical Center, J.H.J. Hamelbergweg, Willemstad, Curaçao.
| | - Catharina G Faber
- Department of Neurology, Maastricht University Medical Centre+, P. Debyelaan 25, Maastricht 6229 HX, the Netherlands; Mental Health and Neuroscience Research Institute, Maastricht University, Universiteitssingel 40, Maastricht 6229 ER, the Netherlands.
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Yigit S, Usgu S, Albayrak HM, Yücel PP, Yakut Y. Effectiveness of functional trunk training on trunk control and upper limb functions in patients with autosomal recessive hereditary ataxia. NeuroRehabilitation 2022; 51:41-50. [DOI: 10.3233/nre-210320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND: Ataxia is a clinical syndrome characterized by coordination problems and postural disorders. OBJECTIVE: This study aimed to examine the effects of functional trunk training on trunk control and upper limb functions in autosomal recessive hereditary ataxia. METHODS: Twenty patients were randomly divided into treatment and control groups. Both groups received trunk stabilization and balance exercises, and the treatment group received additional functional trunk training sessions (3 days/week for 8 weeks). The International Cooperative Ataxia Rating Scale, Trunk Impairment Scale, Modified Functional Reach Test, Nine-Hole Peg Test and Quick-Disabilities of the Arm Shoulder and Hand questionnaire were used for assessments. RESULTS: The treatment group showed an increase in the upper limb performance bilaterally, whereas increased performance was seen only in the dominant upper limb in the control group. While the functional reach improved in the anterior-posterior (AP) and medial-lateral (ML) directions in the treatment group, it was improved only in the AP direction in the control group. Also, the mean changes in outcomes were not significantly different between the groups except for modified functional reach test. CONCLUSIONS: Functional trunk training may be a more effective method to improve upper limb performance and dynamic trunk balance in autosomal recessive hereditary ataxia.
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Affiliation(s)
- Sedat Yigit
- Department of Physical Therapy and Rehabilitation, Health Science Faculty, Hasan Kalyoncu University, Gaziantep, Turkey
| | - Serkan Usgu
- Department of Physical Therapy and Rehabilitation, Health Science Faculty, Hasan Kalyoncu University, Gaziantep, Turkey
| | - Hatice Mutlu Albayrak
- Department of Pediatric Genetics, Ankara Bilkent City Hospital- Children’s Hospital, Ankara, Turkey
| | - Peren Perk Yücel
- Department of Pediatric Neurology, Faculty of Medicine, Trakya University, Edirne, Turkey
| | - Yavuz Yakut
- Department of Physical Therapy and Rehabilitation, Health Science Faculty, Hasan Kalyoncu University, Gaziantep, Turkey
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Kronlage C, Grimm A, Romano A, Stahl JH, Martin P, Winter N, Marquetand J. Muscle Ultrasound Shear Wave Elastography as a Non-Invasive Biomarker in Myotonia. Diagnostics (Basel) 2021; 11:diagnostics11020163. [PMID: 33498617 PMCID: PMC7911703 DOI: 10.3390/diagnostics11020163] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/15/2021] [Accepted: 01/21/2021] [Indexed: 12/31/2022] Open
Abstract
Myotonia, i.e., delayed muscle relaxation in certain hereditary muscle disorders, can be assessed quantitatively using different techniques ranging from force measurements to electrodiagnostics. Ultrasound shear wave elastography (SWE) has been proposed as a novel tool in biomechanics and neuromuscular medicine for the non-invasive estimation of muscle elasticity and, indirectly, muscle force. The aim of this study is to provide ‘proof-of-principle’ that SWE allows a quantitative measurement of the duration of delayed muscle relaxation in myotonia in a simple clinical setting. In six myotonic muscle disorder patients and six healthy volunteers, shear wave velocities (SWV) parallel to the fiber orientation in the flexor digitorum superficialis muscle in the forearm were recorded with a temporal resolution of one per second during fist-clenching and subsequent relaxation; the relaxation time to 10% of normalized shear wave velocity (RT0.1) was calculated. Forty-six SWE imaging sequences were acquired, yielding a mean RT0.1 of 7.38 s in myotonic muscle disorder patients, significantly higher than in healthy volunteers (1.36 s), which is comparable to data obtained by mechanical dynamometry. SWV measurements during the baseline relaxation and voluntary contraction phases did not differ significantly between groups. We conclude that SWE is a promising, non-invasive, widely available tool for the quantitative assessment of myotonia to aid in diagnosis and therapeutic monitoring.
