Mary R. Prasad

Neuroimaging, Physical, and Developmental Findings After Inflicted and Noninflicted Traumatic Brain Injury in Young Children

Objective. To characterize neuroimaging, physical, neurobehavioral, and developmental findings in children with inflicted and noninflicted traumatic brain injury (TBI) and to identify characteristic features of inflicted TBI. Methods and Patients. Forty children, 0 to 6 years of age, hospitalized for TBI who had no documented history of previous brain injury were enrolled in a prospective longitudinal study. TBI was categorized as either inflicted (n = 20) or noninflicted (n = 20) based on the assessment of hospital and county protective services. Glasgow Coma Scale scores and neonatal history were comparable in both groups. Outcome Measures. Acute computed tomography/magnetic resonance imaging studies and physical findings were evaluated. Glasgow Outcome Scale scores, cognitive development, and motor functioning were assessed an average of 1.3 months after TBI. χ2 analyses assessed differences in the distribution of findings in the inflicted and noninflicted TBI groups. Results. Signs of preexisting brain injury, including cerebral atrophy, subdural hygroma, and ex vacuo ventriculomegaly, were present in 45% of children with inflicted TBI and in none of the children with noninflicted TBI. Subdural hematomas and seizures occurred significantly more often in children with inflicted TBI. Intraparenchymal hemorrhage, edema, skull fractures, and cephalohematomas were similar in both groups. Retinal hemorrhage was only identified in the inflicted TBI group. Glasgow Outcome Scale scores indicated a significantly less favorable outcome after inflicted than noninflicted TBI. Mental deficiency was present in 45% of the inflicted and 5% of the noninflicted TBI groups. Conclusions. Characteristic features of inflicted TBI included acute computed tomography/magnetic resonance imaging findings of preexisting brain injury, extraaxial hemorrhages, seizures, retinal hemorrhages, and significantly impaired cognitive function without prolonged impairment of consciousness.

Arrested development and disrupted callosal microstructure following pediatric traumatic brain injury: relation to neurobehavioral outcomes.

Chronic pediatric traumatic brain injury (TBI) is associated with significant and persistent neurobehavioral deficits. Using diffusion tensor imaging (DTI), we examined area, fractional anisotropy (FA), radial diffusion, and axial diffusion from six regions of the corpus callosum (CC) in 41 children and adolescents with TBI and 31 comparison children. Midsagittal cross-sectional area of the posterior body and isthmus was similar in younger children irrespective of injury status; however, increased area was evident in the older comparison children but was obviated in older children with TBI, suggesting arrested development. Similarly, age was correlated significantly with indices of tissue microstructure only for the comparison group. TBI was associated with significant reduction in FA and increased radial diffusivity in the posterior third of the CC and in the genu. The axial diffusivity did not differ by either age or group. Logistic regression analyses revealed that FA and radial diffusivity were equally sensitive to post-traumatic changes in 4 of 6 callosal regions; radial diffusivity was more sensitive for the rostral midbody and splenium. IQ, working memory, motor, and academic skills were correlated significantly with radial diffusion and/or FA from the isthmus and splenium only in the TBI group. Reduced size and microstructural changes in posterior callosal regions after TBI suggest arrested development, decreased organization, and disrupted myelination. Increased radial diffusivity was the most sensitive DTI-based surrogate marker of the extent of neuronal damage following TBI; FA was most strongly correlated with neuropsychological outcomes.

Executive functions following traumatic brain injury in young children: A preliminary analysis

To examine executive processes in young children with traumatic brain injury (TBI), we evaluated performance of 44 children who sustained moderate-to-severe TBI prior to age 6 and to 39 comparison children on delayed response (DR), stationary boxes, and spatial reversal (SR) tasks. The tasks have different requirements for holding mental representations in working memory (WM) over a delay, inhibiting prepotent responses, and shifting response set. Age at the time of testing was divided into 10- to 35- and 36- to 85-month ranges. In relation to the community comparison group, children with moderate-to-severe TBI scored significantly lower on indexes of WM/inhibitory control (IC) on DR and stationary boxes tasks. On the latter task, the Age × Group interaction indicated that performance efficiency was significantly reduced in the older children with TBI relative to the older comparison group; performance was similar in younger children irrespective of injury status. The TBI and comparison groups did not differ on the SR task, suggesting that shifting response set was not significantly altered by TBI. In both the TBI and comparison groups, performance improved with age on the DR and stationary boxes tasks. Age at testing was not significantly related to scores on the SR task. The rate of acquisition of working memory (WM) and IC increases steeply during preschool years, but the abilities involved in shifting response set show less increase across age groups (Espy, Kaufmann, & Glisky, 2001; Luciana & Nelson, 1998). The findings of our study are consistent with the rapid development hypothesis, which predicts that skills in a rapid stage of development will be vulnerable to disruption by brain injury.

Acute neuroradiologic findings in young children with inflicted or noninflicted traumatic brain injury

Abstract Acute CT/MRI findings were examined in a prospective, longitudinal study of 60 children 0–6 years of age hospitalized for moderate to severe traumatic brain injury (TBI). TBI was categorized as either inflicted (n=31) or noninflicted (n=29). Glasgow Coma Scale scores and perinatal history were comparable in both groups. Acute CT/MRI studies were visually inspected by a radiologist blind to group membership. Compared with the noninflicted TBI group, the inflicted TBI group had significantly elevated rates of subdural interhemispheric and convexity hemorrhages as well as signs of pre-existing brain abnormality, including cerebral atrophy, subdural hygroma, and ex vacuo ventriculomegaly. Intraparenchymal hemorrhage, shear injury, and skull fractures were more frequent after noninflicted TBI. Subarachnoid hemorrhage and infarct/edema occurred with comparable frequency in both groups. Characteristic acute neuroimaging findings of inflicted TBI included multiple extraaxial hemorrhages in addition to the mild atrophy, subdural hygromas, and ventriculomegaly that suggest prior brain abnormality.

