Verbal learning and memory following pediatric closed-head injury

Consensus-Based Evaluation of Outcome Measures in Pediatric Stroke Care: A Toolkit

Following a pediatric stroke, outcome measures selected for monitoring functional recovery and development vary widely. We sought to develop a toolkit of outcome measures that are currently available to clinicians, possess strong psychometric properties, and are feasible for use within clinical settings. A multidisciplinary group of clinicians and scientists from the International Pediatric Stroke Organization comprehensively reviewed the quality of measures in multiple domains described in pediatric stroke populations including global performance, motor and cognitive function, language, quality of life, and behavior and adaptive functioning. The quality of each measure was evaluated using guidelines focused on responsiveness and sensitivity, reliability, validity, feasibility, and predictive utility. A total of 48 outcome measures were included and were rated by experts based on the available evidence within the literature supporting the strengths of their psychometric properties and practical use. Only three measures were found to be validated for use in pediatric stroke: the Pediatric Stroke Outcome Measure, the Pediatric Stroke Recurrence and Recovery Questionnaire, and the Pediatric Stroke Quality of Life Measure. However, multiple additional measures were deemed to have good psychometric properties and acceptable utility for assessing pediatric stroke outcomes. Strengths and weaknesses of commonly used measures including feasibility are highlighted to guide evidence-based and practicable outcome measure selection. Improving the coherence of outcome assessment will facilitate comparison of studies and enhance research and clinical care in children with stroke. Further work is urgently needed to close the gap and validate measures across all clinically significant domains in the pediatric stroke population.

A Preliminary DTI Tractography Study of Developmental Neuroplasticity 5-15 Years After Early Childhood Traumatic Brain Injury

Plasticity is often implicated as a reparative mechanism when addressing structural and functional brain development in young children following traumatic brain injury (TBI); however, conventional imaging methods may not capture the complexities of post-trauma development. The present study examined the cingulum bundles and perforant pathways using diffusion tensor imaging (DTI) in 21 children and adolescents (ages 10–18 years) 5–15 years after sustaining early childhood TBI in comparison with 19 demographically-matched typically-developing children. Verbal memory and executive functioning were also evaluated and analyzed in relation to DTI metrics. Beyond the expected direction of quantitative DTI metrics in the TBI group, we also found qualitative differences in the streamline density of both pathways generated from DTI tractography in over half of those with early TBI. These children exhibited hypertrophic cingulum bundles relative to the comparison group, and the number of tract streamlines negatively correlated with age at injury, particularly in the late-developing anterior regions of the cingulum; however, streamline density did not relate to executive functioning. Although streamline density of the perforant pathway was not related to age at injury, streamline density of the left perforant pathway was significantly and positively related to verbal memory scores in those with TBI, and a moderate effect size was found in the right hemisphere. DTI tractography may provide insight into developmental plasticity in children post-injury. While traditional DTI metrics demonstrate expected relations to cognitive performance in group-based analyses, altered growth is reflected in the white matter structures themselves in some children several years post-injury. Whether this plasticity is adaptive or maladaptive, and whether the alterations are structure-specific, warrants further investigation.

The Impact of Traumatic Injury to the Immature Human Brain: A Scoping Review with Insights from Advanced Structural Neuroimaging

Traumatic brain injury (TBI) during critical periods of early-life brain development can affect the normal formation of brain networks responsible for a range of complex social behaviors. Because of the protracted nature of brain and behavioral development, deficits in cognitive and socioaffective behaviors may not become evident until late adolescence and early adulthood, when such skills are expected to reach maturity. In addition, multiple pre- and post-injury factors can interact with the effects of early brain insult to influence long-term outcomes. In recent years, with advancements in magnetic-resonance-based neuroimaging techniques and analysis, studies of the pediatric population have revealed a link between neurobehavioral deficits, such as social dysfunction, with white matter damage. In this review, in which we focus on contributions from Australian researchers to the field, we have highlighted pioneering longitudinal studies in pediatric TBI, in relation to social deficits specifically. We also discuss the use of advanced neuroimaging and novel behavioral assays in animal models of TBI in the immature brain. Together, this research aims to understand the relationship between injury consequences and ongoing brain development after pediatric TBI, which promises to improve prediction of the behavioral deficits that emerge in the years subsequent to early-life injury.

Acute pediatric traumatic brain injury severity predicts long-term verbal memory performance through suppression by white matter integrity on diffusion tensor imaging

Mediation analysis was used to investigate the role of white matter integrity in the relationship between injury severity and verbal memory performance in participants with chronic pediatric traumatic brain injury (TBI). DTI tractography was used to measure fractional anisotropy (FA) within the corpus callosum, fornix, cingulum bundles, perforant pathways, and uncinate fasciculi. Injury severity was indexed using Glasgow Coma Scale (GCS) scores obtained at the time of the injury. Verbal memory was measured by performance on the long-delay free recall (LDFR) trial of the California Verbal Learning Test-Children's version. Participants were between the ages of 10-18 and included 21 children with TBI (injured before age 9) and 19 typically-developing children (TDC). Children with TBI showed lower FA across all pathways and poorer LDFR performance relative to TDC. Within the TBI group, mediation analysis revealed neither a significant total effect of GCS on LDFR nor significant direct effects of GCS on LDFR across pathways; however, the indirect effects of GCS on LDFR through FA of the corpus callosum, left perforant pathway, and left uncinate fasciculus were significant and opposite in sign to their respective direct effects. These results suggests that the predictive validity of GCS for LDFR is initially suppressed by the substantial variance accounted for by FA, which is uncorrelated with GCS, and the predictive validity of GCS increases only when FA is considered, and the opposing path is controlled. These findings illustrate the complex associations between acute injury severity, white matter pathways, and verbal memory several years following pediatric TBI.

