Muscle Channelopathies

PURPOSE OF REVIEW This article describes the clinical features, diagnosis, pathophysiology, and management of nondystrophic myotonia and periodic paralysis.

RECENT FINDINGS An increasing awareness exists about the genotype-phenotype overlap in skeletal muscle channelopathies, and thus genetic testing is needed to make a definitive diagnosis. Electrodiagnostic testing in channelopathies is highly specialized with significant overlap in various mutation subtypes. Randomized clinical trials have now been conducted in these disorders with expanded treatment options for patients with muscle channelopathies.

SUMMARY Skeletal muscle channelopathies are rare heterogeneous conditions characterized by lifelong symptoms that require a comprehensive management plan that includes pharmacologic and nonpharmacologic interventions. The significant variability in biophysical features of various mutations, coupled with the difficulties of performing clinical trials in rare diseases, makes it challenging to design and implement treatment trials for muscle channelopathies.

Address correspondence to Dr Jaya Trivedi, Department of Neurology & Neurotherapeutics, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, [email protected].

RELATIONSHIP DISCLOSURE: Dr Trivedi has received personal compensation in the range of $500 to $4999 for serving on a scientific advisory or data safety monitoring board for argenx. The institution of Dr Trivedi has received research support from the National Institutes of Health (NIH).

UNLABELED USE OF PRODUCTS/INVESTIGATIONAL USE DISCLOSURE: Dr Trivedi discusses the use of acetazolamide, carbamazepine, eplerenone, flecainide, hydrochlorothiazide, lacosamide, lamotrigine, mexiletine, phenytoin, procainamide, quinine, ranolazine, rufinamide, spironolactone, tocainide, and triamterene as treatment options that are not US Food and Drug Administration (FDA) approved for the for the conditions discussed in this article.