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Hu JY, Kirilina E, Nierhaus T, Ovadia-Caro S, Livne M, Villringer K, Margulies D, Fiebach JB, Villringer A, Khalil AA. A novel approach for assessing hypoperfusion in stroke using spatial independent component analysis of resting-state fMRI. Hum Brain Mapp 2021; 42:5204-5216. [PMID: 34323339 PMCID: PMC8519861 DOI: 10.1002/hbm.25610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 07/09/2021] [Accepted: 07/20/2021] [Indexed: 01/03/2023] Open
Abstract
Individualized treatment of acute stroke depends on the timely detection of ischemia and potentially salvageable tissue in the brain. Using functional MRI (fMRI), it is possible to characterize cerebral blood flow from blood‐oxygen‐level‐dependent (BOLD) signals without the administration of exogenous contrast agents. In this study, we applied spatial independent component analysis to resting‐state fMRI data of 37 stroke patients scanned within 24 hr of symptom onset, 17 of whom received follow‐up scans the next day. Our analysis revealed “Hypoperfusion spatially‐Independent Components” (HICs) whose spatial patterns of BOLD signal resembled regions of delayed perfusion depicted by dynamic susceptibility contrast MRI. These HICs were detected even in the presence of excessive patient motion, and disappeared following successful tissue reperfusion. The unique spatial and temporal features of HICs allowed them to be distinguished with high accuracy from other components in a user‐independent manner (area under the curve = 0.93, balanced accuracy = 0.90, sensitivity = 1.00, and specificity = 0.85). Our study therefore presents a new, noninvasive method for assessing blood flow in acute stroke that minimizes interpretative subjectivity and is robust to severe patient motion.
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Affiliation(s)
- Jiun-Yiing Hu
- Department of Internal Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Evgeniya Kirilina
- Department of Neurophysics, Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.,Neurocomputation and Neuroimaging Unit, Center for Cognitive Neuroscience Berlin (CCNB), Department of Education and Psychology, Freie Universität Berlin, Berlin, Germany
| | - Till Nierhaus
- Neurocomputation and Neuroimaging Unit, Center for Cognitive Neuroscience Berlin (CCNB), Department of Education and Psychology, Freie Universität Berlin, Berlin, Germany.,Department of Neurology, Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | | | - Michelle Livne
- Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Kersten Villringer
- Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Daniel Margulies
- Centre National de la Recherche Scientifique (CNRS) UMR 7225, Frontlab, Institut du Cerveau et de la Moelle Épinière, Paris, France
| | - Jochen B Fiebach
- Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Arno Villringer
- Department of Neurology, Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.,Berlin School of Mind and Brain, Humboldt Universität zu Berlin, Berlin, Germany
| | - Ahmed A Khalil
- Department of Neurology, Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.,Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Berlin School of Mind and Brain, Humboldt Universität zu Berlin, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
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Striem-Amit E, Ovadia-Caro S, Tong N, Wang X, Bi Y, Caramazza A. Visual cortex connectivity variability in congenitally blind individuals. J Vis 2019. [DOI: 10.1167/19.10.159c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Ella Striem-Amit
- Department of Psychology, Harvard University, Cambridge, MA 02138 USA
| | - Smadar Ovadia-Caro
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany
| | | | - Xiaoying Wang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Yanchao Bi
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Alfonso Caramazza
- Department of Psychology, Harvard University, Cambridge, MA 02138 USA
- Center for Mind/Brain Sciences, University of Trento, 38068 Rovereto, Italy
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Bayrak Ş, Khalil AA, Villringer K, Fiebach JB, Villringer A, Margulies DS, Ovadia-Caro S. The impact of ischemic stroke on connectivity gradients. Neuroimage Clin 2019; 24:101947. [PMID: 31376644 PMCID: PMC6676042 DOI: 10.1016/j.nicl.2019.101947] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 07/08/2019] [Accepted: 07/17/2019] [Indexed: 11/19/2022]
Abstract
The functional organization of the brain can be represented as a low-dimensional space that reflects its macroscale hierarchy. The dimensions of this space, described as connectivity gradients, capture the similarity of areas' connections along a continuous space. Studying how pathological perturbations with known effects on functional connectivity affect these connectivity gradients provides support for their biological relevance. Previous work has shown that localized lesions cause widespread functional connectivity alterations in structurally intact areas, affecting a network of interconnected regions. By using acute stroke as a model of the effects of focal lesions on the connectome, we apply the connectivity gradient framework to depict how functional reorganization occurs throughout the brain, unrestricted by traditional definitions of functional network boundaries. We define a three-dimensional connectivity space template based on functional connectivity data from healthy controls. By projecting lesion locations into this space, we demonstrate that ischemic strokes result in dimension-specific alterations in functional connectivity over the first week after symptom onset. Specifically, changes in functional connectivity were captured along connectivity Gradients 1 and 3. The degree of functional connectivity change was associated with the distance from the lesion along these connectivity gradients (a measure of functional similarity) regardless of the anatomical distance from the lesion. Together, these results provide support for the biological validity of connectivity gradients and suggest a novel framework to characterize connectivity alterations after stroke.
