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Prolonged Exercise Test in Patients With History of Thyrotoxicosis. J Clin Neurophysiol 2022; 39:307-311. [PMID: 32773648 DOI: 10.1097/wnp.0000000000000766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Thyrotoxic periodic paralysis is characterized by recurrent episodes of reversible, severe proximal muscle weakness associated with hypokalemia and hyperthyroidism. Prolonged exercise test is an easy, noninvasive method of demonstrating abnormal muscle membrane excitability in periodic paralyses. Although abnormal in thyrotoxic periodic paralysis patients, the effects thyroid hormone levels in non-thyrotoxic periodic paralysis thyrotoxicosis patients have not been well studied. The study aims to evaluate thyrotoxicosis patients (regardless of thyrotoxic periodic paralysis history) with prolonged exercise test and correlate it with their thyroid status. METHODS This is a prospective, cross-sectional study of consecutive thyrotoxicosis patients seen at the endocrine clinic of a tertiary medical center. Thyroid status was determined biochemically before prolonged exercise test. Compound muscle action potential (CMAP) amplitudes postexercise were compared against pre-exercise amplitudes and recorded as percentage of mean baseline CMAP amplitude. Comparisons of time-dependent postexercise CMAP amplitudes and mean CMAP amplitude decrement were made between hyperthyroid and nonhyperthyroid groups. RESULTS Seventy-four patients were recruited, 23 (31%) men, 30 (41%) Chinese, and the mean age was 48.5 ± 16.8 years. Of 74 patients, 32 (43%) were hyperthyroid and 42 (57%) were nonhyperthyroid viz. euthyroid and hypothyroid. Time-dependent CMAP amplitudes from 10 to 45 minutes after exercise were significantly lower in hyperthyroid patients compared with nonhyperthyroid patients (P < 0.01). Mean CMAP amplitude decrement postexercise was significantly greater in hyperthyroid than nonhyperthyroid patients (23.4% ± 11.4% vs. 17.3% ± 10.5%; P = 0.02). CONCLUSIONS Compound muscle action potential amplitude declines on prolonged exercise test were significantly greater in hyperthyroid patients compared with nonhyperthyroid patients. Muscle membrane excitability is highly influenced by thyroid hormone level. Thyrotoxic periodic paralysis occurs from increased levels of thyroid hormone activity in susceptible patients.
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Ribeiro A, Suetterlin KJ, Skorupinska I, Tan S, Morrow JM, Matthews E, Hanna MG, Fialho D. The long exercise test as a functional marker of periodic paralysis. Muscle Nerve 2022; 65:581-585. [PMID: 34817893 PMCID: PMC7614949 DOI: 10.1002/mus.27465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 11/14/2021] [Accepted: 11/16/2021] [Indexed: 11/07/2022]
Abstract
AIMS The aim of this study was to evaluate the sensitivity of the long exercise test (LET) in the diagnosis of periodic paralysis (PP) and assess correlations with clinical phenotypes and genotypes. METHODS From an unselected cohort of 335 patients who had an LET we analyzed 67 patients with genetic confirmation of PP and/or a positive LET. RESULTS 32/45 patients with genetically confirmed PP had a significant decrement after exercise (sensitivity of 71%). Performing the short exercise test before the LET in the same hand confounded results in four patients. Sensitivity was highest in patients with frequent (daily or weekly) attacks (8/8, 100%), intermediate with up to monthly attacks (15/21, 71%) and lowest in those with rare attacks (9/16, 56%) (p = .035, Mann-Whitney U-test). Patients with a positive LET without confirmed PP mutation comprised those with typical PP phenotype and a group with atypical features. DISCUSSION In our cohort, the LET is strongly correlated with the frequency of paralytic attacks suggesting a role as a functional marker. A negative test in the context of frequent attacks makes a diagnosis of PP unlikely but it does not rule out the condition in less severely affected patients.
