Neuroanatomic correlates of CVLT-C performance following pediatric traumatic brain injury

Exploring the measurement of pediatric cognitive-communication disorders in traumatic brain injury research: A scoping review

OBJECTIVE

To synthesize information about the constructs measured, measurement instruments used, and the timing of assessment of cognitive-communication disorders (CCDs) in pediatric traumatic brain injury (TBI) research.

METHODS AND PROCEDURES

Scoping review conducted in alignment with Arksey and O'Malley's five-stage methodological framework and reported per the PRISMA extension for Scoping Reviews. Inclusion criteria: (a) cohort description, case-control, and treatment studies; (b) participants with TBI aged 5-18 years; (c) communication or psychosocial outcomes; and (d) English full-text journal articles. The first author reviewed all titles, abstracts, and full-text articles; 10% were independently reviewed.

OUTCOMES AND RESULTS

Following screening, a total of 687 articles were included and 919 measurement instruments, measuring 2134 unique constructs, were extracted. The Child Behavior Checklist was the most used measurement instrument and 'Global Outcomes/Recovery' was the construct most frequently measured. The length of longitudinal monitoring ranged between ≤3 months and 16 years.

CONCLUSIONS AND IMPLICATIONS

We found considerable heterogeneity in the constructs measured, the measurement instruments used, and the timing of CCD assessment in pediatric TBI research. A consistent approach to measurement may support clinical decision-making and the efficient use of data beyond individual studies in systematic reviews and meta-analyses.

Clinical Utility of the Child and Adolescent Memory Profile (ChAMP) After Pediatric Traumatic Brain Injury

Sixty-one children and adolescents with traumatic brain injury completed the Child and Adolescent Memory Profile (ChAMP; Sherman & Brooks, 2015) within 1 to 12 months post injury. Most of the ChAMP index scores demonstrated statistically significant negative correlations with time to follow commands following traumatic brain injury. Compared with demographically matched neurologically healthy controls, selected from the ChAMP standardization sample, participants with traumatic brain injury had statistically significantly lower scores on all ChAMP index scores but sensitivity and specificity were suboptimal. We conclude that the ChAMP has modest clinical utility as part of a more comprehensive evaluation of sequelae of traumatic brain injury in children and adolescents.

Depletion of microglia immediately following traumatic brain injury in the pediatric rat: Implications for cellular and behavioral pathology

The inflammatory response is a significant component of the pathophysiology of pediatric traumatic brain injury. High levels of inflammatory mediators have been found in the cerebrospinal fluid of brain-injured children which have been linked to poor prognosis. Targeting aspects of the inflammatory response in the hopes of finding a viable post-injury therapeutic option has gained attention. Microglia are largely responsible for perpetuating the injury-induced inflammatory response but in the developing brain they play beneficial roles in both normal and disease states. Following closed head injury in the neonate rat, depletion of microglia with intracerebral injections of liposomes containing clodronate was associated with an increase in neurodegeneration in the early post-injury period (3 days) relative to those injected with empty liposomes suggestive of a decrease in clearance of dying cells. In sham-injured animals, microglia repopulated the clodrosome-mediated depleted brain regions over a period of 2-4 weeks and exhibited morphology typical of a resting phenotype. In brain-injured animals, the repopulated microglia in clodrosome-injected animals exhibited rod-like and amoeboid morphologies. However, fluoro-Jade B reactivity in these brain regions was more extensive than in empty liposome-injected animals suggesting that the active microglia may be unable to clear dying neurons. This was accompanied by an induction of hyperexcitability in the local cortical circuitry. Depletion of microglia within the white matter tracts and the thalamus did not affect the extent of injury-induced traumatic axonal injury. Increased neurodegeneration in the dorsal subiculum was not accompanied by any changes to injury-induced deficits in spatial learning and memory. These data suggest that activation of microglia may be important for removal of dying neurons in the traumatically-injured immature brain.