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Antisense oligonucleotide and adjuvant exercise therapy reverse fatigue in old mice with myotonic dystrophy. MOLECULAR THERAPY. NUCLEIC ACIDS 2020; 23:393-405. [PMID: 33473325 PMCID: PMC7787993 DOI: 10.1016/j.omtn.2020.11.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/17/2020] [Indexed: 02/06/2023]
Abstract
Patients with myotonic dystrophy type 1 (DM1) identify chronic fatigue as the most debilitating symptom, which manifests in part as prolonged recovery after exercise. Clinical features of DM1 result from pathogenic gain-of-function activity of transcripts containing an expanded microsatellite CUG repeat (CUGexp). In DM1 mice, therapies targeting the CUGexp transcripts correct the molecular phenotype, reverse myotonia, and improve muscle pathology. However, the effect of targeted molecular therapies on fatigue in DM1 is unknown. Here, we use two mouse models of DM1, age-matched wild-type controls, an exercise-activity assay, electrical impedance myography, and therapeutic antisense oligonucleotides (ASOs) to show that exaggerated exercise-induced fatigue progresses with age, is unrelated to muscle fiber size, and persists despite correction of the molecular phenotype for 3 months. In old DM1 mice, ASO treatment combined with an exercise training regimen consisting of treadmill walking 30 min per day 6 days per week for 3 months reverse all measures of fatigue. Exercise training without ASO therapy improves some measures of fatigue without correction of the molecular pathology. Our results highlight a key limitation of ASO monotherapy for this clinically important feature and support the development of moderate-intensity exercise as an adjuvant for targeted molecular therapies of DM1.
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Correlation of proximal and distal muscle strength with upper limb functional ability in patients with essential tremor. Acta Neurol Belg 2020; 120:601-607. [PMID: 30565036 DOI: 10.1007/s13760-018-01068-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 12/12/2018] [Indexed: 12/14/2022]
Abstract
Despite being considered as a benign, genetic and monosymptomatic disorder, ET is a poorly understood entity with etiological and pathological heterogeneity. The aim of the present study was to examine the relation between proximal and distal muscle strength and upper limb functionality and tremor severity in patients with essential tremor (ET). The study enrolled 25 tremor patients followed at the neurology clinic of a university hospital and 19 healthy controls. Demographic data, risk factors, disease duration and dominant hand of the participants were recorded. Back and leg strength was assessed using a back and leg dynamometer and hand dynamometer and pinchmeter were used to determine hand strength. Functional ability of the participants was evaluated using the Minnesota Manual Dexterity Test (MMDT), Perdue Pegboard (PPBT) and Nine Hole Peg Test (NHPT). Tremor severity was assessed using the Fahn-Tolosa-Marin Tremor Rating Scale (FTMTRS) and the Lower Extremity Clinical Tremor Assessment Scale (LECTAS). A significant difference was found in the average back and leg muscle strength between ET patients and healthy controls (p < 0.05). The mean values for right/left hand muscle strength were not significantly different between the two groups (p > 0.05). Among the upper limb functional ability tests, significant differences were found between the two groups in the mean time to complete NHPT, Minnesota placing subtest and PPBT test (p < 0.05). While gender and risk factors were not significantly different between the two groups (p > 0.05), there was a significant difference with respect to the educational level (p < 0.01). No significant difference was found between back and leg muscle strength and FTMTRS and LECTAS (p > 0.05). A negative correlation and a significant association were found between average strength measurements obtained with the left hand dynamometer and FTMTRS in the ET group (p = 0.030, r = - 0.434). A positive correlation and a significant association were found between left hand strength and mean turning time in the MMDT in the control group (p = 0.041, r = 0.473). ET patients experience loss of proximal muscle strength and functional disability. Further studies are planned to investigate the effects of physical therapy modalities targeting increased proximal muscle strength on tremor severity and functional ability in ET patients.