Sport Contact Level Affects Post-Concussion Neurocognitive Performance in Young Athletes

OBJECTIVE

Contact level affects the incidence of sports-related concussion. However, the effects of contact level on injury severity and recovery are less clear and are the focus of this study.

METHOD

Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) for athletes aged 12-22 was performed at baseline (n = 10,907 for 7,058 athletes), after suspected concussion determined by physicians or athletic trainers (n = 5,062 for 4,419 athletes), and during follow-up visits (n = 3,264 for 2,098 athletes). Athletes played contact/collision (CC), limited contact (LC), and noncontact (NC) sports. Injury incidence, severity, and recovery were measured using raw and change from baseline neurocognitive test scores. Comparisons between groups used univariate analysis and multivariable regression controlling for demographic variables.

RESULTS

Compared to CC athletes, LC and NC athletes showed decreased suspected concussion incidence. At initial post-injury testing, all neurocognitive test scores were similar between groups except changes from baseline for processing speed were improved for LC compared to CC athletes. Upon follow-up testing, raw neurocognitive scores were better for NC compared to the contact collision athletes in verbal memory, processing speed, total symptom score, migraine cluster, cognitive cluster, and neuropsychiatric cluster scores. For change from baseline scores, LC athletes exhibited better performance on verbal memory, processing speed, and reaction time but also showed higher neuropsychiatric scores than CC athletes.

CONCLUSION

Neurocognitive scores between contact levels were similar at the first post-injury test. However, follow up showed many improved scores and symptoms for limited and NC sports compared to CC sports, which may indicate faster recovery.

Cognitive and spectral coherence of EEG alterations in resting state in children with chronic TBI

Introduction. TBI is associated with alterations in cortico-subcortical connectivity. However, little attention has been paid to its clinical characteristics and functional connectivity in pediatric patients with chronic TBI. Objective. To evaluate the cognitive performance and spectral coherence of a group of children with TBI in non-acute phase. Method. Cross-sectional study of 15 children with chronic TBI and 17 healthy children. The Neuropsychological Assessment of Children (Evaluación Neuropsicológica Infantil, ENI) was used and the resting activity of the EEG with eyes-closed was recorded. Offline, two-second epochs of the EEG of each participant were chosen and the spectral coherence was estimated in a range of 1.6 to 30 Hz. The cognitive performance between groups was compared with T-test/Mann-Whitney U Test and MANOVA for the coherence values. Results. The TBI group showed a lower performance (p ≤ 0.05) in metalinguistic, visuospatial skills, attention, memory, non-verbal flexibility, planning, and organization. Differences (p ≤ 0.000) were found both inter and intrahemispherically in the spectral coherence between the groups, particularly on F1-F3 (95% CI: 0.543 - 0.557) over the whole frequency range and F3-C3 (95% CI: 0.503 - 0.515) in delta, theta, alpha2, and beta frequencies. Discussion and conclusión. Our findings suggest alterations of hypo and hyper functional connectivity, particularly on the frontal and parietal lobes of both hemispheres, even after several years of a TBI. It is possible that a subtle difference in the degree of connectivity is crucial in the genesis or successful development of attentional, mnesic, executive, and visuospatial processes.

Is Computerized Cognitive Testing Useful in Children and Adolescents with Moderate-to-Severe Traumatic Brain Injury?

OBJECTIVES

Children and adolescents with moderate-to-severe traumatic brain injury (TBI) present with short and long-term neuropsychological deficits following their injury. The aim of this study was to investigate the utility of a brief computerized test battery for evaluating cognitive functioning sub-acutely following a TBI.

METHODS

Participants (n=33) sustained a moderate-to-severe TBI, were between 8 and 18 years old, and were assessed using CNS Vital Signs (CNSVS) within 6 months post-injury (median=0.6 month). Participants with TBI were matched to 33 healthy controls based on age, sex, and handedness to compare their cognitive functioning on the CNSVS battery.

RESULTS

Children and adolescents with moderate-to-severe TBI had significantly lower scores and large effect sizes on Reaction Time, Complex Attention, and Cognitive Flexibility domains, as well as medium effect sizes on two Visual Memory test scores and one Psychomotor Speed test score. A significantly higher percentage of participants with TBI had cognitive impairment on Reaction Time domain score compared to the control group. Finally, CNSVS domain scores correctly categorized 76% of participants as either group with TBI or control group.

CONCLUSIONS

CNSVS may be a useful tool for screening cognitive abilities in children and adolescents who are early in their recovery from a moderate-to-severe TBI, particularly when a rapid screening evaluation can help guide management, interventions, and track recovery. (JINS, 2017, 23, 304-313).

