Narcolepsy

Narcolepsy Symptoms

People with narcolepsy experience frequent “attacks” of sleep, which last from a few seconds to 30 minutes or more. These attacks come while a person is awake and are unrelated to the amount and quality of nighttime sleep. Other symptoms may include:

* Cataplexy: Sudden muscle weakness often triggered by strong emotions such as laughter, anger or surprise. This weakness may cause the head to drop, the knees to give out, facial muscles to sag or even a complete collapse of the body.
* Sleep Paralysis: People with narcolepsy may be unable to talk or move when waking up or falling asleep.
* Vivid Dreams: These dreams often occur when first falling asleep and can be “hallucinogenic” in nature and easily confused with real life.


Causes of Narcolepsy

In narcolepsy, the border between being asleep and being awake can be blurred. A person with narcolepsy tends to fall directly into REM sleep without passing through the normal sleep stages. This may cause the “sleep paralysis” and “vivid dreams” symptoms. Researchers have discovered that people with narcolepsy have a lower amount of a protein called hypocretin that helps keep your awake. Some researchers think that narcolepsy is an autoimmune disease in which the immune system (due to a prior infection or injury) attacks and destroys hypocretin.

Who Has Narcolepsy?

Fewer than 50,000 Americans have been diagnosed with narcolepsy, but it is estimated that between 250,000 and 350,000 people have the disorder in the U.S. Narcolepsy is often misdiagnosed as depression, epilepsy (a seizure disorder) or other conditions. About 10 percent of people with narcolepsy have a close family member who also has it, suggesting a hereditary connection. Narcolepsy symptoms usually begin in young adults or adolescents.

Management of Narcolepsy

Currently there is no cure for narcolepsy, however the symptoms can be managed. A doctor may prescribe stimulants, antidepressants or other medications to treat narcolepsy. Some people find that taking short 15-minute naps several times a day reduces daytime sleepiness. Treatment for cataplexy may include REM sleep-suppressing medication (e.g., venlafaxine, fluoxetine or atomoxetine).

A Narcolepsy Breakthrough?

Researchers studying dogs discovered that a gene can cause narcolepsy. This gene (hypocretin receptor-2) gives the instructions for how to produce hypocretin, a protein necessary for sleep regulation. When the gene is defective, the protein that is built doesn’t function correctly. While this gene exists in humans, it is still unknown if people with narcolepsy have a defective version of hypocretin receptor-2.

Sources

National Institutes of Health; National Heart, Lung and Blood Institute. Your Guide to Healthy Sleep. NIH Publication No. 06-5271.

National Institutes of Health, National Institute of Neurological Disorders and Stroke, Understaning Sleep