Thyrotoxic periodic paralysis: an endocrine cause of paraparesis.

Periodic paralysis is a muscle disorder that belongs to the family of diseases called channelopathies, manifested by episodes of painless muscle weakness. Periodic paralysis is classified as hypokalemic when episodes occur in association with low potassium levels. Most cases are hereditary. Acquired cases have been described in association with hyperthyroidism. Diagnosis is made on clinical and biochemical grounds. Patients may be markedly hypokalemic during the episode and respond well to potassium supplementation. Episodes can be prevented by achieving a euthyroid state. This report describes a young gentleman presenting with thyrotoxic hypokalemic paraparesis. The condition needs to be considered in the differential diagnosis of neuromuscular weakness in the context of hypokalemia by the treating physicians.