Triiodothyronine (T3) toxicosis with hypokalemic periodic paralysis.

A case of triiodothyronine (T3) toxicosis associated with hypokalemic periodic paralysis is reported. Thyrotoxic manifestation was minimal except for mild struma. Serum T3 levels were moderately elevated, though other thyroid function tests were within the normal range. The patient was treated with methimazole, and paralytic attacks ceased. This is the first report of this combination and the necessity of careful thyroid function tests in sporadic periodic paralysis is emphasized.