Intelligence after traumatic brain injury: meta-analysis of outcomes and prognosis

Association Between Traumatic Brain Injury and Psychopathic Traits Among Justice-Involved Adolescents

Traumatic brain injury (TBI) is a global public health problem and is highly prevalent among justice-involved populations. Pediatric TBI is linked with long-term negative outcomes and is correlated with substance use, criminal behavior, psychiatric disorders, and disruptions in neurocognition. These same TBI correlates are evident among youth with psychopathic traits. Given ongoing neurobiological and social development in adolescence, understanding the link between psychopathic traits and TBI in justice-involved youth is critical. A sample of 263 male adolescents were recruited from a maximum-security juvenile justice facility. Using a structural equation modeling (SEM) framework, measurement invariance of psychopathic traits (TBI ±) was tested, and psychopathy scores were accounted for in terms of TBI variables (severity, age of first TBI, total number), participant's age, IQ, substance use, and internalizing psychopathology. There was evidence of strong invariance across TBI status and those with TBI had higher affective and impulsive lifestyle psychopathic traits than adolescents without TBI. The SEM indicated that TBI severity was associated with lower IQ scores, which in turn were associated with increased lifestyle/antisocial (Factor 2) psychopathic traits. Total number of TBIs was associated with higher substance use, which was associated with both increased interpersonal/affective (Factor 1) and Factor 2 psychopathic traits. These TBI variables also had indirect associations with psychopathic traits through IQ and substance use. The findings indicate that TBI is associated with psychopathic traits and suggest that disturbances in cognition and substance use may be treatment targets for youth with TBI and psychopathic traits.

PGK1 Is Involved in the HIF-1 Signaling Pathway as a Hub Gene for Ferroptosis After Traumatic Brain Injury

The pathogenesis of ferroptosis in traumatic brain injury (TBI) is unclear; therefore, we aimed to identify key molecules associated with ferroptosis in TBI using bioinformatics analysis to determine its underlying mechanisms. GSE128543 dataset was downloaded from the Gene Expression Omnibus (GEO) database, and TBI-associated modules were obtained by weighted gene co-expression network analysis (WGCNA). We identified 60 differentially expressed genes (DEGs) by intersecting the modules with ferroptosis and glycolysis/gluconeogenesis gene libraries. The hypoxia-inducible factor-1 (HIF-1) signaling pathway was identified to be critical for ferroptosis post-TBI, and protein-protein interaction (PPI) network identified 20 hub genes, including phosphoglycerate kinase 1 (PGK1), ribosomal protein (RP) family, pyruvate kinase M1/2 (PKM), hypoxia-inducible factor 1α subunit (HIF-1α), and MYC genes. In this study, we further explored the role of PGK1, a gene involved in HIF-1 signaling pathway; however, its role and mechanism in TBI are still unclear. Moreover, we constructed a TBI mouse model and examined PGK1 and HIF-1α expression levels, and the results revealed their expressions increased after cortical injury in mice and they co-localized in the same cells. Furthermore, we examined the expressions of PGK1 in the cerebrospinal fluid of 20 clinical patients with different degrees of brain injuries within 48 h of surgery and examined the cognitive function of patients according to the Glasgow Coma Scale (GCS). The results revealed that PGK1 expression level was negatively correlated with the severity of the brain injury. These findings suggest that PGK1 may become a potential hub gene for ferroptosis via the HIF-1 signaling pathway, second to neurological injury after TBI, thereby affecting patient prognosis.

Neuroinflammation and neurodegeneration following traumatic brain injuries

Traumatic brain injuries (TBI) commonly occur following head trauma. TBI may result in short- and long-term complications which may lead to neurodegenerative consequences, including cognitive impairment post-TBI. When investigating the neurodegeneration following TBI, studies have highlighted the role reactive astrocytes have in the neuroinflammation and degeneration process. This review showcases a variety of markers that show reactive astrocyte presence under pathological conditions, including glial fibrillary acidic protein (GFAP), Crystallin Alpha-B (CRYA-B), Complement Component 3 (C3) and S100A10. Astrocyte activation may lead to white-matter inflammation, expressed as white-matter hyperintensities. Other white-matter changes in the brain following TBI include increased cortical thickness in the white matter. This review addresses the gaps in the literature regarding post-mortem human studies focussing on reactive astrocytes, alongside the potential uses of these proteins as markers in the future studies that investigate the proportions of astrocytes in the post-TBI brain has been discussed. This research may benefit future studies that focus on the role reactive astrocytes play in the post-TBI brain and may assist clinicians in managing patients who have suffered TBI.

