Narcolepsy

[Greta]

(n) a chronic and usually hereditary sleep disorder in which the person affected will suffer spontaneous bouts of sleep (or sleep attacks) during the day. Symptoms include: [extreme sleepiness], typically followed by sleep attacks and last for fifteen minutes; dream-like hallucinations; [sleep paralysis], where you cannot move when you start to fall asleep or just after you wake up; and [cataplexy], which is an abrupt loss of muscle tone (basically, your muscles fail you).

The disorder is not fatal, but can be depending on the situation you find yourself having a sleep episode. There is no cure for narcolepsy at the moment.

[Jason Yan]

A condition characterized by an extreme tendency to fall asleep whenever in relaxing surroundings.

[Magaret]

Narcolepsy is a sleep disorder marked by excessive sleepiness during the day or recurring, uncontrollable episodes of sleep during normal waking hours, usually with sudden episodes of muscle weakness (cataplexy). Other symptoms include sleep paralysis, vivid dreams, and hallucinations while falling asleep or waking up from sleep.

Testing in a sleep laboratory, with polysomnography and multiple sleep latency testing, is needed to confirm the diagnosis.
Drugs are used to help keep people awake and to control other symptoms.

(See also Overview of Sleep.)
Narcolepsy occurs in about 1 of 2,000 people in the United States, Europe, and Japan. It is equally common among men and women.
What causes narcolepsy is unknown. Some people with narcolepsy have a similar group of genes, but the cause is not thought to be genetic. Environmental factors seem to be involved and may trigger the disorder. Some evidence suggests that narcolepsy may be caused by an autoimmune reaction that destroys nerve cells in a certain area of the brain. (An autoimmune reaction occurs when the immune system attacks the body

[Luis Fok]

a medical condition that makes you go to sleep suddenly and when you do not expect it