title: Working memory and corpus callosum microstructural integrity after pediatric traumatic brain injury: a diffusion tensor tractography study.
abstract: Deficits in working memory (WM) are a common consequence of pediatric traumatic brain injury (TBI) and are believed to contribute to difficulties in a range of cognitive and academic domains. Reduced integrity of the corpus callosum (CC) after TBI may disrupt the connectivity between bilateral frontoparietal neural networks underlying WM. In the present investigation, diffusion tensor imaging (DTI) tractography of eight callosal subregions (CC1-CC8) was examined in relation to measures of verbal and visuospatial WM in 74 children sustaining TBI and 49 typically developing comparison children. Relative to the comparison group, children with TBI demonstrated poorer visuospatial WM, but comparable verbal WM. Microstructure of the CC was significantly compromised in brain-injured children, with lower fractional anisotropy (FA) and higher axial and radial diffusivity metrics in all callosal subregions. In both groups of children, lower FA and/or higher radial diffusivity in callosal subregions connecting anterior and posterior parietal cortical regions predicted poorer verbal WM, whereas higher radial diffusivity in callosal subregions connecting anterior and posterior parietal, as well as temporal, cortical regions predicted poorer visuospatial WM. DTI metrics, especially radial diffusivity, in predictive callosal subregions accounted for significant variance in WM over and above remaining callosal subregions. Reduced microstructural integrity of the CC, particularly in subregions connecting parietal and temporal cortices, may act as a neuropathological mechanism contributing to long-term WM deficits. The future clinical use of neuroanatomical biomarkers may allow for the early identification of children at highest risk for WM deficits and earlier provision of interventions for these children.
authors.affiliation: 1 Department of Psychology, University of Houston , Houston, Texas.
authors.forename: Amery
authors.initials: A
authors.lastname: Treble
authors.forename: Khader M
authors.initials: KM
authors.lastname: Hasan
authors.forename: Amal
authors.initials: A
authors.lastname: Iftikhar
authors.forename: Karla K
authors.initials: KK
authors.lastname: Stuebing
authors.forename: Larry A
authors.initials: LA
authors.lastname: Kramer
authors.forename: Charles S
authors.initials: CS
authors.lastname: Cox
authors.forename: Paul R
authors.initials: PR
authors.lastname: Swank
authors.forename: Linda
authors.initials: L
authors.lastname: Ewing-Cobbs
mesh_terms: D000293:Adolescent; D001930:Brain Injuries / Q000473:pathology* / Q000523:psychology*; D002540:Cerebral Cortex / Q000473:pathology; D002648:Child; D003244:Consciousness Disorders / Q000523:psychology; D003337:Corpus Callosum / Q000473:pathology*; D020833:Diffuse Axonal Injury / Q000473:pathology; D056324:Diffusion Tensor Imaging; D005006:Ethnicity; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D007091:Image Processing, Computer-Assisted; D015601:Injury Severity Score; D008297:Male; D008570:Memory, Short-Term; D009483:Neuropsychological Tests; D011597:Psychomotor Performance; D012044:Regression Analysis; D013028:Space Perception; D014796:Visual Perception