Impaired rich club and increased local connectivity in children with traumatic brain injury: Local support for the rich?

Abstract Recent evidence has shown the presence of a “rich club” in the brain, which constitutes a core network of highly interconnected and spatially distributed brain regions, important for high‐order cognitive processes. This study aimed to map the rich club organization in 17 young patients with moderate to severe TBI (15.71 ± 1.75 years) in the chronic stage of recovery and 17 age‐ and gender‐matched controls. Probabilistic tractography was performed on diffusion weighted imaging data to construct the edges of the structural connectomes using number of streamlines as edge weight. In addition, the whole‐brain network was divided into a rich club network, a local network and a feeder network connecting the latter two. Functional outcome was measured with a parent questionnaire for executive functioning. Our results revealed a significantly decreased rich club organization ( p values < .05) and impaired executive functioning ( p < .001) in young patients with TBI compared with controls. Specifically, we observed reduced density values in all three subnetworks ( p values < .005) and a reduced mean strength in the rich club network ( p = .013) together with an increased mean strength in the local network ( p = .002) in patients with TBI. This study provides new insights into the nature of TBI‐induced brain network alterations and supports the hypothesis that the local subnetwork tries to compensate for the biologically costly subnetwork of rich club nodes after TBI.