Distal Myopathies

원위 근병증

The distal myopathies(DM) are clinically defined as inherited or sporadic primary muscle disorders characterized by progressive muscular weakness and atrophy beginning in the hands or feet and pathologically by myopathic changes in skeletal muscles. The pathologic changes are somewhat similar to those seen in chronic muscular dystrophy, but necrotic and regenerative processes are less prominent and creatine kinase levels are either normal or only mildly elevated. The most representative diseases are dominantly inherited Welander distal myopathy and tibial muscular dystrophy, and the recessively inherited distal myopathy with rimmed vacuoles and distal muscular dystrophy(Miyoshi myopathy). At present, further study is necessary to determine why rimmed vacuoles are so common in the DM, and what role they play in the pathogenesis of muscle fiber atrophy and loss, predominantly in the distal portions of the extremities.