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Roussel MP, Morin M, Gagnon C, Duchesne E. What is known about the effects of exercise or training to reduce skeletal muscle impairments of patients with myotonic dystrophy type 1? A scoping review. BMC Musculoskelet Disord 2019; 20:101. [PMID: 30836978 PMCID: PMC6402179 DOI: 10.1186/s12891-019-2458-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 02/06/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Myotonic dystrophy type 1 (DM1) is a neuromuscular disease characterized by multisystemic involvements including a progressive loss of maximal muscle strength and muscle wasting. Poor lower-limb strength is an important factor explaining disrupted social participation of affected individuals. This review aims to map what is known about the effects of exercise and training programs undertaken to counteract skeletal muscle impairments in DM1 patients. METHODS Medline, CINAHL and EMBASE databases were searched. Regarding study eligibility, title and abstract of 704 studies followed by 45 full articles were reviewed according to the following eligibility criteria. Inclusion: (1) humans with DM1 and (2) experimental protocol relying on exercise or training. Exclusion: (1) studies that do not evaluate skeletal muscle responses or adaptations, (2) reviews covering articles already included and (3) pharmacological intervention at the same time of exercise or training program. RESULTS Twenty-one papers were selected for in-depth analysis. Different exercise or training protocols were found including: acute exercise, neuromuscular electric stimulation, strength training, aerobic training, balance training and multiple rehabilitation interventions. Seven studies reported clinical measurements only, five physiological parameters only and nine both types. CONCLUSION This scoping review offers a complete summary of the current scientific literature on the effect of exercise and training in DM1 and a framework for future studies based on the concomitant evaluation of the several outcomes in present literature. Although there were a good number of studies focusing on clinical measurements, heterogeneity between studies does not allow to identify what are the adequate training parameters to obtain exercise or training-induced positive impacts on muscle function. Scientific literature is even more scarce regarding physiological parameters, where much more research is needed to understand the underlying mechanisms of exercise response in DM1.
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Affiliation(s)
- Marie-Pier Roussel
- Département des sciences de la santé, physiothérapie, Université du Québec à Chicoutimi, 555, boulevard de l'Université, Chicoutimi, Quebec, G7H 2B1, Canada.,Groupe de recherche interdisciplinaire sur les maladies neuromusculaires, Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-St-Jean, 2230 rue de l'Hôpital, Saguenay, Québec, Canada.,Centre de recherche Charles-Le Moyne - Saguenay-Lac-Saint-Jean sur les innovations en santé, 2230 rue de l'Hôpital, Saguenay, Québec, Canada., Longueuil, Québec, Canada
| | - Marika Morin
- Département des sciences de la santé, physiothérapie, Université du Québec à Chicoutimi, 555, boulevard de l'Université, Chicoutimi, Quebec, G7H 2B1, Canada
| | - Cynthia Gagnon
- Groupe de recherche interdisciplinaire sur les maladies neuromusculaires, Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-St-Jean, 2230 rue de l'Hôpital, Saguenay, Québec, Canada.,Centre de recherche Charles-Le Moyne - Saguenay-Lac-Saint-Jean sur les innovations en santé, 2230 rue de l'Hôpital, Saguenay, Québec, Canada., Longueuil, Québec, Canada.,Faculté de médecine et des sciences de la santé, Université de Sherbrooke, 3001, 12e Avenue Nord, Sherbrooke, Québec, Canada
| | - Elise Duchesne
- Département des sciences de la santé, physiothérapie, Université du Québec à Chicoutimi, 555, boulevard de l'Université, Chicoutimi, Quebec, G7H 2B1, Canada. .,Groupe de recherche interdisciplinaire sur les maladies neuromusculaires, Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-St-Jean, 2230 rue de l'Hôpital, Saguenay, Québec, Canada. .,Centre de recherche Charles-Le Moyne - Saguenay-Lac-Saint-Jean sur les innovations en santé, 2230 rue de l'Hôpital, Saguenay, Québec, Canada., Longueuil, Québec, Canada.
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7
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Hogrel JY, Ollivier G, Ledoux I, Hébert LJ, Eymard B, Puymirat J, Bassez G. Relationships between grip strength, myotonia, and CTG expansion in myotonic dystrophy type 1. Ann Clin Transl Neurol 2017; 4:921-925. [PMID: 29296622 PMCID: PMC5740258 DOI: 10.1002/acn3.496] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 10/02/2017] [Accepted: 10/02/2017] [Indexed: 02/01/2023] Open
Abstract
In myotonic dystrophy type 1, several studies have suggested causal relationships between CTG repeat length and the severity of symptoms, such as weakness or myotonia. We aimed to explore these relationships in a large population of 144 DM1 patients. All patients underwent clinical and functional assessments using a standardized test for grip strength and myotonia assessment. Myotonia was assessed using a fully automatic software based on mathematical modeling of relaxation force curve. CTG repeat length was statistically correlated with both myotonia and grip strength, which are two major primary neuromuscular symptoms of DM1 patients. However, these relationships are not clinically meaningful and not predictive at the individual level.