Construct validity for the verbal associated pairs screen

The present study introduces the Verbal Associated Pairs Screen (VAPS) as a new measure for assessing performance validity in pediatric populations. This study presents initial data on psychometric properties and establishes construct validity for the VAPS in a sample of 30 adolescent healthy controls and 206 youths with traumatic brain injury (TBI: moderate/severe, N = 30; mild, N = 176). The control group's age (M = 14.93, SD = 1.8) was significantly higher than the moderate/severe TBI (M = 13.9, SD = 2.8), t(68.508) = -3.038, p = .003, and mild TBI (mTBI) groups (M = 14, SD = 2.8), t(54.147) = 2.038, p = .046. The TBI groups were administered the VAPS in accord with other established performance validity tests (PVTs) and well-established  memory tests as part of routine clinical evaluations. The healthy control group was administered the VAPS only. VAPS score distributions for the control group were negatively skewed and highly kurtotic. VAPS scores from the moderate/severe TBI and control groups were indistinguishable for Trial 2 (U = 274, p < .01) and the Delay (U = 396, p = .218). In the mTBI group, convergent and divergent validity was established with other well-validated PVTs and memory tests, respectively. ROC curve analyses identified optimal cutoff scores for the VAPS Total Score, with acceptable sensitivity (55%) and excellent specificity (100%), as well as strong detectability (AUC = .829, 95% CI: 0.731 - 0.928, p < .001). Clinical applications, limitations, and directions for future research with the VAPS are discussed.

Neuropsychological outcome of children with traumatic brain injury and its association with late magnetic resonance imaging findings: A cohort study

OBJECTIVES

To evaluate neuropsychological outcome after traumatic brain injury (TBI) and its association with trauma severity and late magnetic resonance imaging (MRI) findings.

METHODS

Prospective cohort study of patients with TBI admitted to the paediatric intensive care unit over 5 years. Trauma severity was determined by Glasgow Coma Scale (GCS), neurological outcome by King's Outcome Scale for Childhood Head Injury (KOSCHI) and neuropsychological outcome by Wechsler Intelligence Scale for Children - Fourth Edition.

RESULTS

Twenty-five children (median age 6 years at trauma) were included. Patients were divided into Disability (DIS)(n = 10) and Good Recovery (GR)(n = 15) groups. Initial GCS score was not significantly different in both groups (median 6 vs. 10; p = 0.34). DIS group had lower values ​​of working memory index (WMI)(median 74 vs. 94; p = 0.004), perceptual reasoning index (PRI)(75 vs. 96; p = 0.03), verbal comprehension index (VCI)(65 vs. 84; p = 0.02), processing speed index (PSI)(74 vs. 97; p = 0.01) and full-scale intelligence quotient (FSIQ)(65 vs. 87; p = 0.008). In the GR group, 60% of patients had normal or minimally altered MRI versus 10% of patients in the DIS group (p = 0.018). Fractional anisotropy positively correlated with WMI(r = 0.65; p = 0.005), PRI(r = 0.52; p = 0.03) and FSIQ(r = 0.50; p = 0.04).

CONCLUSIONS

Neuropsychological impairment was observed in 40% of children who suffered a TBI and was associated with late MRI abnormalities.

The relationship between uncinate fasciculus white matter integrity and verbal memory proficiency in children

During childhood, verbal learning and memory are important for academic performance. Recent functional MRI studies have reported on the functional correlates of verbal memory proficiency, but few have reported the underlying structural correlates. The present study sought to test the relationship between fronto-temporal white matter integrity and verbal memory proficiency in children. Diffusion weighted images were collected from 17 Black children (age 8-11 years) who also completed the California Verbal Learning Test. To index white matter integrity, fractional anisotropy values were calculated for bilateral uncinate fasciculus. The results revealed that low anisotropy values corresponded to poor verbal memory, whereas high anisotropy values corresponded to significantly better verbal memory scores. These findings suggest that a greater degree of myelination and cohesiveness of axonal fibers in uncinate fasciculus underlie better verbal memory proficiency in children.

