Narcolepsy
 

  Narcolepsy is a chronic sleep disorder with no known cause. The main characteristic of narcolepsy is excessive and overwhelming daytime sleepiness, even after adequate sleep during the night.

A person with narcolepsy is likely to become drowsy or to fall asleep, often at inappropriate times and places. Daytime sleep attacks may be irresistible and occur with or without warning; these attacks can occur repeatedly in a single day. Drowsiness may persist for prolonged periods of time.  In addition, nighttime sleep may be fragmented with frequent awakenings.

Three other classic symptoms of narcolepsy, which may not occur in all patients, are:

  • Cataplexy:
    Sudden episodes of loss of muscle function, ranging from slight weakness (such as limpness at the neck or knees, sagging facial muscles, or inability to speak clearly), to complete body collapse attacks may be triggered by sudden emotional reactions such as laughter, anger, or fear and may last from a few seconds to several minutes. The person remains conscious throughout the episode
  • Sleep paralysis:
    Temporary inability to talk or move when falling asleep or waking up. It may last from a few seconds to a few minutes
  • Hypnagogic hallucinations:
    vivid, often frightening, dream-like experiences that occur while dozing or falling asleep.
  • Daytime sleepiness, sleep paralysis, hypnagogic hallucinations 
    Can also occur in people who do not have narcolepsy

In most cases, the first symptom of narcolepsy is excessive and overwhelming daytime sleepiness. The other symptoms may begin alone or in combination months or years after the onset of the daytime sleep attacks.

There are wide variations in the development, severity, and order of appearance of cataplexy, sleep paralysis and hypnagogic hallucinations in individuals.  Only about 20 to 25 percent of people with narcolepsy experience all four symptoms.  The excessive daytime sleepiness generally persists throughout life, but sleep paralysis and hypnagogic hallucinations may not.

The symptoms of narcolepsy, especially the excessive daytime sleepiness and cataplexy, often become severe enough to cause serious disruptions in a person's social, personal, and professional lives and severely limit activities.

You should be checked for narcolepsy if:

  • You often feel excessively and overwhelmingly sleepy during the day, even after having had a full night's sleep
  • You fall asleep when you do not intend to, such as while having dinner, talking, driving, or working
  • You collapse suddenly or your neck muscles feel too weak to hold up your head when you laugh, become angry, surprised or shocked
  • You find yourself briefly unable to talk or move while falling asleep or waking up


Although it is estimated that narcolepsy afflicts as many as 200,000 Americans, fewer than 50,000 are diagnosed. It is as widespread as Parkinson's Disease or Multiple Sclerosis and more prevalent than Cystic Fibrosis, but it is less well known. Narcolepsy is often mistaken for depression, epilepsy or the side effects of medications.

Narcolepsy can occur in both men and women at any age, although its symptoms are usually first noticed in teenagers or young adults. There is strong evidence that narcolepsy may run in families; eight to 12 percent of people with narcolepsy have a close relative with the disease.

Note: This information is from the NIH web site. Please visit www.nih.gov for further details