Thyrotoxic periodic paralysis; a reversible cause of paralysis to remember.

A young Chinese American male presented with progressive proximal muscle weakness and inability to stand and walk. Investigations revealed marked hypokalemia and thyroid studies revealed hyperthyroidism consistent with Graves' disease. Thyrotoxic periodic paralysis is a rare disorder in the Western hemisphere, yet needs to be considered as a cause particularly in patients of Oriental origin presenting with sudden weakness. The case history and update of current knowledge of thyrotoxic periodic paralysis is presented.