Diffusion tensor imaging in moderate-to-severe pediatric traumatic brain injury: changes within an 18 month post-injury interval

Traumatic brain injury (TBI) is a leading cause of death and disability in children, yet little is known regarding the pattern of TBI-related microstructural change and its impact on subsequent development. Diffusion tensor imaging (DTI) was used to examine between-group differences at two time points (planned intervals of 3 months and 18 months post-injury) and within-group longitudinal change in a group of children and adolescents aged 7-17 years with moderate-to-severe TBI (n = 20) and a comparison group of children with orthopedic injury (OI) (n = 21). In the 3- and 18-month cross-sectional analyses, tract-based spatial statistics (TBSS) generally revealed decreased fractional anisotropy (FA) and increased apparent diffusion coefficient (ADC) in the TBI group in regions of frontal, temporal, parietal, and occipital white matter as well as several deep subcortical structures, though areas of FA decrease were more prominent at the 3-month assessment, and areas of ADC increase were more prominent at the 18 month assessment, particularly in the frontal regions. In terms of the within-group changes over time, the OI group demonstrated primarily diffuse increases in FA over time, consistent with previous findings of DTI-measured white matter developmental change. The TBI group demonstrated primarily regions of FA decrease and ADC increase over time, consistent with presumed continued degenerative change, though regions of ADC decrease were also appreciated. These results suggest that TBI-related microstructural changes are dynamic in children and continue until at least 18 months post-injury. Understanding the course of these changes in DTI metrics may be important in TBI for facilitating advances in management and intervention.

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's 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.

Observer Rating of Memory in Children: A Review

Research on observer rating of memory in children is examined in relation to the potential to develop screening instruments to improve efficiency in memory assessment, to shed light on the area of everyday memory in children, and to develop observer rating to the point where it may substitute for objective assessment. Several scales including the Parent Memory Questionnaire, the Children's Memory Questionnaire, the Observer Memory Questionnaire — Parent Form and the Working Memory Rating Scale are reviewed. Only the Working Memory Rating Scale has been published. Some of the other scales have good internal consistency and test–retest reliability but none have proven to be effective screening instruments and none can yet be recommended for clinical application. Relationships with objective test results have been at best modest, an issue that requires more detailed analysis if such instruments are to become effective screeners or even substitutes for objective assessment. Further observer rating research will shed light on everyday memory in children including its relationship to objective assessment and its place in models of memory. It remains to be established whether observer ratings add unique information to memory assessment or whether they can become a reliable, cost-effective substitute for objective assessment.

Diffusion tensor imaging of incentive effects in prospective memory after pediatric traumatic brain injury

Few studies exist investigating the brain-behavior relations of event-based prospective memory (EB-PM) impairments following traumatic brain injury (TBI). To address this, children with moderate-to-severe TBI performed an EB-PM test with two motivational enhancement conditions and underwent concurrent diffusion tensor imaging (DTI) at 3 months post-injury. Children with orthopedic injuries (OI; n=37) or moderate-to-severe TBI (n=40) were contrasted. Significant group differences were found for fractional anisotropy (FA) and apparent diffusion coefficient for orbitofrontal white matter (WM), cingulum bundles, and uncinate fasciculi. The FA of these WM structures in children with TBI significantly correlated with EB-PM performance in the high, but not the low motivation condition. Regression analyses within the TBI group indicated that the FA of the left cingulum bundle (p=0.003), left orbitofrontal WM (p<0.02), and left (p<0.02) and right (p<0.008) uncinate fasciculi significantly predicted EB-PM performance in the high motivation condition. We infer that the cingulum bundles, orbitofrontal WM, and uncinate fasciculi are important WM structures mediating motivation-based EB-PM responses following moderate-to-severe TBI in children.

Patterns of cortical thinning in relation to event-based prospective memory performance three months after moderate to severe traumatic brain injury in children

While event-based prospective memory (EB-PM) tasks are a familiar part of daily life for children, currently no data exists concerning the relation between EB-PM performance and brain volumetrics after traumatic brain injury (TBI). This study investigated EB-PM in children (7 to 17 years) with moderate to severe TBI or orthopedic injuries. Participants performed an EB-PM task and concurrently underwent neuroimaging at three months postinjury. Surface reconstruction and cortical thickness analysis were performed using FreeSurfer software. Cortical thickness was significantly correlated with EB-PM (adjusting for age). Significant thinning in the left (dorsolateral and inferior prefrontal cortex, anterior and posterior cingulate, temporal lobe, fusiform, and parahippocampal gyri), and right hemispheres (dorsolateral, inferior, and medial prefrontal cortex, cingulate, and temporal lobe) correlated positively and significantly with EB-PM performance; findings are comparable to those of functional neuroimaging and lesion studies of EB-PM.

