Abstract

In a case of Engelmann's disease in an 11-year-old Japanese boy the muscular changes were studied in detail. Muscle weakness was maximal about the pelvic girdle. Muscle biopsy showed the selective atrophy of type II fibres, and no degenerative change could be seen histologically, histochemically, or electron-microscopically. Although the distribution of muscular weakness in Engelmann's disease is similar to that of a progressive muscular dystrophy, the disease does not seem to be a myopathy.