PMON285 Hypokalemic Periodic Paralysis: A Rare Presentation of Primary Hyperaldosteronism

Abstract

Background Primary hyperaldosteronism (PHA) is caused by excessive production of aldosterone from the adrenal glands. Aldosterone levels are usually independent of renin, angiotensin II or sodium status, and often result in hypertension (HTN), hypokalemia and metabolic alkalosis. The most common presentation of this condition is with asymptomatic mild to severe or refractory HTN. This case highlights a patient presenting with hypokalemic periodic paralysis as the first sign of PHA. Clinical Case A 35 year old previously healthy Chinese male, presented with sudden onset bilateral lower extremity weakness for 1 day. This was associated with mild transient lower back pain and fatigue. He had no history of trauma, recent travel, exposure to animal or tick bites. He reported no recent illness or vaccination. His family history was negative for hypertension and various endocrinopathies. The patient was not on any medications and did not consume licorice. His exam was significant for a blood pressure (BP) of 217/136 mmHg, with lower limb evaluation revealing power of 3/5, normal reflexes and a positive heel to shin test. He demonstrated an unsteady gait but Romberg's sign was negative. Upper limb exam was normal. Laboratory findings were remarkable for potassium 1.9 mmol/L, bicarbonate (CO2) 37 mmol/L, normal magnesium (Mg), normal TSH and blood gas showing metabolic alkalosis. Subsequent testing showed renin 0.35 ng/ml/hr, aldosterone 23 ng/dl and aldosterone/pra ratio 66. Saline infusion test confirmed the diagnosis of PHA. Other endocrinologic tests were normal. Electrocardiogram showed prolonged QT interval and U waves. Renal ultrasound was negative for renal artery stenosis and CT abdomen/pelvis showed a 2.4 cm left adrenal adenoma. The patient was admitted to the intensive care unit for 24 hours, where he received intravenous potassium replacement and was started on spironolactone and other antihypertensive medications, which he was discharged on, along with oral potassium. His symptoms resolved after potassium levels normalized and he subsequently had a left adrenalectomy. Conclusion With PHA being the most common endocrinological cause of HTN, clinicians should recognize indicators of underlying PHA even in rare presentations such as this. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.