Thyrotoxic Hypokalemic Periodic Paralysis: Report of Four Cases in Black American Males1

Thyrotoxic periodic paralysis (TPP) is an unusual complication of a fairly common disease affecting mostly Asian males. In the United States, there have been several reports of TPP in different ethnic populations and it appears that the incidence is approximately one-tenth of that found in Asian countries. Only six reports of TPP in African-Americans could be found in the literature; however, we are reporting four cases diagnosed within a 13-year period at our institution. We conclude that TPP may occur more often in Blacks than previously suspected and should be considered when patients present with unexplained hypokalemia, muscular weakness and rhabdomyolysis. The epidemiology, clinical manifestations, pathophysiology, and treatment of TPP are reviewed.