Cataplexy

Cataplexy is a sudden, transient episode of muscle weakness triggered by strong emotions, typically occurring in patients with narcolepsy type 1. Pathophysiology involves dysregulation of hypocretin (orexin) neurons in the hypothalamus, disrupting normal sleep-wake and motor control mechanisms. Clinically, cataplexy presents as partial or complete loss of voluntary muscle tone while consciousness is preserved. Diagnosis is based on polysomnography and multiple sleep latency testing, often in conjunction with hypocretin measurement. Management includes pharmacologic therapy (sodium oxybate, antidepressants) and behavioral strategies; prognosis is chronic, with symptom severity varying among individuals.