Disruptive behaviour disorders and disruptive symptoms after severe paediatric traumatic brain injury

OBJECTIVE

To determine pre-injury prevalence and post-injury incidence of DSM-III-R oppositional defiant disorder (ODD) and conduct disorder (CD), increase in disruptive symptoms after severe paediatric traumatic brain injury (TBI) and risk factors associated with development of these disturbances.

METHODS

Ninety-four children were followed 1 one year after severe TBI. Assessments of pre-injury and 1-year psychiatric status were ascertained by parent report. The 1-year incidence of disruptive behaviour disorders/symptoms was the main outcome measure.

RESULTS

The pre-injury prevalence of ODD and CD in the TBI sample was 6% and 8%, respectively, the prevalence of pre-injury CD being significantly higher than in a reference population. The incidence of new-onset ODD and CD 1-year post-injury was 9% and 8%, respectively, the incidence of new-onset CD being significantly higher than in a reference population. ODD symptoms and total number of disruptive symptoms increased significantly over the first post-injury year. Significant risk factors for disruptive disorders/symptoms included higher pre-injury psychosocial adversity, delinquency ratings and affective lability.

CONCLUSIONS

Pre-injury conduct disorder is a significant risk factor for post-injury disruptive behaviours. New-onset CD and disruptive symptoms are consequences of TBI at 1-year post-injury. Risk factors for these post-injury disturbances are similar to risk factors in non-TBI populations.

Neurodevelopmental outcomes of pediatric traumatic brain injury

Pediatric traumatic brain injury is a major cause for concern when considering both the number of children sustaining injuries and the large number of children incurring life-long difficulties that impact on quality of life. Research is continuing to investigate outcomes and predictors of recovery in both cognitive and behavioral domains. Findings have contributed to better identification of children at high risk for neurobehavioral difficulties. The challenge is to now develop intervention programs to prevent or lessen the impact of such difficulties.

Predictors of outcome following acquired brain injury in children

Acquired brain injury (ABI) in children and adolescents can result from multiple causes, including trauma, central nervous system infections, noninfectious disorders (epilepsy, hypoxia/ischemia, genetic/metabolic disorders), tumors, and vascular abnormalities. Prediction of outcomes is important, to target interventions, allocate resources, provide education to family or caregivers, and begin appropriate planning for the future. Researchers have identified several factors associated with better or worse outcomes after ABI, including variables related to the injury itself, postinjury factors related to intervention or trajectory of recovery, and preinjury or demographic factors. When examining the scientific literature, it is important to identify how "outcome" is defined, as the predictors may change depending on the outcome studied. In addition, key variables may be specific to the etiology of injury. Therefore, predictors of outcome cannot be generalized across the various etiologies of ABI, and this review will discuss predictors within the context of multiple etiologies of ABI. This article reviews the current literature on predicting outcomes after pediatric ABI, and areas in need of further research are discussed.

Neuroimaging in pediatric traumatic brain injury: current and future predictors of functional outcome

Although neuroimaging has long played a role in the acute management of pediatric traumatic brain injury (TBI), until recently, its use as a tool for understanding and predicting long-term brain-behavior relationships after TBI has been limited by the relatively poor sensitivity of routine clinical imaging for detecting diffuse axonal injury (DAI). Newer magnetic resonance-based imaging techniques demonstrate improved sensitivity to DAI. Early research suggests that these techniques hold promise for identifying imaging predictors and correlates of chronic function, both globally and within specific neuropsychological domains. In this review, we describe the principles of new, advanced imaging techniques including diffusion weighted and diffusion tensor imaging, susceptibility weighted imaging, and (1)H-magnetic resonance spectroscopy. In addition, we summarize current research demonstrating their early success in establishing relationships between imaging measures and functional outcomes after TBI. With the ongoing research, these imaging techniques may allow earlier identification of possible chronic sequelae of tissue injury for each child with TBI, thereby facilitating efficacy and efficiency in delivering successful rehabilitation services.

