OF HYPOKALEMIC PERIODIC PARALYSIS AS AN INITIAL MANIFESTATION OF THYROTOXICOSIS: CASE REPORT AND LITERATURE REVIEW

Abstract

Introduction: Hypokalemic periodic paralysis (HPP) secondary to thyrotoxicosis is a rare and potentially serious condition characterized by episodes of acute muscle weakness associated with hypokalemia in patients with hyperthyroidism. Although more common in Asian populations, it can affect individuals in other regions and is often underdiagnosed due to the absence of classic signs of thyrotoxicosis. (1,3,4) Case report: A healthy 18-year-old male patient presented with a sudden episode of pain followed by flaccid paralysis in both lower limbs, associated with tremors and tachycardia. Laboratory tests revealed severe hypokalemia and thyroid function suggestive of thyrotoxicosis. Doppler ultrasound of the thyroid revealed diffuse enlargement of the gland and increased peak systolic blood pressure in the arterial component, suggesting thyroid disease/glandular hyperfunction. Anti-TSH receptor antibody (TRAB) results were above normal, confirming the diagnosis of HPP secondary to Graves' disease. The patient received electrolyte correction, symptomatic management, and antithyroid medication (tapazole), with complete improvement in clinical status. Discussion: The pathophysiology of PPH is related to increased Na+/K+-ATPase pump activity induced by thyroid hormones, with consequent intracellular potassium shift. Early recognition and appropriate management of thyrotoxicosis are essential to prevent recurrences and complications.(1,8,9) Conclusion: This case reinforces the importance of considering thyrotoxicosis as an etiology of flaccid paralysis in patients with hypokalemia, especially in the absence of obvious secondary causes.