Narcolepsy is a sleep disorder in which the sleep-wake center of the brain is unable to maintain wakefulness during the daytime. It can vary in severity from mild to severe and usually begins in the teenage years, but often goes undiagnosed for several years.
Causes, incidence & risk
It is a neurological (nervous system) disorder. The exact cause is still unknown, but it is thought to be the result of a deficiency in the chemicals in the brain that tell the body when to sleep and when to wake up. There also appears to be a genetic link, so most patients with narcolepsy can have one or more family members with it as well.
- Excessive daytime somnolence (sleepiness)
- Uncontrollable sleep attacks that may occur up to 10 times a day and may last from 30 seconds to 30 minutes. An attack leaves a person feeling refreshed, but another attack may occur quickly. These attacks can occur while driving, talking, working, or at social event.
- Hallucinations (seeing or hearing things that really are not there), right at the point of falling asleep or waking up. This is called hypnagogic or hypnopompic hallucinations.
- A short period of paralysis, right at the point of falling asleep or waking up.
- Sudden feelings of muscle weakness that occur with sudden, strong emotion such as anger, fear or joy. This is called cataplexy.
- Nighttime sleep is disturbed by leg jerks, tossing and turning, nightmare, and frequent awakenings.
A special sleep and nap study is required to diagnose narcolepsy. Also, other causes of excessive sleepiness, such as depression and thyroid disorders, must be evaluated.
There are several medications available for the treatment of narcolepsy and the effectiveness depends on the severity of the disorder and the type of medication. Medications currently used to treat narcolepsy include central nervous system stimulants such as Ritalin, a non-stimulant wakefulness promoter called Provigil, and antidepressants.