Functional connectivity changes with concentration of sevoflurane anesthesia

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<2.5×10−5) 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.

[1]  B. Biswal,et al.  Functional connectivity in the motor cortex of resting human brain using echo‐planar mri , 1995, Magnetic resonance in medicine.

[2]  J. Zacny,et al.  Subjective, Psychomotor, Cognitive, and Analgesic Effects of Subanesthetic Concentrations of Sevoflurane and Nitrous Oxide , 1997, Anesthesiology.

[3]  B. Biswal,et al.  Hypercapnia Reversibly Suppresses Low-Frequency Fluctuations in the Human Motor Cortex during Rest Using Echo–Planar MRI , 1997, Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism.

[4]  E A Disbrow,et al.  Isoflurane anesthesia blunts cerebral responses to noxious and innocuous stimuli: a fMRI study. , 1997, Life sciences.

[5]  M. Lowe,et al.  Functional Connectivity in Single and Multislice Echoplanar Imaging Using Resting-State Fluctuations , 1998, NeuroImage.

[6]  E. Puil,et al.  Mechanism of anesthesia revealed by shunting actions of isoflurane on thalamocortical neurons. , 1999, Journal of neurophysiology.

[7]  Alan C. Evans,et al.  Brain Mechanisms of Propofol-Induced Loss of Consciousness in Humans: a Positron Emission Tomographic Study , 1999, The Journal of Neuroscience.

[8]  V. Haughton,et al.  Mapping functionally related regions of brain with functional connectivity MR imaging. , 2000, AJNR. American journal of neuroradiology.

[9]  J. H. Fallon,et al.  Toward a Unified Theory of Narcosis: Brain Imaging Evidence for a Thalamocortical Switch as the Neurophysiologic Basis of Anesthetic-Induced Unconsciousness , 2000, Consciousness and Cognition.

[10]  B. Biswal,et al.  Cocaine administration decreases functional connectivity in human primary visual and motor cortex as detected by functional MRI , 2000, Magnetic resonance in medicine.

[11]  Bharat Biswal,et al.  Slow vasomotor fluctuation in fMRI of anesthetized child brain , 2000, Magnetic resonance in medicine.

[12]  Robert A. Veselis,et al.  Anesthesia—A Descent or a Jump into the Depths? , 2001, Consciousness and Cognition.

[13]  E. Kharasch,et al.  Bispectral Index Monitoring during Sedation with Sevoflurane, Midazolam, and Propofol , 2001, Anesthesiology.

[14]  Alan C. Evans,et al.  Propofol anesthesia and cerebral blood flow changes elicited by vibrotactile stimulation: a positron emission tomography study. , 2001, Journal of neurophysiology.

[15]  M. Steriade.  Impact of network activities on neuronal properties in corticothalamic systems. , 2001, Journal of neurophysiology.

[16]  E. John,et al.  A Field Theory of Consciousness , 2001, Consciousness and Cognition.

[17]  J. Lurito,et al.  Multiple sclerosis: low-frequency temporal blood oxygen level-dependent fluctuations indicate reduced functional connectivity initial results. , 2002, Radiology.

[18]  V. Feshchenko,et al.  A Neuroanatomical Construct for the Amnesic Effects of Propofol , 2002, Anesthesiology.

[19]  S. J. Peltier,et al.  T2 * Dependence of Low Frequency Functional Connectivity , 2002, NeuroImage.

[20]  Peter Århem,et al.  Mechanisms of Anesthesia: Towards Integrating Network, Cellular, and Molecular Level Modeling , 2003, Neuropsychopharmacology.

[21]  C. Koch,et al.  A framework for consciousness , 2003, Nature Neuroscience.

[22]  Nathan S White,et al.  Impaired thalamocortical connectivity in humans during general-anesthetic-induced unconsciousness , 2003, NeuroImage.

[23]  George A Mashour,et al.  Consciousness Unbound: Toward a Paradigm of General Anesthesia , 2004, Anesthesiology.

[24]  P. Brown,et al.  Changes in functional coupling patterns during bimanual task performance , 2004, Neuroreport.