Multiple Sleep Latency Test (MSLT)

The following Multiple Sleep Latency Test (MSLT) protocol should be adhered to by patients:

• The MSLT will be performed immediately following polysomnography recorded during the patient’s major sleep period.
• The MSLT consists of five nap opportunities performed at two hour intervals.  The initial nap begins 1.5 to 3 hours after termination of the nocturnal recording.  The final nap should be completed by 6 p.m.
• The sleep technician will place electrodes on the scalp, left and right eye, chin, and heart for the recording.
• Drug screening is usually performed on the morning of the MSLT.
• Stimulants, stimulant-like medications, and REM suppressing medications should be stopped 2 weeks before the MSLT.  Use of the patient’s other usual medications (e.g., antihypertensives, insulin, et cetera) should be discussed with the sleep physician before MSLT testing so that undesired influences by the stimulating or sedating properties of the medications are minimized.
• Sleep logs should be kept for 1 week prior to the MSLT to assess sleep-wake schedules and confirm adequate amounts of sleep have been obtained prior to the overnight polysomnogram and next day MSLT.
• Smoking should be stopped at least 30 minutes prior to each nap opportunity.
• Vigorous physical activity should be avoided during the day and any stimulating activities by the patient should end at least 15 minutes prior to each nap opportunity.
• The patient should abstain from any caffeinated beverages and avoid unusual exposures to bright sunlight.
• A light breakfast will be provided one hour prior to the first trial, and a light lunch will be provided immediately after the termination of the second noon trial.
• Prior to each nap opportunity, the patient should use the restroom if necessary and make other adjustments for comfort.
• The patient will be given standard instructions for bio-calibrations prior to each nap: 1) lie quietly with your eyes open for 30 seconds, 2) close both eyes for 30 seconds, 3) without moving your head, look to the right and then left, 4) blind your eyes slowly five times, and 5) clench or grit your teeth tightly together.
• With each nap opportunity, the patient will be instructed as follow:  “Please lie quietly, assume a comfortable position, keep your eyes closed and try to fall asleep.”  Immediately after these instructions are given, the bedroom lights are turned off, signaling the start of the test.
• Between naps, the patient should be out of bed and prevented from sleeping.
• A nap session is terminated after 20 minutes if sleep does not occur.  If sleep does occur during a nap session, the patient will be allowed to sleep for an additional 15 minutes to check for the occurrence of REM sleep.