Narcolepsy

Narcolepsy is characterized by excessive daytime sleepiness and intermittent, uncontrollable episodes of rapid eye movement (REM) sleep. During REM sleep, images such as dreams occur while the body is immobile as if paralyzed. Narcoleptic individuals often experience aspects of REM sleep, such as seeing images or feeling partially paralyzed, with the onset of sudden emotional situations like laughter or surprise. It is a relatively rare condition, affecting approximately 1 in 2000 people.

The sleepiness in narcolepsy occurs as a result of problems in the part of the brain that regulates wakefulness. This also causes sudden spells of REM sleep to unexpectedly intrude into wakefulness and last from a few seconds to many minutes. Sleep studies on narcolepsy patients usually demonstrate abnormal sleep patterns, including fragmentation of sleep due to multiple short awakenings, sleep maintenance insomnia, and sleep onset REM.

The primary symptoms of narcolepsy are excessive daytime sleepiness and cataplexy, which is the sudden onset of partial paralysis caused by emotional situations. Intrusions of REM sleep into wakefulness and non-REM sleep periods are common in narcolepsy and may result in vivid visual hallucinations or temporary paralysis while falling asleep or upon awakening.

Excessive Daytime Sleepiness

The symptom that all narcoleptics exhibit is excessive daytime sleepiness. This type of sleepiness is extreme and irresistible which is why many narcoleptics can fall asleep in the middle of the day, even during physical activities.

Naps may occur suddenly and last for minutes to hours and are frequently refreshing. Unfortunately, the sense of sleepiness quickly returns, and narcoleptics continue to battle the urge to fall asleep all day long. To compensate, many narcoleptics use excessive amounts of stimulants like caffeine or other drugs.

Cataplexy

The second most common symptom of narcolepsy is called Cataplexy. It is the abrupt loss of strength and muscle tone in the body which may seem like partial paralysis. In some cases all the muscles in the body are affected, leading to complete collapse. In milder cases, the loss in muscle strength may only involve a few muscles of the face, legs, hands or neck.

During cataplexy attacks, the person is aware of the surroundings, but may also experience dream-like images. Cataplexy is usually brought on by strong emotions like joy, fear, anger or surprise.

Hallucinations

20-40% of narcoleptics experience Hypnogogic hallucinations while falling asleep, and Hypnopompic hallucinations upon awakening. Both can last up to a few minutes and involve visual, auditory, or tactile sensations. Like some REM sleep dreams they also may include emotion such as fear or dread. These sorts of hallucinations also occur in non-narcoleptic individuals and, therefore, are not exclusive symptoms of narcolepsy.

Sleep Paralysis

Another 20-40% of narcoleptics have Sleep Paralysis which is an inability to move immediately before falling asleep or upon awakening. People who experience this may describe feeling afraid, as if a person or creature were sitting on their chest or holding them down. Sleep paralysis usually lasts a few seconds to minutes and can be resolved by waking up the person. Sleep Paralysis is not specific to narcolepsy and may occur in many non-narcoleptic people.

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