title: Altered structural networks and executive deficits in traumatic brain injury patients.
abstract: Recent research on traumatic brain injury (TBI) has shown that impairments in cognitive and executive control functions are accompanied by a disrupted neural connectivity characterized by white matter damage. We constructed binary and weighted brain structural networks in 21 patients with chronic TBI and 17 healthy young adults utilizing diffusion tensor tractography and calculated topological properties of the networks using a graph theoretical method. Executive function was assessed with the local global task and the trail making task, requiring inhibition, updating, and switching. The results revealed that TBI patients were less successful than controls on the executive tasks, as shown by the higher reaction times, higher switch costs, and lower accuracy rates. Moreover, both TBI patients and controls exhibited a small world topology in their white matter networks. More importantly, the TBI patients demonstrated increased shortest path length and decreased global efficiency of the structural network. These findings suggest that TBI patients have a weaker globally integrated structural brain network, resulting in a limited capacity to integrate information across brain regions. Furthermore, we showed that the white matter networks of both groups contained highly connected hub regions that were predominately located in the parietal cortex, frontal cortex, and basal ganglia. Finally, we showed significant correlations between switching performance and network property metrics within the TBI group. Specifically, lower scores on the switching tasks corresponded to a lower global efficiency. We conclude that analyzing the structural brain network connectivity provides new insights into understanding cognitive control changes following brain injury.
authors.affiliation: Movement Control and Neuroplasticity Research Group, Department of Kinesiology, Biomedical Sciences Group, K.U.Leuven, Leuven, Belgium, Karen.Caeyenberghs@UGent.be.
authors.forename: K
authors.initials: K
authors.lastname: Caeyenberghs
authors.forename: A
authors.initials: A
authors.lastname: Leemans
authors.forename: I
authors.initials: I
authors.lastname: Leunissen
authors.forename: J
authors.initials: J
authors.lastname: Gooijers
authors.forename: K
authors.initials: K
authors.lastname: Michiels
authors.forename: S
authors.initials: S
authors.lastname: Sunaert
authors.forename: S P
authors.initials: SP
authors.lastname: Swinnen
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000473:pathology*; D001930:Brain Injuries / Q000150:complications* / Q000473:pathology*; D001931:Brain Mapping; D003072:Cognition Disorders / Q000209:etiology*; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D009483:Neuropsychological Tests; D015599:Trauma Severity Indices; D055815:Young Adult