Malingering assessment after severe traumatic brain injury in forensic psychology with a potential embedded symptom validity indicator of Symptom Checklist 90

Objective

Malingering of neuropsychological damage is common among traumatic brain injury patients pursuing disability compensation in forensic contexts. There is an urgent need to explore differences in neuropsychological assessment outcomes with different levels of cooperation.

Methods

A total of 420 participants with severe traumatic brain injury were classified into malingering group, partial cooperation group, and complete cooperation group according to the Binomial forced-choice digit memory test. The Wechsler Adult Intelligence Scale, event-related potential component, and Symptom Checklist 90 were applied subsequently to assess the psychological status of participants.

Results

Participants in the malingering group presented lower scores in the binomial forced-choice digit memory test and the Wechsler Adult Intelligence Scale, lower P3 amplitude, and simultaneously higher scores in the Symptom Checklist 90 than the other two groups. The actual intelligence quotient of participants with malingering tendencies ranged mostly between normal and marginal damage, and they often reported elevated whole scale scores in the Symptom Checklist 90. The Cooperation Index (defined as the ratio of positive symptom distress index to global severity index, CI) was proposed and validated to function as an embedded validity indicator of the Symptom Checklist 90, and the area under the receiver operating characteristic (ROC) curve was 0.938. When valued at 1.28, CI has the highest classification ability in differentiating malingering from non-malingering. Combined with the CI and P3 amplitude, the area under the ROC curve for malingering diagnosis further reached 0.952.

Conclusion

Any non-optimal effort in a forensic context will lead to unexpected deviation in psychology evaluation results. CI is a potential candidate to act as an embedded validity indicator of the Symptom Checklist 90. The combination of CI and P3 amplitude can help to identify malingering in participants after severe traumatic brain injury.

Dynamic Emotion Recognition and Social Inference Ability in Traumatic Brain Injury: An Eye-Tracking Comparison Study

Emotion recognition and social inference impairments are well-documented features of post-traumatic brain injury (TBI), yet the mechanisms underpinning these are not fully understood. We examined dynamic emotion recognition, social inference abilities, and eye fixation patterns between adults with and without TBI. Eighteen individuals with TBI and 18 matched non-TBI participants were recruited and underwent all three components of The Assessment of Social Inference Test (TASIT). The TBI group were less accurate in identifying emotions compared to the non-TBI group. Individuals with TBI also scored lower when distinguishing sincere and sarcastic conversations, but scored similarly to those without TBI during lie vignettes. Finally, those with TBI also had difficulty understanding the actor's intentions, feelings, and beliefs compared to participants without TBI. No group differences were found for eye fixation patterns, and there were no associations between fixations and behavioural accuracy scores. This conflicts with previous studies, and might be related to an important distinction between static and dynamic stimuli. Visual strategies appeared goal- and stimulus-driven, with attention being distributed to the most diagnostic area of the face for each emotion. These findings suggest that low-level visual deficits may not be modulating emotion recognition and social inference disturbances post-TBI.

Regional Cortical Thickness Correlates of Intellectual Abilities Differ in Children With Traumatic Brain Injury Versus Those With Orthopedic Injury in the Chronic Post-Injury Phase

