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AASM publishes new MSLT and MWT standards!

 
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sleepadmin
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PostPosted: Wed Oct 06, 2004 7:25 am    Post subject: AASM publishes new MSLT and MWT standards! Reply with quote

In a soon to be “officially” published edition of the journal Sleep, the AASM will outline its new practice parameters for the MSLT and also establish clearer parameters for the MWT. Razz

Most notably the paper recognizes a long standing issue some sleep experts had raised about the nature of what the MSLT measures. Previous to this practice parameter, the AASM considered the MSLT as an objective measure of sleepiness. While this statement still rings true with the new paper, they further expanded the concept to include what many researchers described as “sleep ability.” Simply put, they argued that a when a person, without a sleep disorder, is given the opportunity to fall asleep (without consequence), they would likely do so, if they were so inclined. Hence the term “sleep ability.” The group of sleep experts who held this belief have long argued that many (otherwise sleep healthy) people might be misdiagnosed/labeled with idiopathic hyprsomnolence, or even narcolepsy. The new AASM paper states:

“The MSLT is a validated objective measure of the ability or tendency to fall asleep.”

In addition to this new perspective on the purpose of the MSLT, they also further define some new guidelines on how to perform the MSLT. Some things different I noticed:

-The first nap begins 1.5 to 3 hours following the patients “major sleep period.”
-The test “should” be performed following an NPSG with at least 6 hours of TST if testing for narcolepsy.
-“Stimulants, stimulant-like medications, and REM suppressing medications should be stopped 2 weeks before the MSLT.”
-“The patient must abstain from any caffeinated beverages and avoid unusual exposures to bright sunlight.”
-Breakfast is recommended 1 hour before the first nap. Lunch should be immediately after the second nap.

MWT

The new paper also gives much needed guidelines for the use of the MWT. As many variations have existed (some said 20 minutes, other said 40), it’s refreshing to now have one endorsed by the AASM. Here are the specifics:

The MWT consists of four 40 minute trials performed at two hour intervals beginning 1.5 to 3 hours following the patients usual wakeup time.

Performing a PSG prior to the MWT is optional, decided by the clinician. Sleep logs (diary) are also to be used at the clinician’s discretion.

The patient should be seated in bed with their head supported by pillows.

The room should be maximally insulated from light, with the exception of only a night light (7.5 W). The light should not shine directly into the patents eyes, but placed behind them just out of their view. Place the night light 1 foot off the floor, and 3 three feet laterally removed from their head.

Use of tobacco, caffeine and other medications are at the discretion of the clinition.

The MTW montage includes: EEG (C3, C4, O1, O2), L & R EOG, chin EMG, and an EKG.

Prior to each trial:

Ask the patient if they need to use the restroom.
Perform bio-cals; eyes open, eyes closed, eye movements, blink, and grit teeth.

The instruction to the patient for every nap should be: “Please sit still and remain awake for as long as possible. Look directly ahead of you, and do not look directly at the light.”

Sleep onset is defined as the first 30 second epoch of stage one.

Trials are ended after 40 minutes of no sleep, OR three consecutive epochs of stage one sleep, OR one epoch of any other stage of sleep.

(This information is provided for discussion of an educational and empirical nature as provided by the fair use clause of copyright law. Only excerpts of the original material have been reproduced for commentary. The reader is encouraged to purchase the official full publication from the American Academy of Sleep Medicine, Standards of Practice Committee, Michael Littner MD et al. 2004)
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sleeper
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PostPosted: Thu Oct 07, 2004 11:49 am    Post subject: Reply with quote

Thanks for this info! In everything I've read in the past, MWTs could be anywhere from 20-40 min. It's good to finally have a standard. Interesting changes to the MSLT as well.
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sleepy steve
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PostPosted: Wed Jul 13, 2005 3:09 am    Post subject: Reply with quote

What paperwork do you use? Is there a pre-test questionnaire to be filled out before each 40 min. period. Questions to ask after each period? Anything else anyone does with an MWT?
Thanks.
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slope
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PostPosted: Wed Jul 13, 2005 1:07 pm    Post subject: another change to the MSLT protocol Reply with quote

Another change very likely to come into effect soon will be switching the 5-minute cutoff to 8 minutes in order to get a positive result.
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somnonaut
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PostPosted: Thu Jul 14, 2005 3:19 am    Post subject: Tsk, tsk Andrew... Reply with quote

you didn't spend the $5 and buy the nice laminated card with the new MSLT rules on one side and the MWT rules on the other side at APSS? Too much drinking I guess Wink
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sleepadmin
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PostPosted: Thu Jul 14, 2005 5:06 am    Post subject: Reply with quote

Eh?

(The original post was from October of last year)
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somnonaut
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PostPosted: Thu Jul 14, 2005 7:06 am    Post subject: I'll beat Stew to the punch Reply with quote

OK, I am a wiseass. My bad Andrew. It was so dang long I didn't even go to the end. DId you get the card though? It is nice. And it has the 3 key words I have always stressed, right there as the last step on each side.
"Document, Document, Document"
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SCNVsleep
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PostPosted: Thu Jul 14, 2005 7:26 am    Post subject: Reply with quote

Beat THIS, pal...! Mr. Green
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Rick
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PostPosted: Thu Jul 14, 2005 4:04 pm    Post subject: A question about this here MSLT rules Reply with quote

So, What about ending the MSLT "nap"?
In my early days in sleep it was said to end the nap-time after definitive REM had been reached. Last I heard was allow 15 minutes of sleep, regardless of stage.
What are the parameters for ending it now?
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sleepadmin
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PostPosted: Thu Jul 14, 2005 10:24 pm    Post subject: Reply with quote

Neither... well the second is close;

End the nap after either no sleep within the first 20 minutes OR 15 minutes (not 15 minutes of sleep) after sleep onset (first epoch of sleep).

I believe the method of waiting until REM was a research protocol.
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SCNVsleep
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PostPosted: Thu Jul 14, 2005 10:27 pm    Post subject: Reply with quote

sleepadmin wrote:
Neither... well the second is close;

End the nap after either no sleep within the first 20 minutes OR 15 minutes (not 15 minutes of sleep) after sleep onset (first epoch of sleep).

I believe the method of waiting until REM was a research protocol.

As usual, Andrew, you are correct. One additional thing: lots of people end naps at the first sign of REM, as Rick alluded to. This was also part oof the original research protocol to validate the MSLT. Was never intended to be part of the practical protocol.
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Rick
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PostPosted: Thu Jul 14, 2005 10:36 pm    Post subject: Practical Schmactical Reply with quote

I had site visitors comment during their visit that I had not ended a nap as soon as there had been an epoch of REM. That stayed with me for quite a few years. Of course that was 1991....
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