Case Presentation: We report a 22 year-old male with no past medical history presented to the emergency department with acute onset of weakness, most pronounced in the lower extremities. The patient was last reported to be in his normal state of health the night prior to presentation in which he consumed approximately six beers. Upon awakening, he experienced severe weakness and was unable to sit up or get out of bed. Physical exam revealed a Hispanic male with BP on admission of 154/80, HR 110. Neurologic exam positive for significantly reduced grip strength, 3/5 motor strength in bilateral upper and lower extremities. BMP was notable for a serum potassium of 2.2 mEq/L (3.5-5.0 mEq/L). Initial hypokalemia was immediately treated with 60 mEq of oral potassium (KCl) which corrected the potassium level to 4.1 mEq/L with resolution of myalgia and paralysis.Upon further questioning, patient reported that he had similar symptoms about one year ago at a hospital within our system. Review of this medical record showed an overnight admission one year prior for chest pain with associated bilateral lower extremity pain and weakness that started in the early morning. The patient reported working outdoors all day as a landscaper the day before. BMP was remarkable for potassium of 1.5 mEq/L (3.5-5.0 mEq/L). Given the rapid improvement in potassium, the low value was believed to be a lab error. Family history was significant for hyperthyroidism in his mother with high T3, T4, and low TSH, which confirmed undiagnosed hyperthyroidism. Given a prior documented episode of paralysis and hypokalemia with thyroid studies confirming hyperthyroidism, we were able to confirm the diagnosis of Thyrotoxic Periodic Paralysis. A positive thyroid-stimulating immunoglobulin of 4.34 IU/L (0.0-0.55 IU/L) suggested Graves’ disease as the most likely cause.
Discussion: Diagnosis of thyrotoxic periodic paralysis is often delayed or missed due to its rarity in western countries and subtlety of any features of hyperthyroidism on initial presentation. In the United States, the incidence rate of TPP is reported to be around 0.1-0.2% in thyrotoxic patients (1). TPP is a unique form of hypokalemic periodic paralysis that occurs in association with hyperthyroidism, often due to Graves’ disease. Attacks characterized by recurrent, transient paralysis affecting lower extremities (2). Our patient had two documented attacks; one was triggered after strenuous physical activity while another attack was likely triggered by excess alcohol consumption (3, 4).The most definitive treatment is prevention of future episodes with adequate control of underlying hyperthyroidism maintaining euthyroid status. TPP can lead to prevention of fatal complications if left untreated including ventricular arrhythmias, and respiratory muscle paralysis (4).
Conclusions: Our patient represented the epitome of a “between the cracks” situation as he was presenting to a different hospital than before, was previously lost to follow up, and represented a condition not known to occur in his demographic. Owing to the shared medical record between local hospitals, the patient’s previous episode could be studied. We educated the patient extensively as to the importance of follow up for treatment of his hyperthyroidism and we were particularly concerned, as he had been lost to follow before, that it might occur again. Owing to a more global society, enhanced testing, and translational data, this rarely seen condition in western countries ought to be considered and addressed at first presentation.