Download PSG 100 – PSG Basics

MSLT - MWT
MSLT Protocol
• Consider drug testing
• Should follow an overnight PSG
• 4 or 5 naps, 2 hours apart
– naps last 20 minutes, or 15 minutes after
onset of sleep (longest can be 35 mins)
– unit of measure:
• minutes to sleep onset (stage 1)
• minutes to REM sleep onset (beginning with
stage 1)
MSLT Procedure
MSLT Results Table
Sleep Latency Data Plot
Calculation of Mean Sleep Latency
Sleepiness Index
• Take total number of minutes of sleep latencies
and subtract from 100 (if no sleep, the index is
0)
• If only 4 naps are conducted, subtract total
number of minutes of sleep latencies and
subtract from 80. Divide the resulting number
by 80 and multiply by 100.
MSLT findings
• Mean sleep latency
– normal is > 10 minutes
– 5-10 minutes is “gray zone”
– <5 minutes is pathological sleepiness
• REM-onset sleep periods
– normal is < 2
– if there is only one, it is most likely to be in first nap
– one SOREM obligates you to 5th nap or second
SOREM