If not treated, people with narcolepsy can fall asleep at any time, such as when at work, while driving and while engaged in a conversation. Narcolepsy is linked to a chemical in the brain called hypocretin, which normally stimulates arousal and helps regulate sleep. Most people with narcolepsy do not produce hypocretin in the deep part of the brain called the hypothalamus. As a result, the body's messages about when to sleep and when to stay awake sometimes occur at the wrong times and places.
Narcolepsy is a lifelong condition that affects an estimated one in 1,000 to 1,500 people. Although it occurs in both men and women, it is slightly more common among men. The condition can begin at any age, although its symptoms usually appear between the ages of 10 and 20. Narcolepsy has been found to be hereditary in some cases.
The hallmark symptom of narcolepsy is an excessive daytime sleepiness (EDS), in which a person falls asleep at times when they want to be awake. EDS may include daytime sleep attacks that occur with or without warning, persistent drowsiness and fleeting moments of sleep that occur in between a person's waking state.
Other symptoms may include:
To diagnose narcolepsy, your doctor will conduct a physical examination and ask about your medical history and symptoms. In addition, a number of tests are available to assist the diagnosis of narcolepsy:
Treatment for narcolepsy typically involves medications to increase daytime alertness and reduce cataplexy and other symptoms. Stimulants are usually prescribed to improve alertness. Antidepressants as well as a new drug called gammahydroxybutyrate, or Xyrem, may be used to control cataplexy, hypnagogic hallucinations and sleep paralysis.
Common stimulants include the following:
There are a few common side effects of stimulants that you may experience when taking these medications. They include headache, irritability, nervousness, insomnia, irregular heartbeat and mood changes.
Reviewed by health care specialists at UCSF Medical Center.