Thyrotoxic normokalemic periodic paralysis

Am J Emerg Med. 2003 Jan;21(1):71-3.

An unrecognized cause of paralysis in ED: thyrotoxic normokalemic periodic paralysis.

Wu CC, Chau T, Chang CJ, Lin SH.

Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.

Hypokalemic paralysis associated with hyperthyroidism (TPP) is a well-known acute electrolyte and muscle function disorder. Lesser known is normokalemic periodic paralysis associated with hyperthyroidism. We describe two cases of young men with acute muscular paralysis and bilateral impairment of sensation over the lower legs who had normal plasma potassium concentrations. They were initially misdiagnosed as having Guillain-Barre syndrome or hysterical paralysis. However, thyroid function tests showed elevated serum T(3) and T(4) and markedly depressed thyroid-stimulating hormone findings consistent with hyperthyroidism. Control of the hyperthyroidism completely abolished their periodic paralysis. Thyrotoxic normokalemic periodic paralysis (TNPP) should be kept in mind as a cause of acute muscle weakness to avoid missing a treatable and curable condition. Copyright 2003, Elsevier Science (USA). All rights
reserved.)

PMID: 12563586