title: Midazolam sedation increases fluctuation and synchrony of the resting brain BOLD signal.
abstract: The blood oxygen level-dependent (BOLD) magnetic resonance signal of functional brain cortices is dominated by very low frequency (VLF) fluctuations in anesthetized child patients. The temporal synchrony of the BOLD signal is also higher in anesthetized children compared with awake adults. The origin of the synchronous fluctuations can be related to maturation, pathological status or the anesthesia used in the imaging. Two of the three confounding variables (maturation and pathology) were controlled in this study. The effect of midazolam (4+/-0.8 mg) sedation on the BOLD signal was assessed in 12 healthy adults (aged 24+/-1.5 years) at 1.5 T. The VLF fluctuation power and temporal synchrony of the BOLD signal increased significantly after the sedation in the auditory and visual cortices. The fast Fourier transformation power spectral baseline fit parameters of the BOLD signal were also found to change significantly after sedation. It is concluded that the VLF fluctuation and temporal synchrony of the BOLD signal become increased after sedation in functional brain regions.
authors.affiliation: Department of Diagnostic Radiology, Oula University Hospital, P.O. Box 50, OYS 90029, Finland. vkivinie@mail.student.oulu.fi
authors.forename: Vesa J
authors.initials: VJ
authors.lastname: Kiviniemi
authors.forename: Hannu
authors.initials: H
authors.lastname: Haanpää
authors.forename: Juha-Heikki
authors.initials: JH
authors.lastname: Kantola
authors.forename: Jukka
authors.initials: J
authors.lastname: Jauhiainen
authors.forename: Vilho
authors.initials: V
authors.lastname: Vainionpää
authors.forename: Seppo
authors.initials: S
authors.lastname: Alahuhta
authors.forename: Osmo
authors.initials: O
authors.lastname: Tervonen
mesh_terms: D000328:Adult; D016477:Artifacts; D001303:Auditory Cortex / Q000033:anatomy & histology*; D016292:Procedural Sedation / Q000379:methods*; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008874:Midazolam / Q000008:administration & dosage*; D010100:Oxygen / Q000097:blood; D014793:Visual Cortex / Q000033:anatomy & histology*
chemical_list: D006993:Hypnotics and Sedatives; D008874:Midazolam; D010100:Oxygen