Acute and Chronic Altitude-Induced Cognitive Dysfunction in Children and Adolescents

OBJECTIVE

To assess whether exposure to high altitude induces cognitive dysfunction in young healthy European children and adolescents during acute, short-term exposure to an altitude of 3450 m and in an age-matched European population permanently living at this altitude.

STUDY DESIGN

We tested executive function (inhibition, shifting, and working memory), memory (verbal, short-term visuospatial, and verbal episodic memory), and speed processing ability in: (1) 48 healthy nonacclimatized European children and adolescents, 24 hours after arrival at high altitude and 3 months after return to low altitude; (2) 21 matched European subjects permanently living at high altitude; and (3) a matched control group tested twice at low altitude.

RESULTS

Short-term hypoxia significantly impaired all but 2 (visuospatial memory and processing speed) of the neuropsychological abilities that were tested. These impairments were even more severe in the children permanently living at high altitude. Three months after return to low altitude, the neuropsychological performances significantly improved and were comparable with those observed in the control group tested only at low altitude.

CONCLUSIONS

Acute short-term exposure to an altitude at which major tourist destinations are located induces marked executive and memory deficits in healthy children. These deficits are equally marked or more severe in children permanently living at high altitude and are expected to impair their learning abilities.

Evaluation of an attention and memory intervention post-childhood acquired brain injury: Preliminary efficacy, immediate and 6 months post-intervention

OBJECTIVE

Impairments in attention and memory are common sequelae following paediatric acquired brain injury (ABI). While it has been established that such impairments are long-term and, therefore, affect quality-of-life, there is a scarcity of evidence-based interventions to treat these difficulties. The current study aimed to pilot the efficacy of the Amsterdam Memory and Attention Training for Children (Amat-c: English version) using both neuropsychological and ecologically sensitive measures. It was expected that children with attention and memory difficulties post-ABI would show improved performance post-intervention on cognitive and ecological measures, with maintenance at 6 months post-intervention.

METHODS AND PROCEDURES

Ten children with an ABI, between the ages of 8-13 years at the time of recruitment were identified through audits of presentations to a metropolitan paediatric hospital. Each child underwent screening, the 18 week intervention programme, pre-intervention, immediate and 6 month post-intervention assessments.

OUTCOMES/RESULTS

Findings supported the hypothesis that children would show post-intervention (immediate and 6 month) improvement in areas of attention and memory, with generalization to everyday life.

CONCLUSIONS/IMPLICATIONS

Preliminary results provide support for the efficacy of the Amat-c post-childhood ABI. A larger study is needed to confirm these findings, as a reduction in attention and memory difficulties will enhance everyday functioning.

Deficits in social behavior emerge during development after pediatric traumatic brain injury in mice

The pediatric brain may be particularly vulnerable to social deficits after traumatic brain injury (TBI) due to the protracted nature of psychosocial development through adolescence. However, the majority of pre-clinical studies fail to assess social outcomes in experimental pediatric TBI. The current study evaluated social behavior in mice subjected to TBI at post-natal day (p)21. Social behaviors were assessed by a partition test, resident-intruder, three-chamber, and tube dominance tasks during adolescence (p35-42) and again during early adulthood (p60-70), during encounters with unfamiliar, naïve stimulus mice. Despite normal olfactory function and normal social behaviors during adolescence, brain-injured mice showed impaired social investigation by adulthood, evidenced by reduced ano-genital sniffing and reduced following of stimulus mice in the resident-intruder task, as well as a loss of preference for sociability in the three-chamber task. TBI mice also lacked a preference for social novelty, suggestive of a deficit in social recognition or memory. By adulthood, brain-injured mice exerted more frequent dominance in the tube task compared to sham-operated controls, a finding suggestive of aggressive tendencies. Together these findings reveal reduced social interaction and a tendency towards increased aggression, which evolves across development to adulthood. This emergence of aberrant social behavior, which parallels the development of other cognitive deficits in this model and behaviors seen in brain-injured children, is consistent with the hypothesis that the full extent of deficits is not realized until the associated skills reach maturity. Thus, efficacy of therapeutics for pediatric TBI should take into account the time-dependent emergence of abnormal behavioral patterns.

Association of parent ratings of executive function with global- and setting-specific behavioral impairment after adolescent traumatic brain injury

OBJECTIVE

To determine the association of primary caregiver-rated behavioral and metacognitive aspects of executive function (EF) with impaired functioning after adolescent traumatic brain injury (TBI).

DESIGN

Multicenter cross-sectional study.

SETTING

Outpatient.

PARTICIPANTS

Primary caregivers and children (N=132) aged 12 to 17 years who sustained a moderate or severe TBI within the past 1 to 6 months.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Primary caregiver ratings of EF, tests of memory and processing speed (PS), and a structured parent interview to assess clinical impairments in behavioral functioning were used. Logistic regression was used to examine the relation of ratings of EF with clinical ratings of impairment in global adolescent functioning and in functioning in the home, school, and community settings after controlling for sex, race, socioeconomic status, injury severity, and performance on the tests of memory and PS.

