title: Changes in brain activation induced by visual stimulus during and after propofol conscious sedation: a functional MRI study.
abstract: Conscious sedation with propofol sometimes causes amnesia while keeping the patient awake. However, it remains unknown how propofol compromises the memory function. Therefore, we investigated the changes in brain activation induced by visual stimulation during and after conscious sedation with propofol using serial functional MRI. Healthy volunteers received a target-controlled infusion of propofol, and underwent functional MRI scans with a block-design paradigm of visual stimulus before, during, and after conscious sedation. Random-effect model analyses were performed using Statistical Parametric Mapping software. Among the areas showing significant activation in response to the visual stimulus, the visual cortex and fusiform gyrus were significantly suppressed in the sedation session and tended to recover in the early-recovery session of ∼20 min (P<0.001, uncorrected). In contrast, decreased activations of the hippocampus, thalamus, inferior frontal cortex (ventrolateral prefrontal cortex), and cerebellum were maintained during the sedation and early-recovery sessions (P<0.001, uncorrected) and were recovered in the late-recovery session of ∼40 min. Temporal changes in the signals from these areas varied in a manner comparable to that described by the random-effect model analysis (P<0.05, corrected). In conclusion, conscious sedation with propofol may cause prolonged suppression of the activation of memory-related structures, such as the hippocampus, during the early-recovery period, which may lead to transient amnesia.
authors.affiliation: aDepartment of Reconstructive Oral and Maxillofacial Surgery, School of Dentistry, Division of Dental Anesthesiology bDivision of Ultrahigh Field MRI, Institute for Biomedical Sciences cDepartment of Conservative Dentistry, School of Dentistry, Division of Operative Dentistry and Endodontics dDepartment of Prosthodontics and Oral Implantology, School of Dentistry, Division of Dysphagia Oral Rehabilitation, Iwate Medical University, Morioka, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Shinohe
authors.forename: Satomi
authors.initials: S
authors.lastname: Higuchi
authors.forename: Makoto
authors.initials: M
authors.lastname: Sasaki
authors.forename: Masahito
authors.initials: M
authors.lastname: Sato
authors.forename: Mamoru
authors.initials: M
authors.lastname: Noda
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Joh
authors.forename: Kenichi
authors.initials: K
authors.lastname: Satoh
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging* / Q000187:drug effects*; D016292:Procedural Sedation; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D015742:Propofol / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D006993:Hypnotics and Sedatives; D010100:Oxygen; D015742:Propofol