Symptoms Of Narcolepsy - Narcolepsy: Sleep Disorders

Content provided by the Faculty of the Harvard Medical School

Symptoms of narcolepsy

Narcolepsy may manifest itself in any of several ways:

• Excessive sleepiness. People with narcolepsy often feel extremely tired and struggle to stay awake during the daytime.

• Sleep attacks. A person may suddenly fall asleep for 5–10 minutes when relaxing or even while carrying on a conversation. If REM sleep and dreaming occur immediately, the individual sometimes makes conversation that is appropriate to the dream instead of the actual situation.

• Cataplexy. In cataplexy, the brain mechanism that paralyzes muscles during REM sleep becomes activated during the day. Thus, you may be fully alert but suffer partial paralysis or a complete muscle collapse, often brought on by laughter, anger, or other strong emotions. Cataplexy may set in several years after daytime sleepiness first appears, although sometimes it's the first symptom of narcolepsy. In mild cataplexy, your knees may buckle, or the muscles of your jaw or neck may become weak and difficult to control. When it's severe, the muscles become completely paralyzed, and you may fall to the ground. You are usually fully awake and aware of what's going on, but unable to talk. Although a few people then fall asleep, most recover spontaneously after several seconds or minutes.

• Sleep paralysis. A terrifying feeling of paralysis may occur during the transition between wakefulness and sleep if REM begins before a person is fully asleep. Although muscle control usually returns within a few minutes, it can cause great anxiety.

• Hypnagogic hallucinations. When REM dreaming occurs during wakefulness, the vivid and often frightening images, known as hypnagogic hallucinations, are difficult to distinguish from reality. A person may see prowlers or believe that his or her house is on fire. This usually happens just at sleep onset or upon awakening. This condition can be confused with mental illness because its symptoms resemble those of some psychotic disorders.

• Disturbed nighttime sleep. Just as sleep intrudes during the day, unwelcome awakenings can occur at night, depriving narcoleptics of restorative rest and exacerbating daytime drowsiness. Some feel as if they have hardly slept at all.

• Automatic behavior. Because of their profound sleepiness, people with narcolepsy perform many routine tasks without being fully aware of what they are doing. For example, one man washed and dried the dishes and then stacked them in the refrigerator but had no recollection of doing so.

Last updated:	January 23, 2007