RESULTS

Caregiver ratings of poor EF were associated with impairment in both global behavioral functioning (odds ratio [OR]=4.73; 95% confidence interval [CI], 1.54-14.52; P<.01) and community functioning (OR=13.28; 95% CI, 1.94-90.87; P<.01).

CONCLUSIONS

Caregiver ratings of deficits in EF were associated with impaired behavioral functioning after adolescent TBI and were independent of performance on tests of memory and processing speed. Understanding the relation of EF with clinical impairments as manifested in different settings will help hone assessment batteries and focus treatments where they are needed most.

Demographic and injury-related moderators of memory and achievement outcome in pediatric TBI

Critical factors affecting traumatic brain injury (TBI) outcome in children and adolescents are explored with an emphasis on an examination of age at injury as a predictor of memory functioning. Age at injury and other injury-related and demographic predictors (i.e., severity, time postinjury, gender, and socioeconomic status [SES]) of memory and achievement outcome were examined in 65 children and adolescents post-TBI compared to 65 age-matched noninjured controls. Although robust findings have been found for age at injury as a general predictor of outcome, age was not found to be a significant predictor of memory functioning following pediatric TBI. Structural equation modeling suggests that the most parsimonious model of post-TBI outcome contains two causally related latent variables: one defined by gender, SES, injury severity, and age at injury, and one defined by general cognitive functioning.

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.

Assessment of the learning curve from the California Verbal Learning Test-Children's Version with the first-order system transfer function

A mathematical model is proposed to measure the learning curve in the California Verbal Learning Test-Children's Version. The model is based on the first-order system transfer function in the form Y = B3*exp[-B2*(X-1)]+B4*{1-exp[-B2*(X-1)]}, where X is the trial number, Y is the number of recalled correct words, B2 is the learning rate, B3 is interpreted as readiness to learn and B4 as the ability to learn. Children's readiness to learn and ability to learn were lower than adults. Modeling revealed that girls had greater readiness to learn and ability to learn than boys.

Comparison of verbal learning and memory in children with heavy prenatal alcohol exposure or attention-deficit/hyperactivity disorder

BACKGROUND

Children with fetal alcohol spectrum disorders (FASD) have deficits in verbal learning and recall. However, the specificity of these deficits has not been adequately tested. In the current study, verbal learning and memory performance of children with heavy prenatal alcohol exposure was compared to children with attention-deficit/hyperactivity disorder (ADHD), a disorder commonly seen in alcohol-exposed children.

METHODS

Performance on the California Verbal Learning Test-Children's Version (CVLT-C) was examined in 3 groups of children (N=22/group): (i) heavy prenatal alcohol exposure and ADHD (ALC), (ii) nonexposed with ADHD (ADHD), and (iii) nonexposed typically developing (CON). Groups were matched on age, sex, race, ethnicity, handedness, and socioeconomic status (SES).

RESULTS

Group differences were noted on learning trials (CON >ADHD> ALC). On the delayed recall trial, CON children performed better than both clinical groups, who did not differ from each other. Children in the ALC group demonstrated poorer recognition than children in the CON and ADHD groups, who did not differ from each other. Marginally significant group differences were noted on retention of previously learned material. Post hoc analyses indicated that ADHD children showed worse retention relative to the CON group, whereas retention in the ALC children remained intact.

CONCLUSIONS

These data suggest that children with heavy prenatal alcohol exposure and nonexposed children with ADHD show differential patterns of deficit on the CVLT-C. Performance of alcohol-exposed children reflects inefficient encoding of verbal material, whereas performance of the ADHD group may be better characterized by a deficit in retrieval of learned material. Differences noted between clinical groups add to a growing neurobehavioral profile of FASD that may aid in differential diagnosis.

Differential effects of injury severity on cognition and cellular pathology after contusive brain trauma in the immature rat

Although diffuse brain damage has been suggested to be the predominant predictor of neurological morbidity following closed head injury in infants and children, the presence of contusions also predicts long-term neurobehavioral dysfunction. Contusive brain trauma in the 17-day-old rat resulted in neurodegeneration and caspase activation in the cortex at 1 day, and in the thalamus at 3 days post-injury, and to a greater extent following a deeper impact. Cortical tissue loss in the 4-mm impact group was significantly greater than that in the 3-mm impact group (p < 0.05), and exhibited a time-dependent increase over the first 3 weeks post-injury. Traumatic axonal injury was observed in the white matter tracts below the site of impact at 1 day, and in the corpus callosum at 3 days, to a greater extent following 4-mm impact. In contrast, cellular caspase-3 activation in these white matter tracts was only observed at 24 h post-injury and was not affected by impact depth. Similarly, neurodegeneration and caspase activation in the hippocampus was restricted to the dentate gyrus and occurred to a similar extent in both injured groups. Only the 4-mm impact group exhibited learning deficits in the first week (p < 0.0001) that was sustained until the third week post-injury (p < 0.0001), while deficits in the 3-mm impact group were seen only at 3 weeks post-injury (p < 0.02). These observations demonstrate that increasing severity of injury in immature animals does not uniformly increase the extent of cellular damage, and that the progression of tissue damage and behavioral deficits varies as a function of injury severity.

