Accelerated corpus callosum development in prematurity predicts improved outcome.

OBJECTIVES: To determine: (1) whether corpus callosum (CC) size and microstructure at 7 years of age or their change from infancy to 7 years differed between very preterm (VP) and full-term (FT) children; (2) perinatal predictors of CC size and microstructure at 7 years; and (3) associations between CC measures at 7 years or trajectories from infancy to 7 years and neurodevelopmental outcomes. EXPERIMENTAL DESIGN: One hundred and thirty-six VP (gestational age [GA] <30 weeks and/or birth weight <1,250 g) and 33 FT children had usable magnetic resonance images at 7 years of age, and of these, 76 VP and 16 FT infants had usable data at term equivalent age. The CC was traced and divided into six sub-regions. Fractional anisotropy, mean, axial, radial diffusivity and volume were measured from tractography. Perinatal data were collected, and neurodevelopmental tests administered at 7 years' corrected age. PRINCIPAL OBSERVATIONS: VP children had smaller posterior CC regions, higher diffusivity and lower fractional anisotropy compared with FT 7-year-olds. Reduction in diffusivity over time occurred faster in VP than FT children (P ≤ 0.002). Perinatal brain abnormality and earlier GA were associated with CC abnormalities. Microstructural abnormalities at 7 years or slower development of the CC were associated with motor dysfunction, poorer mathematics and visual perception. CONCLUSIONS: This study is the first to demonstrate an accelerated trajectory of CC white matter diffusion following VP birth, associated with improved neurodevelopmental functioning. Findings suggest there is a window of opportunity for neurorestorative intervention to improve outcomes. Hum Brain Mapp 36:3733-3748, 2015. © 2015 Wiley Periodicals, Inc.

Longitudinal outcome and recovery of social problems after pediatric traumatic brain injury (TBI): Contribution of brain insult and family environment.

Pediatric traumatic brain injury (TBI) can result in a range of social impairments, however longitudinal recovery is not well characterized, and clinicians are poorly equipped to identify children at risk for persisting difficulties. Using a longitudinal prospective design, this study aimed to evaluate the contribution of injury and non-injury related risk and resilience factors to longitudinal outcome and recovery of social problems from 12- to 24-months post-TBI. 78 children with TBI (injury age: 5.0-15.0 years) and 40 age and gender-matched typically developing (TD) children underwent magnetic resonance imaging including a susceptibility-weighted imaging (SWI) sequence 2-8 weeks post-injury (M=39.25, SD=27.64 days). At 12 and 24-months post- injury, parents completed questionnaires rating their child's social functioning, and environmental factors including socioeconomic status, caregiver mental health and family functioning. Results revealed that longitudinal recovery profiles differed as a function of injury severity, such that among children with severe TBI, social problems significantly increased from 12- to 24-months post-injury, and were found to be significantly worse than TD controls and children with mild and moderate TBI. In contrast, children with mild and moderate injuries showed few problems at 12-months post-injury and little change over time. Pre-injury environment and SWI did not significantly contribute to outcome at 24-months, however concurrent caregiver mental health and family functioning explained a large and significant proportion of variance in these outcomes. Overall, this study shows that longitudinal recovery profiles differ as a function of injury severity, with evidence for late-emerging social problems among children with severe TBI. Poorer long-term social outcomes were associated with family dysfunction and poorer caregiver mental health at 24-months post injury, suggesting that efforts to optimize the child's environment and bolster family coping resources may enhance recovery of social problems following pediatric TBI.