title: Oxygen availability and spreading depolarizations provide complementary prognostic information in neuromonitoring of aneurysmal subarachnoid hemorrhage patients.
abstract: Multimodal neuromonitoring in neurocritical care increasingly includes electrocorticography to measure epileptic events and spreading depolarizations. Spreading depolarization causes spreading depression of activity (=isoelectricity) in electrically active tissue. If the depression is long-lasting, further spreading depolarizations occur in still isoelectric tissue where no activity can be suppressed. Such spreading depolarizations are termed isoelectric and are assumed to indicate energy compromise. However, experimental and clinical recordings suggest that long-lasting spreading depolarization-induced depression and isoelectric spreading depolarizations are often recorded outside of the actual ischemic zones, allowing the remote diagnosis of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage. Here, we analyzed simultaneous electrocorticography and tissue partial pressure of oxygen recording in 33 aneurysmal subarachnoid hemorrhage patients. Multiple regression showed that both peak total depression duration per recording day and mean baseline tissue partial pressure of oxygen were independent predictors of outcome. Moreover, tissue partial pressure of oxygen preceding spreading depolarization was similar and differences in tissue partial pressure of oxygen responses to spreading depolarization were only subtle between isoelectric spreading depolarizations and spreading depressions. This further supports that, similar to clustering of spreading depolarizations, long spreading depolarization-induced periods of isoelectricity are useful to detect energy compromise remotely, which is valuable because the exact location of future developing pathology is unknown at the time when the neurosurgeon implants recording devices.
authors.affiliation: 1 Center for Stroke Research Berlin, Charité University Medicine Berlin, Berlin, Germany.
authors.forename: Maren Kl
authors.initials: MK
authors.lastname: Winkler
authors.affiliation: 2 Department of Neurosurgery, Charité University Medicine Berlin, Berlin, Germany.
authors.forename: Nora
authors.initials: N
authors.lastname: Dengler
authors.affiliation: 2 Department of Neurosurgery, Charité University Medicine Berlin, Berlin, Germany.
authors.forename: Nils
authors.initials: N
authors.lastname: Hecht
authors.affiliation: 3 Department of Neurosurgery, University of Cincinnati, Cincinnati, OH, USA.
authors.forename: Jed A
authors.initials: JA
authors.lastname: Hartings
authors.affiliation: 1 Center for Stroke Research Berlin, Charité University Medicine Berlin, Berlin, Germany.|4 Department of Experimental Neurology, Charité University Medicine Berlin, Berlin, Germany.
authors.forename: Eun J
authors.initials: EJ
authors.lastname: Kang
authors.affiliation: 1 Center for Stroke Research Berlin, Charité University Medicine Berlin, Berlin, Germany.|4 Department of Experimental Neurology, Charité University Medicine Berlin, Berlin, Germany.|5 Department of Neurology, Charité University Medicine Berlin, Berlin, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Major
authors.affiliation: 6 Institute for Clinical Epidemiology and Applied Biometry, University of Tübingen, Tübingen, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Martus
authors.affiliation: 2 Department of Neurosurgery, Charité University Medicine Berlin, Berlin, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Vajkoczy
authors.affiliation: 2 Department of Neurosurgery, Charité University Medicine Berlin, Berlin, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Woitzik
authors.affiliation: 1 Center for Stroke Research Berlin, Charité University Medicine Berlin, Berlin, Germany.|4 Department of Experimental Neurology, Charité University Medicine Berlin, Berlin, Germany.|5 Department of Neurology, Charité University Medicine Berlin, Berlin, Germany.
authors.forename: Jens P
authors.initials: JP
authors.lastname: Dreier
mesh_terms: D001785:Blood Gas Monitoring, Transcutaneous; D002560:Cerebrovascular Circulation / Q000502:physiology; D013181:Cortical Spreading Depression / Q000502:physiology*; D003422:Critical Care / Q000379:methods*; D000069280:Electrocorticography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D064926:Neurophysiological Monitoring / Q000379:methods*; D010100:Oxygen / Q000032:analysis*; D010313:Partial Pressure; D011379:Prognosis; D011446:Prospective Studies; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology*
chemical_list: D010100:Oxygen
keywords: Spreading depolarization; oxygen availability; spreading depression; stroke; subarachnoid hemorrhage; vasospasm