We report a case of thyrotoxic hypokalemic periodic paralysis occurrin
g in a black man. This previously healthy 41-year-old man had a 3-year
history of recurrent paroxysmal episodes of paresis in the upper and
lower extremities proximally, often occurring after heavy exercise. Th
e patient had no history of hyperthyroidism, nor family history of per
iodic paralysis. This case reveals a particularly rare characteristic
of this disorder in which periodic paralysis is the presenting symptom
of hyperthyroidism. This condition has been reported most commonly am
ong Asians and is extremely rare in black men, only five cases having
been described during the past 30 years.