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Abstract Introduction Aging is associated with disruptions in non-rapid eye movement (NREM) sleep expression, but the mechanisms driving this effect remain unclear. Cerebral small vessel disease (CSVD) burden increases with age and is associated with clinical sleep disturbance, but little is known about its relationship with local expression of oscillatory activity during NREM sleep. Here, we explore associations between CSVD burden and local electroencephalography (EEG) measures during NREM sleep in older adults. Methods Fifteen cognitively intact older adults (mean age 71.8±6.3 years, 10 female, Apnea Hypopnea Index (AHI)=7.82±7.95) completed T2-weighted fluid-attenuated inversion recovery magnetic resonance imaging on a 3T scanner to quantify total and lobar white matter hyperintensity (WMH) volumes using a validated semi-automated toolbox and an in-lab overnight polysomnography with 128-channel EEG, separated by 1.95±1.02 years. EEG was preprocessed and multi-tapered to derive absolute spectral power. Topographical correlations between NREM multi-tapered absolute spectra bands were run with 5000-permutation threshold free cluster enhancement. Results Older age was associated with lower absolute posterior total (all p 0.016, r-0.61) and slow sigma power (all p 0.018, r-0.60) and slow wave activity (SWA) (all p 0.017, r-0.61) over centro-posterior EEG derivations. Age was also positively associated with frontal (τ=0.51, p 0.01) and parietal (τ=0.49, p 0.01) but not occipital (τ=0.33, p=0.092) or temporal (τ=0.36, p=0.064) WMH burden. Occipital WMH burden was also not associated with AHI (τ=0.038, p=0.843). Occipital WMH burden was associated with global reductions in alpha activity (all p 0.043, τ-0.78), centro-posterior reductions in SWA (all p 0.043, τ-0.63) and Delta (all p 0.009, τ-0.63), frontal reductions in total (all p 0.043, τ-0.71) and fast sigma power (all p 0.004, τ-0.57), global reductions in slow sigma power (all p 0.043, τ-0.71), and central reductions in theta activity (all p 0.042, τ-0.57). Conclusion Collectively, these findings indicate that WMH burden in older adults is associated with local disruptions in NREM sleep expression in multiple frequency bands associated with sleep-dependent cognitive functions. Future studies should examine the role of NREM sleep expression in cognitive decline associated with CSVD burden. Support (if any) Supported by NIH grants R01AG053555, R21AG079552, K01AG068353, F31AG074703, P30AG066519, and the AASM Foundation SRA-1818
Berisha et al. (Sat,) studied this question.