Quantification of the spatiotemporal microstructural organization of the human brain association, projection and commissural pathways across the lifespan using diffusion tensor tractography.

Using diffusion tensor tractography, we quantified the microstructural changes in the association, projection, and commissural compact white matter pathways of the human brain over the lifespan in a cohort of healthy right-handed children and adults aged 6-68 years. In both males and females, the diffusion tensor radial diffusivity of the bilateral arcuate fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, corticospinal, somatosensory tracts, and the corpus callosum followed a U-curve with advancing age; fractional anisotropy in the same pathways followed an inverted U-curve. Our study provides useful baseline data for the interpretation of data collected from patients

Recommendations for the use of common outcome measures in pediatric traumatic brain injury research

This article addresses the need for age-relevant outcome measures for traumatic brain injury (TBI) research and summarizes the recommendations by the inter-agency Pediatric TBI Outcomes Workgroup. The Pediatric Workgroup\u27s recommendations address primary clinical research objectives including characterizing course of recovery from TBI, prediction of later outcome, measurement of treatment effects, and comparison of outcomes across studies. Consistent with other Common Data Elements (CDE) Workgroups, the Pediatric TBI Outcomes Workgroup adopted the standard three-tier system in its selection of measures. In the first tier, core measures included valid, robust, and widely applicable outcome measures with proven utility in pediatric TBI from each identified domain including academics, adaptive and daily living skills, family and environment, global outcome, health-related quality of life, infant and toddler measures, language and communication, neuropsychological impairment, physical functioning, psychiatric and psychological functioning, recovery of consciousness, social role participation and social competence, social cognition, and TBI-related symptoms. In the second tier, supplemental measures were recommended for consideration in TBI research focusing on specific topics or populations. In the third tier, emerging measures included important instruments currently under development, in the process of validation, or nearing the point of published findings that have significant potential to be superior to measures in the core and supplemental lists and may eventually replace them as evidence for their utility emerges

Linguistic functions following closed head injury in children and adolescents

An important issue in the field of developmental neuropsychology concerns the effect of age at the time of cerebral insult upon cognitive status. The Neurosensory Center Comprehensive Examination for Aphasia was used to examine linguistic performance in 57 children and adolescents who sustained either a mild or a moderate/severe closed head injury. The design was a 2 (Age) X 2 (Severity) factorial. Analysis of variance indicated no sparing of language functions in children. Moreover, as compared to adolescents, children were disproportionately affected on measures of written language. Naming and writing functions were adversely affected by moderate/severe injury. In contrast, neither expressive nor receptive language skills were differentially influenced by the severity of injury. Coma duration was a better predictor of linguistic functioning than the Glasgow Coma Scale score. Results were discussed in terms of previous studies of acquired language disorders in children. Implications of the effect of cerebral injury on developing cognitive skills were examined.Psychology, Department o

Neuropsychological functions following closed head injury in infants and preschoolers

The traditional plasticity hypothesis proposes that recovery from brain injury is enhanced in children as compared with adults. To evaluate the plasticity hypothesis, performance on intelligence, motor, expressive language, and receptive language tests was examined during the subacute stage of recovery as well as eight months post-injury in 21 infants and preschoolers who sustained a closed head injury (CHI). Children with severe injuries (n=13) exhibited impaired consciousness for at least one day while children sustaining mild-moderate injuries (n=8) were rendered comatose for less than 24 hours. The design was a 2 (severity) x 2 (time of testing) factorial. To evaluate the effect of severity of CHI and to compare neuropsychological performance on baseline and follow up examinations, a repeated measures multivariate analysis of variance (MANOVA) was performed on summary scores from each of the four neuropsychological areas. On the baseline evaluation, children sustaining severe CHI were impaired on intelligence (p<.005), motor (p<.005), expressive language (p<.05), and receptive language (p<.001) functions relative to children with mild-moderate injuries. To determine which skill areas were most disrupted by CHI, the baseline and follow up summary scores from the 1) intelligence and motor and 2) expressive and receptive language areas were compared using a within-subjects MANOVA. Motor scores were more impaired than the intelligence scores on the baseline (p<.05) and follow up (p<.05) evaluations. Expressive language skills were significantly impaired relative to the receptive language skills on the baseline evaluation (p<.05). However, no significant differences were present on the follow up evaluation. The level of expressive language skills improved considerably over time while changes in performance on receptive language tasks was modest. The duration of impaired consciousness was a better predictor of the level of neuropsychological performance during the subacute stage of recovery from CHI than Glasgow Coma Scale scores obtained either at admission or 24 hours post Injury. Significant disruption of ability was observed in all of the skill areas examined and persistent behavioral deficits were apparent eight months post injury in children sustaining severe injuries. These findings are incompatible with the traditional plasticity hypothesis. Moreover, the incidence of dysphasia/dyspraxia was higher in the severely injured children than previously reported in older children and adults sustaining CHI. Since language skills develop rapidly during the preschool years, these findings support the hypothesis that skills in a rapid stage of development are more vulnerable to the effects of cerebral injury than are well consolidated skills.Psychology, Department o

Altered stress system reactivity after pediatric injury: Relation with post-traumatic stress symptoms.

