Distinct and Dissociable EEG Networks Are Associated With Recovery of Cognitive Function Following Anesthesia-Induced Unconsciousness

Frontiers in Human Neuroscience, Vol. 15 (2021)

Keywords
Authors
  • Alexander Rokos
  • Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
  • Bratislav Mišić
  • Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
  • Kathleen Berkun
  • Cognitive Science, McGill University, Montreal, QC, Canada
  • Catherine Duclos
  • School of Physical and Occupational Therapy, McGill University, Montreal, QC, Canada
  • Vijay Tarnal
  • Department of Anesthesiology, Center of Consciousness Science, University of Michigan Medical School, Ann Arbor, MI, United States
  • Ellen Janke
  • Department of Anesthesiology, Center of Consciousness Science, University of Michigan Medical School, Ann Arbor, MI, United States
  • Paul Picton
  • Department of Anesthesiology, Center of Consciousness Science, University of Michigan Medical School, Ann Arbor, MI, United States
  • Goodarz Golmirzaie
  • Department of Anesthesiology, Center of Consciousness Science, University of Michigan Medical School, Ann Arbor, MI, United States
  • Mathias Basner
  • Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
  • Michael S. Avidan
  • Department of Anesthesiology, Washington University School of Medicine, St. Louis, WA, United States
  • Max B. Kelz
  • Deparment of Anesthesiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
  • George A. Mashour
  • Department of Anesthesiology, Center of Consciousness Science, University of Michigan Medical School, Ann Arbor, MI, United States
  • Stefanie Blain-Moraes
  • School of Physical and Occupational Therapy, McGill University, Montreal, QC, Canada

Abstract

The temporal trajectories and neural mechanisms of recovery of cognitive function after a major perturbation of consciousness is of both clinical and neuroscientific interest. The purpose of the present study was to investigate network-level changes in functional brain connectivity associated with the recovery and return of six cognitive functions after general anesthesia. High-density electroencephalograms (EEG) were recorded from healthy volunteers undergoing a clinically relevant anesthesia protocol (propofol induction and isoflurane maintenance), and age-matched healthy controls. A battery of cognitive tests (motor praxis, visual object learning test, fractal-2-back, abstract matching, psychomotor vigilance test, digital symbol substitution test) was administered at baseline, upon recovery of consciousness (ROC), and at half-hour intervals up to 3 h following ROC. EEG networks were derived using the strength of functional connectivity measured through the weighted phase lag index (wPLI). A partial least squares (PLS) analysis was conducted to assess changes in these networks: (1) between anesthesia and control groups; (2) during the 3-h recovery from anesthesia; and (3) for each cognitive test during recovery from anesthesia. Networks were maximally perturbed upon ROC but returned to baseline 30–60 min following ROC, despite deficits in cognitive performance that persisted up to 3 h following ROC. Additionally, during recovery from anesthesia, cognitive tests conducted at the same time-point activated distinct and dissociable functional connectivity networks across all frequency bands. The results highlight that the return of cognitive function after anesthetic-induced unconsciousness is task-specific, with unique behavioral and brain network trajectories of recovery.

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