Study of myopathy in chronic alcoholics with neurological complication.

This study was undertaken to understand the myopathic manifestations as well as the electrophysiological, pathological, and histochemical changes in muscle tissues of chronic alcoholics. Twenty eight cases of chronic alcoholics with neurological complications and confirmed myopathy were included in this study. Of these, 11 cases (39.3%) belonged to the subclinical forms with either Korsakoff-Wernicke encephalopathy or cerebellar atrophy. The remaining 17 cases (60.7%) were clinical forms with various manifestations, such as hypokalemic periodic paralysis, alcoholic rhabdomyolysis, vacuolar myopathy with phosphorylase deficiency, chronic proximal limb-girdle myopathy and neuro-myopathy. Electromyography (EMG) study showed both myopathic and neurogenic changes. The single fiber EMG revealed increased jitter and blocking rate suggesting reinnervation. In muscle biopsy, the histological and histochemical abnormalities included random atrophic fibers, necrotic fibers, fibers with internal nuclei, phagocytosis and moth-eaten fibers. There was selective atrophy of type 2 muscle fibers, particularly of type 2B fiber. Total or partial myophosphorylase deficiency was observed in some cases (33%). All these findings indicate typical myopathic changes, which might be caused by defects in the energy pathways, especially in the glycolytic processes. In some muscle specimens, there were angular atrophic fibers and fiber type groupings suggesting denervation and reinnervation changes. In conclusion, both myopathic and neurogenic alterations were frequently observed in muscles of chronic alcoholics.