The nondystrophic myotonias are rare muscle hyperexcitability disorders caused by gain-of-function mutations in the SCN4A gene or loss-of-function mutations in the CLCN1 gene. Clinically, they are characterized by myotonia, defined as delayed muscle relaxation after voluntary contraction, which leads to symptoms of muscle stiffness, pain, fatigue, and weakness. Diagnosis is based on history and examination findings, the presence of electrical myotonia on electromyography, and genetic confirmation. In the absence of genetic confirmation, the diagnosis is supported by detailed electrophysiological testing, exclusion of other related disorders, and analysis of a variant of uncertain significance if present. Symptomatic treatment with a sodium channel blocker, such as mexiletine, is usually the first step in management, as well as educating patients about potential anesthetic complications.
Guidelines on clinical presentation and management of nondystrophic myotonias / B.C. Stunnenberg, S. Lo Russo, W. David Arnold, R.J. Barohn, S.C. Cannon, B. Fontaine, R.C. Griggs, M.G. Hanna, E. Matthews, G. Meola, V.A. Sansone, J.R. Trivedi, B.G.M. van Engelen, S. Vicart, J.M. Statland. - In: MUSCLE & NERVE. - ISSN 0148-639X. - 62:4(2020 Oct), pp. 430-444.
|Titolo:||Guidelines on clinical presentation and management of nondystrophic myotonias|
|Parole Chiave:||management; myotonia congenita; nondystrophic myotonias; paramyotonia congenita; skeletal muscle channelopathies;|
|Settore Scientifico Disciplinare:||Settore MED/26 - Neurologia|
|Data di pubblicazione:||ott-2020|
|Data ahead of print / Data di stampa:||27-mag-2020|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1002/mus.26887|
|Appare nelle tipologie:||01 - Articolo su periodico|