title: Disrupting posterior cingulate connectivity disconnects consciousness from the external environment.
abstract: Neurophysiological and neuroimaging studies including both patients with disorders of consciousness and healthy subjects with modified states of consciousness suggest a crucial role of the medial posteroparietal cortex in conscious information processing. However no direct neuropsychological evidence supports this hypothesis and studies including patients with restricted lesions of this brain region are almost non-existent. Using direct intraoperative electrostimulations, we showed in a rare patient that disrupting the subcortical connectivity of the left posterior cingulate cortex (PCC) reliably induced a breakdown in conscious experience. This acute phenomenon was mainly characterized by a transient behavioral unresponsiveness with loss of external connectedness. In all cases, when he regained consciousness, the patient described himself as in dream, outside the operating room. This finding suggests that functional integrity of the PPC connectivity is necessary for maintaining consciousness of external environment.
authors: Department of Neurosurgery, Montpellier University Medical Center, Montpellier 34295, France; Institute for Neuroscience of Montpellier, INSERM U-1051, Hôpital Saint Eloi, Montpellier 34298, France; University of Montpellier 1, Montpellier 34967, France. Electronic address: guillaume.herbet@gmail.com.
authors: Guillaume
authors: G
authors: Herbet
authors: Functional Neuroscience and Pathologies Lab, EA-4559, Université Lille Nord de France, Loos 59120, France.
authors: Gilles
authors: G
authors: Lafargue
authors: Institute for Neuroscience of Montpellier, INSERM U-1051, Hôpital Saint Eloi, Montpellier 34298, France; Department of Neuroradiology, Montpellier University Medical Center, Montpellier 34295, France.
authors: Nicolas Menjot
authors: NM
authors: de Champfleur
authors: Institute for Neuroscience of Montpellier, INSERM U-1051, Hôpital Saint Eloi, Montpellier 34298, France; Department of Neurology, Montpellier University Medical Center, Montpellier 34295, France.
authors: Sylvie
authors: S
authors: Moritz-Gasser
authors: Institute for Neuroscience of Montpellier, INSERM U-1051, Hôpital Saint Eloi, Montpellier 34298, France; Department of Neuroradiology, Montpellier University Medical Center, Montpellier 34295, France.
authors: Emmanuelle
authors: E
authors: le Bars
authors: Cognition, Action and Sensorimotor Plasticity Lab, INSERM U-1093, UFR STAPS, Dijon 21078, France; University of Montpellier 2, LIRMM, DEMAR Team, CNRS, INRIA, Montpellier 34095, France.
authors: François
authors: F
authors: Bonnetblanc
authors: Department of Neurosurgery, Montpellier University Medical Center, Montpellier 34295, France; Institute for Neuroscience of Montpellier, INSERM U-1051, Hôpital Saint Eloi, Montpellier 34298, France.
authors: Hugues
authors: H
authors: Duffau
mesh_terms: D001931:Brain Mapping; D003244:Consciousness Disorders / Q000209:etiology / Q000473:pathology*; D004832:Epilepsy, Absence / Q000150:complications / Q000473:pathology / Q000601:surgery; D005910:Glioma / Q000150:complications / Q000473:pathology / Q000601:surgery; D006179:Gyrus Cinguli / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000503:physiopathology*; D009483:Neuropsychological Tests; D009493:Neurosurgery / Q000379:methods; D010775:Photic Stimulation
keywords: Consciousness disorders; Electrical stimulations; External awareness; Posterior cingulate; Precuneus