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Affiliation(s)
- Ana Ribeiro
- Department of Clinical Neurophysiology, King’s College Hospital, London, UK
| | - Karen J Suetterlin
- Queen Square Centre for Neuromuscular Diseases, University College London, UK
- Department of Clinical Neurophysiology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK
| | - Iwona Skorupinska
- Queen Square Centre for Neuromuscular Diseases, University College London, UK
| | - S.Veronica Tan
- Department of Neurology and Neurophysiology, St Thomas’ Hospital, Guy’s and St Thomas’ NHS Foundation Trust and Department of Academic Neurosciences, Kings College London, UK
| | - Jasper M Morrow
- Queen Square Centre for Neuromuscular Diseases, University College London, UK
| | - Emma Matthews
- Queen Square Centre for Neuromuscular Diseases, University College London, UK
- Atkinson-Morley Neuromuscular Centre, St George’s University Hospitals NHS Foundation Trust, London, UK
| | - Michael G Hanna
- Queen Square Centre for Neuromuscular Diseases, University College London, UK
| | - Doreen Fialho
- Department of Clinical Neurophysiology, King’s College Hospital, London, UK
- Queen Square Centre for Neuromuscular Diseases, University College London, UK
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Zhang L, Niu J, Li Y, Guan Y, Cui L, Liu M. Abduction range: A potential parameter for the long exercise test in hypokalemic periodic paralysis during inter-attack periods. Muscle Nerve 2019; 61:104-107. [PMID: 31587332 DOI: 10.1002/mus.26721] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 09/14/2019] [Accepted: 09/16/2019] [Indexed: 11/09/2022]
Abstract
BACKGROUND The abduction range of the little finger in the long exercise test (ET) has rarely been reported in patients with hypokalemic periodic paralysis (HypoPP) during inter-attack periods, and the diagnostic value requires clarification. METHODS The long ET was performed in 43 HypoPP patients during inter-attack periods and in 20 healthy controls (HCs). The compound muscle action potential (CMAP) and the abduction range of the little finger were recorded concurrently. RESULTS There were significant differences in the percent changes of the CMAP amplitudes and the abduction ranges after exercise between HypoPP patients and the HCs. The curve of percent changes in abduction ranges overlapped substantially with that of the CMAP amplitudes, and the sensitivity, specificity, and cutoff values were 0.860, 0.900, and 22.6%, respectively. CONCLUSIONS The abduction range of the little finger can serve as a novel parameter in the long ET for the diagnosis of HypoPP during inter-attack periods.
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Affiliation(s)
- Lei Zhang
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Jingwen Niu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Yi Li
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Yuzhou Guan
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Liying Cui
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Mingsheng Liu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
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Long Exercise Test in the Interattack Period of Periodic Paralysis: A Useful and Sensitive Diagnostic Tool. J Clin Neurophysiol 2017; 34:497-501. [PMID: 28742635 DOI: 10.1097/wnp.0000000000000405] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE The reference values of long exercise test are inconsistent in previous studies. Our research aims to determine the reference values and improve diagnostic efficiency of long exercise test in periodic paralysis. METHODS In this study, 100 healthy controls, 35 non-periodic paralysis patients, and 47 patients with periodic paralysis were recruited. The procedures of long exercise test were conducted following McMannis(1986) method. RESULTS The decrease rate in compound muscle action potential amplitudes was correlated with gender, and it was not influenced by age, height, weight, and exercise. After analyzing receiver operating characteristic curves, the compound muscle action potential amplitude decrease rate was stratified by sex. The mean area under the curve, sensitivity, and specificity were higher in male and female than all pooled subjects. The reference values of compound muscle action potential amplitude decrease rate were 46.8% in male and 26.9% in female, respectively. CONCLUSIONS The long exercise test is a useful and sensitive diagnostic tool for primary periodic paralysis and thyrotoxic periodic paralysis. However, the reference values should be set by sex, which has better diagnostic performance, sensitivity, and specificity.
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Nagamine S, Sakoda S, Koide R, Kawata A, Yuan J, Takashima H, Nakano I. A case of Andersen-Tawil syndrome presenting periodic paralysis exacerbated by acetazolamide. J Neurol Sci 2014; 347:385-6. [PMID: 25284084 DOI: 10.1016/j.jns.2014.09.040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 08/23/2014] [Accepted: 09/22/2014] [Indexed: 01/22/2023]
Affiliation(s)
- Satoshi Nagamine
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan.
