Weakness in the Emergency Department: Hypokalemic Periodic Paralysis Induced By Strenuous Physical Activity

Abstract

Hypokalemic periodic paralysis is a rare but serious disorder that is typically caused by a channelopathy. Thyrotoxicosis, heavy exercise, high carbohydrate meal and some drugs can trigger channelopathy in genetically predisposed individuals. A 33-year-old male patient presented to the emergency department with weakness in the lower extremities. He stated that he had done heavy physical activity during the previous week. The patient exhibited motor weakness in the lower extremities (2/5 strength) during the physical examination. Initial laboratory tests showed a potassium level of 1.89 mEq/L. The initial electrocardiogram demonstrated T wave inversion and prominent U waves. The patient was treated in the emergency department with oral and intravenous potassium. The physical and ECG symptoms resolved within 16 hours of potassium supplementation and biochemical tests showed normal serum potassium levels. The patient was discharged shortly after the resolution of the symptoms. Weakness is an important but nonspecific symptom that may be brought on by a number of underlying physiological processes. Hypokalemic periodic paralysis is a rare disease that may be triggered by heavy physical activity and presents with recurrent admissions due to weakness.

Keywords: Emergency department; hypokalemic periodic paralysis; muscle weakness.

Figure 1

ECG at the presentation to the ED (U-waves were shown with black arrows).

Figure 2

ECG at discharge from ED.