title: Infraslow EEG activity modulates cortical excitability in postanoxic encephalopathy.
abstract: Infraslow activity represents an important component of physiological and pathological brain function. We study infraslow activity (<0.1 Hz) in 41 patients with postanoxic coma after cardiac arrest, including the relationship between infraslow activity and EEG power in the 3-30 Hz range, using continuous full-band scalp EEG. In all patients, infraslow activity (0.015-0.06 Hz) was present, irrespective of neurological outcome or EEG activity in the conventional frequency bands. In two patients, low-amplitude (10-30 μV) infraslow activity was present while the EEG showed no rhythmic activity above 0.5 Hz. In 13/15 patients with a good outcome and 20/26 patients with a poor one, EEG power in the 3-30 Hz frequency range was correlated with the phase of infraslow activity, quantified by the modulation index. In 9/14 patients with burst-suppression with identical bursts, bursts appeared in clusters, phase-locked to the infraslow oscillations. This is substantiated by a simulation of burst-suppression in a minimal computational model. Infraslow activity is preserved in postanoxic encephalopathy and modulates cortical excitability. The strongest modulation is observed in patients with severe postanoxic encephalopathy and burst-suppression with identical bursts.
authors.affiliation: Department of Neurology and Clinical Neurophysiology, Medisch Spectrum Twente, Enschede, the Netherlands; Clinical Neurophysiology, MIRA-Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, the Netherlands; and m.j.a.m.vanputten@utwente.nl.
authors.forename: Michel J A M
authors.initials: MJ
authors.lastname: van Putten
authors.affiliation: Department of Neurology and Clinical Neurophysiology, Medisch Spectrum Twente, Enschede, the Netherlands; Clinical Neurophysiology, MIRA-Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, the Netherlands; and.
authors.forename: Marleen C
authors.initials: MC
authors.lastname: Tjepkema-Cloostermans
authors.affiliation: Clinical Neurophysiology, MIRA-Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, the Netherlands; and Department of Neurology, Rijnstate Ziekenhuis, Arnhem, the Netherlands.
authors.forename: Jeannette
authors.initials: J
authors.lastname: Hofmeijer
mesh_terms: D000470:Alkaloids; D001927:Brain Diseases / Q000209:etiology* / Q000473:pathology* / Q000628:therapy; D058256:Brain Waves / Q000502:physiology*; D002540:Cerebral Cortex / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D006323:Heart Arrest / Q000150:complications; D006801:Humans; D007362:Intensive Care Units; D008297:Male
chemical_list: D000470:Alkaloids; C110131:Wilcox compound
keywords: EEG; burst-suppression; infraslow fluctuations; postanoxic coma