FRI550 Case Of Thyrotoxic Periodic Paralysis In African American Man With Cannabis Use

Abstract

Abstract Disclosure: H. Al Jumaili: None. A. Mahaldar: None. S. Campbell: None. A. Gosmanova: None. Introduction: Recent changes in cannabis use (CU) laws led to growing interest in its use for recreational and therapeutic purposes. may have serious health problems such as hypokalemia, paralysis and rhabdomyolysis. Thyrotoxic Periodic Paralysis (TPP) is a rare and life-threatening complication of the thyrotoxicosis characterized by acute reversable painless muscle weakness or paralysis and hypokalemia due to massive intracellular shift of potassium. This condition is mainly seen males of Asian descent. Case: A 31-year-old African American man with Graves’ disease admitted to the hospital for upper and lower extremities weakness after Thanksgiving Day. He woke up with sudden inability to move any of his extremities with. He had high carbohydrate meal, on the evening. Patient reported having similar periodic episodes of paralysis, usually worse in the lower extremities for the last 2 years. This episode lasted longer than usual. On exam, he had enlarged thyroid gland and tachycardia. motor weakness, worse on lower extremities, hyporeflexia and intact sensation. Potassium was 1.8 mmol/l, magnesium 1.5 mg/dl, TSH <0.01 mIU/ml, FT4 4.3 ng/dl, FT3 18.3 ng/dl, anti-thyroid antibodies were elevated at 18 IU/L, and urine screen was positive for cannabinoid. Potassium was replaced, he was given propranolol and continued on methimazole. Patient's paralysis had improved in all four limbs, with serum potassium of 4.1 mmol/L. Discussion: TPP is a rarely seen condition in US but is known in an eastern Asian population, and in US the incidence rate was reported to be around 0.1 to 0.2%. American Indian are thought to be the higher risk. Underlying mechanism is imbalance in potassium homeostasis due to increased cellular Na-K ATPase pump activity with shift of potassium to the intracellular space. There are many theories regarding the cause of exaggerated intracellular potassium influx in TPP. Na-K ATPase activity is directly stimulated by thyroid hormone and insulin response to carbohydrate ingestion which promotes potassium uptake into muscle correlating with clinical observation that paralysis seen after a high carbohydrate meal. KCNJ18 gene mutations which alter the function of an inwardly rectifying potassium channel named Kir2.6 have been detected in some patients. In our patient, additional factor such as cannabis use potentiated intracellular potassium shift and hypokalemia. Recent evidence suggests that the CB1 receptor is expressed not only in the brain, but also found in lungs, heart, and skeletal muscle. Stimulation of (CB1) and activation of G protein-coupled inwardly rectifying potassium (GIRK) channels through intra-cellular signal cascades promotes hypokalemia and paralysis. Conclusion: This case raises awareness of TPP in non-Asian population and highlights the importance to consider cannabis as additional trigger for hypokalemia and paralysis. Presentation: Friday, June 16, 2023