Does the sleeping brain 'wake up' if only just a little with ev...( roblems or hyperactivity in children. ...),Health

Typical measures for assessing sleep apnea involve counting the number of times a patient's breathing is obstructed or partly obstructed. But sleep specialists also know that people with sleep apnea often work harder than normal to breathe even in between these episodes.

"Our idea was that maybe every snore or every difficult breath is actually arousing the brain to some small extent," Chervin explains. "The problem is that much of what happens in brain waves cannot be seen by the human eye, even though highly trained sleep technicians and physicians carefully review the sleep study."

And this is where Altarum Institute engineers were able to help. Working with Chervin, they applied their long experience in signal pattern detection to develop a novel computer program. The computer measures the extent to which brain wave activity varies, on average, with the breathing cycle during sleep.

To test the new algorithm, the researchers used sleep studies that had been recorded from children scheduled to have tonsillectomy surgery to correct sleep apnea. The first paper details results from one child, and shows for the first time that on average brain wave activity as reflected in the electroencephalogram (EEG) did change with the child's breathing cycle, even when no pauses in breathing occurred. This brain wave link to the breathing cycle was less prominent when the child was retested one year after his tonsils were removed.

For the second paper, the researchers looked at results from 10 children, most suspected to have sleep apnea, to determine whether the new link between brain activity and breathing predicted daytime sleepiness or decreased attention.

"We looked at the relationship between one EEG signal and the breathing cycle, and in most of the children we found significant correlation between the amount of energy in the EEG signal and different phases in the
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Contact: Nicole Fawcett
nfawcett@umich.edu
734-764-2220
University of Michigan Health System
3-Feb-2004