The multiple sleep latency test (MSLT)
MSLT, otherwise known as the “nap study,” is a test performed during the day. The test measures how long it takes one to fall asleep, and when you sleep becomes REM. You’ll be told to take a nap every 2 hours four to five times during the tests.
People with narcolepsy often fall asleep in about 10 minutes or less and go into the REM phase during at least 2 of the naps. Once the test confirms your condition, your doctor will immediately create a treatment plan, starting with eliminating drugs that could cause your condition.