Normokalemic thyrotoxic periodic paralysis: a new therapeutic strategy.

An unusual presentation of periodic paralysis in a Mexican man with thyrotoxicosis is presented. The patient suffered paralysis of the lower extremities without apparent precipitating factors such as hypokalemia, exercise, carbohydrate or alcohol ingestion. Hyperthyroidism was managed first with a thyroid suppressant (methimazole) and propranolol. Prednisone was added after another episode of paralysis. Definitive treatment of hyperthyroidism was achieved with radioactive iodine, which subsequently required substitution therapy with thyroxine. A moderate dose of thyroxine (100 microg) caused muscular weakness. Treatment of thyrotoxicosis and flaccid paralysis as well as the effects of glucocorticoids on thyroid function are discussed.