Thyrotoxic periodic paralysis in a Caucasian man in treatment for Graves' disease

Thyrotoxic periodic paralysis (TPP) is the main secondary form of hypokalem ic periodic paralysis and is mostly associated with Graves' disease. Initia lly diagnosed in Asian countries, TPP has been sporadically reported in dif ferent populations of the Western World. Increased Na+/K+-ATPase activity s eems to be responsible for the marked hypokalemia observed during the trans ient paralysis attacks. We report on a 35-year-old Italian man without hist ory of hypokalemic periodic paralysis and hyperthyroidism, in treatment for Graves' disease, who suffered episodes of flaccid paralysis even with norm al thyroid hormone levels, An insulin-glucose provocation test confirmed ou r diagnosis. Oral and parenteral potassium reverse the symptoms. Monitoring of thyroid function is also important to prevent further attacks.