Multiple Sleep Latency Testing
This daytime sleep study measures how sleepy you are. It is typically done is a quiet room while you relax for about 30 minutes while a technician checks your brain activity.
The MSLT records whether you fall asleep during the test and what types and stages of sleep you're having. Sleep has two basic types: rapid eye movement (REM) and non-REM. Non-REM sleep has three distinct stages. REM sleep and the three stages of non-REM sleep occur in regular cycles throughout the night.
The types and stages of sleep you have during the day can help your doctor diagnose sleep disorders such as narcolepsy and idiopathic hypersomnia.
An MSLT is repeated four or five times throughout the day. This is because your ability to fall asleep also changes throughout the day.