A Case of Thyrotoxic Periodic Paralysis in Adolescent with Graves' Disease

Thyrotoxic periodic paralysis (TPP) is a rare complication of hyperthyroidism characterized by recurrent paralysis of skeletal muscle and hypokalemia caused by a massive intracellular shift of potassium. TPP mainly affects young male patients of Asian descent. We describe a case of TPP in a 14-year-old girl who presented with palpitation and intermittent weakness of the lower extremities especially after physical exercises. The patient showed sinus tachycardia, proximal weakness of both legs and a severe hypokalemia. Thyroid function tests showed hyperthy- roidism, and thyroid scan revealed diffusely enlarged goiter consistent with Graves' disease. After the management with antithyroid drug, beta-adrenergic blocker and potassium supplementation for TPP, she has remained euthyroid state and symptom free on the follow-up. TPP should be considered in children with acute paralysis of skeletal muscle and hypokalemia, also thyroid function should be evaluated.