Narcolepsy
Definition
Causes
Symptoms
- Excessive daytime sleepiness
- Daytime involuntary sleep attacks
- Unrefreshing sleep
- Sudden loss of muscle tone without loss of consciousness (cataplexy)
- Temporary paralysis while awakening
- Frightening mental images that appear as one falls asleep
- Memory problems
-
Symptoms may be triggered by:
- A monotonous environment
- A warm environment
- Eating a large meal
- Strong emotions
| Brainstem—Area of Brain Related to Alertness |
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Diagnosis
- Multiple sleep latency test (MSLT)—measures the onset of rapid eye movement sleep, which occurs earlier than normal in narcolepsy
-
General sleep lab study—often done the night before an MSLT; helps to rule out other causes of daytime sleepiness by monitoring:
- Brain waves
- Eye movements
- Muscle activity
- Respiration
- Heart beat
- Blood oxygen levels
- Total nighttime sleep
- Amount of nighttime REM sleep
- Time of onset of REM sleep
- Degree of daytime sleepiness
Treatment
-
Stimulant medicines that increase levels of daytime alertness, such as:
- Methylphenidate
- Dextroamphetamine
- Methamphetamine
- Modafinil
- Armodafinil
- Gamma-hydroxybutyrate (GHB)—for excessive daytime sleepiness and cataplexy, such as sodium oxybate
- Antidepressants—to help treat many symptoms of narcolepsy (eg, cataplexy, hallucinations, sleep paralysis)
- Planned short naps throughout the day
- Counseling to cope with issues of self esteem
- Wearing a medical alert bracelet or pendant
Prevention
- Exercising on a regular basis
- Getting adequate sleep at night
RESOURCES
Narcolepsy Network http://www.narcolepsynetwork.org/
National Sleep Foundation http://www.sleepfoundation.org/
CANADIAN RESOURCES
Better Sleep Council of Canada http://www.bettersleep.ca/
Health Canada http://www.hc-sc.gc.ca/index%5Fe.html/
References
Bhat A, El Sohl AA. Management of narcolepsy. Expert Opin Pharmacotherapy . 2008;9(10):1721-1733.
Dauvilliers Y, Arnulf I, Mignot E. Narcolepsy with cataplexy. Lancet . 2007;369:499-511.
Feldman NT. Narcolepsy. Southern Medical Journal . 2003;96:277-282.
Narcolepsy fact sheet. National Heart, Lung, and Blood Institute. National Institutes of Health website. Available at: http://www.ninds.nih.gov/disorders/narcolepsy/detail%5Fnarcolepsy.htm . Updated October 2009. Accessed February 8, 2010.
Narcolepsy: new understanding of irresistible sleep. Mayo Clinic Proceedings . 2001.