Memory and learning in pediatric traumatic brain injury: a review and examination of moderators of outcome

This article reviews empirically supported assessment methods to examine impairments in memory and learning following pediatric traumatic brain injury (TBI). Critical factors affecting outcome are explored with an emphasis on an examination of age at injury. The article closes with discussion of current evidence-based interventions for deficits in memory and learning following pediatric TBI.

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.

The efficacy of donepezil hydrochloride on memory functioning in three adolescents with severe traumatic brain injury

OBJECTIVE

To explore efficacy of donepezil on memory in adolescents with severe traumatic brain injury (TBI).

DESIGN

Single subject, unblinded, multiple baseline design.

METHODS AND PROCEDURES

Memory functioning was examined in three adolescents with TBI on and off medication (5 and 10 mg) using the Selective Reminding Test. Four variables were examined: Total recall (TR) = number of words total words recalled, Long Term Storage (LTS) = words recalled on two trials in a row, Consistency of Long Term Retrieval (CLTR) = words continuously recalled, Delay = number of words recalled after delay.

RESULTS

On medication, three out of three participants demonstrated better memory. Two showed greatest improvement on 10 mg. All participants demonstrated improvement in TR and LTS. Two participants demonstrated improved CLTR. No participants displayed improvement in Delay. No adverse side effects were reported.

CONCLUSIONS

Results suggests that donepezil may be effective in improving memory in adolescents with severe TBI and warrant further examination.

Long-term neuropsychological performance in a cohort of children and adolescents after severe paediatric traumatic brain injury

OBJECTIVE

The purpose of the present study was to evaluate progress in neuropsychological performance in children and adolescents with severe paediatric traumatic brain injury (TBI), from admission to the rehabilitation centre up to 3-12 years after the trauma.

METHODS

Children and adolescents (n = 31, mean age at injury 11.8 years, SD = 3.8; at follow-up 18.8 years; SD = 4.5) who all had suffered a TBI participated. A comprehensive neuropsychological test battery was administered at the start of rehabilitation (T1), around discharge (T2) and in the long-term (at least 3 years after rehabilitation; T3). T1 and T2 were clinical assessments; T3 was executed as a follow-up measurement for this study.

RESULTS

At T1 and T2, most problems were in the domains of attention, memory and executive functioning. At the start of rehabilitation most deficits were with performal intelligence (61%); at discharge (mean length of stay 411 days) considerably less children had severe deficits on the intelligence domain (23%). At long-term follow-up, most problems were in the domains attention, mental speed and memory. From admission to discharge 42% of the children improved on two or more cognitive tests; from discharge to follow-up this percentage was 13%.

CONCLUSIONS

In this unique study a clinical cohort of children with severe TBI was followed for many years after injury. Most cognitive deficits were found in the early phase of rehabilitation. Most children did improve on cognitive functioning (40%) during the first year after their injury, whereas at follow-up most children had not changed. At follow-up, more than half of the children (54%) attended a regular school or had a regular job, corresponding to their age and pre-morbid functioning.

Predicting longitudinal patterns of functional deficits in children with traumatic brain injury

Longitudinal patterns of functional deficits were investigated in 37 children with severe traumatic brain injury (TBI), 40 children with moderate TBI, and 44 children with orthopedic injuries. They were from 6 to 12 years of age when injured. Their neuropsychological, behavioral, adaptive, and academic functioning were assessed at 6 months, 12 months, and 3-5 years postinjury. Functional deficits (<10th percentile for age) were identified within each outcome domain at each occasion. Children were classified into 4 a priori longitudinal patterns of outcomes within domains (i.e., no deficits, improvement, deterioration, persistent deficits). In multinomial logistic regression analyses, severe TBI predicted an increased likelihood of persistent deficits in all outcome domains, as well as deterioration in behavioral functioning and improvement in neuropsychological, adaptive, and academic functioning. Severe TBI also predicted a greater total number of functional deficits across domains at each occasion. However, many children with severe TBI showed no deficits from 6 months to 4 years postinjury in 1 or more outcome domains. The findings help clarify the course of recovery for individual children following TBI.

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.

Memory outcome at 5 years post-childhood traumatic brain injury

PRIMARY OBJECTIVE

This study seeks to extend previous findings by documenting memory performance in a sample of 70 children at 5 years post-injury. It was anticipated that increasing injury severity would be associated with decreased performance on working and complex memory tasks. It was also expected that injury severity would significantly predict memory, but that the time from insult to subsequent testing would be associated with an increased relationship to non-injury factors.

RESEARCH DESIGN

Participants were assessed at 5 years post-injury, aged between 6-14 years, using measures of immediate, working and complex memory.

METHODS AND PROCEDURES

The sample comprised 18 children who had sustained a severe TBI, 24 with a moderate TBI, 11 with a mild TBI and 17 healthy controls, matched for age, gender and socio-economic-status.

RESULTS

Results indicated that severe TBI was associated with decreased complex auditory-verbal memory performance, although children with TBI did not display impairment on immediate, working or complex visual-spatial memory. While injury severity significantly predicted complex memory outcome, non-injury factors failed to significantly predict either working or complex memory performance.

CONCLUSIONS

Future research should be engineered towards further clarifying what influences recovery from childhood TBI in the elongated post-injury period.

