narcolepsy(redirected from Gelineau disease)
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narcolepsy, a sleep disorder characterized by excessive daytime sleepiness and recurring unwanted episodes of sleep (“sleep attacks”). People with narcolepsy may abruptly fall asleep at almost any time, including while talking, eating, or even walking. The attacks may range from embarrassing or inconvenient to severely disabling, interfering with a person's daily life. An estimated 125,000–250,000 people in the United States have narcolepsy; it occurs about equally in males and females.
Most people with narcolepsy also experience cataplexy, sudden muscular weakness without loss of consciousness, which usually accompanies laughter or anger. Other symptoms, occurring just after falling asleep or upon awakening, include sleep paralysis (a feeling that one cannot move) and vivid hallucinations.
The cause of narcolepsy is not known with certainty, but most people with narcolepsy have low levels of orexin (or hypocretin), a neurotransmitter that promotes wakefulness. In the case of people with narcolepsy and cataplexy, the cause appears to be an autoimmune response that attacks the brain's orexin-producing neurons. There is no cure. Treatment, including regular planned naps and the use of stimulant drugs (e.g., amphetamines) plus antidepressants for cataplexy, can help to control its symptoms.
a disease the main symptom of which is an uncontrollable desire for sleep. Narcolepsy can develop after infections (epidemic encephalitis and malaria, for example) or head injuries; it may also be caused by certain brain tumors. Sometimes no apparent cause can be discovered, as in congenital, or genuine, narcolepsy. In addition to being characterized by an uncontrollable desire for sleep, narcolepsy is characterized by cataplectic attacks (loss of muscle tone brought about by exaggerated emotion) and by sudden arousals from nocturnal sleep with a loss of muscle tone. The duration of narcoleptic attacks is brief—from one to 30 minutes. The course of narcolepsy is chronic, but the intensity diminishes with age. Treatment involves both the elimination of the underlying cause and the use of pharmacotherapeutic techniques.