ABSTRACT
Aim: We report an extremely unusual case of thyrotoxicosis presenting as recurrent acute flaccid quadriparesis in a south Indian male. This case is reported to disseminate knowledge about this rare presentation of thyrotoxicosis among medical professionals. Presentation of Case: This patient presented with sudden onset of symmetrical weakness of both upper and lower limb since early morning with unexplained hypokalemia. He had diffuse toxic goiter with subtle features of hyperthyroidism associated with flaccid quadriparesis. Laboratory investigation revealed marked hypokalemia and hyperthyroidism. He was clinically diagnosed to have hyperthyroidism presenting as thyrotoxic periodic paralysis. He improved with potassium supplementation, beta blocker & anti-thyroid agent. Discussion: Thyrotoxic periodic paralysis (TPP) may be the initial presentation of thyrotoxicosis in rare occasion. Proximal muscle weakness of lower limb is often the first symptom noted. Hypokalemia noted in TPP is the consequence of a rapid and massive shift of potassium from the extracellular into the intracellular compartment, mainly into the muscles. TPP is distinguished from other forms of periodic paralysis (especially hypokalemic periodic paralysis) with thyroid function tests. Failure to recognize this rare disorder may result in fatal cardiac arrhythmia which is a potential cause of mortality. Conclusion: Clinicians should be aware of this atypical presentation of thyrotoxicosis as it is lethal if not treated. Young people with unexplained hypokalemic paralysis even without apparent evidence of thyroid dysfunction should be subjected to thyroid function test to identify this rare disorder.