Multiple Sleep Latency Test

The Multiple Sleep Latency Test (MSLT) is a diagnostic tool that measures daytime sleepiness and evaluates sleep disorders, including narcolepsy. During the MSLT, a person is instructed to take multiple 20-minute naps at set times throughout the day. The amount of time it takes to fall asleep and the type of brain waves that are generated are used to assess the severity of a person's sleepiness and the likelihood of a sleep disorder. Results from the MSLT are used to assess a patient's risk of excessive daytime sleepiness and their need for treatment. Furthermore, the MSLT is also used to monitor the effects of certain medications on a person's sleepiness.