Injury is the leading cause of death and disability in childhood. Injured children are at high risk for developing alterations in stress response systems and post-traumatic stress symptoms (PTSS) that may compromise long-term physical and psychological health. In a prospective, observational cohort study, we examined individual differences in, and correlates of, stress-reactivity of the hypothalamic-pituitary-adrenal axis (HPA; salivary cortisol) and autonomic nervous system (ANS; salivary alpha amylase, sAA) following pediatric injury. Participants were 8-15 years of age and hospitalized for traumatic brain injury (TBI; n=55; M age=13.9 yrs; 40 males) or extracranial injury (EI; n=29; M age 12.3 yrs, 20 males) following vehicular accidents. Six months post-injury, saliva was collected before and after the Trier Social Stress Test and later assayed for cortisol and sAA. Relative to a healthy non-injured comparison group (n=33; M age=12.5 yrs, 16 males), injured children (ages 8-12 years), but not adolescents (ages 13-15 yrs), had higher cortisol levels; regardless of age, injured participants showed dampened cortisol reactivity to social evaluative threat. Compared to participants with EI, children with TBI had elevated cortisol and adolescents had elevated sAA. With respect to PTSS, individual differences in sAA were negatively correlated with avoidance in the TBI group and positively correlated with emotional numbing within the EI group. Importantly, psychological and neurobiological sequelae were weakly related to injury severity. Given the high prevalence of pediatric injury, these sequelae affect many children and represent a significant public health concern. Consequently, surveillance of post-traumatic sequelae should include the full spectrum of injury severity. Monitoring the activity, reactivity, and regulation of biological systems sensitive to environmental insults may advance our understanding of individual differences in sequelae and adaptation following traumatic pediatric injury

Quantitative Diffusion Tensor Tractography of Association and Projection Fibers in Normally Developing Children and Adolescents

Whole-brain diffusion tensor tractography (DTT) at high signal-to-noise ratio and angular and spatial resolutions were utilized to study the effects of age, sex differences, and lateral asymmetries of 6 white matter pathways (arcuate fasciculus [AF], inferior longitudinal fasciculus, inferior fronto-occipital fasciculus [IFOF], uncinate fasciculus [UF], corticospinal tract [CST], and somatosensory pathway [SS]) in 31 right-handed children (6–17 years). Fractional anisotropy (FA), a measure of the orientational variance in water molecular diffusivity, and the magnitude of water diffusivity (parallel, perpendicular, and mean diffusivity) along the pathways were quantified. Three major patterns of maturation were observed: 1) significant increase in FA with age, accompanied by significant decreases in all 3 diffusivities (e.g., left IFOF); 2) significant decreases in all three diffusivities with age without significant changes in FA (e.g., left CST); and 3) no significant age-related changes in FA or diffusivity (e.g., SS). Sex differences were minimal. Many pathways showed lateral asymmetries. In the right hemisphere, the frontotemporal (FT) segment of AF was not visualized in a substantial (29%) number of participants. FA was higher in the left hemisphere in the FT segment of AF, UF, and CST, whereas it was lower in the frontoparietal segment of AF. This study provides normative data essential for the interpretation of pediatric brain DTT measurements in both health and disease

Healthcare Utilization and Missed Workdays for Parents of Children With Traumatic Brain Injury.

BACKGROUND: We enrolled patients in a prospective study in which we obtained estimates of the direct and indirect burden for families of children with traumatic brain injury (TBI) relative to a control group of families of children with orthopedic injury (OI). METHODS: Parents were surveyed at 3 time points following injury: 3, 6, and 12 months. At each follow-up contact, we asked parents to list the number of workdays missed, number of miles traveled, amount of travel-related costs, and whether their child had an emergency department (ED) visit, hospital admission, any over-the-counter (OTC) medications, and any prescription medications during that time period. We assessed the difference in these outcomes between the TBI and OI groups using multivariable logistic and 2-part regression models to account for high concentrations of zero values. RESULTS: Children with TBI had significantly greater odds of having an ED visit (3.04; 95% CI, 1.12-8.24), OTC medications (1.98; 95% CI, 1.34-2.94), and prescription medications (2.34; 95% CI, 1.19-4.59) than those with OI. In addition, parents of children with TBI missed significantly more days of work (19.91 days; 95% CI, 11.64-28.17) overall during the 12 months following injury than their OI counterparts. CONCLUSION: Extrapolating our results to the entire country, we estimate that pediatric TBI is associated with more than 670 000 lost workdays annually over the 12 months following injury, which translates into more than $150 million in lost productivity. These missed workdays and lost productivity may be prevented through safety efforts to reduce pediatric TBI