Working memory performance following paediatric traumatic brain injury

PRIMARY OBJECTIVE

The present study investigated working memory ability in children who sustained moderate-to-severe traumatic brain injuries in relation to pre-injury, injury-related and developmental factors. It was hypothesized that there would be a correlation between performance- and rater-based working memory measures; factors predictive of working memory impairment would include earlier age at injury, more severe injury, longer time since injury and poorer overall cognitive functioning; and working memory performance would be significantly impaired when compared to normative populations.

METHODS AND PROCEDURES

Working memory was assessed in 62 children using a traditional performance measure (digit span backward) and parent report (Behaviour Rating Inventory of Executive Function (BRIEF)).

MAIN OUTCOMES AND RESULTS

Contrary to prediction, there was no statistical association between performance- and rater-based measures of working memory. Regression analyses revealed injury severity, time-since-injury, overall cognitive ability and attention span were predictive of working memory performance. As a group, working memory was impaired relative to normative samples on both measures.

CONCLUSIONS

Performance- and rater-based working memory measures, while not significantly correlated, are both sensitive to acquired cognitive dysfunction following paediatric traumatic brain injury. Demographic and clinical factors may be used to predict cognitive outcomes, educate caregivers and design clinical interventions.

Neural correlates of verbal associative memory and mnemonic strategy use following childhood traumatic brain injury

Children with traumatic brain injury (TBI) often experience memory deficits, although the nature, functional implication, and recovery trajectory of such difficulties are poorly understood. The present fMRI study examined the neural activation patterns in a group of young children who sustained moderate TBI in early childhood (n = 7), and a group of healthy control children (n = 13) during a verbal paired associate learning (PAL) task that promoted the use of two mnemonic strategies differing in efficacy. The children with TBI demonstrated intact memory performance and were able to successfully utilize the mnemonic strategies. However, the TBI group also demonstrated altered brain activation patterns during the task compared to the control children. These findings suggest early childhood TBI may alter activation within the network of brain regions supporting associative memory even in children who show good behavioral performance.

Effects of prenatal alcohol exposure on hippocampal volume, verbal learning, and verbal and spatial recall in late childhood

Children with prenatal alcohol exposure (PAE) show deficits in verbal learning and spatial memory, as well as abnormal hippocampal development. The relationship between their memory and neuroanatomic impairments, however, has not been directly explored. Given that the hippocampus is integral for the synthesis and retrieval of learned information and is particularly vulnerable to the teratogenic effects of alcohol, we assessed whether reduced learning and recall abilities in children with fetal alcohol spectrum disorders (FASDs) are associated with abnormal hippocampal volumes. Nineteen children with FASDs and 18 typically developing controls aged 9 to 15 years were assessed for verbal learning and verbal and spatial recall and underwent structural magnetic resonance imaging. Images were analyzed for total intracranial volume and for right and left hippocampal volumes. Results revealed smaller left hippocampi and poorer verbal learning and verbal and spatial recall performance in children with FASDs than controls, as well as positive correlations between selective memory indices and hippocampal volumes only in the FASD group. Additionally, hippocampal volumes increased significantly with age in controls only, suggesting that PAE may be associated with long-term abnormalities in hippocampal development that may contribute to impaired verbal learning and verbal and spatial recall.

Neurocognitive and neuroimaging correlates of pediatric traumatic brain injury: a diffusion tensor imaging (DTI) study

This study examined the sensitivity of diffusion tensor imaging (DTI) to microstructural white matter (WM) damage in mild and moderate pediatric traumatic brain injury (TBI). Fourteen children with TBI and 14 controls ages 10-18 had DTI scans and neurocognitive evaluations at 6-12 months post-injury. Groups did not differ in intelligence, but children with TBI showed slower processing speed, working memory and executive deficits, and greater behavioral dysregulation. The TBI group had lower fractional anisotropy (FA) in three WM regions: inferior frontal, superior frontal, and supracallosal. There were no group differences in corpus callosum. FA in the frontal and supracallosal regions was correlated with executive functioning. Supracallosal FA was also correlated with motor speed. Behavior ratings showed correlations with supracallosal FA. Parent-reported executive deficits were inversely correlated with FA. Results suggest that DTI measures are sensitive to long-term WM changes and associated with cognitive functioning following pediatric TBI.