| | - Shunichi Sakoda
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Reiji Koide
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Akihiro Kawata
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Junhui Yuan
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Hiroshi Takashima
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Imaharu Nakano
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
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Reference value of long-time exercise test in the diagnosis of primary periodic paralysis. Chin Med J (Engl) 2014. [DOI: 10.1097/00029330-201409200-00005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Dengue-associated hypokalemic paralysis: Causal or incidental? J Neurol Sci 2014; 340:19-25. [DOI: 10.1016/j.jns.2014.03.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 03/06/2014] [Accepted: 03/07/2014] [Indexed: 11/18/2022]
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Arimura Y, Nakamura T, Yoshimura M, Uehara A, Arimura K, Sakoda SI, Takashima H. [The electrophysiologic diagnosis for muscle ion channelopathies]. Rinsho Shinkeigaku 2012. [PMID: 23196580 DOI: 10.5692/clinicalneurol.52.1252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The periodic paralysis (PP) and myotonic syndromes have been recognized as muscle ion channelopathies (MIC) consequent to the discovery of genetic abnormalities of muscle ion channels. Genetic studies are therefore indispensable in the diagnosis of MIC. However, it is not practical to examine all muscle ion channels immediately upon identification of clinical symptoms. Clinical symptoms of MIC occur due to the abnormal excitability of the muscle membrane which is in turn related to abnormal ion channel genes. Therefore, a series of electrophysiologic tests is useful in examining the characteristics of abnormal excitability and predicting the abnormal ion channel Needle EMG studies can detect myotonic discharges while the prolonged exercise test can distinguish between primary and secondary PP. For myotonia, pattern I which includes the repeated short exercise test at room temperature or at cold skin temperature is specific for paramyotonia congenita, pattern II is characteristic for myotonia congenita, and pattern III is useful for Na channel myotonia. The decrement of CMAP with 10 Hz repetitive stimulation is related to mutation type in myotonia congenita. Thus, these electrophysiological tests may be of use in screening for MIC to narrow down the diagnosis and the selection of candidates for gene analysis.
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Affiliation(s)
- Yumiko Arimura
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences
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Tan SV, Matthews E, Barber M, Burge JA, Rajakulendran S, Fialho D, Sud R, Haworth A, Koltzenburg M, Hanna MG. Refined exercise testing can aid DNA-based diagnosis in muscle channelopathies. Ann Neurol 2011; 69:328-40. [PMID: 21387378 DOI: 10.1002/ana.22238] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To improve the accuracy of genotype prediction and guide genetic testing in patients with muscle channelopathies we applied and refined specialized electrophysiological exercise test parameters. METHODS We studied 56 genetically confirmed patients and 65 controls using needle electromyography, the long exercise test, and short exercise tests at room temperature, after cooling, and rewarming. RESULTS Concordant amplitude-and-area decrements were more reliable than amplitude-only measurements when interpreting patterns of change during the short exercise tests. Concordant amplitude-and-area pattern I and pattern II decrements of >20% were 100% specific for paramyotonia congenita and myotonia congenita, respectively. When decrements at room temperature and after cooling were <20%, a repeat short exercise test after rewarming was useful in patients with myotonia congenita. Area measurements and rewarming distinguished true temperature sensitivity from amplitude reduction due to cold-induced slowing of muscle fiber conduction. In patients with negative short exercise tests, symptomatic eye closure myotonia predicted sodium channel myotonia over myotonia congenita. Distinctive "tornado-shaped" neuromyotonia-like discharges may be seen in patients with paramyotonia congenita. In the long exercise test, area decrements from pre-exercise baseline were more sensitive than amplitude decrements-from-maximum-compound muscle action potential (CMAP) in patients with Andersen-Tawil syndrome. Possible ethnic differences in the normative data of the long exercise test argue for the use of appropriate ethnically-matched controls. INTERPRETATION Concordant CMAP amplitude-and-area decrements of >20% allow more reliable interpretation of the short exercise tests and aid accurate DNA-based diagnosis. In patients with negative exercise tests, specific clinical features are helpful in differentiating sodium from chloride channel myotonia. A modified algorithm is suggested.
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Affiliation(s)
- S Veronica Tan
- Medical Research Council Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, University College London, Institute of Neurology London, UK.