A decline in intellectual functioning (intelligence quotient [IQ]) is often observed following more severe forms of traumatic brain injury (TBI) and is a useful index for long-term outcome. Identifying brain correlates of IQ can serve to inform developmental trajectories of behavior in this population. Using magnetic resonance imaging (MRI), we examined the relationship between intellectual abilities and patterns of cortical thickness in children with a history of TBI or with orthopedic injury (OI) in the chronic phase of injury recovery. Participants were 47 children with OI and 58 children with TBI, with TBI severity ranging from complicated-mild to severe. Ages ranged from 8 to 14 years old, with an average age of 10.47 years, and an injury-to-test range of ∼1-5 years. The groups did not differ in age or sex. The intellectual ability estimate (full-scale [FS]IQ-2) was derived from a two-form (Vocabulary and Matrix Reasoning subtests) Wechsler Abbreviated Scale of Intelligence (WASI). MRI data were processed using the FreeSurfer toolkit and harmonized across data collection sites using neuroComBat procedures, while holding demographic features (i.e., sex, socioeconomic status [SES]), TBI status, and FSIQ-2 constant. Separate general linear models per group (TBI and OI) and a single interaction model with all participants were conducted with all significant results withstanding correction for multiple comparisons via permutation testing. Intellectual ability was higher (p < 0.001) in the OI group (FSIQ-2 = 110.81) than in the TBI group (FSIQ-2 = 99.81). In children with OI, bi-hemispheric regions, including the right pre-central gyrus and precuneus and bilateral inferior temporal and left occipital areas were related to IQ, such that higher IQ was associated with thicker cortex in these regions. In contrast, only cortical thickness in the right pre-central gyrus and bilateral cuneus positively related to IQ in children with TBI. Significant interaction effects were found in the bilateral temporal, parietal, and occipital lobes and left frontal regions, indicating that the relationship between IQ and cortical thickness differed between groups in these regions. Changes in cortical associations with IQ after TBI may reflect direct injury effects and/or adaptation in cortical structure and intellectual functioning, particularly in the bilateral posterior parietal and inferior temporal regions. This suggests that the substrates of intellectual ability are particularly susceptible to acquired injury in the integrative association cortex. Longitudinal work is needed to account for normal developmental changes and to investigate how cortical thickness and intellectual functioning and their association change over time following TBI. Improved understanding of how TBI-related cortical thickness alterations relate to cognitive outcome could lead to improved predictions of outcome following brain injury.

Randomized clinical trial on the effects of a computerized cognitive training for pediatric patients with acquired brain injury or congenital malformation

Both acquired injuries and congenital malformations often cause lifelong disabilities in children, with a significant impact on cognitive abilities. Remote computerized cognitive training (CCT) may be delivered in ecological settings to favour rehabilitation continuity. This randomized clinical trial (RCT) evaluated the efficacy of an 8-week multi-domain, home-based CCT in a sample of patients aged 11-16 years with non-progressive acquired brain injury (ABI), brain tumor (BT) and congenital brain malformation (CBM). Following a stepped-wedge research design, patients were randomized into two groups: Training-first group, which started the CCT immediately after baseline assessment and Waiting-first group, which started the CCT after a period of time comparable to that required by the training (8 weeks). Post-training and long-term (6 months) changes were assessed. Both groups improved on visual-spatial working memory after the CCT, with benefits maintained after 6 months, while no other changes in cognitive or psychological measures were found. These findings suggest that a multi-domain CCT can generate benefits in visual-spatial working memory, in accordance with data from extant literature reporting that computer games heavily engage visuo-spatial abilities. We speculate that is tapping on the same cognitive ability with a prolonged training that may generate the greatest change after a CCT.

IQ After Pediatric Concussion

OBJECTIVES

This study investigated IQ scores in pediatric concussion (ie, mild traumatic brain injury) versus orthopedic injury.

METHODS

Children (N = 866; aged 8-16.99 years) were recruited for 2 prospective cohort studies from emergency departments at children's hospitals (2 sites in the United States and 5 in Canada) ≤48 hours after sustaining a concussion or orthopedic injury. They completed IQ and performance validity testing postacutely (3-18 days postinjury; United States) or 3 months postinjury (Canada). Group differences in IQ scores were examined using 3 complementary statistical approaches (linear modeling, Bayesian, and multigroup factor analysis) in children performing above cutoffs on validity testing.

RESULTS

Linear models showed small group differences in full-scale IQ (d [95% confidence interval] = 0.13 [0.00-0.26]) and matrix reasoning (0.16 [0.03-0.30]), but not in vocabulary scores. IQ scores were not related to previous concussion, acute clinical features, injury mechanism, a validated clinical risk score, pre- or postinjury symptom ratings, litigation, or symptomatic status at 1 month postinjury. Bayesian models provided moderate to very strong evidence against group differences in IQ scores (Bayes factor 0.02-0.23). Multigroup factor analysis further demonstrated strict measurement invariance, indicating group equivalence in factor structure of the IQ test and latent variable means.

