title: Recovery of White Matter following Pediatric Traumatic Brain Injury Depends on Injury Severity.
abstract: Previous studies in pediatric traumatic brain injury (TBI) have been variable in describing the effects of injury severity on white-matter development. The present study used diffusion tensor imaging to investigate prospective sub-acute and longitudinal relationships between early clinical indicators of injury severity, diffusion metrics, and neuropsychological outcomes. Pediatric patients with TBI underwent magnetic resonance imaging (MRI) (n = 78, mean [M] = 10.56, standard deviation [SD] = 2.21 years) at the sub-acute stage after injury (M = 5.55, SD = 3.05 weeks), and typically developing children were also included and imaged (n = 30, M = 10.60, SD = 2.88 years). A sub-set of the patients with TBI (n = 15) was followed up with MRI 2 years post-injury. Diffusion MRI images were acquired at sub-acute and 2-year follow-up time points and analyzed using Tract-Based Spatial Statistics. At the sub-acute stage, mean diffusivity and axial diffusivity were significantly higher in the TBI group compared with matched controls (p < 0.05). TBI severity significantly predicted diffusion profiles at the sub-acute and 2-year post-injury MRI. Patients with more severe TBI also exhibited poorer information processing speed at 6-months post-injury, which in turn correlated with their diffusion metrics. These findings highlight that the severity of the injury not only has an impact on white-matter microstructure, it also impacts its recovery over time. Moreover, findings suggest that sub-acute microstructural changes may represent a useful prognostic marker to identify children at elevated risk for longer term deficits.
authors.affiliation: 1 Developmental Imaging, Clinical Sciences, Murdoch Childrens Research Institute , Melbourne, Australia .
authors.forename: Sila
authors.initials: S
authors.lastname: Genc
authors.affiliation: 1 Developmental Imaging, Clinical Sciences, Murdoch Childrens Research Institute , Melbourne, Australia .|2 Melbourne School of Psychological Sciences, The University of Melbourne , Melbourne, Australia .
authors.forename: Vicki
authors.initials: V
authors.lastname: Anderson
authors.affiliation: 1 Developmental Imaging, Clinical Sciences, Murdoch Childrens Research Institute , Melbourne, Australia .|2 Melbourne School of Psychological Sciences, The University of Melbourne , Melbourne, Australia .
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Ryan
authors.affiliation: 1 Developmental Imaging, Clinical Sciences, Murdoch Childrens Research Institute , Melbourne, Australia .
authors.forename: Charles B
authors.initials: CB
authors.lastname: Malpas
authors.affiliation: 1 Developmental Imaging, Clinical Sciences, Murdoch Childrens Research Institute , Melbourne, Australia .|2 Melbourne School of Psychological Sciences, The University of Melbourne , Melbourne, Australia .
authors.forename: Cathy
authors.initials: C
authors.lastname: Catroppa
authors.affiliation: 3 Department of Psychology, The University of Montreal , Montreal, Quebec, Canada .|4 Ste-Justine Hospital Research Center , Montreal, Quebec, Canada .
authors.forename: Miriam H
authors.initials: MH
authors.lastname: Beauchamp
authors.affiliation: 1 Developmental Imaging, Clinical Sciences, Murdoch Childrens Research Institute , Melbourne, Australia .|5 Department of Paediatrics, University of Melbourne , The Royal Children's Hospital, Melbourne, Australia .
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Silk
mesh_terms: D000070642:Brain Injuries, Traumatic / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D002648:Child; D060825:Cognitive Dysfunction / Q000209:etiology / Q000503:physiopathology*; D056324:Diffusion Tensor Imaging; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011379:Prognosis; D012720:Severity of Illness Index; D066127:White Matter / Q000000981:diagnostic imaging / Q000473:pathology*
keywords: diffusion tensor imaging; pediatric; severity; traumatic brain injury; white matter