title: Increased EEG sigma and beta power during NREM sleep in primary insomnia.
abstract: The hyperarousal model of primary insomnia suggests that a deficit of attenuating arousal during sleep might cause the experience of non-restorative sleep. In the current study, we examined EEG spectral power values for standard frequency bands as indices of cortical arousal and sleep protecting mechanisms during sleep in 25 patients with primary insomnia and 29 good sleeper controls. Patients with primary insomnia demonstrated significantly elevated spectral power values in the EEG beta and sigma frequency band during NREM stage 2 sleep. No differences were observed in other frequency bands or during REM sleep. Based on prior studies suggesting that EEG beta activity represents a marker of cortical arousal and EEG sleep spindle (sigma) activity is an index of sleep protective mechanisms, our findings may provide further evidence for the concept that a simultaneous activation of wake-promoting and sleep-protecting neural activity patterns contributes to the experience of non-restorative sleep in primary insomnia.
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Freiburg Medical Center, Germany. Kai.Spiegelhalder@uniklinik-freiburg.de
authors.forename: Kai
authors.initials: K
authors.lastname: Spiegelhalder
authors.forename: Wolfram
authors.initials: W
authors.lastname: Regen
authors.forename: Bernd
authors.initials: B
authors.lastname: Feige
authors.forename: Johannes
authors.initials: J
authors.lastname: Holz
authors.forename: Hannah
authors.initials: H
authors.lastname: Piosczyk
authors.forename: Chiara
authors.initials: C
authors.lastname: Baglioni
authors.forename: Dieter
authors.initials: D
authors.lastname: Riemann
authors.forename: Christoph
authors.initials: C
authors.lastname: Nissen
mesh_terms: D000328:Adult; D001143:Arousal / Q000502:physiology*; D002540:Cerebral Cortex / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012890:Sleep / Q000502:physiology*; D007319:Sleep Initiation and Maintenance Disorders / Q000503:physiopathology*; D012894:Sleep Stages / Q000502:physiology