Narcolepsy update.

Narcolepsy, a disorder of excessive daytime sleepiness that affects more than 125,000 people in the United States, is technically defined as a daytime mean sleep latency (time elapsed before falling asleep) of less than 5 minutes in conjunction with verification of rapid eye movement sleep in at least two of five daytime nap periods. Cataplexy, hypnagogic hallucinations, and sleep paralysis are frequently associated with narcolepsy. Currently, overnight polysomnography and multiple sleep latency testing in a sleep disorders laboratory are used to diagnose narcolepsy. Standard pharmacologic therapy consists of the judicious use of stimulants to improve alertness and the administration of tricyclic and other antidepressant drugs to suppress cataplexy. In addition, good sleep hygiene (a regular sleep-wake schedule, an adequate amount of sleep at night, and scheduled daytime naps) is essential for optimal management of this disorder. Patient and family education about narcolepsy and its treatment is also important. Even with use of the best available treatment regimens, many patients with narcolepsy have substantial vocational and social impairments.