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.
Sleep Disorders Center and Department of Neurology, University of Michigan, Ann Arbor, Mich, USA. chervin@umich.edu
Ronald D
RD
Chervin
Joseph W
JW
Burns
Nikolas S
NS
Subotic
Christopher
C
Roussi
Brian
B
Thelen
Deborah L
DL
Ruzicka
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