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Affiliation(s)
- Şeyma Bayrak
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Department of Cognitive Neurology, University Hospital Leipzig and Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - Ahmed A Khalil
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany; Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Kersten Villringer
- Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jochen B Fiebach
- Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Arno Villringer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Department of Cognitive Neurology, University Hospital Leipzig and Faculty of Medicine, University of Leipzig, Leipzig, Germany; Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany; Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Daniel S Margulies
- Centre National de la Recherche Scientifique (CNRS) UMR 7225, Frontlab, Institut du Cerveau et de la Moelle épinière, Paris, France.
| | - Smadar Ovadia-Caro
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany; Department of Neurology, Campus Benjamin Franklin, Charité - Universitätsmedizin Berlin, Berlin, Germany.
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Ovadia-Caro S, Khalil AA, Sehm B, Villringer A, Nikulin VV, Nazarova M. Predicting the Response to Non-invasive Brain Stimulation in Stroke. Front Neurol 2019; 10:302. [PMID: 31001190 PMCID: PMC6454031 DOI: 10.3389/fneur.2019.00302] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Accepted: 03/11/2019] [Indexed: 01/10/2023] Open
Affiliation(s)
- Smadar Ovadia-Caro
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany
- Neurophysics Group, Department of Neurology, Campus Benjamin Franklin, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Ahmed A. Khalil
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany
- Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Bernhard Sehm
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Arno Villringer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany
- Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Department of Cognitive Neurology, University Hospital Leipzig and Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - Vadim V. Nikulin
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Neurophysics Group, Department of Neurology, Campus Benjamin Franklin, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Bernstein Center for Computational Neuroscience, Berlin, Germany
- Center for Cognition and Decision Making, Institute for Cognitive Neuroscience, National Research University Higher School of Economics, Moscow, Russia
| | - Maria Nazarova
- Center for Cognition and Decision Making, Institute for Cognitive Neuroscience, National Research University Higher School of Economics, Moscow, Russia
- Federal Center for Cerebrovascular Pathology and Stroke, The Ministry of Healthcare of the Russian Federation, Federal State Budget Institution, Moscow, Russia
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Striem-Amit E, Ovadia-Caro S, Caramazza A, Margulies DS, Villringer A, Amedi A. Functional connectivity of visual cortex in the blind follows retinotopic organization principles. Brain 2015; 138:1679-95. [PMID: 25869851 PMCID: PMC4614142 DOI: 10.1093/brain/awv083] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 02/01/2015] [Indexed: 11/13/2022] Open
Abstract
Although early visual experience is essential for the proper development of visual cortex, Striem-Amit et al. show that the underlying connectivity structure of retinotopic mapping is retained even in congenitally blind individuals. This basic organisational principle emerges independently of visual input and persists despite lifelong experience-dependent plasticity. Is visual input during critical periods of development crucial for the emergence of the fundamental topographical mapping of the visual cortex? And would this structure be retained throughout life-long blindness or would it fade as a result of plastic, use-based reorganization? We used functional connectivity magnetic resonance imaging based on intrinsic blood oxygen level-dependent fluctuations to investigate whether significant traces of topographical mapping of the visual scene in the form of retinotopic organization, could be found in congenitally blind adults. A group of 11 fully and congenitally blind subjects and 18 sighted controls were studied. The blind demonstrated an intact functional connectivity network structural organization of the three main retinotopic mapping axes: eccentricity (centre-periphery), laterality (left-right), and elevation (upper-lower) throughout the retinotopic cortex extending to high-level ventral and dorsal streams, including characteristic eccentricity biases in face- and house-selective areas. Functional connectivity-based topographic organization in the visual cortex was indistinguishable from the normally sighted retinotopic functional connectivity structure as indicated by clustering analysis, and was found even in participants who did not have a typical retinal development in utero (microphthalmics). While the internal structural organization of the visual cortex was strikingly similar, the blind exhibited profound differences in functional connectivity to other (non-visual) brain regions as compared to the sighted, which were specific to portions of V1. Central V1 was more connected to language areas but peripheral V1 to spatial attention and control networks. These findings suggest that current accounts of critical periods and experience-dependent development should be revisited even for primary sensory areas, in that the connectivity basis for visual cortex large-scale topographical organization can develop without any visual experience and be retained through life-long experience-dependent plasticity. Furthermore, retinotopic divisions of labour, such as that between the visual cortex regions normally representing the fovea and periphery, also form the basis for topographically-unique plastic changes in the blind.