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Affiliation(s)
| | | | | | | | - Bruno Eymard
- Institut de Myologie GH Pitié-Salpêtrière Paris France
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8
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Alemdaroğlu I, Karaduman A, Yilmaz ÖT, Topaloğlu H. Different types of upper extremity exercise training in Duchenne muscular dystrophy: Effects on functional performance, strength, endurance, and ambulation. Muscle Nerve 2015; 51:697-705. [DOI: 10.1002/mus.24451] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2014] [Indexed: 01/30/2023]
Affiliation(s)
- Ipek Alemdaroğlu
- Faculty of Health Sciences; Physiotherapy and Rehabilitation Department; Bezmialem Vakıf University; Fatih Istanbul Turkey
| | - Ayşe Karaduman
- Faculty of Health Sciences; Physiotherapy and Rehabilitation Department; Hacettepe University; Ankara Turkey
| | - Öznur Tunca Yilmaz
- Faculty of Health Sciences; Physiotherapy and Rehabilitation Department; Hacettepe University; Ankara Turkey
| | - Haluk Topaloğlu
- İhsan Doğramacı Children Hospital; Pediatric Neurology Department; Hacettepe University; Ankara Turkey
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9
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Heatwole CR, Statland JM, Logigian EL. The diagnosis and treatment of myotonic disorders. Muscle Nerve 2013; 47:632-48. [PMID: 23536309 DOI: 10.1002/mus.23683] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2012] [Indexed: 12/12/2022]
Abstract
Myotonia is a defining clinical symptom and sign common to a relatively small group of muscle diseases, including the myotonic dystrophies and the nondystrophic myotonic disorders. Myotonia can be observed on clinical examination, as can its electrical correlate, myotonic discharges, on electrodiagnostic testing. Research interest in the myotonic disorders continues to expand rapidly, which justifies a review of the scientific bases, clinical manifestations, and numerous therapeutic approaches associated with these disorders. We review the pathomechanisms of myotonia, the clinical features of the dystrophic and nondystrophic myotonic disorders, and the diagnostic approach and treatment options for patients with symptomatic myotonia.
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Affiliation(s)
- Chad R Heatwole
- Department of Neurology, Box 673, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, New York, New York 14642, USA.
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10
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Andersen G, Ørngreen MC, Preisler N, Colding-Jørgensen E, Clausen T, Duno M, Jeppesen TD, Vissing J. Muscle phenotype in patients with myotonic dystrophy type 1. Muscle Nerve 2012; 47:409-15. [PMID: 23169601 DOI: 10.1002/mus.23535] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2012] [Indexed: 11/06/2022]
Abstract
INTRODUCTION The pathogenesis of muscle involvement in patients with myotonic dystrophy type 1 (DM1) is not well understood. In this study, we characterized the muscle phenotype in patients with confirmed DM1. METHODS In 38 patients, muscle strength was tested by hand-held dynamometry. Myotonia was evaluated by a handgrip test and by analyzing the decrement of the compound muscle action potential. Muscle biopsies were assessed for morphological changes and Na(+)-K(+) pump content. RESULTS Muscle strength correlated with a decline in Na(+)-K(+) pump content (r = 0.60, P < 0.001) and with CTG expansion. CTG expansion did not correlate with severity of myotonia, proximal histopathological changes, or Na(+)-K(+) pump content. Histopathologically, we found few centrally placed nuclei (range 0.2-6.9%). CONCLUSIONS The main findings of this study are that muscle weakness correlated inversely with CTG expansion and that central nuclei are not a prominent feature of proximal muscles in DM1.
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Affiliation(s)
- Grete Andersen
- Neuromuscular Research Unit, Department of Neurology, 3342, Rigshospitalet Blegdamsvej 9, DK-2100, Copenhagen, Denmark.
