Diagnosis of Narcolepsy

If you have the most classic symptoms of narcolepsy, such as involuntary sleep attacks and weakness attacks (cataplexy), diagnosis of your disorder may be relatively simple. If your healthcare provider isn’t sure whether your symptoms are caused by narcolepsy, however, he or she may order some tests. There are two tests that can help diagnose narcolepsy: the polysomnogram and the multiple sleep latency test. A sleep specialist usually administers both of these tests.

Polysomnogram Tests – For this test, you’ll have to spend the night in a sleep center. Tiny electrodes will be attached to various areas of your body in order to closely monitor your heart rate, eye movements, brain waves, and muscle activity throughout the night. Monitors will also record information about your breathing, changes in the concentration of oxygen in your blood, and your body position.

Multiple Sleep Latency Test – This test is usually done the day after the polysomnogram. With the same set of electrodes still attached, you’ll be asked to take a series of 20-minute naps, every 2 hours throughout the day. The electrodes collect information about how quickly you fall asleep and how quickly you reach various levels of sleep—particularly rapid eye movement (REM) sleep.


National Heart, Lung, and Blood Institute. National Institutes of Health website. Available at: http://www.nhlbi.nih.gov/ .

Textbook of Clinical Neurology . W.B. Saunders Company; 1999.

Last reviewed February 2007 by Edward R. Rosick, DO, MPH, MS

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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