Retrieval processes in adults with ADHD: a RAVLT study

Attention-deficit hyperactivity disorder (ADHD) is associated with memory deficiencies. In the current study we compared different aspects of verbal memory using standard and constructed measures of the Rey auditory verbal learning test (RAVLT). Performance on learning and recognition measures of RAVLT was similar in both ADHD and control groups. In contrast, adults with ADHD committed more double recalls and intrusion errors, indicating inaccurate recall processes. These findings suggest that memory problems in adults with ADHD may be caused by deficient executive processes that support retrieval from memory.

Prediction of cognitive sequelae based on abnormal computed tomography findings in children following mild traumatic brain injury

OBJECT

The aim of this study was to determine whether the presence of intracranial pathophysiology on computed tomography (CT) scans obtained within 24 hours of mild traumatic brain injury (MTBI) in children adversely affects neuropsychological outcome during the 1st year postinjury.

METHODS

A prospective longitudinal design was used to examine the neuropsychological outcomes in children (ages 5-15 years) who had been treated for MTBI, which was defined as a loss of consciousness for up to 30 minutes and a lowest Glasgow Coma Scale (GCS) score of 13-15. Exclusion criteria included any preinjury neurological disorder. Outcome assessments were performed within 2 weeks and at 3, 6, and 12 months postinjury. Outcomes were compared between patients with MTBI whose postinjury CT scans revealed complications of brain pathophysiology (32 patients, CMTBI group) and those with MTBI but without complications (48 patients, MTBI group).

RESULTS

Significant interactions confirmed that the pattern of recovery over 12 months after injury differed depending on the intracranial pathology, presence and severity of injuries to body regions other than the head, preinjury attention-deficit hyperactivity disorder (ADHD), and socioeconomic status. Children in the CMTBI group had significantly poorer episodic memory, slower cognitive processing, diminished recovery in managing cognitive interference, and poorer performance in calculating and reading than patients in the MTBI group. Among the patients with mild or no extracranial injury, visuomotor speed was slower in those in the CMTBI group; and among patients without preinjury ADHD, working memory was worse in those in the CMTBI group.

CONCLUSIONS

Neuropsychological recovery during the 1st year following MTBI is related to the presence of radiographically detectable intracranial pathology. Children with intracranial pathology on acute CT performed more poorly in several cognitive domains when compared with patients whose CT findings were normal or limited to a linear skull fracture. Depending on the presence of preinjury ADHD and concomitant extracranial injury, working memory and visuomotor speed were also diminished in patients whose CT findings revealed complications following MTBI. Computed tomography within 24 hours postinjury appears to be useful for identifying children with an elevated risk for residual neuropsychological changes.

Using magnetic resonance imaging to predict new learning outcome at 5 years after childhood traumatic brain injury

Memory and learning entail the recruitment of a number of neural areas, including the medial temporal lobes, temporal association areas, and prefrontal cortices. This study examined the effects of injury severity on long-term memory function in 55 children who sustained traumatic brain injury 5 years earlier and compared this with 17 healthy controls. It also investigated cortical damage and diffuse axonal injury and their association to memory and learning outcomes 5 years after traumatic brain injury. Children were administered memory tests of increasing complexity. Results indicated that injury severity affected aspects of complex memory, with no significant influence on working memory; that focal cortical damage was not predictive of working or complex memory, whereas diffuse axonal injury predicted outcome on complex memory tasks. Findings suggest that the implementation of diffuse axonal injury as an index of injury may assist in predicting memory outcome after childhood traumatic brain injury.

The Color Object Association Test (COAT): the development of a new measure of declarative memory for 18- to 36-month-old toddlers

Few methods exist to measure declarative (explicit) memory in children during the toddler and preschool stages of development. We report the development and psychometric properties of a new measure of declarative memory for this age group, the Color Object Association Test (COAT). In pilot testing and large scale application of the test, the COAT was demonstrated to be a reliable and a valid measure of declarative memory for healthy children ages 18-36 months, living in a disadvantaged community. The test shows a linear developmental trajectory, which allows longitudinal examination of the development of declarative memory in children.

Working memory and new learning following pediatric traumatic brain injury

Working memory (WM), the ability to monitor, process and maintain task relevant information on-line to respond to immediate environmental demands, is controlled by frontal systems (D'Esposito et al., 2006), which are particularly vulnerable to damage from a traumatic brain injury (TBI). This study employed the adult-based Working Memory model of Baddeley and Hitch (1974) to examine the relationship between working memory function and new verbal learning in children with TBI. A cross-sectional sample of 36 school-aged children with a moderate to severe TBI was compared to age-matched healthy Controls on a series of tasks assessing working memory subsystems: the Phonological Loop (PL) and Central Executive (CE). The TBI group performed significantly more poorly than Controls on the PL measure and the majority of CE tasks. On new learning tasks, the TBI group consistently produced fewer words than Controls across the learning and delayed recall phases. Results revealed impaired PL function related to poor encoding and acquisition on a new verbal learning task in the TBI group. CE retrieval deficits in the TBI group contributed to general memory dysfunction in acquisition, retrieval and recognition memory. These results suggest that the nature of learning and memory deficits in children with TBI is related to working memory impairment.