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Tang ZZ, Yarotskyy V, Wei L, Sobczak K, Nakamori M, Eichinger K, Moxley RT, Dirksen RT, Thornton CA. Muscle weakness in myotonic dystrophy associated with misregulated splicing and altered gating of Ca(V)1.1 calcium channel. Hum Mol Genet 2011; 21:1312-24. [PMID: 22140091 DOI: 10.1093/hmg/ddr568] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Myotonic dystrophy type 1 and type 2 (DM1 and DM2) are genetic diseases in which mutant transcripts containing expanded CUG or CCUG repeats cause cellular dysfunction by altering the processing or metabolism of specific mRNAs and miRNAs. The toxic effects of mutant RNA are mediated partly through effects on proteins that regulate alternative splicing. Here we show that alternative splicing of exon 29 (E29) of Ca(V)1.1, a calcium channel that controls skeletal muscle excitation-contraction coupling, is markedly repressed in DM1 and DM2. The extent of E29 skipping correlated with severity of weakness in tibialis anterior muscle of DM1 patients. Two splicing factors previously implicated in DM1, MBNL1 and CUGBP1, participated in the regulation of E29 splicing. In muscle fibers of wild-type mice, the Ca(V)1.1 channel conductance and voltage sensitivity were increased by splice-shifting oligonucleotides that induce E29 skipping. In contrast to human DM1, expression of CUG-expanded RNA caused only a modest increase in E29 skipping in mice. However, forced skipping of E29 in these mice, to levels approaching those observed in human DM1, aggravated the muscle pathology as evidenced by increased central nucleation. Together, these results indicate that DM-associated splicing defects alter Ca(V)1.1 function, with potential for exacerbation of myopathy.
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Affiliation(s)
- Zhen Zhi Tang
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
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Moyer M, Berger DS, Ladd AN, Van Lunteren E. Differential susceptibility of muscles to myotonia and force impairment in a mouse model of myotonic dystrophy. Muscle Nerve 2011; 43:818-27. [PMID: 21404300 DOI: 10.1002/mus.21988] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/07/2010] [Indexed: 01/01/2023]
Abstract
INTRODUCTION Myotonic dystrophy, or dystrophia myotonica (DM), is characterized by prominent muscle wasting and weakness as well as delayed muscle relaxation resulting from persistent electrical discharges. METHODS We hypothesized heterogeneity among muscles in degree of weakness and myotonia in an expanded [(CUG)(250)] repeats transgenic (HSA(LR)) mouse DM model. Muscle contraction was compared among diaphragm, extensor digitorum longus (EDL), and soleus muscles. RESULTS Myotonia was found only in EDL, as manifested by longer late-relaxation time and elevated myotonic index. EDL, but not the other two muscles, had impaired force over a wide range of stimulation frequencies. During fatigue-inducing stimulation, DM EDL muscle force per cross-sectional area was significantly impaired during 25-Hz stimulation, whereas there were no differences in fatigue response for DM diaphragm or soleus. CONCLUSION In an expanded repeats model of DM the EDL is more susceptible to myotonia and force impairment than muscles with lower proportions of fast-twitch fibers.
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Affiliation(s)
- Michelle Moyer
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep, Cleveland VA Medical Center, K201, 10701 East Boulevard, Cleveland, Ohio 44106, USA
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Matthews E, Fialho D, Tan SV, Venance SL, Cannon SC, Sternberg D, Fontaine B, Amato AA, Barohn RJ, Griggs RC, Hanna MG. The non-dystrophic myotonias: molecular pathogenesis, diagnosis and treatment. ACTA ACUST UNITED AC 2009; 133:9-22. [PMID: 19917643 DOI: 10.1093/brain/awp294] [Citation(s) in RCA: 142] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The non-dystrophic myotonias are an important group of skeletal muscle channelopathies electrophysiologically characterized by altered membrane excitability. Many distinct clinical phenotypes are now recognized and range in severity from severe neonatal myotonia with respiratory compromise through to milder late-onset myotonic muscle stiffness. Specific genetic mutations in the major skeletal muscle voltage gated chloride channel gene and in the voltage gated sodium channel gene are causative in most patients. Recent work has allowed more precise correlations between the genotype and the electrophysiological and clinical phenotype. The majority of patients with myotonia have either a primary or secondary loss of membrane chloride conductance predicted to result in reduction of the resting membrane potential. Causative mutations in the sodium channel gene result in an abnormal gain of sodium channel function that may show marked temperature dependence. Despite significant advances in the clinical, genetic and molecular pathophysiological understanding of these disorders, which we review here, there are important unresolved issues we address: (i) recent work suggests that specialized clinical neurophysiology can identify channel specific patterns and aid genetic diagnosis in many cases however, it is not yet clear if such techniques can be refined to predict the causative gene in all cases or even predict the precise genotype; (ii) although clinical experience indicates these patients can have significant progressive morbidity, the detailed natural history and determinants of morbidity have not been specifically studied in a prospective fashion; (iii) some patients develop myopathy, but its frequency, severity and possible response to treatment remains undetermined, furthermore, the pathophysiogical link between ion channel dysfunction and muscle degeneration is unknown; (iv) there is currently insufficient clinical trial evidence to recommend a standard treatment. Limited data suggest that sodium channel blocking agents have some efficacy. However, establishing the effectiveness of a therapy requires completion of multi-centre randomized controlled trials employing accurate outcome measures including reliable quantitation of myotonia. More specific pharmacological approaches are required and could include those which might preferentially reduce persistent muscle sodium currents or enhance the conductance of mutant chloride channels. Alternative strategies may be directed at preventing premature mutant channel degradation or correcting the mis-targeting of the mutant channels.
