Reference : Reaching across the abyss: recent advances in functional magnetic resonance imaging a...
Scientific journals : Article
Human health sciences : Neurology
Social & behavioral sciences, psychology : Neurosciences & behavior
http://hdl.handle.net/2268/33009
Reaching across the abyss: recent advances in functional magnetic resonance imaging and their potential relevance to disorders of consciousness
English
Soddu, Andrea mailto [Université de Liège - ULg > > Centre de recherches du cyclotron >]
Boly, Mélanie mailto [Université de Liège - ULg > Département des sciences cliniques > Neurologie >]
Nir, Yval [> >]
Noirhomme, Quentin mailto [Université de Liège - ULg > > Centre de recherches du cyclotron >]
Vanhaudenhuyse, Audrey mailto [Université de Liège - ULg > > Centre de recherches du cyclotron >]
Demertzi, Athina mailto [Université de Liège - ULg > > Centre de recherches du cyclotron >]
Arzi, A. [> >]
Ovadia, S. [> >]
Stanziano, M. [> >]
Papa, M. [> >]
Laureys, Steven mailto [Université de Liège - ULg > > Centre de recherches du cyclotron >]
Malach, R. [> >]
2009
Progress in Brain Research
Elsevier
177
261-274
Yes (verified by ORBi)
International
0079-6123
1875-7855
Amsterdam
The Netherlands
[en] Coma ; consciousness ; resting state ; spontaneous activity ; resonance imaging ; default network
[en] Disorders of consciousness (DOC) raise profound scientific, clinical, ethical, and philosophical issues. Growing knowledge on fundamental principles of brain organization in healthy individuals offers new opportunities for a better understanding of residual brain function in DOCs. We here discuss new perspectives derived from a recently proposed scheme of brain organization underlying consciousness in healthy individuals. In this scheme, thalamo-cortical networks can be divided into two, often antagonistic, global systems: (i) a system of externally oriented, sensory-motor networks (the "extrinsic" system); and (ii) a system of inward-oriented networks (the "intrinsic" or default system). According to this framework, four distinct mental states would be possible that could be relevant for understanding DOCs. In normal healthy volunteers and locked-in syndrome patients, a state of high functionality of both the extrinsic and intrinsic or default systems is expected--associated with full awareness of environment and self. In this case, mental imagery tasks combined with fMRI can be used to detect covert awareness in patients that are unable to communicate.
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<br />According to the framework, two complementary states of system imbalance are also possible, in which one system is in a hyperfunctional state, while the other is hypoactive. Extrinsic system hyperfunction is expected to lead to a state of total sensory-motor "absorption" or "lost self." In contrast, intrinsic or default system hyperfunction is expected to lead to a state of complete detachment from the external world. A state where both extrinsic and intrinsic systems are hypofunctional is predicted to lead to markedly impaired consciousness as seen in DOCs. Finally, we review the potential use of ultra-slow fluctuations in BOLD signal as a tool for assessing the functional integrity of extrinsic and intrinsic systems during "resting state" fMRI acquisitions. In particular, we discuss the potential provided by assessment of these slow spontaneous BOLD fluctuations as a novel tool in assessing the cognitive state and chances of recovery from brain pathologies underlying DOCs.
Fonds de la Recherche Scientifique (Communauté française de Belgique) - F.R.S.-FNRS ; ISF 160/07 ; Minerva grants (RM) ; MIUR-Progetto FIRB Internazionalizzazione-RBIN04KW43 ; the European Commission ; the McDonnell Foundation ; the Mind Science Foundation ; the Reine Elisabeth Medical Foundation
http://hdl.handle.net/2268/33009
also: http://hdl.handle.net/2268/94344
10.1016/S0079-6123(09)17718-X
http://www.ncbi.nlm.nih.gov/pubmed?term=%22Stanziano%20M%22%5BAuthor%5D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstract

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