Narcolepsy (NAR-ko-lep-see) is a disorder that causes a person to have difficulty staying awake. In extreme cases, narcolepsy can cause a person to suddenly fall asleep during the day. These ¡°sleep attacks¡± occur even after getting enough sleep at night. The unusual sleep pattern that people with narcolepsy have can affect their schooling, work, and social life.

The two main types of sleep are rapid eye movement (REM) sleep and nonrapid eye movement (NREM) sleep. During REM sleep, your eyes move rapidly even though your eyelids stay shut. Dreaming mainly happens during REM sleep, when your body becomes limp and you are unable to move your muscles. This temporary inability to move prevents you from acting out any dreams that you may be having.

Normally, when people fall asleep they first have NREM sleep. Then they go through a period of REM sleep. People with narcolepsy have a different sleep pattern. They often fall into REM sleep before NREM sleep. Also, in people with narcolepsy, the fine line between being asleep and being awake can be blurred. They often find that certain aspects of REM sleep can happen while they are awake. This causes them to:

• Suddenly lose muscle tone and control when awake (cataplexy). This can appear to be muscle weakness and sometimes can trigger the body to collapse.
• Not be able to move or speak while falling asleep or waking up (sleep paralysis).
• Have vivid dreams while falling asleep or waking up (hallucinations).

Effects of Narcolepsy

People with narcolepsy often fall asleep without warning at inappropriate times. Sleep attacks don¡¯t just happen during quiet times, such as when reading or watching TV. These attacks can occur during driving, eating, or other activities and can cause:

• Accidents and injuries
• Problems at work or at school
• Social problems
• Impaired memory, thinking, or ability to concentrate
• Depression

Outlook

There is no cure yet for narcolepsy. This lifelong condition can be disabling if left untreated. But medicines and lifestyle changes can improve the symptoms of narcolepsy so that it is easier to live with.