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Affiliation(s)
- E Matthews
- MRC Centre for Neuromuscular Diseases, UCL, Institute of Neurology, Queen Square, London, WC1N 3BG, England
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Abstract
The lack of a robust quantitative measure of myotonia has been underlined in previous studies. Recent publications have proposed methods to quantify myotonia based on the measurement of force relaxation times during maximal contractions. However, they present several drawbacks mainly due to unstable force, odd peaks or digital noise. A possible solution to this issue consists in fitting the force curve with a convenient regression model. The aim of this study was, therefore, to provide a regression model in order to fit the force relaxation time curve automatically and to provide a robust index for quantitative assessment of myotonia in clinical settings. Force curves were fitted by an asymmetric sigmoidal function. The inverse function was then used to compute various absolute and relative relaxation times automatically. These variables were calculated for 16 controls and 16 patients with myotonic dystrophy type 1 (DM1). All variables were significantly increased in DM1 patients compared to controls. For instance, the relaxation time between 40 and 60% of the initial contraction level was 18.2 (SD: 3.3) ms in controls and 40.1 (SD: 17.7) ms in DM1 patients. All relaxation variables were highly discriminant. Force curve modelling provides an objective and effective quantification of myotonia.
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Affiliation(s)
- J-Y Hogrel
- Institut de Myologie, GH Pitié-Salpêtrière, 75651 Paris Cedex 13, France.
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15
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Moxley RT, Logigian EL, Martens WB, Annis CL, Pandya S, Moxley RT, Barbieri CA, Dilek N, Wiegner AW, Thornton CA. Computerized hand grip myometry reliably measures myotonia and muscle strength in myotonic dystrophy (DM1). Muscle Nerve 2007; 36:320-8. [PMID: 17587223 DOI: 10.1002/mus.20822] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The aim of this study was to develop a reliable, sensitive, quantitative measure of grip myotonia and strength and to determine whether CTG repeat length is correlated with grip myotonia and with muscle strength in myotonic dystrophy type 1 (DM1). Three maximum voluntary isometric contractions (MVICs) of the finger flexors (i.e., handgrip) were recorded on 2 successive days using a computerized handgrip myometer in 29 genetically confirmed DM1 patients and 17 normals. An automated computer program calculated MVIC peak force (PF) and relaxation times (RTs) along the declining (relaxation) phase of the force recordings at 90%, 75%, 50%, 10%, and 5% of PF. Patients also underwent quantitative strength testing (QST) manual muscle testing (MMT). The patients had longer grip RTs and lower PFs than normals. RT (90% to 5%) was above the normal mean +2.5 SD in 25 (86%) patients. In DM1, prolongation of RT was mainly in the terminal (50% to 5%), rather than the initial (90% to 50%) phase of relaxation. PFs and RTs for each patient were reproducible on consecutive days. RTs were positively correlated with leukocyte CTG repeat length, whereas measures of muscle strength, such as PF, QST, and MMT, were negatively correlated with repeat length. We conclude that computerized handgrip myometry provides a sensitive, reliable measure of myotonia and strength in DM1 and offers a method to assess natural history and response to treatment.
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Affiliation(s)
- Richard T Moxley
- Department of Neurology, University of Rochester Medical Center, Box 673, 601 Elmwood Avenue, Rochester, New York 14642, USA.
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16
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Cleland JC, Logigian EL. Clinical evaluation of membrane excitability in muscle channel disorders: potential applications in clinical trials. Neurotherapeutics 2007; 4:205-15. [PMID: 17395130 DOI: 10.1016/j.nurt.2007.01.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Muscle channelopathies are inherited disorders that cause paralysis and myotonia. Molecular technology has contributed immeasurably to diagnostic testing, to correlation of genotype with phenotype, and to insight into the pathophysiology of these disorders. In most cases, the diagnosis of muscle channelopathy is still made on clinical grounds, but is supported by ancillary laboratory and electrodiagnostic testing such as serum potassium measurement, exercise testing, repetitive nerve stimulation, needle electromyography, calculation of muscle fiber conduction velocity, or electromyography power spectra. Although provocative glucose or potassium challenges are now infrequently performed, they have contributed greatly to our understanding of the pathophysiology of these disorders, and to our ability to differentiate between periodic paralysis types. Despite considerable progress, ample opportunity remains for future clinical research, particularly in expanding genotype-phenotype correlations and in optimizing electrodiagnostic methods. With respect to diagnostic testing, there is a need for accurate, efficient, and cost-effective bedside testing, given the substantial proportion (as high as 20%) of genetically undefined cases. Even in genetically defined cases, minimal clinical expressivity due to incomplete penetrance poses a significant challenge to currently available nonmolecular testing.
