Narcolepsy.

Narcolepsy is a disabling, chronic sleep-wake disorder that typically starts in a patient's second or third decade of life. Its key features are hypersomnia and cataplexy. Sleep paralysis, hallucinations, and disrupted sleep are nonspecific symptoms and are not always present. Disability relates primarily to sleepiness- related cognitive impairment, accidents, and psychosocial problems. Treatment, which includes counseling, scheduled napping, and pharmacologic intervention, is effective for most patients. Hypersomnia is best treated with such indirect sympathomimetics as mazindol, pemoline, methylphenidate, and amphetamine. Modafinil may become the drug of choice because it has fewer side effects. Cataplexy, sleep paralysis, and hallucinations may be ameliorated by compounds, including clomipramine and imipramine, that suppress rapid eye movement (REM) sleep. Regular follow-up visits enable the clinician to recognize uncommon but serious side effects (tolerance, substance abuse, psychosis, and hypertension) and additional sleep disturbances (sleep apnea, periodic limb movements in sleep, REM sleep behavior disorder), which can be specifically treated.