Metabolism in Myotonia Atrophica

Myotonia atrophica or dystrophica is one of the rarer forms of myopathy, which, in addition to the typical myotonia, is characterized by the following conditions: (1) onset usually in the third decade; (2) limitation of the myotonia to special groups of muscles, namely, those of the hands, the tongue and the legs; (3) typical distribution of the atrophy to the face, the sternocleidomastoid muscles, the hand and the forearm and the muscles of the leg; (4) general emaciation; (5) baldness; (6) testicular atrophy; (7) cataract; (8) defect in speech; (9) combination with ataxia and Westphal's sign.¹ The etiology of this disease is obscure. Naegeli²regarded the pathogenesis of the disease as originating in a polyglandular disturbance, presumably with a marked hereditary predisposition. This relation to endocrine involvement was also assumed by Barkman³and others, though the evidence for this is more circumstantial than direct. The occurrence of