What does MSLT stand for?

• A. Morning Sleep Latency Test
• B. Minimal Sleep Latency Test
• C. Multiple Sleep Latency Test
• D. Manual Sleep Latency Test

Answer: (C)

MSLT stands for Multiple Sleep Latency Test. The name captures what the test does: it measures how long it takes to fall asleep across several daytime nap opportunities, usually five, after an overnight sleep study. “Latency” is the time from lights out to sleep onset, and “multiple” reflects the repeated naps rather than a single nap. This standardized protocol helps quantify daytime sleepiness and aids in diagnosing narcolepsy and hypersomnia. The other terms aren’t standard descriptions of this procedure—there isn’t a morning-specific, minimal, or manual version of this multi-nap test.