Discrete patterns of cross-hemispheric functional connectivity underlie impairments of spatial cognition after stroke

Article Article scientifique Article Discrete patterns of cross-hemispheric functional connectivity underlie impairments of spatial cognition after stroke eng 2020 author Ptak Radek 0000-0003-4708-9201 128547 author Bourgeois Alexia 814396 author Cavelti Silvia 832206 author Doganci Naz 841065 author Schnider Armin 124141 author Iannotti Giannina Rita 791431 6638-6648 10.1523/JNEUROSCI.0625-20.2020 32709694 0270-6474 Despite intense research, the neural correlates of stroke-induced deficits of spatial cognition remain controversial. For example, several cortical regions and white-matter tracts have been designated as possible anatomic predictors of spatial neglect. However, many studies focused on local anatomy, an approach that does not harmonize with the notion that brain-behavior relationships are flexible and may involve interactions among distant regions. We studied in humans of either sex resting-state fMRI connectivity associated with performance in line bisection, reading and visual search, tasks commonly used for he clinical diagnosis of neglect. We defined left and right frontal, parietal, and temporal areas as seeds (or regions of interest, ROIs), and measured whole-brain seed-based functional connectivity (FC) and ROI-to-ROI connectivity in subacute right-hemisphere stroke patients. Performance on the line bisection task was associated with decreased FC between the right fusiform gyrus and left superior occipital cortex. Complementary increases and decreases of connectivity between both temporal and occipital lobes predicted reading errors. In addition, visual search deficits were associated with modifications of FC between left and right inferior parietal lobes and right insular cortex. These distinct connectivity patterns were substantiated by analyses of FC between left- and right-hemispheric ROIs, which revealed that decreased interhemispheric and right intrahemispheric FC was associated with higher levels of impairment. Together, these findings indicate that intrahemispheric and interhemispheric cooperation between brain regions lying outside the damaged area contributes to spatial deficits in a way that depends on the different cognitive components recruited during reading, spatial judgments, and visual exploration.SIGNIFICANCE STATEMENT Focal damage to the right cerebral hemisphere may result in a variety of deficits, often affecting the domain of spatial cognition. The neural correlates of these disorders have traditionally been studied with lesion-symptom mapping, but this method fails to capture the network dynamics that underlie cognitive performance. We studied functional connectivity in patients with right-hemisphere stroke and found a pattern of correlations between the left and right temporo-occipital, inferior parietal, and right insular cortex that were distinctively predictive of deficits in reading, spatial judgment, and visual exploration. This finding reveals the importance of interhemispheric interactions and network adaptations for the manifestation of spatial deficits after damage to the right hemisphere. Dewey 150 Dewey 616.8 Swiss National Science Foundation Core functions of large-scale brain networks: the foundations of higher-order cognition? 32003B_184702 CH Project funding Swiss National Science Foundation Orbitofrontal Reality Filtering: Diagnosis and Mechanisms 320030_175472 CH Project funding 61 Département des neurosciences cliniques 226 108 Section de psychologie 71 false 227 Amnésie 289 432 Lésions cérébrales et attention spatiale 705 Journal of Neuroscience 40 34 85be1f5a-3d48-4502-b216-e6515c02805f Article (Published version) Public ptak_jnsci_20.pdf 3242036 application/pdf OA OTHER Restricted 2021-02-12 openAccess Faculté de médecine / Section de médecine clinique / Département des neurosciences cliniques Faculté de psychologie et des sciences de l'éducation / Section de psychologie

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Discrete patterns of cross-hemispheric functional connectivity underlie impairments of spatial cognition after stroke	Journal of Neuroscience	2020	295	296
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