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Affiliation(s)
- Ella Striem-Amit
- 1 Department of Medical Neurobiology, The Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91220, Israel 2 Department of Psychology, Harvard University, Cambridge, MA 02138 USA
| | - Smadar Ovadia-Caro
- 3 Mind and Brain Institute, Berlin School of Mind and Brain, Humboldt University, Berlin, Germany 4 Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Alfonso Caramazza
- 2 Department of Psychology, Harvard University, Cambridge, MA 02138 USA 5 Centre for Mind/Brain Sciences, Università degli Studi di Trento, Polo di Rovereto, Italy
| | - Daniel S Margulies
- 3 Mind and Brain Institute, Berlin School of Mind and Brain, Humboldt University, Berlin, Germany 4 Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Arno Villringer
- 3 Mind and Brain Institute, Berlin School of Mind and Brain, Humboldt University, Berlin, Germany 4 Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Amir Amedi
- 1 Department of Medical Neurobiology, The Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91220, Israel 6 The Edmond and Lily Safra Centre for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem 91220, Israel 7 Cognitive Sciences Program, The Hebrew University of Jerusalem, Jerusalem 91220, Israel 8 Sorbonne Universités, UPMC Univ Paris 06, Institut de la Vision, UMR_S 968, Paris, F-75012, France
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6
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Affiliation(s)
- Smadar Ovadia-Caro
- From the Mind-Brain Institute at the Berlin School of Mind and Brain, Charité and Humboldt University, Berlin, Germany (S.O.-C., D.S.M., A.V.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (S.O.-C., D.S.M., A.V.); Institute of Psychology, Humboldt University, Berlin, Germany (S.O.-C.); Center for Stroke Research, Charité Universitätsmedizin Berlin, Berlin, Germany (A.V.); and Department of Cognitive Neurology, University Hospital, Leipzig, Germany (A.V.).
| | - Daniel S Margulies
- From the Mind-Brain Institute at the Berlin School of Mind and Brain, Charité and Humboldt University, Berlin, Germany (S.O.-C., D.S.M., A.V.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (S.O.-C., D.S.M., A.V.); Institute of Psychology, Humboldt University, Berlin, Germany (S.O.-C.); Center for Stroke Research, Charité Universitätsmedizin Berlin, Berlin, Germany (A.V.); and Department of Cognitive Neurology, University Hospital, Leipzig, Germany (A.V.)
| | - Arno Villringer
- From the Mind-Brain Institute at the Berlin School of Mind and Brain, Charité and Humboldt University, Berlin, Germany (S.O.-C., D.S.M., A.V.); Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (S.O.-C., D.S.M., A.V.); Institute of Psychology, Humboldt University, Berlin, Germany (S.O.-C.); Center for Stroke Research, Charité Universitätsmedizin Berlin, Berlin, Germany (A.V.); and Department of Cognitive Neurology, University Hospital, Leipzig, Germany (A.V.)
