Improvements in cognitive function and quantitative sleep electroencephalogram in obstructive sleep apnea after six months of continuous positive airway pressure treatment

Angela L D'Rozario; Camilla M Hoyos; Keith K H Wong; Gunnar Unger; Jong Won Kim; Andrew Vakulin; Chien-Hui Kao; Sharon L Naismith; Delwyn J Bartlett; Ronald R Grunstein

doi:10.1093/sleep/zsac013

Improvements in cognitive function and quantitative sleep electroencephalogram in obstructive sleep apnea after six months of continuous positive airway pressure treatment

Sleep. 2022 Jun 13;45(6):zsac013. doi: 10.1093/sleep/zsac013.

Authors

Angela L D'Rozario^{1

2

3

4}, Camilla M Hoyos^{1

2

3

4}, Keith K H Wong^{2

5

6}, Gunnar Unger², Jong Won Kim^{2

7}, Andrew Vakulin⁸, Chien-Hui Kao³, Sharon L Naismith^{1

3

4}, Delwyn J Bartlett^{2

5}, Ronald R Grunstein^{2

5

6}

Affiliations

¹ Faculty of Science, School of Psychology, University of Sydney, Sydney, New South Wales, Australia.
² Sleep and Circadian Research Group, Woolcock Institute of Medical Research, University of Sydney, Glebe, New South Wales, Australia.
³ Healthy Brain Ageing Program, Brain and Mind Centre, University of Sydney, Sydney, New South Wales, Australia.
⁴ Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia.
⁵ Sydney Medical School, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia.
⁶ Department of Respiratory and Sleep Medicine, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia.
⁷ Department of Healthcare IT, Inje University, Inje-ro 197, Kimhae, Kyunsangnam-do, 50834,South Korea.
⁸ Adelaide Institute for Sleep Health/FHMRI Sleep Health, College of Medicine and Public Health, Flinders University, Bedford Park, South Australia, Australia.

Abstract

Study objectives: Untreated obstructive sleep apnea (OSA) is associated with cognitive deficits and altered brain electrophysiology. We evaluated the effect of continuous positive airway pressure (CPAP) treatment on quantitative sleep electroencephalogram (EEG) measures and cognitive function.

Methods: We studied 167 patients with OSA (age 50 ± 13, AHI 35.0 ± 26.8) before and after 6 months of CPAP. Cognitive tests assessed working memory, sustained attention, visuospatial scanning, and executive function. All participants underwent overnight polysomnography at baseline and after CPAP. Power spectral analysis was performed on EEG data (C3-M2) in a sub-set of 90 participants. Relative delta EEG power and sigma power in NREM and EEG slowing in REM were calculated. Spindle densities (events/min) in N2 were also derived using automated spindle event detection. All outcomes were analysed as change from baseline.

Results: Cognitive function across all cognitive domains improved after six months of CPAP. In our sub-set, increased relative delta power (p < .0001) and reduced sigma power (p = .001) during NREM were observed after the 6-month treatment period. Overall, fast and slow sleep spindle densities during N2 were increased after treatment.

Conclusions: Cognitive performance was improved and sleep EEG features were enhanced when assessing the effects of CPAP. These findings suggest the reversibility of cognitive deficits and altered brain electrophysiology observed in untreated OSA following six months of treatment.

Keywords: neurophysiology; performance; positive airway pressure; power spectral analysis; sleep-disordered breathing.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Cognition
Continuous Positive Airway Pressure*
Electroencephalography
Humans
Middle Aged
Sleep / physiology
Sleep Apnea, Obstructive*