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Affiliation(s)
- James C Cleland
- University of Rochester School of Medicine and Dentistry, Rochester, New York, USA.
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17
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Féasson L, Camdessanché JP, El Mhandi L, Calmels P, Millet G. Fatigue and neuromuscular diseases. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.annrmp.2006.04.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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18
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Krishnan AV, Kiernan MC. Axonal function and activity-dependent excitability changes in myotonic dystrophy. Muscle Nerve 2006; 33:627-36. [PMID: 16453325 DOI: 10.1002/mus.20516] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
To investigate peripheral nerve function and its potential contribution to symptoms of weakness in myotonic dystrophy type 1 (MD), nerve excitability was assessed in 12 MD patients. Compound muscle action potentials (CMAPs) were recorded at rest from abductor pollicis brevis (APB) following stimulation of the median nerve. Stimulus-response behavior, threshold electrotonus, a current-threshold relationship, and recovery cycles were successfully recorded in each patient. Compared with controls, there was significant reduction in CMAP amplitude in MD patients. This was accompanied by reduction in depolarizing threshold electrotonus and an increase in refractoriness and in the duration of the relative refractory period. To determine whether alteration in axonal resting membrane potential was a factor underlying these changes, axonal excitability was assessed following maximal contraction of APB for 60 seconds. Following contraction, there was reduction in CMAP amplitude for a submaximal stimulus (by 51.5+/-11.8%) and an increase in super-excitability (of 22.2+/-12.0%), consistent with activity-dependent hyperpolarization, with a greater increase in threshold for MD patients compared to controls (MD group, 22.3+/-5.1%; controls, 11.7+/-2.1%; P<0.04) and prolonged recovery to baseline. The present study has established that greater activity-dependent changes in excitability may be induced in MD patients by maximal voluntary contraction when compared to controls. The excitability changes and prolonged recovery of threshold following contraction are likely to contribute to symptoms of fatigue and weakness in MD patients.
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Affiliation(s)
- Arun V Krishnan
- Prince of Wales Medical Research Institute and Prince of Wales Clinical School, University of New South Wales, Barker Street, Randwick, Sydney, NSW 2031, Australia
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19
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Féasson L, Camdessanché JP, El Mandhi L, Calmels P, Millet GY. Fatigue and neuromuscular diseases. ACTA ACUST UNITED AC 2006; 49:289-300, 375-84. [PMID: 16780988 DOI: 10.1016/j.annrmp.2006.04.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
PURPOSE To identify the role of fatigue, its evaluation and its causes in the pathophysiology context of acquired or hereditary neuromuscular diseases of the spinal anterior horn cell, peripheral nerve, neuromuscular junction and muscle. MATERIAL AND METHODS A literature review has been done on Medline with the following keywords: neuromuscular disease, peripheral neuropathy, myopathy, fatigue assessment, exercise intolerance, force assessment, fatigue scale and questionnaire, then with the terms: Fatigue Severity Scale, Chalder Fatigue Scale, Fatigue Questionnaire, Piper Fatigue Scale, electromyography and the combination of the word Fatigue with the following terms: Amyotrophic Lateral Sclerosis (ALS), Post-Polio Syndrome (PPS), Guillain-Barre Syndrome, Immune Neuropathy, Charcot-Marie-Tooth Disease, Myasthenia Gravis (MG), Metabolic Myopathy, Mitochondrial Myopathy, Muscular Dystrophy, Facioscapulohumeral Dystrophy, Myotonic Dystrophy. RESULTS Fatigue is a symptom very frequently reported by patients. Fatigue is mainly evaluated by strength loss after an exercise, by change in electromyographic activity during a given exercise and by questionnaires that takes into account the subjective (psychological) part of fatigue. Due to the large diversity of motor disorders, there are multiple clinical expressions of fatigue that differ in their presentation, consequences and therapeutic approach. CONCLUSION This review shows that fatigue has to be taken into account in patients with neuromuscular diseases. In this context, pathophysiology of fatigue often implies the motor component but the disease evolution and the physical obligates of daily life also induce an important psychological component.
