What is Multiple Sleep Latency test (MSLT)?
An Multiple Sleep Latency test (MSLT) consists of a series of five 20-minute nap opportunities that measure the physiologic tendency to fall asleep in quiet situations, since it varies during the day.
Mean sleep latencies should be considered a continuum of values in which below 5 minutes indicates sleepiness and those over 10 minutes indicates normal alertness.
An MSLT may help identify the etiology of excessive daytime sleepiness.
A PSG prior to MSLT testing is useful to exclude other major sleep disorders that could contribute to hypersomnia and to confirm that a sufficient amount of sleep is obtained (at least 6 hours) prior to the MSLT.
