title: Molecular concentration of deoxyHb in human prefrontal cortex predicts the emergence and suppression of consciousness.
abstract: This is the first study to use fNIRS to explore anaesthetic depth and awakening during surgery with general anaesthesia. A 16 channel continuous wave (CW) functional near-infrared system (fNIRS) was used to monitor PFC activity. These outcomes were compared to BIS measures. The results indicate that deoxyHb concentration in the PFC varies during the suppression and emergence of consciousness. During suppression, deoxyHb levels increase, signalling the deactivation of the PFC, while during emergence, deoxyHb concentration drops, initiating PFC activation and the recovery of consciousness. Furthermore, BIS and deoxyHb concentrations in the PFC display a high negative correlation throughout the different anaesthetic phases. These findings suggest that deoxyHb could be a reliable marker for monitoring anaesthetic depth, and that the PFC intervenes in the suppression and emergence of consciousness.
authors.affiliation: Department of Psychiatry, School of Medicine, Autonomous University of Madrid, Spain; Center for Brain Injury Rehabilitation (CRECER), Seville, Spain.
authors.forename: Umberto
authors.initials: U
authors.lastname: Leon-Dominguez
authors.forename: Meltem
authors.initials: M
authors.lastname: Izzetoglu
authors.forename: Jose
authors.initials: J
authors.lastname: Leon-Carrion
authors.forename: Ignacio
authors.initials: I
authors.lastname: Solís-Marcos
authors.forename: Francisco Jose
authors.initials: FJ
authors.lastname: Garcia-Torrado
authors.forename: Ana
authors.initials: A
authors.lastname: Forastero-Rodríguez
authors.forename: Patricia
authors.initials: P
authors.lastname: Mellado-Miras
authors.forename: Diego
authors.initials: D
authors.lastname: Villegas-Duque
authors.forename: Juan Luis
authors.initials: JL
authors.lastname: Lopez-Romero
authors.forename: Banu
authors.initials: B
authors.lastname: Onaral
authors.forename: Kurtulus
authors.initials: K
authors.lastname: Izzetoglu
mesh_terms: D000368:Aged; D000762:Anesthesia Recovery Period; D000768:Anesthesia, General; D000777:Anesthetics / Q000008:administration & dosage / Q000494:pharmacology; D001519:Behavior / Q000187:drug effects; D003243:Consciousness / Q000187:drug effects*; D056805:Consciousness Monitors; D003627:Data Interpretation, Statistical; D005260:Female; D059907:Functional Neuroimaging; D006439:Hemodynamics / Q000502:physiology; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000378:metabolism*; D019265:Spectroscopy, Near-Infrared
chemical_list: D000777:Anesthetics; D006454:Hemoglobins; C100003:deoxyhemoglobin
keywords: Anaesthesia; BIS; Consciousness; Prefrontal cortex; fNIRS