Diagnosis

To diagnose narcolepsy, your doctor will ask you about your history of typical episodes and will have you undergo an overnight sleep study. The sleep study checks for other explanations that could account for daytime sleepiness, such as sleep apnea or other causes of sleep interruptions. The sleep test measures brain waves, eye movements, muscle activity, heartbeat, blood oxygen levels and breathing.

A specific study called a multiple sleep latency test is a necessary part of the evaluation for narcolepsy. This test must be done after the person has had an adequate night's sleep. A multiple sleep latency test consists of four 20-minute opportunities to nap, which are offered every two hours throughout the day. Patients with narcolepsy fall asleep in approximately five minutes or less, and move into REM sleep during at least two of the four naps. Normal well-rested sleepers take about 12 to 14 minutes to fall asleep for a daytime nap, and don't fall directly into REM sleep.

Expected Duration

Narcolepsy cannot be cured and does not go away. In most cases, symptoms can be diminished with medications, regularly scheduled naps and good sleep habits.