multiple sleep latency test
Also written as: MSLT — multiple sleep latency test
Daytime sleep study measuring the tendency to fall asleep, used primarily to diagnose narcolepsy and assess excessive daytime sleepiness.
Full Definition
The multiple sleep latency test (MSLT) is an objective measure of sleepiness consisting of five scheduled 20-minute nap opportunities at two-hour intervals throughout the day. The test measures sleep onset latency and the presence of sleep-onset REM periods (SOREMPs). A mean sleep latency of less than 8 minutes indicates pathological sleepiness, while two or more SOREMPs combined with short sleep latency strongly suggests narcolepsy. The MSLT must be preceded by adequate nighttime sleep documentation and is typically performed the day after polysomnography to rule out other sleep disorders.
Usage
Usage note: Commonly abbreviated as MSLT. Hyphenate when used as a compound modifier.
In Context
- "The multiple sleep latency test revealed a mean sleep latency of 3 minutes with three sleep-onset REM periods." — Narcolepsy evaluation report
- "An MSLT is scheduled following tonight's polysomnography to assess for narcolepsy." — Sleep study scheduling note