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Affiliation(s)
- L Féasson
- Unité de Recherche PPEH-EA 3062, Faculté de Médecine Jacques-Lisfranc, Université Jean-Monnet, Saint-Etienne, France.
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20
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Boissy P, Bourbonnais D, Gravel D, Arsenault AB, Leblanc M. A static dynamometer measuring simultaneous torques exerted at the upper limb. IEEE TRANSACTIONS ON REHABILITATION ENGINEERING : A PUBLICATION OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY 1998; 6:309-15. [PMID: 9749908 DOI: 10.1109/86.712229] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The majority of available dynamometers are designed to measure force or torque in one specific direction, one joint at a time. For the quantification of motor incoordination in neurological patient populations, these dynamometers provide limited information about the global behavior of the limb under investigation. This report describes the potential use and function of a static dynamometer measuring torques exerted simultaneously at the shoulder (flexion-extension, abduction-adduction, internal-external rotation), elbow (flexion-extension), and forearm (pronation-supination). Orthogonal forces were measured at the arm and wrist using strain gauge transducers interfaced with a laboratory computer. The lever arms were specified to a software program and the joint torques were calculated in real time according to static equilibrium equations. The use of the dynamometer is illustrated by characterizing for one hemiparetic subject, the joints torques recorded at the shoulder, elbow, and forearm during isolated submaximal grip exertions at different force levels on both sides. The torques generated at the shoulder, elbow and forearm during the hand grip tasks on the affected side were significantly higher than those obtained on the nonaffected side and increased with the grip force level. These differences probably reflect the loss of movement selectivity observed following a lesion in the central nervous system. Further studies are currently being undertaken in neurological patient populations to characterize and quantify motor deficits using this dynamometer. As a long term goal, we hope that the method and technologies described here will contribute to the evaluation and rehabilitation of these populations.
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Affiliation(s)
- P Boissy
- Research Center, Montreal Rehabilitation Institute and the School of Rehabilitation, Faculty of Medicine, University of Montreal, P.Q., Canada
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21
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Bourbonnais D, Duval P. Static dynamometer for the measurement of multidirectional forces exerted by the thumb. Med Biol Eng Comput 1991; 29:413-8. [PMID: 1787758 DOI: 10.1007/bf02441663] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The functioning of a static dynamometer designed to measure simultaneous forces exerted by the thumb in the vertical and horizontal axes is described. The analysis of the output signals by a desktop computer program provides information regarding the forces generated in eight directions covering a plane transverse to the thumb by 45 degree increments. In 12 normal female subjects, the maximum voluntary torques exerted at the trapezo-metacarpal joint of the thumb were examined and the muscle activation patterns of the interosseus, flexor pollicis brevis and adductor pollicis brevis muscles were recorded in one subject. Torques and muscle activation patterns were depicted using polar plots. Dynamometric data indicate that strength varies with direction and that higher torques are obtained in directions that bring the thumb towards the palm, i.e. flexion, adduction, combined flexion-adduction and extension-adduction. Patterns of muscle activity vary according to the direction evaluated suggesting that strength depends on the number of activated muscles as well as the relative force contribution of each muscle.
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Affiliation(s)
- D Bourbonnais
- School of Rehabilitation, Faculty of Medicine, University of Montreal, Quebec, Canada
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22
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23
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Grant R, Sutton DL, Behan PO, Ballantyne JP. Nifedipine in the treatment of myotonia in myotonic dystrophy. J Neurol Neurosurg Psychiatry 1987; 50:199-206. [PMID: 3553433 PMCID: PMC1031492 DOI: 10.1136/jnnp.50.2.199] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Abnormal calcium transport may be implicated in the membrane defect in myotonic dystrophy. A single blind crossover trial of placebo (t.i.d.), nifedipine 10 mg (t.i.d.) and nifedipine 20 mg (t.i.d.), was performed in 10 patients with myotonic dystrophy. The severity of myotonia was assessed by measuring finger extension time after maximum voluntary finger flexion. A significant improvement in myotonia, after nifedipine, was recorded by this technique and supported by a subjective improvement in 50% of patients and clinical improvement of greater than 20% in five patients. Initial grip strength and muscle fatiguability measured by grip strength ergometry were not significantly altered.
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