Narcolepsy is a sleep disorder that causes excessive sleepiness and frequent daytime sleep attacks.
Alternative NamesDaytime sleep disorder; Cataplexy
Causes, incidence, and risk factorsNarcolepsy is a nervous system disorder, not a mental illness. Anxiety does not cause narcolepsy.
Experts believe that narcolepsy is caused by reduced amounts of a protein called hypocretin, which is made in the brain. What causes the brain to produce less of this protein is unclear.
Narcolepsy tends to run in families.
Conditions that cause insomnia, such as disrupted work schedules, can make narcolepsy worse.
SymptomsThe most common symptoms of narcolepsy are:
Not all patients have all four symptoms.
Signs and testsThe doctor will perform a physical exam and order blood work to rule out conditions that can cause similar symptoms. Conditions that can cause excessive sleepiness include:
Other tests may include:
Tests will also include a sleep study(polysomnogram). The Multiple Sleep Latency Test (MSLT) may be used to help diagnose narcolepsy. This test measures how long it takes you to fall asleep during a daytime nap. Patients with narcolepsy fall asleep much faster than people without the condition.
TreatmentThere is no known cure for narcolepsy. The goal of treatment is to control symptoms.
Lifestyle adjustments and learning to cope with the emotional and other effects of the disorder may help you function better in work and social activities. This involves:
You may need to take prescription medications. The stimulant drug modafinil (Provigil) is the first choice of treatment for narcolepsy. It is much less likely to be abused than other stimulants. The medicine also helps you stay awake. Other stimulants include dextroamphetamine (Dexedrine, DextroStat) and methylphenidate (Ritalin).
Antidepressant medications can help reduce episodes of cataplexy, sleep paralysis, and hallucinations. Antidepressants include:
Sodium oxybate (Xyrem) is prescribed to certain patients for use at night.
If you have narcolepsy, you may have driving restrictions. Restrictions vary from state to state.
Expectations (prognosis)Narcolepsy is a chronic, lifelong condition. It is not a deadly illness, but it may be dangerous if episodes occur during driving, operating machinery, or similar activities. Narcolepsy can usually be controlled with treatment. Treating other underlying sleep disorders can improve symptoms of narcolepsy.
ComplicationsCall your health care provider if:
There is no known way to prevent narcolepsy. Treatment may reduce the number of attacks. Avoid situations that aggravate the condition if you are prone to attacks of narcolepsy.
ReferencesDauvilliers Y, Arnulf I, Mignot E. Narcolepsy with cataplexy. Lancet. 2007;369(9560):499-511.
Morgenthaler TI, Kapur VK, Brown T, Swick TJ, Alessi C, Aurora RN, et al. Practice parameters for the treatment of narcolepsy and other hypersomnias of central origin. Sleep. 2007;30(12):1705-1711.