title: Evidence of Resting-state Activity in Propofol-anesthetized Patients with Intracranial Tumors.
abstract: OBJECTIVE
  Resting-state (RS) networks, revealed by functional magnetic resonance imaging (fMRI) studies in healthy volunteers, have never been evaluated in anesthetized patients with brain tumors. Our purpose was to examine the presence of residual brain activity on the auditory network during propofol-induced loss of consciousness in patients with brain tumors.
  
  
  METHODS
  Twenty subjects with intracranial masses were prospectively studied by means of intraoperative RS-fMRI acquisitions before any craniectomy. After performing single-subject independent component analysis, spatial maps and time courses were assigned to an auditory RS network template from the literature and compared via spatial regression coefficients.
  
  
  RESULTS
  All fMRI data were of sufficient quality for further postprocessing. In all but two patients, the RS functional activity of the auditory network could be successfully mapped. In almost all patients, contralateral activation of the auditory network was present. No significant difference was found between the mean distance of the RS activity clusters and the lesion periphery for tumors located in the temporal gyri vs. those in other brain regions. The spatial deviation between the activated cluster in our experiment and the template was significantly (P = 0.04) higher in patients with tumors located in the temporal gyri than in patients with tumors located in other regions.
  
  
  CONCLUSIONS
  Propofol-induced anesthesia in patients with intracranial lesions does not alter the blood-oxygenation level-depended signal, and independent component analysis of intraoperative RS-fMRI may allow assessment of the auditory network in a clinical setting.
authors.affiliation: Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, University College London Hospitals, Box 65, Queen Square, London WC1N 3BG, United Kingdom. Electronic address: sotirios.bisdas@uclh.nhs.uk.
authors.forename: Sotirios
authors.initials: S
authors.lastname: Bisdas
authors.affiliation: Department of Neuroradiology, University of Tübingen, Germany; Department of Biomedical Magnetic Resonance, University of Tübingen, Germany.
authors.forename: Edyta
authors.initials: E
authors.lastname: Charyasz-Leks
authors.affiliation: Department of Neurosurgery, Eberhard Karls University, Tübingen, Germany.
authors.forename: Constantin
authors.initials: C
authors.lastname: Roder
authors.affiliation: Department of Neurosurgery, Eberhard Karls University, Tübingen, Germany.
authors.forename: Marcos Soares
authors.initials: MS
authors.lastname: Tatagiba
authors.affiliation: Department of Neuroradiology, University of Tübingen, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Ernemann
authors.affiliation: Department of Neuroradiology, University of Tübingen, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Klose
mesh_terms: D000236:Adenoma / Q000503:physiopathology; D000328:Adult; D000368:Aged; D000771:Anesthesia, Intravenous / Q000379:methods*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D001303:Auditory Cortex / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods*; D001932:Brain Neoplasms / Q000503:physiopathology*; D015331:Cohort Studies; D005260:Female; D005910:Glioma / Q000503:physiopathology; D006179:Gyrus Cinguli / Q000503:physiopathology; D006801:Humans; D007430:Intraoperative Care; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000503:physiopathology; D015742:Propofol / Q000008:administration & dosage*; D011446:Prospective Studies; D015173:Supratentorial Neoplasms / Q000503:physiopathology; D013702:Temporal Lobe / Q000503:physiopathology; D055815:Young Adult
chemical_list: D018686:Anesthetics, Intravenous; D015742:Propofol
keywords: Functional MRI (fMRI); auditory cortex; brain tumor; independent component analysis; resting state