The impact of ischemic stroke on connectivity gradients

Publication date: Available online 19 July 2019Source: NeuroImage: ClinicalAuthor(s): Şeyma Bayrak, Ahmed A. Khalil, Kersten Villringer, Jochen B. Fiebach, Arno Villringer, Daniel S. Margulies, Smadar Ovadia-CaroAbstractThe 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...

Source: NeuroImage: Clinical - July 19, 2019 Category: Radiology Source Type: research