A multiple sleep latency test (MSLT) is a diagnostic study used to evaluate patients with suspected narcolepsy or excessive daytime sleepiness. This test requires that you stay at the Sleep Center for most of the day for a series of short naps, scheduled at set intervals throughout the day. The amount and type of sleep you get during naps can help sleep specialists better understand your sleep complaints and make decisions about specific sleep disorders and treatments. Frequently, multiple sleep latency tests will be performed the day after an all-night sleep test.

What can I expect?

A qualified sleep technologist performs the study. The technologist will apply the various electrodes used to record brain waves, eye movement and muscle tone activity. Throughout the day you will be given four or five opportunities to fall asleep and take a short nap. These naps are usually scheduled with two-hour intervals in between. During these two-hour intervals, you will need to stay awake.

The study will be evaluated by a technologist and reviewed by a physician. A report will be available within two to three weeks, and you or your physician will be contacted with the results. Some patients will require a return appointment.

Lahey’s Sleep Laboratory

The Sleep Laboratory consists of 10 bedrooms total, with six located at Lahey Hospital & Medical Center in Burlington, Mass., and four based at Lahey Medical Center, North Shore, in Peabody, Mass. Adjacent to the bedrooms are technicians’ areas to monitor patients’ sleep patterns. Both all-night sleep studies and multiple sleep latency tests are performed.

The laboratory is equipped with a CPAP/BiPAP unit for the evaluation of appropriate positive-pressure levels in the treatment of sleep apnea.