孤立性 REM 睡眠行为障碍中的周期性振荡减慢与非周期性宽带偏移与表型转化相关

Study objectives Conventional EEG slowing in isolated REM sleep behavior disorder (iRBD) may be confounded by disease-related shifts in the aperiodic background. We separated periodic and aperiodic EEG components to clarify oscillatory slowing and examine associations with phenoconversion and clinical measures. Methods Resting-state EEG was recorded from 134 patients with iRBD and 51 healthy controls (HC). During follow-up, 26 converted to Parkinson's disease or dementia with Lewy bodies. Power spectra (2-50 Hz) were parameterized using FOOOF to extract aperiodic offset, low-frequency slope (2-30 Hz), and high-frequency slope (30-50 Hz), and to derive the periodic spectrum after aperiodic removal. Group differences, spatial distributions, survival associations, and clinical correlations were analyzed. Results After removing the aperiodic component, iRBD showed higher band-averaged periodic 4-8 Hz power than HC (p=0.042), consistent with slowing of the dominant alpha rhythm. In aperiodic analyses, iRBD exhibited higher offset than HC (p Conclusions Separating periodic from aperiodic EEG activity revealed distinct RBD- and phenoconversion-related oscillatory slowing and aperiodic alterations. These findings suggest that aperiodic components may provide additional prognostic and clinical information beyond conventional band power.