Hyperkalemic periodic paralysis associated with thyrotoxicosis.

A 32 year old male presented with episodic pure motor weakness for 1 1/2 months. On evaluation he was found to be thyrotoxic. Hyperkalemic challenge test provoked similar weakness with raised serum potassium (6 meq/L). He responded to treatment with neomercazole. Till he became euthyroid, he responded to the addition of acetazolamide to his medication. He is symptom free on antithyroid drug alone over 8 months of follow up.