title: Bimanual coordination and corpus callosum microstructure in young adults with traumatic brain injury: a diffusion tensor imaging study.
abstract: Bimanual actions are ubiquitous in daily life. Many coordinated movements of the upper extremities rely on precise timing, which requires efficient interhemispheric communication via the corpus callosum (CC). As the CC in particular is known to be vulnerable to traumatic brain injury (TBI), furthering our understanding of its structure-function association is highly valuable for TBI diagnostics and prognosis. In this study, 21 young adults with TBI and 17 controls performed object manipulation tasks (insertion of pegs with both hands and bilateral daily life activities) and cognitive control tasks (i.e., switching maneuvers during spatially and temporally coupled bimanual circular motions). The structural organization of 7 specific subregions of the CC (prefrontal, premotor/supplementary motor, primary motor, primary sensory, parietal, temporal, and occipital) was subsequently investigated in these subjects with diffusion tensor imaging (DTI). Findings revealed that bimanual coordination was impaired in TBI patients as shown by elevated movement time values during daily life activities, a decreased number of peg insertions, and slower response times during the switching task. Furthermore, the DTI analysis demonstrated a significantly decreased fractional anisotropy and increased radial diffusivity in prefrontal, primary sensory, and parietal regions in TBI patients versus controls. Finally, multiple regression analyses showed evidence of the high specificity of callosal subregions accounting for the variance associated with performance of the different bimanual coordination tasks. Whereas disruption in commissural pathways between occipital areas played a role in performance on the clinical tests of bimanual coordination, deficits in the switching task were related to disrupted interhemispheric communication in prefrontal, sensory, and parietal regions. This study provides evidence that structural alterations of several subregional callosal fibers in adults with TBI are associated with differential behavioral manifestations of bimanual motor functioning.
authors.affiliation: Motor Control Laboratory, Research Center for Movement Control and Neuroplasticity, K.U. Leuven, Belgium. Karen.Caeyenberghs@faber.kuleuven.be
authors.forename: Karen
authors.initials: K
authors.lastname: Caeyenberghs
authors.forename: Alexander
authors.initials: A
authors.lastname: Leemans
authors.forename: James
authors.initials: J
authors.lastname: Coxon
authors.forename: Inge
authors.initials: I
authors.lastname: Leunissen
authors.forename: David
authors.initials: D
authors.lastname: Drijkoningen
authors.forename: Monique
authors.initials: M
authors.lastname: Geurts
authors.forename: Jolien
authors.initials: J
authors.lastname: Gooijers
authors.forename: Karla
authors.initials: K
authors.lastname: Michiels
authors.forename: Stefan
authors.initials: S
authors.lastname: Sunaert
authors.forename: Stephan P
authors.initials: SP
authors.lastname: Swinnen
mesh_terms: D000293:Adolescent; D000328:Adult; D001930:Brain Injuries / Q000473:pathology* / Q000503:physiopathology*; D015331:Cohort Studies; D003337:Corpus Callosum / Q000293:injuries / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D009069:Movement Disorders / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D055815:Young Adult