Hypokalemic myopathy due to chronic alcoholism

A patient with hypokalemic myopathy occurring in the context of chronic alcoholism was reported. A 56-year-old male patient, heavy drinker for 20 years, complained of marked weakness and acutely developing pains in his limbs. The principal clinical findings were weakness and tenderness of the proximal limbs and girdle muscle. He was unable to lift his head or any extremities from the bed. Deep tendon reflexes were diminished, but not absent. There was no sensory disturbance except for muscle tenderness. These clinical manifestations disappeared gradually by abstinence from drinking, and potassium administration therapy, and the patient recovered completely on the 26th day after onset. On the day after admission (8th day), serum potassium value was 2.2 mEq/L, and serum CPK activity was 4270 IU. The ECG pattern was consistent with a diagnosis of low potassium content in serum, and the EMG pattern was consistent with a diagnosis of myopathy. These electrophysiological findings had a tendency to recover from this pattern to normal range correspondingly with clinical improvement. The repeated muscle biopsies showed that vacuolation, hyaline degeneration and significant phagocyte infiltration were observed in the muscle on the 9th day after the onset of muscle weakness, and that these pathological findings disappeared almost completely three weeks later. The frequently repeated examinations of potassium content and CPK activity in sera showed that there was a close correlation between these biochemical abnormalities and clinical improvement. The pathogenesis of alcoholic myopathy and significance of CPK abnormality in chronic alcoholism were discussed.