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7
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Koehler S, Ovadia-Caro S, van der Meer E, Villringer A, Heinz A, Romanczuk-Seiferth N, Margulies DS. Increased functional connectivity between prefrontal cortex and reward system in pathological gambling. PLoS One 2013; 8:e84565. [PMID: 24367675 PMCID: PMC3868704 DOI: 10.1371/journal.pone.0084565] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Accepted: 11/15/2013] [Indexed: 11/18/2022] Open
Abstract
Pathological gambling (PG) shares clinical characteristics with substance-use disorders and is thus discussed as a behavioral addiction. Recent neuroimaging studies on PG report functional changes in prefrontal structures and the mesolimbic reward system. While an imbalance between these structures has been related to addictive behavior, whether their dysfunction in PG is reflected in the interaction between them remains unclear. We addressed this question using functional connectivity resting-state fMRI in male subjects with PG and controls. Seed-based functional connectivity was computed using two regions-of-interest, based on the results of a previous voxel-based morphometry study, located in the prefrontal cortex and the mesolimbic reward system (right middle frontal gyrus and right ventral striatum). PG patients demonstrated increased connectivity from the right middle frontal gyrus to the right striatum as compared to controls, which was also positively correlated with nonplanning aspect of impulsiveness, smoking and craving scores in the PG group. Moreover, PG patients demonstrated decreased connectivity from the right middle frontal gyrus to other prefrontal areas as compared to controls. The right ventral striatum demonstrated increased connectivity to the right superior and middle frontal gyrus and left cerebellum in PG patients as compared to controls. The increased connectivity to the cerebellum was positively correlated with smoking in the PG group. Our results provide further evidence for alterations in functional connectivity in PG with increased connectivity between prefrontal regions and the reward system, similar to connectivity changes reported in substance use disorder.
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Affiliation(s)
- Saskia Koehler
- Berlin School of Mind and Brain and the Mind-Brain Institute, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Charité Campus Mitte, Berlin, Germany
- Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- * E-mail: -berlin.de
| | - Smadar Ovadia-Caro
- Berlin School of Mind and Brain and the Mind-Brain Institute, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Elke van der Meer
- Berlin School of Mind and Brain and the Mind-Brain Institute, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Arno Villringer
- Berlin School of Mind and Brain and the Mind-Brain Institute, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Andreas Heinz
- Berlin School of Mind and Brain and the Mind-Brain Institute, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Charité Campus Mitte, Berlin, Germany
| | - Nina Romanczuk-Seiferth
- Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Charité Campus Mitte, Berlin, Germany
| | - Daniel S. Margulies
- Berlin School of Mind and Brain and the Mind-Brain Institute, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
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Ovadia-Caro S, Nir Y, Soddu A, Ramot M, Hesselmann G, Vanhaudenhuyse A, Dinstein I, Tshibanda JFL, Boly M, Harel M, Laureys S, Malach R. Reduction in inter-hemispheric connectivity in disorders of consciousness. PLoS One 2012; 7:e37238. [PMID: 22629375 PMCID: PMC3358327 DOI: 10.1371/journal.pone.0037238] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 04/18/2012] [Indexed: 01/25/2023] Open
Abstract
Clinical diagnosis of disorders of consciousness (DOC) caused by brain injury poses great challenges since patients are often behaviorally unresponsive. A promising new approach towards objective DOC diagnosis may be offered by the analysis of ultra-slow (<0.1 Hz) spontaneous brain activity fluctuations measured with functional magnetic resonance imaging (fMRI) during the resting-state. Previous work has shown reduced functional connectivity within the “default network”, a subset of regions known to be deactivated during engaging tasks, which correlated with the degree of consciousness impairment. However, it remains unclear whether the breakdown of connectivity is restricted to the “default network”, and to what degree changes in functional connectivity can be observed at the single subject level. Here, we analyzed resting-state inter-hemispheric connectivity in three homotopic regions of interest, which could reliably be identified based on distinct anatomical landmarks, and were part of the “Extrinsic” (externally oriented, task positive) network (pre- and postcentral gyrus, and intraparietal sulcus). Resting-state fMRI data were acquired for a group of 11 healthy subjects and 8 DOC patients. At the group level, our results indicate decreased inter-hemispheric functional connectivity in subjects with impaired awareness as compared to subjects with intact awareness. Individual connectivity scores significantly correlated with the degree of consciousness. Furthermore, a single-case statistic indicated a significant deviation from the healthy sample in 5/8 patients. Importantly, of the three patients whose connectivity indices were comparable to the healthy sample, one was diagnosed as locked-in. Taken together, our results further highlight the clinical potential of resting-state connectivity analysis and might guide the way towards a connectivity measure complementing existing DOC diagnosis.
