Improvement of EEG slowing in OSAS after CPAP treatment.
OBJECTIVE
This study was done to investigate change of electroencephalography (EEG) slowing and its relationship to daytime sleepiness and cognitive functions by continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea syndrome (OSAS).


METHODS
We enrolled thirteen male subjects with severe OSAS, and all the subjects were treated with CPAP for 3 months. Quantitative EEG (QEEG) and neuropsychological tests were performed before and after CPAP treatment.


RESULTS
After CPAP treatment, delta absolute power decreased in the frontal, central, parietal and temporal regions and the slowing ratio was reduced in the frontal region. The Epworth Sleepiness Scale (ESS) score was reduced after CPAP treatment. Reduction in the ESS score was correlated with a decrease in delta absolute power in the frontal region (r=0.559) and a decrease in slowing ratio in frontal, central, parietal, and temporal regions (frontal, r=0.650; other regions, r=0.603). Results of neuropsychological tests assessing memory and attention were improved after CPAP treatment.


CONCLUSIONS
EEG slowing was decreased across all cerebral regions in patients with severe OSAS after CPAP treatment accompanied by improvement of cognitive functions involving several brain areas. These findings suggest that CPAP can induce improvement of cerebral function in OSAS without regional specificity.
Department of Neuropsychiatry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
Sang Don
SD
Lee
Gawon
G
Ju
Jeong-Whun
JW
Kim
In-Young
IY
Yoon
D000328:Adult; D001288:Attention / Q000502:physiology; D002540:Cerebral Cortex / Q000503:physiopathology*; D045422:Continuous Positive Airway Pressure; D004569:Electroencephalography; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011788:Quality of Life; D011930:Reaction Time / Q000502:physiology; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology* / Q000523:psychology / Q000628:therapy*; D016896:Treatment Outcome