What is a cortical arousal?

SelfSeeker · Post by **SelfSeeker** » Wed Apr 18, 2007 2:41 pm

According to my Polysomnograpy Report this was used as recording Protocol:

Apneas were scored when no airflow was detected for at least 10 seconds.

Hypopnea were scored when a 30% or more drop in airflow with coincident deesaturation of at least 4% lasting at least 10 seconds was observed.

AASM Mild hypopnea were scored if a 50% drop in flow was seen, or a lesser drop followed by either a 3% desaturation or AASM cortical arousal.

American Association of Sleep Medicine (AASM)

What is a cortical arousal?

Are cortical arousals it counted with the either the Respiratory-related arousals or the Spontaneous EEG arousals or neither. (The only other possible arousals on the PSG were PLM-related.)

I am wondering if the AASM Mild hypopneas are related to UARS.

Why would it be so hard to find concrete information.

cohodependent · Post by **cohodependent** » Thu Apr 19, 2007 4:44 am

Cortical Arrousals are the arrousals that occur in the Cerebral Cortex. We monitor four different channels of brain activity with the main ones being the right and left Cortex, or C3 for the left and C4 for the right. These are the baseline channels for identifying arrousals.

To put it into context for what you posted, in order to score a "Mild Hypopnea" you need to have a 50% drop in air flow followed by a 3% drop in O2 sat, OR an arrousal in order to be scored....

I hope that helps

tangents · Post by **tangents** » Thu Apr 19, 2007 7:40 am

Thanks for the explanation, Coho. It's really nice to have some resident experts here on the forum!

RosemaryB · Post by **RosemaryB** » Thu Apr 19, 2007 8:08 pm

Coho, thank you for the good info. Also, what would be the best way to learn about the technical details of an EEG and how it is used in a sleep study?

Rose

cohodependent · Post by **cohodependent** » Thu Apr 19, 2007 9:20 pm

Rosemary,

The thing to keep in mind is the EEG that we use for a sleep study is not the same as an EEG that you would have for say, a seizure disorder. We do not use any where close to the same number of electodes. We use EEG only to identify sleep and wake, and then the sleep stages, i.e stages 1-5.

So, what we use is really pretty basic in comparison. There are many paths that bring folks into the world of being a Sleep Tech. Some are Respitory Therapist and some are true EEG techs. I myself am a Paramedic by training, and then there are those who enter the field with very little in the way of medical background. We each bring some thing different to the lab.

If you want to really get in to EEG you should be able to go down to a book store and find old reference books and or text books. One way for sure to get some sleep is to start reading those. The main book is the Princiles and Practice of Sleep Medacine. An other one is the Principles of Polysomngraphy.

blarg · Post by **blarg** » Fri Apr 20, 2007 2:27 am

You could always audit an online course like:

http://www.highline.edu/home/catalog/co ... q.html#psg

That would give you more than you probably ever wanted to know.

rested gal · Post by **rested gal** » Fri Apr 20, 2007 8:24 am

cohodependent wrote: One way for sure to get some sleep is to start reading those.

RosemaryB · Post by **RosemaryB** » Fri Apr 20, 2007 11:40 am

rested gal wrote:
cohodependent wrote: One way for sure to get some sleep is to start reading those.

Thanks, Coho. I can see that I'll need to become very successful with my treatment before I try to learn more about them.

SelfSeeker · Post by **SelfSeeker** » Fri Apr 20, 2007 1:53 pm

Thank you cohodependent.

I can't find the link now to show. I was reading something that regular sleep apneas, arouse something different then the Coritcal arousals that are seen mild hypoapneas. Is this true?

I found this intresting article about swaddling an infant. I did not realize there are different types of arousals that can disturbe your sleep.

http://www.ncbi.nlm.nih.gov/entrez/quer ... t=Abstract

rested gal · Post by **rested gal** » Fri Apr 20, 2007 4:38 pm

SelfSeeker, here are some more links you might find interesting. As you probably know, "sleepydave" on that board is the same person as "StillAnotherGuest" on this board:

http://www.apneasupport.org/viewtopic.php?p=27820

sleepydave writes:
"An arousal is simply a 3 to 15 second break in sleep continuity, and an awakening is 15 seconds or more. It's usually to an alpha pattern. You may be aware of awakenings (not to be confused with really being "awake") but you won't be aware of arousals.

A hypopnea needs either an arousal and/or a desaturation to be scored as such. In adults, virtually all respiratory events will be terminated by an arousal (the rule kind forces that issue)."

________________________________________

"Stage changes occur normally (not caused by arousal) about 7 times per hour, 40-50 times per night in a "normal" night's sleep, perhaps a few more in the first 90 minute sleep cycle, let's say 11 and maybe a few more after that due to "lab effect". I've seen the number 70-75 stage changes as "normal" during a first-night sleep study.

An arousal will often cause a stage change, but that's not a requirement, and there's plenty of cases where that won't happen, so you can have a bunch of arousals not reflected in the stage changes.
sleepydave"

_________________________________________

Interesting discussion about "arousals":

http://apneasupport.org/about1644.html
Nov 12, 2005 subject: why so many spontaneous arousals?

SelfSeeker · Post by **SelfSeeker** » Fri Apr 20, 2007 7:36 pm

Thank you Rested Gal.

I will read everything.

No I do not think I made the connection.