Electromyographic Findings in Scleroderma

Abstract

Muscular involvement in scleroderma (SD) has long been extensively referred to in classical neurological as well as dermatological literature. It is occasionally distinctly manifest clinically, but sometimes demonstrable only by histopathological studies. Electromyography in scleroderma is a relatively new method. It can not only reveal muscular involvement in the disease, but also determine its degree, intensity, and extent. Electromyographic studies were made in diffuse scleroderma by, among others, O'Leary, Lambert, et al.,¹ who in 1 of 3 scleroderma and 9 of 17 acrosclerosis cases obtained electromyograms resembling those described in dermatomyositis,^1-8 i.e., pseudomyotonic insertion discharges, occasionally spontaneous activity resembling fibrillation, and a complex interference pattern even from weak contractions, greatly reduced in amplitude and mean action potential duration. In circumscribed scleroderma, other authors⁹ observed interferential recording with short polyphasic potentials only, though not always, from muscles underlying affected skin. Material and Methods Our studies involved two groups