[Generalized muscle weakness mimicking periodic paralysis in a patient with toluene abuse]

A 23-year-old Japanese man was admitted to our hospital because of acute generalized muscle weakness and frequent vomiting. He had been diagnosed as having hypokalemic periodic paralysis, since he had recurrent episodes of transient generalized muscle weakness with a hypokalemia. Laboratory studies have revealed a severe hypokalemic hyperchloremic metabolic acidosis, elevated serum levels of creatine phosphokinase and ammonia. The urinary level of the hippuric acid, a metabolic product of toluene, was found to be extremely high, suggesting that he had been exposed to toluene. With intravenous supplement of potasium, his muscle strength improved. Chronic exposure to toluene induces various neurological disorders, such as encephalopathy, cerebellar and pyramidal signs, peripheral neuropathy. In addition, it should be kept in mind that hypokalemic muscle weakness can be induced by the renal tubular acidosis resulting from chronic toluene exposure, and that it is by no means easy to distinguish hypokalemic periodic paralysis if it occurs recurrently.