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Alternative names Return to top
Daytime sleep disorderDefinition Return to top
Narcolepsy is a sleep disorder associated with uncontrollable sleepiness and frequent daytime sleeping.Causes, incidence, and risk factors Return to top
The exact cause of narcolepsy is unknown. Studies using gene markers have indicated that the disorder may be genetic. A small group of neurons in the brain has been implicated in producing transitions from sleep to wakefulness and vice-versa. People with narcolepsy may have fewer of these neurons or they may have been damaged.
The condition may be aggravated by conditions that cause insomnia, such as disruption of work schedules.
Narcolepsy is characterized by episodes of frequent, uncontrollable daytime sleeping, usually preceded by drowsiness. The episodes usually occur after meals, but sudden onset of sleep may occur while working or driving a vehicle, having a conversation, or being in any sedentary or nonstimulating situation.
There is a brief period of sleep, and the person awakens feeling refreshed. However, the person may again become uncontrollably sleepy a short time later.
Narcolepsy may also be associated with cataplexy, a brief episode of severe loss of tone of various muscles. Generalized weakness may occur for a few moments during the transition between sleep and wake (sleep paralysis). Many people with narcolepsy also have dreamlike hallucinations in the transition between sleep and wakefulness.
Symptoms Return to top
Signs and tests Return to top
Examination and testing are used to rule out disorders that may cause similar symptoms, including sleepiness that results from seizures, sleep apnea, insomnia, restless leg syndrome, or other sleep disorders.Recently, patients with narcolepsy have been found to have low levels of hypocretin (a protein made by the brain) in their spinal fluid. More research will determine how useful this test is in diagnosing narcolepsy.
Treatment Return to top
There is no known cure for narcolepsy. Treatment is aimed at control of the symptoms.
Lifestyle adjustments and learning to cope with the emotional and other effects of the disorder may improve functioning in work and social activities. Planned naps can help regulate daytime sleep and reduce the number of unplanned, sudden sleep attacks. It is important to tell teachers and supervisors about this condition so that those affected are not punished for being "lazy" at school or work.
Eating light or vegetarian meals during the day and avoiding heavy meals prior to important activities may help reduce the odds of an attack after daytime meals. If possible, schedule a brief nap (10 to 15 minutes) after meals.
Prescription medications may be necessary, including stimulants such as dextroamphetamine and methylphenidate (Ritalin). Modafinil, a new type of stimulant that is believed to have less abuse potential than other stimulants, has recently been found to be effective in maintaining wakefulness.
Antidepressant medications such as imipramine can help to reduce the number of episodes of cataplexy, but they usually do not reduce the number of sleeping episodes.
Patients with narcolepsy may have driving restrictions placed on them. These restrictions vary from state to state.
Expectations (prognosis) Return to top
Narcolepsy is a chronic, life-long condition. It is not a fatal illness, but it may be dangerous if episodes occur during driving, operating machinery or similar activities. Narcolepsy is usually controllable with treatment. Treating other underlying sleep disorders can improve symptoms of narcolepsy markedly.Complications Return to top
Calling your health care provider Return to top
Call your health care provider if symptoms suggestive of narcolepsy occur.Prevention Return to top
There is no known prevention for narcolepsy. Treatment may reduce the number of attacks. Avoid situations that aggravate the condition if prone to attacks of narcolepsy. Update Date: 8/1/2004 Updated by: Joseph V. Campellone, M.D., Division of Neurology, Cooper University Hospital, Camden, NJ. Review provided by VeriMed Healthcare Network.
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Page last updated: 28 October 2004 |