title: EEG beta power and heart rate variability describe the association between cortical and autonomic arousals across sleep.
abstract: Cortical and autonomic arousals have been found to be closely associated. As arousal events are not evenly dispersed across sleep, we hypothesized the relationship between high frequency electroencephalogram (EEG) power and autonomic arousal indices differ between non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. One night of polysomnographic recording was performed on a group of 18 subjects using a portable recorder. The EEG was collected from C3/Fz. Sleep stages and cortical arousals were visually scored. Cardiac autonomic modulation was assessed from heart rate variability, where the high frequency power (HF) indicates parasympathetic modulation, and the low frequency to high frequency power ratio (LF/HF) represents sympathetic modulation. During NREM sleep, EEG beta power was significantly correlated with LF/HF (r=0.40 ± 0.06), and the relationships were more positive than during REM sleep (LF/HF: r=0.20 ± 0.08; EOG power: r=-0.13 ± 0.05). The relationship of beta power with LF/HF was associated with the incidence of cortical arousal, particularly during NREM sleep. With respect to alpha power, it was only marginally related to HF or LF/HF. In addition, the coefficients of determination were lower for alpha power than for beta power in terms of the relationships to HF, LF/HF and EOG power. This study shows a higher relationship between cortical and autonomic activation during NREM sleep, and the association is better described by beta power. This finding suggests NREM sleep may be of greater therapeutic potential in view of reducing cardiovascular disease associated with sleep fragmentation, and beta power may provide a better index to evaluate the effect.
authors.affiliation: Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Sleep Research Center, National Yang-Ming University, Taipei, Taiwan; Department of Education and Research, Taipei City Hospital, Taipei, Taiwan; Institute of Translational and Interdisciplinary Medicine, National Central University, Taoyuan, Taiwan.
authors.forename: Terry B J
authors.initials: TB
authors.lastname: Kuo
authors.affiliation: Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Chun-Yu
authors.initials: CY
authors.lastname: Chen
authors.affiliation: Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Ya-Chuan
authors.initials: YC
authors.lastname: Hsu
authors.affiliation: Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Sleep Research Center, National Yang-Ming University, Taipei, Taiwan; Department of Education and Research, Taipei City Hospital, Taipei, Taiwan. Electronic address: cchyang@ym.edu.tw.
authors.forename: Cheryl C H
authors.initials: CC
authors.lastname: Yang
mesh_terms: D000704:Analysis of Variance; D001143:Arousal / Q000502:physiology*; D001341:Autonomic Nervous System / Q000502:physiology*; D001611:Beta Rhythm / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D004562:Electrocardiography; D004569:Electroencephalography; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D017286:Polysomnography; D012890:Sleep / Q000502:physiology*; D055815:Young Adult
keywords: Autonomic arousal; Beta power; Cortical arousal; Heart rate variability; NREM sleep; REM sleep