Article

Peltier, S. J. et al. Functional connectivity changes with concentration of sevoflurane anaesthesia. Neuroreport 16, 285-288

Department of Psychology, Emory University, Atlanta, Georgia, United States
Neuroreport (Impact Factor: 1.52). 03/2005; 16(3):285-8. DOI: 10.1097/00001756-200502280-00017
Source: PubMed

ABSTRACT

Low-frequency oscillations (<0.08 Hz) have been detected in functional magnetic resonance imaging studies, and appear to be synchronized between functionally related areas. The effect of anesthetic agents on cortical activity is not completely characterized. This study assessed the effect of anesthesia on the temporal relations in activity in the motor cortices. Resting-state magnetic resonance data were acquired on six volunteers under different anesthetic states (using 0.0%, 2.0% and 1.0% stable end-tidal sevoflurane). Across all volunteers, the number of significant voxels (p<2.5 x 10) in the functional connectivity maps was reduced by 78% for light anesthesia and by 98% for deep anesthesia, compared with the awake state. Additionally, significant correlations in the connectivity maps were bilateral in the awake state but unilateral in the light anesthesia state.

Download full-text

Full-text

Available from: Stephan B Hamann
  • Source
    • "reduction in functional connectivity is observed in humans as well under the analogous anesthetic sevoflurane ( Peltier et al . , 2005 ) . In a dose dependent manner , between 78% ( light anesthesia ) and 98% ( heavy anesthesia ) of the motor cortex voxels that were significantly correlated under the awake state become disconnected ."

    Full-text · Dataset · Sep 2015
  • Source
    • "reduction in functional connectivity is observed in humans as well under the analogous anesthetic sevoflurane ( Peltier et al . , 2005 ) . In a dose dependent manner , between 78% ( light anesthesia ) and 98% ( heavy anesthesia ) of the motor cortex voxels that were significantly correlated under the awake state become disconnected ."

    Full-text · Dataset · Sep 2015
  • Source
    • "Termed resting state functional connectivity (rs-fcMRI), this technique has proven valuable for mapping functional networks including the motor system (Biswal et al., 1995; Fox and Raichle, 2007). Spontaneous activity mapping can be performed when subjects are asleep (Fukunaga et al., 2006; Horovitz et al., 2006) and sedated (Greicius et al., 2008; Kiviniemi et al., 2003; Peltier et al., 2005; Vincent et al., 2007), expanding applicable patient populations. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Noninvasive localization of brain function is used to understand and treat neurological disease, exemplified by pre-operative fMRI mapping prior to neurosurgical intervention. The principal approach for generating these maps relies on brain responses evoked by a task and, despite known limitations, has dominated clinical practice for over 20years. Recently, pre-operative fMRI mapping based on correlations in spontaneous brain activity has been demonstrated, however this approach has its own limitations and has not seen widespread clinical use. Here we show that spontaneous and task-based mapping can be performed together using the same pre-operative fMRI data, provide complimentary information relevant for functional localization, and can be combined to improve identification of eloquent motor cortex. Accuracy, sensitivity, and specificity of our approach are quantified through comparison with electrical cortical stimulation mapping in eight patients with intractable epilepsy. Broad applicability and reproducibility of our approach are demonstrated through prospective replication in an independent dataset of six patients from a different center. In both cohorts and every individual patient, we see a significant improvement in signal to noise and mapping accuracy independent of threshold, quantified using receiver operating characteristic curves. Collectively, our results suggest that modifying the processing of fMRI data to incorporate both task-based and spontaneous activity significantly improves functional localization in pre-operative patients. Because this method requires no additional scan time or modification to conventional pre-operative data acquisition protocols it could have widespread utility.
    Full-text · Article · Sep 2015 · NeuroImage
Show more