Denouement and Discussion
Kocher1 first reported the association of generalized muscular "hypertrophy" and hypothyroidism; Debré and Semelaigne2 subsequently noted the decrease in muscle size after thyroid therapy. Because of generalized muscle enlargement, especially of the calf muscles, patients with this syndrome usually have an athletic appearance.3 The cause of the large muscles is not known and histopathological findings are not consistent.4Other conditions in which muscles may appear enlarged are certain types of muscular dystrophy, hypertrophia muscularum vera, de Lange's extrapyramidal syndrome of muscular hypertrophy, familial periodic paralysis, lipodystrophy, and myotonia congenita. Large muscles are occasionally found in children with primary hypothyroidism and therefore it may be difficult to determine if these patients should be classified as having Kocher-Debré-Semelaigne syndrome, especially since the pathogenesis of the muscle enlargement is not known.
An autosomal recessive mode of inheritance has been suggested.
After treatment with levo-thyroxine decrease