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Arimura K, Arimura Y, Ng AR, Sakoda SI, Higuchi I. Muscle membrane excitability after exercise in thyrotoxic periodic paralysis and thyrotoxicosis without periodic paralysis. Muscle Nerve 2007; 36:784-8. [PMID: 17722048 DOI: 10.1002/mus.20865] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We evaluated whether the paralytic attacks in thyrotoxic periodic paralysis (TPP) are primarily due to the abnormal excitability of the muscle membrane caused by a preexisting latent abnormality or to the effects of thyroid hormone. The prolonged exercise (PE) test was used to evaluate muscle membrane excitability in 21 patients with TPP and 11 patients with thyrotoxicosis without paralytic attacks (Tw/oPP) in the hyperthyroid state. The PE tests were compared between the hyperthyroid and euthyroid states in five of the TPP and three of the Tw/oPP patients. Compared to 20 healthy subjects, a significant increase in compound muscle action potential (CMAP) amplitudes immediately after exercise and a significant time-dependent gradual decline in CMAP amplitudes starting from 20 min after exercise were observed in the TPP patients. A significant decline in CMAP amplitudes was also observed in the Tw/oPP patients but only at 50 min after exercise. All of the TPP and Tw/oPP patients had a tendency to improve in the euthyroid state; the PE tests remained abnormal only in the TPP patients. Paralytic attacks in TPP patients are due primarily to a preexisting latent abnormal excitability of the muscle membrane, possibly genetic in origin.
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Affiliation(s)
- Kimiyoshi Arimura
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
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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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Arimura K, Arimura Y. Clinical electrophysiologic tests and genotype correlations in muscle channelopathies. ACTA ACUST UNITED AC 2005; 57:283-7. [PMID: 16106626 DOI: 10.1016/s1567-424x(09)70364-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Affiliation(s)
- Kimiyoshi Arimura
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Science, Kagoshima 890-8520, Japan.
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Fukudome T, Izumoto H, Goto H, Matsuo H, Yoshimura T, Sakoda SI, Shibuya N. Paramyotonia congenita due to a de novo mutation: a case report. Muscle Nerve 2003; 28:232-5. [PMID: 12872329 DOI: 10.1002/mus.10396] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A Japanese man with a negative family history of paramyotonia congenita (PMC) was evaluated for symptoms of cold-induced weakness and stiffness. Exercise testing revealed findings characteristic of PMC, and a genetic analysis was therefore performed. A well-known sodium channel mutation for PMC (T1313M) was identified in the patient, but was absent in his biological parents. These data demonstrate the occurrence of a de novo mutation, suggesting that evaluation for PMC should be performed in patients with typical symptoms even if the family history is negative.
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Affiliation(s)
- Takayasu Fukudome
- Department of Neurology, Kawatana National Hospital, 2005-1 Shimogumigo Kawatanamachi Higashisonogi-gun, Nagasaki 859-3615, Japan
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Kuntzer T, Flocard F, Vial C, Kohler A, Magistris M, Labarre-Vila A, Gonnaud PM, Ochsner F, Soichot P, Chan V, Monnier G. Exercise test in muscle channelopathies and other muscle disorders. Muscle Nerve 2000; 23:1089-94. [PMID: 10883004 DOI: 10.1002/1097-4598(200007)23:7<1089::aid-mus12>3.0.co;2-q] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We studied the percentage change in compound muscle action potential (CMAP) amplitude and area during and after a 5-min maximal contraction of the muscle. The exercise test (ET) was performed on 64 patients with different muscle disorders and on 46 normal controls. The range of normal ET values was defined as the mean + 2 SD of the control values. The mean sensitivity of the test was 63% in the whole group with ion channel muscle disorders, the highest sensitivity being seen in primary periodic paralysis (81%) and the lowest in chloride channelopathies (17%). In thyrotoxic periodic paralysis, the ET was abnormal in the three of the four patients studied. In patients with myotonic dystrophy, a smaller than normal increase in CMAP amplitude occurred during and after exercise, whereas in proximal myotonic myopathy a normal initial increase in CMAP amplitude was followed by an abnormal decrement. We conclude that the ET can be of use in confirming abnormal muscle membrane excitability in patients with calcium and sodium channelopathies and thyrotoxic periodic paralysis. In chloride channelopathy, the test may also be abnormal, but shows no, or only a small, increase in amplitude or area in the immediate postexercise period. The test may also be abnormal in proximal myotonic myopathy, but is normal in myotonic dystrophy.
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Affiliation(s)
- T Kuntzer
- Service de Neurologie, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
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