An Overview of Diagnosing Narcolepsy
Diagnosing
narcolepsy (a condition characterized by brief attacks of deep sleep) is relatively easy when all the symptoms are present. But if the sleep attacks are isolated and cataplexy (a sudden loss of muscle tone and strength) is mild or absent, a narcolepsy diagnosis is more difficult.
If a person has possible
narcolepsy symptoms, the doctor will do a physical exam and ask about the patient's personal and family medical history. The doctor will also recommend additional tests in order to diagnose narcolepsy.
Two tests used in diagnosing narcolepsy are the polysomnogram and the multiple sleep latency test. These tests are usually performed by a sleep specialist.
Polysomnogram
The polysomnogram involves continuous recording of sleep brain waves and a number of nerve and muscle functions during nighttime sleep. When tested,
people with narcolepsy fall asleep rapidly, enter REM sleep early, and may awaken often during the night. The polysomnogram also helps to detect other possible sleep disorders that could cause daytime sleepiness.
Sleep Latency Test
For the multiple sleep latency test, a person is given a chance to sleep every 2 hours during normal wake times.
Observations are made of the time taken to reach various stages of sleep. This test measures the degree of daytime sleepiness and also detects how soon REM sleep begins. Again, people with narcolepsy fall asleep rapidly and enter REM sleep early.
