Studies on Myotonia: Biochemical and Electron Microscopic Studies on Myotonia Congenita and Myotonia Dystrophica

MYOTONIA, the denominating characteristic of three genetically determined diseases of muscle (myotonia congenita, myotonia dystrophica, and paramyotonia), and dystrophy of muscle fibers, a feature of one of these diseases (myotonia dystrophica), remain obscure.Concerning the localization of myotonia, a number of investigators believe it might reside in the muscle cell. Grund1 and later Schaffer2 noted the persistence of this phenomenon after complete block of the nerve fibers supplying the muscle; and Gregor and Schilder3 and later Lindsley and Curnen4 observed it during the relaxation phase of contraction, when few nerve impulses were reaching the muscle. Brown and Harvey5 in a myotonic disease of goats also demonstrated that complete denervation of muscle failed to abolish the myotonia. Landau6 and Floyd et al7 have shown that curare has no effect on human myotonia. Denny-Brown and Nevin8 confirmed this localization but also obtained evidence