title: Electrical stimulation of a small brain area reversibly disrupts consciousness.
abstract: The neural mechanisms that underlie consciousness are not fully understood. We describe a region in the human brain where electrical stimulation reproducibly disrupted consciousness. A 54-year-old woman with intractable epilepsy underwent depth electrode implantation and electrical stimulation mapping. The electrode whose stimulation disrupted consciousness was between the left claustrum and anterior-dorsal insula. Stimulation of electrodes within 5mm did not affect consciousness. We studied the interdependencies among depth recording signals as a function of time by nonlinear regression analysis (h(2) coefficient) during stimulations that altered consciousness and stimulations of the same electrode at lower current intensities that were asymptomatic. Stimulation of the claustral electrode reproducibly resulted in a complete arrest of volitional behavior, unresponsiveness, and amnesia without negative motor symptoms or mere aphasia. The disruption of consciousness did not outlast the stimulation and occurred without any epileptiform discharges. We found a significant increase in correlation for interactions affecting medial parietal and posterior frontal channels during stimulations that disrupted consciousness compared with those that did not. Our findings suggest that the left claustrum/anterior insula is an important part of a network that subserves consciousness and that disruption of consciousness is related to increased EEG signal synchrony within frontal-parietal networks.
authors: Department of Neurology, George Washington University, 2150 Pennsylvania Avenue, Suite 9-405, Washington, DC 20037, USA. Electronic address: mkoubeissi@mfa.gwu.edu.
authors: Mohamad Z
authors: MZ
authors: Koubeissi
authors: INSERM, U751, Laboratoire de Neurophysiologie et Neuropsychologie, Marseille F-13005, France; Aix Marseille University, Faculté de Médecine, Marseille F-13005, France; CHU Timone, Service de Neurophysiologie Clinique, Assistance Publique des Hôpitaux de Marseille, Marseille F-13005, France.
authors: Fabrice
authors: F
authors: Bartolomei
authors: Epilepsy center, Neurological Institute, University hospitals, Case Western Reserve University. 11100 Euclid Ave. Cleveland, OH 44106, USA.
authors: Abdelrahman
authors: A
authors: Beltagy
authors: Department of Neurology, University Hospital and Medical School of Geneva. 4 rue Gabrielle-Perret-Gentil. 1211 Geneva 14, Switzerland.
authors: Fabienne
authors: F
authors: Picard
mesh_terms: D001931:Brain Mapping / Q000379:methods; D002540:Cerebral Cortex / Q000502:physiology* / Q000503:physiopathology; D003243:Consciousness; D046690:Deep Brain Stimulation / Q000379:methods*; D004599:Electric Stimulation Therapy; D004566:Electrodes; D004567:Electrodes, Implanted; D004827:Epilepsy / Q000503:physiopathology* / Q000628:therapy; D005260:Female; D006801:Humans; D008875:Middle Aged; D012677:Sensation; D013238:Stereotaxic Techniques
keywords: Claustrum; Consciousness; Electrical stimulation; Epilepsy; Insula