Abstract

Long-range cortico-cortical functional connectivity has long been theorized to be necessary for conscious states. In the present work, we estimate long-range cortical connectivity in a series of intracranial and scalp EEG recordings experiments. In the two first experiments intracranial-EEG (iEEG) was recorded during four distinct states within the same individuals: conscious wakefulness (CW), rapid-eye-movement sleep (REM), stable periods of slow-wave sleep (SWS) and deep propofol anaesthesia (PA). We estimated functional connectivity using the following two methods: weighted Symbolic-Mutual-Information (wSMI) and phase-locked value (PLV). Our results showed that long-range functional connectivity in the delta-theta frequency band specifically discriminated CW and REM from SWS and PA. In the third experiment, we generalized this original finding on a large cohort of brain-injured patients. FC in the delta-theta band was significantly higher in patients being in a minimally conscious state (MCS) than in those being in a vegetative state (or unresponsive wakefulness syndrome). Taken together the present results suggest that FC of cortical activity in this slow frequency band is a new and robust signature of conscious states.

Details

Title
Brain-scale cortico-cortical functional connectivity in the delta-theta band is a robust signature of conscious states: an intracranial and scalp EEG study
Author
Bourdillon Pierre 1 ; Bertrand, Hermann 2 ; Guénot Marc 3 ; Bastuji Hélène 4 ; Isnard, Jean 5 ; King Jean-Rémi 6 ; Sitt Jacobo 6 ; Naccache Lionel 7 

 Hospices Civils de Lyon, Department of Neurophysiology, Hospital for Neurology and Neurosurgery, Lyon, France (GRID:grid.413852.9) (ISNI:0000 0001 2163 3825); Université de Lyon, Faculté de médecine Claude Bernard, Lyon, France (GRID:grid.25697.3f) (ISNI:0000 0001 2172 4233); INSERM U1127, CNRS 7225, Brain and Spine Institue, Paris, France (GRID:grid.7429.8) (ISNI:0000000121866389); Sorbonne Université, Paris, France (GRID:grid.462844.8) (ISNI:0000 0001 2308 1657) 
 INSERM U1127, CNRS 7225, Brain and Spine Institue, Paris, France (GRID:grid.7429.8) (ISNI:0000000121866389); Sorbonne Université, Paris, France (GRID:grid.462844.8) (ISNI:0000 0001 2308 1657); Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique Hôpitaux de Paris, Neuro Intensive Care Unit, Paris, France (GRID:grid.411439.a) (ISNI:0000 0001 2150 9058) 
 Hospices Civils de Lyon, Department of Neurophysiology, Hospital for Neurology and Neurosurgery, Lyon, France (GRID:grid.413852.9) (ISNI:0000 0001 2163 3825); Université de Lyon, Faculté de médecine Claude Bernard, Lyon, France (GRID:grid.25697.3f) (ISNI:0000 0001 2172 4233); INSERM U1028, Neuropain Team, Centre de Recherche en Neurosciences de Lyon, Lyon, France (GRID:grid.461862.f) (ISNI:0000 0004 0614 7222) 
 INSERM U1028, Neuropain Team, Centre de Recherche en Neurosciences de Lyon, Lyon, France (GRID:grid.461862.f) (ISNI:0000 0004 0614 7222); Hospices Civils de Lyon, Functional Neurology Department and Sleep Center, Lyon, France (GRID:grid.413852.9) (ISNI:0000 0001 2163 3825) 
 Hospices Civils de Lyon, Functional Neurology Department and Sleep Center, Lyon, France (GRID:grid.413852.9) (ISNI:0000 0001 2163 3825) 
 INSERM U1127, CNRS 7225, Brain and Spine Institue, Paris, France (GRID:grid.7429.8) (ISNI:0000000121866389) 
 INSERM U1127, CNRS 7225, Brain and Spine Institue, Paris, France (GRID:grid.7429.8) (ISNI:0000000121866389); Sorbonne Université, Paris, France (GRID:grid.462844.8) (ISNI:0000 0001 2308 1657); Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique Hôpitaux de Paris, Department of Neurophysiology, Paris, France (GRID:grid.411439.a) (ISNI:0000 0001 2150 9058) 
Publication year
2020
Publication date
2020
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2435634651
Copyright
© The Author(s) 2020. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.