Thyrotoxic Periodic Paralysis as an Initial Presentation of Graves Disease

October 2013, Vol 144, No. 4_MeetingAbstracts Signs and Symptoms of Chest Diseases | October 2013

Thyrotoxic Periodic Paralysis as an Initial Presentation of Graves Disease Jason Lawrence, MD University of Virginia, Charlottesville, VA Chest. 2013;144(4_MeetingAbstracts):925A. doi:10.1378/chest.1670182

Abstract SESSION TITLE: Miscellaneous Cases II SESSION TYPE: Affiliate Case Report Slide PRESENTED ON: Sunday, October 27, 2013 at 01:15 PM - 02:45 PM INTRODUCTION: Thyrotoxic Periodic Paralysis(TPP) is a potentially fatal complication of hyperthyroidism characterized by muscle paralysis and hypokalemia due to an intracellular shift of potassium(1). Patients of Asian descent account for more than 90% of all cases reported in the literature(2). CASE PRESENTATION: We report a case of a 26 year-old Vietnamese man who presented to our emergency department with complaints of weakness. On the day of presentation, he was unable to lift his arm to shut off his alarm clock. During the month prior to his presentation to the emergency department, he noticed hand tremors, weight loss, and feeling warm all the time. He also endorsed a twenty pound unintentional weight loss accompanied by diarrhea over the past year. His physical exam was significant for sinus tachycardia. Neurological exam was remarkable for proximal weakness of all four extremities. An urgent MRI of his cervical spine was performed in the emergency department and showed no acute abnormality. His metabolic panel became was remarkable for a potassium of 1.7 mEq/L. On further evaluation, his TSH was less than 0.01 mIU/L (normal range 0.45 - 4.5 mIU/L) and his T4 was reported as 3.5 ng/dl (normal range 0.7 - 1.5 ng/dl). After potassium supplementation his symptoms resolved.A technetium thyroid scan showed diffuse uptake and confirmed the diangosis of Grave's disease. He was started on propranolol 40 mg three times daily and methimazole 10 mg twice daily. DISCUSSION: TPP is an unusual manifestation of a common disease. It only occurs in 0.1 0.2% of hyperthyroid patients in North America. However it is ten times more frequent in Asian males(3). The pathophysiology behind TPP remains unclear. TPP is often precipitated by ingestion of carbohydrate rich meals, alcohol, or strenous exercise (1). Treatment consists of managing acute hypokalemia with supplementation and managing symptoms of hyperthyroidism with a beta-adrenergic blocker. Definitive treatment calls for management of the thryotoxicosis with medical therapy, radioactive iodine, or surgery (2). CONCLUSIONS: In conclusion, TPP is an uncommon initial presentation of hyperthyroidism. The presence of acute paralysis with the presence of hypokalemia should alert the clinician to the possible diagnosis of TPP.

Reference #1: Annie W. Kung. Clinical Review: Thyrotoxic Periodic Paralysis: A Diagnostic Challenge.Journal of Clinical Endocrinology and Metabolism 91(7):2490-2495. 2006. Reference #2: William Walters, Sang Woo Han, et al. Thyrotoxic Periodic Paralysis in a Jamaican Male. Clinical Communications. Journal of Emergency Medicine. Vol 17, No 1, pp 4751, 1999. Reference #3: Donald Miller, Jorge DelCastillo. Severe Hypokalemia in Thyrotoxic Periodic Paralysis. American Journal of Emergency Medicine 1989;7:584-587 DISCLOSURE: The following authors have nothing to disclose: Jason Lawrence No Product/Research Disclosure Information