brain, spinal cord, and nerve disorders
Narcolepsy
Symptoms of Narcolepsy
Symptoms of narcolepsy usually begin during adolescence or young adulthood and persist throughout life. The main symptoms are Severe excessive daytime sleepiness Cataplexy (sudden, temporary episodes of muscle weakness) Hallucinations while falling asleep or waking up Sleep paralysis Disturbances in nighttime sleep (such as waking up frequently and having vivid, frightening dreams) Only about 10% of people with narcolepsy have all the symptoms. Most people have only a few. All have excessive daytime sleepiness. People with narcolepsy have excessive daytime sleepiness, often despite long periods of excessive sleep. Many people are overcome by sudden episodes of uncontrollable sleep that can occur at any time, often without warning (called sleep attacks). Falling asleep can be resisted only temporarily. People may have many episodes or only a few in a single day. Each usually lasts a few minutes or less but may last hours. People can be awakened as readily as from normal sleep. They typically feel refreshed when they wake up even when the sleep episode lasts a few minutes. However, they may fall asleep again in a few minutes. Episodes of falling asleep are most likely to occur in monotonous situations, as during boring meetings or long periods of highway driving, but may occur while eating, speaking, or writing. While people are awake during the day, a sudden, temporary episode of muscle weakness without loss of consciousness—called cataplexy—may be triggered by a sudden emotional reaction such as anger, fear, joy, laughter, or surprise. People may become limp, drop something being held, or fall to the ground. The jaw may droop, facial muscles may twitch, eyes may close, and the head may nod. Vision may be blurred. People may slur their speech. These episodes resemble the normal muscle paralysis that occurs during rapid eye movement (REM) sleep and, to a lesser degree, the experience of being “weak with laughter.” Cataplexy causes significant problems in about one fifth of people with narcolepsy. Occasionally, when just falling asleep or immediately after awakening, people try to move but cannot. This experience, called sleep paralysis, can be terrifying. The touch of another person may relieve the paralysis. Otherwise, the paralysis disappears on its own after several minutes. Sleep paralysis occurs in about one fourth of people with narcolepsy. It sometimes occurs in healthy children and, less often, in healthy adults. When just falling asleep or, less often, when awakening, people may clearly see images or hear sounds that are not there. These extremely vivid hallucinations are similar to those of normal dreaming but are more intense. Hallucinations are called Hypnagogicwhen they occur while falling asleep Hypnopompicwhen they occur while awakening Hypnagogic hallucinations occur in about one third of people with narcolepsy. They are common among healthy children and occasionally occur in healthy adults. In people with narcolepsy, nighttime sleep may be interrupted periodically by awakenings and vivid, frightening dreams. As a result, sleep is unrefreshing, and people may be even sleepier during the day. People with narcolepsy often have difficulty functioning and concentrating. They are more likely to injure themselves—for example, if they fall asleep while driving. Narcolepsy can cause stress. Productivity and motivation may decrease, and concentration may be poor. People may withdraw from others and thus damage personal relationships. Many become depressed. 