Narcolepsy. Diagnosis and treatment.

Narcolepsy may affect as many as 200,000 Americans. The illness involves a neurologic defect in the regulation of sleep and wakefulness. The chief symptoms are sleepiness, inappropriate sleep episodes, and cataplexy. A characteristic history of cataplexy establishes the diagnosis. Narcoleptic patients also frequently complain of hypnagogic hallucinations, sleep paralysis, blackouts (or automatic behavior), and disturbed nocturnal sleep. Narcolepsy usually develops in adolescence and is a life-long illness. Symptoms may also appear in young children who may be misdiagnosed as hyperactive or psychotic. No completely satisfactory treatment is available at the present time. The current treatments of choice are methylphenidate (for sleepiness and sleep episodes) and imipramine (for cataplexy). Medication dosages must be adjusted for individual patients. A careful history of the illness can rule out hypothyroidism, hypoglycemia, and epilepsy. Sleep apnea is a serious complication of narcolepsy and may be life threatening.