Clinical features, diagnosis and treatment of narcolepsy.

Narcolepsy is characterized by excessive daytime sleepiness, cataplexy, sleep paralysis, and hypnagogic/hypnapompic hallucinations. It is currently believed to be caused by a deficiency in hypocretin-producing neurons in the lateral hypothalamus. Diagnosis is by the presence of appropriate clinical symptoms and confirmation by a polysomnogram followed by a multiple sleep latency test. There are nonpharmacologic (eg, scheduled naps, following proper sleep hygiene) and symptom-directed pharmacologic (eg, central nervous system stimulants, modafinil, sodium oxybate, certain antidepressants) treatments that are usually used together for optimal management of narcolepsy.