D ÉLÈAGE,1in 1890, was the first to describe a case of myotonia atrophica as a distinct clinical entity; but it was Rossolimo,2in 1902, who first associated myotonia with muscular atrophy, giving the disease its present name. Batten and Gibb3simultaneously with Steinert,4in 1909, clarified the disease complex and separated it from other forms of myotonia. Myotonia atrophica is a hereditary disease which characteristically occurs in the third or fourth decade and progresses slowly thereafter until death in the sixth or seventh decade. The most constant course is myotonia, a tonic spasm of muscle, followed by atrophy. The myotonia is usually demonstrable by voluntary, mechanical, or electrical means in the muscles of the forearms, hands, tongue, and jaw. Myotonia occurs when the muscle is strongly stimulated as in a tight grip; it disappears with repetition of the stimulus; and it is intensified by cold. When the patient is