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Affiliation(s)
- Smadar Ovadia-Caro
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
- Berlin School of Mind and Brain, Humboldt University, Berlin, Germany
| | - Yuval Nir
- Department of Psychiatry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Andrea Soddu
- Coma Science Group, Cyclotron Research Center and Neurology department, University of Liège, Liège, Belgium
| | - Michal Ramot
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Guido Hesselmann
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
- Department of Psychiatry, Charité Campus Mitte, Berlin, Germany
| | - Audrey Vanhaudenhuyse
- Coma Science Group, Cyclotron Research Center and Neurology department, University of Liège, Liège, Belgium
| | - Ilan Dinstein
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Jean-Flory L. Tshibanda
- Coma Science Group, Cyclotron Research Center and Neurology department, University of Liège, Liège, Belgium
| | - Melanie Boly
- Coma Science Group, Cyclotron Research Center and Neurology department, University of Liège, Liège, Belgium
| | - Michal Harel
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Steven Laureys
- Coma Science Group, Cyclotron Research Center and Neurology department, University of Liège, Liège, Belgium
| | - Rafael Malach
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
- * E-mail:
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Lohmann G, Ovadia-Caro S, Jungehülsing GJ, Margulies DS, Villringer A, Turner R. Connectivity concordance mapping: a new tool for model-free analysis of FMRI data of the human brain. Front Syst Neurosci 2012; 6:13. [PMID: 22470320 PMCID: PMC3308143 DOI: 10.3389/fnsys.2012.00013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 02/29/2012] [Indexed: 12/14/2022] Open
Abstract
Functional magnetic resonance data acquired in a task-absent condition (“resting state”) require new data analysis techniques that do not depend on an activation model. Here, we propose a new analysis method called Connectivity Concordance Mapping (CCM). The main idea is to assign a label to each voxel based on the reproducibility of its whole-brain pattern of connectivity. Specifically, we compute the correlations of time courses of each voxel with every other voxel for each measurement. Voxels whose correlation pattern is consistent across measurements receive high values. The result of a CCM analysis is thus a voxel-wise map of concordance values. Regions of high inter-subject concordance can be assumed to be functionally consistent, and may thus be of specific interest for further analysis. Here we present two fMRI studies to demonstrate the possible applications of the algorithm. The first is a eyes-open/eyes-closed paradigm designed to highlight the potential of the method in a relatively simple domain. The second study is a longitudinal repeated measurement of a patient following stroke. Longitudinal clinical studies such as this may represent the most interesting domain of applications for this algorithm.
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Affiliation(s)
- Gabriele Lohmann
- Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany
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Soddu A, Vanhaudenhuyse A, Bahri MA, Bruno MA, Boly M, Demertzi A, Tshibanda JF, Phillips C, Stanziano M, Ovadia-Caro S, Nir Y, Maquet P, Papa M, Malach R, Laureys S, Noirhomme Q. Identifying the default-mode component in spatial IC analyses of patients with disorders of consciousness. Hum Brain Mapp 2011; 33:778-96. [PMID: 21484953 DOI: 10.1002/hbm.21249] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 11/21/2010] [Accepted: 12/10/2010] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVES Recent fMRI studies have shown that it is possible to reliably identify the default-mode network (DMN) in the absence of any task, by resting-state connectivity analyses in healthy volunteers. We here aimed to identify the DMN in the challenging patient population of disorders of consciousness encountered following coma. EXPERIMENTAL DESIGN A spatial independent component analysis-based methodology permitted DMN assessment, decomposing connectivity in all its different sources either neuronal or artifactual. Three different selection criteria were introduced assessing anticorrelation-corrected connectivity with or without an automatic masking procedure and calculating connectivity scores encompassing both spatial and temporal properties. These three methods were validated on 10 healthy controls and applied to an independent group of 8 healthy controls and 11 severely brain-damaged patients [locked-in syndrome (n = 2), minimally conscious (n = 1), and vegetative state (n = 8)]. PRINCIPAL OBSERVATIONS All vegetative patients showed fewer connections in the default-mode areas, when compared with controls, contrary to locked-in patients who showed near-normal connectivity. In the minimally conscious-state patient, only the two selection criteria considering both spatial and temporal properties were able to identify an intact right lateralized BOLD connectivity pattern, and metabolic PET data suggested its neuronal origin. CONCLUSIONS When assessing resting-state connectivity in patients with disorders of consciousness, it is important to use a methodology excluding non-neuronal contributions caused by head motion, respiration, and heart rate artifacts encountered in all studied patients.
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Affiliation(s)
- Andrea Soddu
- Coma Science Group, Cyclotron Research Centre, University of Liège, Liège, Belgium.
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