title: Subcortical volume analysis in traumatic brain injury: the importance of the fronto-striato-thalamic circuit in task switching.
abstract: Traumatic brain injury (TBI) is associated with neuronal loss, diffuse axonal injury and executive dysfunction. Whereas executive dysfunction has traditionally been associated with prefrontal lesions, ample evidence suggests that those functions requiring behavioral flexibility critically depend on the interaction between frontal cortex, basal ganglia and thalamus. To test whether structural integrity of this fronto-striato-thalamic circuit can account for executive impairments in TBI we automatically segmented the thalamus, putamen and caudate of 25 patients and 21 healthy controls and obtained diffusion weighted images. We assessed components of executive function using the local-global task, which requires inhibition, updating and switching between actions. Shape analysis revealed localized atrophy of the limbic, executive and rostral-motor zones of the basal ganglia, whereas atrophy of the thalami was more global in TBI. This subcortical atrophy was related to white matter microstructural organization in TBI, suggesting that axonal injuries possibly contribute to subcortical volume loss. Global volume of the nuclei showed no clear relationship with task performance. However, the shape analysis revealed that participants with smaller volume of those subregions that have connections with the prefrontal cortex and rostral motor areas showed higher switch costs and mixing costs, and made more errors while switching. These results support the idea that flexible cognitive control over action depends on interactions within the fronto-striato-thalamic circuit.
authors.affiliation: Movement Control and Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Belgium. Electronic address: inge.leunissen@faber.kuleuven.be.
authors.forename: Inge
authors.initials: I
authors.lastname: Leunissen
authors.affiliation: Movement Neuroscience Laboratory, University of Auckland, New Zealand.
authors.forename: James P
authors.initials: JP
authors.lastname: Coxon
authors.affiliation: Movement Control and Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Belgium; Department of Physical Therapy and Motor Rehabilitation, Ghent University, Belgium.
authors.forename: Karen
authors.initials: K
authors.lastname: Caeyenberghs
authors.affiliation: Department of Physical Medicine and Rehabilitation, University Hospital, Leuven Campus Pellenberg, Belgium.
authors.forename: Karla
authors.initials: K
authors.lastname: Michiels
authors.affiliation: Medical Imaging Research Center, Group Biomedical Sciences, KU Leuven, Belgium.
authors.forename: Stefan
authors.initials: S
authors.lastname: Sunaert
authors.affiliation: Movement Control and Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Belgium; Leuven Research Institute for Neuroscience & Disease (LIND), Belgium.
authors.forename: Stephan P
authors.initials: SP
authors.lastname: Swinnen
mesh_terms: D000328:Adult; D001284:Atrophy / Q000503:physiopathology; D001930:Brain Injuries / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D003072:Cognition Disorders / Q000209:etiology / Q000503:physiopathology; D038524:Diffusion Magnetic Resonance Imaging; D056324:Diffusion Tensor Imaging / Q000379:methods; D056344:Executive Function / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008606:Mental Processes / Q000502:physiology*; D009434:Neural Pathways / Q000503:physiopathology*; D009483:Neuropsychological Tests; D055815:Young Adult
keywords: Basal ganglia; Diffusion tensor imaging; Shape analysis; Task switching; Thalamus; Traumatic brain injury