Thyrotoxic Periodic Paralysis: A case report

Abstract

A rare complication of thyrotoxicosis among Asians is Thyrotoxic Periodic Paralysis (TPP), with an incidence of approximately 2% in patients with thyrotoxicosis from any cause. TPP is characterized by sudden onset of hypokalemia and muscle paralysis. Hypokalemia in TPP results from an intracellular shift of potassium induced by the thyroid hormone sensitization of Na⁺/K⁺–ATPase rather than depletion of total body potassium. Treatment of TPP includes correcting the underlying hyperthyroid state, prevention of potassium shift by using non-selective beta-blockade, and replacing potassium. TPP is curable once a euthyroid state is achieved. We describe here a rare case of TPP in a young Chinese man who presented with sudden bilateral lower limb weakness.