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 Workgroups 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.

Predictors of outcome following traumatic brain injury in young children

The relationship between clinical and neuroimaging variables and multiple outcome measures was examined in a longitudinal, prospective study of 60 children less than 6 years of age who sustained either inflicted or noninflicted traumatic brain injury. Hierarchical multiple regression indicated that the modified Glasgow Coma Scale score, the duration of impaired consciousness and the number of intracranial lesions visualized on CT/MRI accounted for a significant amount of the variance in the Glasgow Outcome Scale (GOS), cognitive and motor scores at baseline, 3- and 12-month evaluations. Inflicted brain injury adversely affected both GOS and cognitive outcomes. Pupillary abnormalities were associated with poorer motor outcome. Neither age at injury nor the Injury Severity Score accounted for significant variability in outcomes.

Inflicted Traumatic Brain Injury: Relationship of Developmental Outcome to Severity of Injury

Inflicted traumatic brain injury (TBI) is a frequent consequence of physical child abuse in infants and children. Twenty-eight children who were 2–42 months of age when hospitalized for moderate to severe TBI were enrolled in a prospective, longitudinal study of neurobehavioral outcome following acquired brain injury. Relative to a comparison group, the children with inflicted TBI had significant deficits in cognitive, motor and behavioral domains when assessed with the Bayley Scales of Infant Development-II 1 and 3 months after the injury. Nearly half of the injured children showed persisting deficits in attention/arousal, emotional regulation and motor coordination. Greater injury severity, as indicated by lower coma scale scores, longer periods of unconsciousness and the presence of edema/cerebral infarctions was associated with poorer outcomes in all domains.

Cognitive and neuroimaging findings in physically abused preschoolers

Aims: To characterise the cognitive, motor, and language skills of toddlers and preschoolers who had been physically abused and to obtain concurrent MRIs of the brain. Methods: A between groups design was used to compare a sample of 19 children, aged 14–77 months, who had been hospitalised for physical abuse with no evidence of neurological injury to a comparison group of 19 children matched for age and socioeconomic status. Children underwent cognitive, language, and motor testing within three months of their discharge from the hospital. Caregivers of the injured children were interviewed and were asked to complete questionnaires to characterise the child’s developmental level and behaviour just prior to the hospitalisation. Results: Children who had been physically abused scored significantly lower than the comparison group on measures of cognitive functioning, motor skills, and language skills. The groups did not differ in child behaviour ratings completed by the caregivers. MRI of the brain was performed for 15 children in the physical abuse group; two were found to have significant cerebral atrophy. Conclusions: Children who have been physically abused are at high risk for delays in cognitive, motor, and language development. Standard of care for these children should include developmental testing as well as neuroimaging of the brain to detect occult brain injury.

The Effects of Pediatric Traumatic Brain Injury on Verbal and Visual-Spatial Working Memory

The purpose of this study was to investigate the effects of pediatric traumatic brain injury (TBI) on verbal and visual-spatial working memory (WM). WM tasks examined memory span through recall of the last item of a series of stimuli. Additionally, both verbal and visual-spatial tests had a dual-task condition assessing the effect of increasing demands on the central executive (CE). Inhibitory control processes in verbal WM were examined through intrusion errors. The TBI group (n = 73) performed more poorly on verbal and visual-spatial WM tasks than orthopedic-injured children (n = 30) and non-injured children (n = 40). All groups performed more poorly on the dual-task conditions, reflecting an effect of increasing CE load. This effect was not greater for the TBI group. There were no group differences in intrusion errors on the verbal WM task, suggesting that problems in WM experienced by children with TBI were not primarily due to difficulties in inhibitory control. Finally, injury-related characteristics, namely days to follow commands, accounted for significant variance in WM performance, after controlling for relevant demographic variables. Findings suggest that WM impairments in TBI are general rather than modality-specific and that severity indices measured over time are better predictors of WM performance than those taken at a single time point.

Predicting behavioral deficits in pediatric traumatic brain injury through uncinate fasciculus integrity.

Behavioral dysregulation is a common and detrimental consequence of traumatic brain injury (TBI) in children that contributes to poor academic achievement and deficits in social development. Unfortunately, behavioral dysregulation is difficult to predict from either injury severity or early neuropsychological evaluation. The uncinate fasciculus (UF) connects orbitofrontal and anterior temporal lobes, which are commonly implicated in emotional and behavioral regulation. Using probabilistic diffusion tensor tractography (DTT), we examined the relationship between the integrity of the UF 3 months post-injury and ratings of executive functions 12 months post-injury in children with moderate to severe TBI and a comparison group with orthopedic injuries. As expected, fractional anisotropy of the UF was lower in the TBI group relative to the orthopedic injury group. DTT metrics from the UF served as a biomarker and predicted ratings of emotional and behavior regulation, but not metacognition. In contrast, the Glasgow Coma Scale score was not related to either UF integrity or to executive function outcomes. Neuroanatomical biomarkers like the uncinate fasciculus may allow for early identification of behavioral problems and allow for investigation into the relationship of frontotemporal networks to brain-behavior relationships.