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Multiple Sleep Latency Test (MSLT)

What is a MSLT?

The mutiple sleep latency test (MSLT) lets us explore your diurnal hypersomnolence and can be useful in diagnosing narcolepsy. Performed during the day at one of Biron's clinics, the MSLT is usually prescribed by your healthcare professional if you have already completed a polysomnography. During the procedure, you will have the opportunity to take 4 or 5 naps at predetermined times and specific intervals.

During your naps, our healthcare professionals trained in sleep care will ask you to try to sleep during each nap and will record your brain waves with an electroencephalogram (EEG).

Preparing for the Examination (for adults)

In order to properly prepare for the examination, we ask that you

  • wake up no later than 6:00 am on the day of your examination. Your appointment at the laboratory is usually at 7:30 am
  • do not drink coffee or other caffeine-based products
  • eat a light breakfast before leaving home. You may also prepare healthy snacks and a light lunch, which may be eaten between naps
  • Bring light, comfortable clothing, slippers, and your medication

Examination procedure

At all times, a Biron healthcare professional trained in sleep care will oversee smooth conduct of the test, recording of data, and your comfort.

When you arrive at the laboratory, various sensors will be installed on your scalp, near your eyes and on your chin. This procedure is painless.

During the day, you will have 4 or 5 rest periods to take. These periods will start at specific times depending on when you arrived in the morning. Each will be separated by a period of 2 hours during which it will be important to distract yourself and not sleep. The maximum duration of the rest periods will be 40 minutes.”

Specificities and Contraindications

Please note that the MSLT cannot be performed if you have been deprived of sleep in the previous days or if you work nights and sleep in the day.


The results of the sleep test will be interpreted by one of our specialist physicians trained in sleep health and will be available via MonBiron.

A medical prescription is required to perform this examination.
