Cataplexy is a medical condition which often affects people who have narcolepsy, a disorder whose principal signs are EDS (Excessive Daytime Sleepiness), sleep attacks, and disturbed nighttime sleep.
The term cataplexy originates from the Greek kata, leaning down, and Alexis, meaning a stroke or seizure.
Cataplexy manifests itself as muscular weakness which may range from a barely perceptible slackening of the facial muscles to the dropping of the jaw or head, weakness at the knees, or a total collapse. Usually, the speech is slurred, vision is impaired (double vision, inability to focus), but hearing and awareness remain normal. These attacks are triggered by strong emotions such as exhilaration, anger, fear, surprise, orgasm, and laughter.
Cataplexy often affects people who have narcolepsy, a disorder in which there is great difficulty remaining awake during the daytime. Cataplexy is also sometimes confused with epilepsy, where a series of flashes or other stimulus cause similar seizures. Despite its relation to narcolepsy, cataplexy must be treated differently and separate medication must be taken. Cataplexy is treated with the drug Xyrem.