Category: Thyroid


Monday, Apr 8
1:00 AM – 2:00 AM

Objective : Thyrotoxic Periodic Paralysis is a sporadic and uncommon form of hypokalemic Periodic Paralysis that may occur in association with hyperthyroidism in which it can present with little to no hyperthyroid symptoms as in our case that we are presenting.

Methods : n/a

Results : n/a

Discussion :

Case presentation:
27 years old Hispanic male initially presented with nausea, vomiting and sudden generalized muscle paralysis for one day with serum potassium of 1.6 and lactic acidosis of 3.9 that resolved with intravenous fluids and potassium supplementation, had a normal Cervical Spinal MRI and was discharged with a diagnosis of severe hypokalemia with muscle paralysis 2nd to dehydration from viral gastroenteritis then he presented again few days later with similar episode of sudden generalized muscle weakness with paralysis, nausea and vomiting for 1 day with serum potassium of 1.1 but otherwise normal initial labs. Patient did not have any family history of similar episodes and never had any hyperthyroid symptoms like weight loss or diarrhea or palpitations or heat intolerance but reported some tremors during these episodes and was found to be in mild sinus tachycardia (heart rate in 100s) so his TSH was checked and was <0.02 with free T4 of 2.79. Patient was treated with both Methimazole and propranolol plus intravenous fluids and potassium supplementation. He was discharged 2 days later in a stable condition.

Conclusion : Since hyperthyroidism can be associated with an acquired and uncommon form of hypokalemic periodic paralysis, thyroid function test should be checked in patients presenting with sudden onset of muscle paralysis with significant hypokalemia even with no to little hyperthyroid symptoms, especially if no clear cause was found on initial labs as diagnosing and treating their underlying hyperthyroidism in addition to treating the hypokalemia will prevent future episodes and recurrences.


Fahd Almohid

Fellow in training
University of Texas medical branch at Galveston
Galveston, Texas

I am a 2nd year Endocrine fellow ta the university of Texas medical branch at Galveston.