[Thyrotoxic periodic paralysis as a form of presentation of primary autoimmune hyperthyroidism: utility of non-selective beta blockers].

A 40-year-old Caucasian man presented to the emergency room of our hospital with bilateral lower extremity weakness with onset 1 hour previously and concurrent hypokalemia. After dramatic clinical progression for the first 5 hours, the episode resolved once serum potassium levels were normalized. Laboratory data revealed primary hyperthyroidism, indicating a diagnosis of thyrotoxic periodic paralysis (TPP). Treatment consisted of potassium, propranolol and methimazole administration. Although the mainstay of therapy is potassium replacement, the role of propranolol in improving the acute clinical manifestations of TPP has yet to be adequately clarified.