Clinical And Experimental Study Of Chronic Alcoholic Skeletal Muscle Myopathy

Objective:(1)To investigate the histopathological characteristics of chronic alcoholic skeletal muscle myopathy.(2)To make an approach to the symptomatic and electrophysilogical characteristics of chronic alcoholic skeletal muscle myopathy.(3)To improve the understanding of chronic alcoholic skeletal muscle myopathy and provide diagnostic clues for clinical practice.Methods:(1)The model of Wistar rats with chronic alcoholic skeletal muscle myopathy were established by using Trounce,s method. The following parameters were measured : body weight, muscle weight, tibial weight and length, serum total protein, serum asprate and alanine aminotrans ferases. The histopathological changes of skeletal muscle were observed.(2)A detailed medical record including individual life history, alcohol consumption, alcohol dependency level, clinical symptoms and physical signs were collected in 60 patiens with chronic alcoholic neuromuscular disorders. An electrophysiological study including electromyography, nerve conduction velocity, evoked potential, single fiber electromyography and mulscle fiber conduction velocity were also performed in all patients. The comparative analysis to clinical situation and electrophysilogical characteristics were performed between patients with chronic alcoholic myopathy and peripheral neuropathy.Result:(1)In the skeletal muscles of the alcohol treated rats, histological findings were mainly myocytolysis, fiber atrophy, infiltration of inflammatory cells and muscle fiber regeneration.(2)The pathological changes in type â…¡ muscle fibers were severer than typeâ… muscle fibers in the alcohol treated rats. Selective atrophy of typeâ…¡b muscle fibers was predominant pathological change.(3)With alcohol toxication,rats had extended histopathological changes in different muscles. The plantaris were most susceptible to ethanol, then the gastrocnemius, and finally the soleus.(4)After alcohol toxication,the composition of fiber types of rat skeletal muscles were not changed.(5)The main clinical manifestations of the patients with chronic alcoholic myopathy were weakness, muscle pain and muscle atrophy, usually in the proximal partsof the limbs symmetrically. Symptoms resulted from injuried muscles were priority to that caused by peripheral nerve injury. (6) 46.9% of the patients with chronic alcoholic skeletal muscle myopathy had peripheral nerve injury, and 46.2% had cardiac disorders. (7) Myopathic patterns of electromyography were observed in the patients with chronic alcoholic skeletal muscle myopathy, including unchanged inserting potential, no spontaneous activity, increased polyphasic potentials, complete recruitments, short duration and low amplitude of motor unit potentials. Mulscle fiber conduction velocity was slowed.Conclusions:(1)Histopathological changes of alcoholic myopathy are various. Selective susceptibility of typeâ…¡b fibers is the predominant characteristics.(2)The main clinical manifestations of chronic alcoholic myopathy are weakness, muscle pain and muscle atrophy, in the proximal parts of the limbs symmetrically.(3)The patients with chronic alcoholic myopathy are usually complicated with lesions of peripheral nerve and heart. (4)The myopathic patterns of electromyography, especially the slowed mulscle fiber conduction velocity, might be as the diagnostic indices of chronic alcoholic myopathy.