Multiple Sleep Latency Test (MSLT)

Your sleep provider has requested your child get an MSLT. This test looks at daytime sleepiness and evaluates for a possible condition of excessive sleepiness called hypersomnia. In this test, your child takes a series of short naps, spaced 2 hours apart. This test is done during the daytime immediately following a nighttime sleep study. The first nap begins 1 ½ to 3 hours after waking up from the nighttime study. A minimum of four naps are needed. A fifth nap may be necessary, depending on what we see during the first four naps. The last MSLT nap will be completed by 5:30 p.m.

The technologist will keep you informed about the expected end-time of the study as soon they know.

It is important your child remains awake between naps. We have a TV and Xbox to help keep your child busy and awake between naps. Please note that you need your own sign-in name to use the Xbox. Please feel free to bring your own DVDs, books or board games for your child to use while at the Sleep Disorders Center. (This may also be a good time to catch up on homework!)

Breakfast and lunch are provided for your child. The family member who stays with the child during testing needs to plan for breakfast and lunch on their own.

Your child may need to be taken off certain medicines for this study as they can interfere with the results. The test may need to be rescheduled if certain medicines are not weaned. Your sleep provider will review this at your appointment.

2 weeks before the test 

• A sleep diary will be mailed to you. Please track your child’s sleep using this sleep diary for 2 weeks prior to the test. Please contact the Sleep Disorders Center if you have not received the sleep diary in the mail or via MyChart.
• A wrist device called an actigraphy watch will be given to your child to wear 24 hours a day for 2 weeks prior to the test. This device records sleep and activity. You will need to bring the watch with you to the Sleep Center when you come for the testing.
• If the daytime actigraphy data or the sleep study (polysomnogram/ PSG) done the night before suggests not enough sleep, the MSLT may be cancelled.

1 week before the test

• We will call you 1 week before the MSLT, at your scheduled phone appointment time, to review what to expect the night/day of the studies, ensure any recommended medication weans have occurred, and answer questions.

The night before the MSLT 

• Your child will have had their sleep study (PGS) the night before the MSLTs happen because these tests are done in conjunction with each other. If the PSG shows another sleep disorder such as sleep apnea or not enough sleep, the MSLT may be cancelled.
• A urine sample will be collected to test for any alerting or sedating medicines your child may be taking that would impact the results of the MSLT.