Active clinical trials for "Myotonic Disorders"

Treatment strategies in non-dystrophic myotonias are based on selective case reports, clinical experience and theoretical benefit. Presently, the most promising antimyotonic medication is mexiletine (MEX) but its manufacturing was stopped. The proposed randomized, double-blind, placebo-controlled, crossover trial is designed to: study the safety and efficacy of mexiletine for the treatment of non-dystrophic myotonias validate electromyographic tests as a standardized outcome measure of myotonia assess the reliability and validity of a new clinical rating scale for myotonia

Nondystrophic myotonias (NDM) are muscle disorders caused by genetic abnormalities in certain muscle cell membrane proteins. Individuals with NDM experience limited muscle relaxation, which causes pain, weakness, and impaired physical activity. The purpose of this study is to better characterize the clinical features and symptoms of NDM.

The aim of this project is (1) to investigate whether or not structural muscle abnormalities could be a consequence of the disorder and (2) to provide further clinical description of this rare phenotype. To do so, the investigators will (1) use Dixon MRI to quantify fatty infiltration in muscle tissue and compare it to muscle strength measurements from isometric dynamometry in order to access contractility and (2) describe the myotonic phenotype with simple squeeze test and questionnaires.