Method for detection of respiratory cycle-related EEG changes in sleep-disordered breathing.
OBJECTIVE
In sleep-disordered breathing (SDB), visual or computerized analysis of electroencephalogram (EEG) signals shows that disruption of sleep architecture occurs in association with apneas and hypopneas. We developed a new signal analysis algorithm to investigate whether brief changes in cortical activity can also occur with individual respiratory cycles.


METHODS
Retrospective.


METHODS
University sleep laboratory.


METHODS
A 6 year-old boy with SDB.


METHODS
Polysomnography before and after clinically indicated adenotonsillectomy.


METHODS
For the first 3 hours of nocturnal sleep, a computer algorithm divided nonapneic respiratory cycles into 4 segments and, for each, computed mean EEG powers within delta, theta, alpha, sigma, and beta frequency ranges. Differences between segment-specific EEG powers were tested by analysis of variance. Respiratory cycle-related EEG changes (RCREC) were quantified.


RESULTS
Preoperative RCREC were statistically significant in delta (P < .0001), theta (P < .001), and sigma (P < .0001) but not alpha or beta (P > .01) ranges. One year after the operation, RCREC in all ranges showed statistical significance (P < .01), but delta, theta, and sigma RCREC had decreased, whereas alpha and beta RCREC had increased. Preoperative RCREC also were demonstrated in a sequence of 101 breaths that contained no apneas or hypopneas (P < .0001). Several tested variations in the signal-analysis approach, including analysis of the entire nocturnal polysomnogram, did not meaningfully improve the significance of RCREC.


CONCLUSIONS
In this child with SDB, the EEG varied with respiratory cycles to a quantifiable extent that changed after adenotonsillectomy. We speculate that RCREC may reflect brief but extremely numerous microarousals.
Chervin
Ronald D
RD
Sleep Disorders Center and Department of Neurology, University of Michigan, Ann Arbor, Mich, USA. chervin@umich.edu
Burns
Joseph W
JW
Subotic
Nikolas S
NS
Roussi
Christopher
C
Thelen
Brian
B
Ruzicka
Deborah L
DL
D000233:Adenoidectomy; D001049:Apnea / Q000150:complications; D002648:Child; D004569:Electroencephalography; D006801:Humans; D008297:Male; D010507:Periodicity; D017286:Polysomnography; D011184:Postoperative Period; D011300:Preoperative Care; D012119:Respiration; D012189:Retrospective Studies; D012891:Sleep Apnea Syndromes / Q000175:diagnosis* / Q000209:etiology; D014068:Tonsillectomy