Recovery in Memory Function, and its Relationship to Academic Success, at 24 Months Following Pediatric TBI*

While a number of research papers have reported findings on memory deficits following traumatic brain injury (TBI), only limited studies have monitored the recovery of these skills over time. The present study examined memory ability and its effect on academic success in a group of children who had sustained a mild, moderate, or severe traumatic brain injury (TBI). Results showed that the severe TBI group exhibited greater deficits on memory tasks, irrespective of modality, in the acute, 6-, 12-, and 24-month postinjury stages, in comparison to mild and moderate TBI groups. Performance on academic measures was dependent on both injury severity and task demands. Preinjury academic ability and verbal memory indices best predicted academic success.

Pediatric brain injury: social, behavioral, and communication disability

Communication-related disability is common after childhood traumatic brain injury. In most cases, the problems are secondary to executive function, cognitive, or behavioral impairments. Many of the problems persist and have been documented in children with mild and severe injuries. Persistent disability tends to be more severe in children injured at younger ages and often grows in severity over the developmental years. After reviewing the outcome literature, this article presents current approaches to behavioral and social-communication disability.

Hippocampus, amygdala, and basal ganglia morphometrics in children after moderate-to-severe traumatic brain injury

While closed head injury frequently results in damage to the frontal and temporal lobes, damage to deep cortical structures, such as the hippocampus, amygdala, and basal ganglia, has also been reported. Five deep central structures (hippocampus, amygdala, globus pallidus, putamen, and caudate) were examined in 16 children (eight males, eight females; aged 9-16y), imaged 1 to 10 years after moderate-to-severe traumatic brain injury (TBI), and in 16 individually-matched uninjured children. Analysis revealed significant volume loss in the hippocampus, amydala, and globus pallidus of the TBI group. Investigation of relative volume loss between these structures and against five cortical areas (ventromedial frontal, superomedial frontal, lateral frontal, temporal, and parieto-occipital) revealed the hippocampus to be the most vulnerable structure following TBI (i.e. greatest relative difference between the groups). In a separate analysis excluding children with focal hippocampal abnormalities (e.g. lesions), group differences in hippocampal volume were still evident, suggesting that hippocampal damage may be diffuse rather than focal.

Inhibitory Control in Children with Frontal Infarcts Related to Sickle Cell Disease

Evidence from past studies indicates that children with traumatic brain injury experience difficulties with inhibitory control. Less is known about inhibitory control in children with frontal brain injury related to cerebral infarction. We compared the inhibitory performance of children with frontal infarcts related to sickle cell disease with that of a control group of children with sickle cell disease but no history of cerebral infarction. On a stimulus-response reversal task, children with frontal infarcts made significantly more accuracy errors in the inhibitory condition than controls. Findings from this study and from previous research suggest that impairments in inhibitory control are common following frontal injury in a range of pediatric populations.

Cluster subtypes on the California verbal learning test-children's version after pediatric traumatic brain injury

The purpose of this study is to determine the presence of profile subtypes on the California Verbal Learning Test-Children's Version (CVLT-C; Delis, Kramer, Kaplan, and Ober, 1994) in 175 children with traumatic brain injury (TBI). Four key z score variables are used in a 2-stage cluster analysis that reveal 4 reliable subtypes. No meaningful differences among the clusters are found on demographic variables. In contrast, statistically significant differences among the 4 clusters in both level and pattern of performance are found on injury severity parameters and the 4 factor index scores from an independent measure of psychometric intelligence (Wechsler Intelligence Scale for Children-Third Edition; Wechsler, 1991). This study concludes that although no unique profile is found on the CVLT-C after TBI in children, performance on this test is affected strongly by injury severity, with a mediating contribution by speed of information processing.

Traumatic injury to the immature brain results in progressive neuronal loss, hyperactivity and delayed cognitive impairments

The immature brain may be particularly vulnerable to injury during critical periods of development. To address the biologic basis for this vulnerability, mice were subjected to traumatic brain injury at postnatal day 21, a time point that approximates that of the toddler-aged child. After motor and cognitive testing at either 2 weeks (juveniles) or 3 months (adults) after injury, animals were euthanized and the brains prepared for quantitative histologic assessment. Brain-injured mice exhibited hyperactivity and age-dependent anxiolysis. Cortical lesion volume and subcortical neuronal loss were greater in brain-injured adults than in juveniles. Importantly, cognitive decline was delayed in onset and coincided with loss of neurons in the hippocampus. Our findings demonstrate that trauma to the developing brain results in a prolonged period of pathogenesis in both cortical and subcortical structures. Behavioral changes are a likely consequence of regional-specific neuronal degeneration.

Neuropsychological function in a group of patients 25 years after sustaining minor head injuries as children and adolescents

Previous studies suggest that neuropsychological impairment following mild to moderate pediatric head injury may become persistent and interrupt the normal course of intellectual development. In this study 45 subjects were assessed with a standardized neuropsychological test battery 25 years after sustaining mild to moderate head injury as children. Although the group scores in the normal range, significant relations between head injury severity and current neuropsychological function were found. The most important predictor of poor outcome was length of PTA at injury, EEG pathology, and loss of consciousness at injury. No significant influence of pre- and post-injury risk factors on current neuropsychological function was evident. The findings support the view that complicated mild and moderate paediatric head injury may heighten the risk of developing subtle neuropsychological problems later in life.

