Reference : Recovery of cortical effective connectivity and recovery of consciousness in vegetati...
Scientific journals : Article
Human health sciences : Anesthesia & intensive care
Human health sciences : Neurology
http://hdl.handle.net/2268/113345
Recovery of cortical effective connectivity and recovery of consciousness in vegetative patients.
English
Rosanova, Mario [> >]
Gosseries, Olivia mailto [Université de Liège - ULg > > Centre de recherches du cyclotron >]
Casarotto, Silvia [> >]
Boly, Mélanie mailto [Coma Science Group, Centre de Recherches du Cyclotron, Université de Liège & Département de Neurologie, CHU Sart Tilman > > > >]
Casali, Adenauer G. [> >]
Bruno, Marie-Aurélie mailto [Coma Science Group, Centre de Recherches du Cyclotron, Université de Liège & Département de Neurologie, CHU Sart Tilman > > > >]
Mariotti, Maurizio [> >]
BOVEROUX, Pierre mailto [Centre Hospitalier Universitaire de Liège - CHU > > Anesthésie et réanimation >]
Tononi, Giulio [> >]
Laureys, Steven mailto [Coma Science Group, Centre de Recherches du Cyclotron, Université de Liège & Département de Neurologie, CHU Sart Tilman > > > >]
Massimini, Marcello [> >]
2012
Brain : A Journal of Neurology
Oxford University Press
135
Pt 4
1308-20
Yes (verified by ORBi)
International
0006-8950
1460-2156
Oxford
United Kingdom
[en] Adult ; Aged ; Brain Mapping ; Brain Waves/physiology ; Cerebral Cortex/physiopathology/radiography ; Consciousness/physiology ; Electroencephalography ; Female ; Humans ; Longitudinal Studies ; Male ; Middle Aged ; Neural Pathways/physiology ; Persistent Vegetative State/pathology/physiopathology ; Recovery of Function/physiology ; Spectrum Analysis ; Tomography, X-Ray Computed ; Transcranial Magnetic Stimulation
[en] Patients surviving severe brain injury may regain consciousness without recovering their ability to understand, move and communicate. Recently, electrophysiological and neuroimaging approaches, employing simple sensory stimulations or verbal commands, have proven useful in detecting higher order processing and, in some cases, in establishing some degree of communication in brain-injured subjects with severe impairment of motor function. To complement these approaches, it would be useful to develop methods to detect recovery of consciousness in ways that do not depend on the integrity of sensory pathways or on the subject's ability to comprehend or carry out instructions. As suggested by theoretical and experimental work, a key requirement for consciousness is that multiple, specialized cortical areas can engage in rapid causal interactions (effective connectivity). Here, we employ transcranial magnetic stimulation together with high-density electroencephalography to evaluate effective connectivity at the bedside of severely brain injured, non-communicating subjects. In patients in a vegetative state, who were open-eyed, behaviourally awake but unresponsive, transcranial magnetic stimulation triggered a simple, local response indicating a breakdown of effective connectivity, similar to the one previously observed in unconscious sleeping or anaesthetized subjects. In contrast, in minimally conscious patients, who showed fluctuating signs of non-reflexive behaviour, transcranial magnetic stimulation invariably triggered complex activations that sequentially involved distant cortical areas ipsi- and contralateral to the site of stimulation, similar to activations we recorded in locked-in, conscious patients. Longitudinal measurements performed in patients who gradually recovered consciousness revealed that this clear-cut change in effective connectivity could occur at an early stage, before reliable communication was established with the subject and before the spontaneous electroencephalogram showed significant modifications. Measurements of effective connectivity by means of transcranial magnetic stimulation combined with electroencephalography can be performed at the bedside while by-passing subcortical afferent and efferent pathways, and without requiring active participation of subjects or language comprehension; hence, they offer an effective way to detect and track recovery of consciousness in brain-injured patients who are unable to exchange information with the external environment.
http://hdl.handle.net/2268/113345
also: http://hdl.handle.net/2268/131463
10.1093/brain/awr340

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