Electrical Activity During Slow-Wave Sleep and the Relationship With Enlarged Perivascular Spaces in Arteriosclerotic Cerebral Small Vessel Disease.

Purpose: We sought to analyze EEG spectral power during slow-wave sleep among patients with arteriosclerotic cerebral small vessel disease (CSVD) compared with community-dwelling individuals. We also sought to determine the relationship between EEG activity and the severity of enlarged perivascular spaces (EPVSs).

Methods: Consecutive subjects with arteriosclerotic CSVD ( n = 36) and community-dwelling individuals ( n = 26) between 50 and 80 years of age were included. Nocturnal polysomnography was performed, and EEG spectral analysis was conducted during slow-wave sleep using the F4/M1 and C4/M1 channel. Regionalized EPVSs in the basal ganglia and centrum semiovale were assessed on a validated 4-point visual rating scale (0 = none, 1 = 1-10, 2 = 11-20, 3 = 21-40, and 4 = >40) using MRI.

Results: CSVD group showed lower delta:beta ratios in the frontal ( P = 0.017) and central ( P = 0.038) regions after adjusting for age, sex, mini-mental state examination score, and arousal index. The significance still remained in the frontal region when including age, sex, mini-mental state examination, and apnea-hypopnea index as covariates ( P = 0.037). Among patients with arteriosclerotic CSVD, decreased delta power ( P = 0.031) and theta power ( P = 0.034) in the frontal region were associated with a higher degree of EPVSs in the centrum semiovale rather than in the basal ganglia. Delta power in the central region showed an extremely weak association with EPVSs in the centrum semiovale ( P = 0.047).

Conclusions: Among patients with arteriosclerotic CSVD, the intrusion of high-frequency EEG activity into slow-wave sleep was identified, and slow-wave activity during slow-wave sleep might be negatively associated with the severity of EPVSs in the centrum semiovale. Further studies are required to corroborate the conclusions.