The Use of Serum Biomarkers to Predict Outcome After Traumatic Brain Injury in Adults and Children

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality in adults and children. Predicting outcome after TBI is difficult, but it is important for acute management, counseling of family members, and provision of rehabilitation services. Serum biomarkers may be useful alone or in combination with clinical variables to predict outcome after TBI. This article reviews the potential uses of serum biomarkers for the clinician, current literature related to the use of serum biomarkers for outcome prediction after adult and pediatric TBI, limitations of the literature, and future direction for this field.

Comparing attentional skills in children with acquired and developmental central nervous system disorders

Attentional impairments in children occur in the context of both developmental and acquired disorders involving the central nervous system (CNS) and may have implications for ongoing development, potentially impeding cognitive, educational, and behavioral functions. Using a continuous performance paradigm (CPT), this study compared attentional profiles of children with developmental and acquired conditions impacting on the CNS: (i) attention deficit-hyperactivity disorder (ADHD: n=27); (ii) moderate traumatic brain injury (TBI: n=41); (iii) acute lymphoblastic leukemia (n=31); and (iv) insulin-dependent diabetes mellitus (n=39). A healthy control group (n=46) was also examined. Groups were compared on measures of sustained attention, selective attention, and response inhibition. In addition, measures of performance variability and deterioration and processing speed were examined. Results showed that children with ADHD exhibited global and severe attentional impairments in contrast to all other groups. Children with moderate TBI displayed mild attentional difficulties, restricted to selective and sustained attention domains. In conclusion, although CPT parameters differentiated the ADHD group from all others, a disorder-specific profile was not observed.

The California Verbal Learning Test-Children's Version: relation to factor indices of the Wechsler Intelligence Scale for Children-Third Edition

The California Verbal Learning Test-Children's Version (CVLT-C) provides clinicians with a method of assessing various aspects of children's verbal memory and has been found to be sensitive to memory deficits resulting from a variety of neurological conditions. Intuitively, the CVLT-C would be expected to be highly related to a child's verbal cognitive abilities; however, with only a few exceptions, the relationship of this test to various domains of cognitive function has not been broadly studied empirically. To examine this issue, we evaluated the amount of unique variance in CVLT-C scores that could be predicted by the Verbal Comprehension, Perceptual Organization, Freedom from Distractibility, and Processing Speed indices of the Wechsler Intelligence Scale for Children, Third Edition (WISC-III) beyond that accounted for by age and gender in a sample of 62 children referred to an outpatient psychiatry clinic for neuropsychological evaluation. While the Processing Speed Index predicted a significant amount of variance for both short and long delay free and cued recall, the Verbal Comprehension Index was a poor predictor of CVLT-C performance on all outcome variables, accounting for only 1.5 to 4.5% additional variance above age and gender. These findings indicate that while the CVLT-C may be relatively independent of influences of verbal intelligence and abstract verbal reasoning, general speed and efficiency of processing play an important role in successful encoding for later retrieval on the CVLT-C.

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

Traumatic brain injury (TBI) frequently results in memory problems, and the degree of memory impairment is related to injury severity and is commonly associated with lesions in frontal and temporal brain areas. This study examined the relationship among injury severity, brain lesions, and memory in children with moderate to severe TBI using Donders' (1999) 5-factor model of performance on the California Verbal Learning Test-Children's Version (CVLT-C). Seventy-six children underwent magnetic resonance imaging (MRI) scans 3 months post-TBI and testing 1 year post-TBI. Results showed injury severity (Glasgow Coma Scale) was not predictive of performance on 4 of the 5 factors. Volume of frontal and/or temporal brain lesions was significantly predictive of performance on 3 of the 5 factors. Unexpectedly, lesion volume outside these areas (extra-frontotemporal) was predictive of performance on all 5 factors. In contrast, Verbal IQ at 1 year was most strongly associated with preinjury factors (socioeconomic status and special education involvement), although extra-frontotemporal lesions also contributed to the variability in this measure. Results suggest that in children with moderate to severe TBI, extra-frontal/temporal lesions are predictive of memory outcome 1 year postinjury above and beyond initial severity or frontal/temporal contusions. This finding may relate to widespread diffuse axonal injury, which potentially disconnects brain circuits mediating memory following moderate to severe TBI.

Construct validity of the California Verbal Learning Test--Children's Version (CVLT-C) after pediatric traumatic brain injury

The purpose of this study was to determine the latent structure of the California Verbal Learning Test--Children's Version (CVLT-C; D. Delis, J. Kramer, E. Kaplan, & B. Ober, 1994) in a sample of 175 children with traumatic brain injury (TBI). Maximum-likelihood confirmatory factor analyses were performed to test 6 competing hypothetical models for fit and parsimony. A 4-factor model consisting of Attention Span, Learning Efficiency, Delayed Recall, and Inaccurate Recall provided the best fit to the data. The results support the construct validity of the CVLT-C in children with TBI and suggest that a multifactorial interpretation of quantitative indexes from this instrument is appropriate for clinical practice.