CONCLUSIONS

Across multisite, prospective study cohorts, 3 complementary statistical models provided no evidence of clinically meaningful differences in IQ scores after pediatric concussion. Instead, overall results provided strong evidence against reduced intelligence in the first few weeks to months after pediatric concussion.

The magnitude of neurocognitive impairment is overestimated in depression: the role of motivation, debilitating momentary influences, and the overreliance on mean differences

BACKGROUND

Meta-analyses agree that depression is characterized by neurocognitive dysfunctions relative to nonclinical controls. These deficits allegedly stem from impairments in functionally corresponding brain areas. Increasingly, studies suggest that some performance deficits are in part caused by negative task-taking attitudes such as poor motivation or the presence of distracting symptoms. A pilot study confirmed that these factors mediate neurocognitive deficits in depression. The validity of these results is however questionable given they were based solely on self-report measures. The present study addresses this caveat by having examiners assess influences during a neurocognitive examination, which were concurrently tested for their predictive value on performance.

METHODS

Thirty-three patients with depression and 36 healthy controls were assessed on a battery of neurocognitive tests. The examiner completed the Impact on Performance Scale, a questionnaire evaluating mediating influences that may impact performance.

RESULTS

On average, patients performed worse than controls at a large effect size. When the total score of the Impact on Performance Scale was accounted for by mediation analysis and analyses of covariance, group differences were reduced to a medium effect size. A total of 30% of patients showed impairments of at least one standard deviation below the mean.

CONCLUSIONS

This study confirms that neurocognitive impairment in depression is likely overestimated; future studies should consider fair test-taking conditions. We advise researchers to report percentages of patients showing performance deficits rather than relying solely on overall group differences. This prevents fostering the impression that the majority of patients exert deficits, when in fact deficits are only true for a subgroup.

Processing Speed in Children with Traumatic Brain Injury

Abstract: Traumatic brain injury (TBI) is a common cause of childhood morbidity and mortality. Information processing speed (IPS) is a central construct of neuropsychology and a mediator for a range of cognitive functions. In adults, the negative effects of TBI on IPS are well documented. This review qualitatively describes the impact of TBI on IPS in children and adolescents and examines various influencing factors. We included a total of 37 studies in the review that explored IPS using various clinical assessments. These clinical assessments often examine other neuropsychological functions besides IPS. In 29 of these studies, we found a negative effect of TBI on IPS. While injury severity has small but consistent effects on IPS, the effects of age at injury, time since injury, and gender were less evident. Because it is a central construct of neuropsychological functions, IPS should be assessed after TBI.

Prediction Models for Neurocognitive Outcome of Mild Traumatic Brain Injury in Children: A Systematic Review

Mild traumatic brain injury (mTBI) is highly prevalent in children. Recent literature suggests that children with mTBI are at considerable risk of persisting neurocognitive deficits, threatening post-injury child development. Nevertheless, clinical tools for early identification of children at risk are currently not available. This systematic review aims to describe the available literature on neurocognitive outcome prediction models in children with mTBI. Findings are highly relevant for early identification of children at risk of persistent neurocognitive deficits, allowing targeted treatment of these children to optimize recovery. The electronic literature search was conducted in PubMed, EMBASE, CINAHL, Cochrane, PsychINFO and Web of Science on February 9, 2022. We included all studies with multi-variate models for neurocognitive outcome based on original data from only children (age <18 years) with mTBI. Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, two authors independently performed data extraction and risk of bias analysis using the Prediction model Risk of Bias Assessment Tool (PROBAST). This systematic review identified eight original studies (nine articles) reporting prediction models for neurocognitive outcome, representing a total of 1033 children diagnosed with mTBI (mean age at injury = 10.5 years, 37.6% girls). Neurocognitive outcome assessment took place between 1 month and 7 years post-injury. Models were identified with significant predictive value for the following outcomes: memory, working memory, inhibition, processing speed, and general neurocognitive functioning. Prediction performance of these models varied greatly between weak and substantial (R² = 10.0%-54.7%). The best performing model was based on demographic and pre-morbid risk factors in conjunction with a subacute neurocognitive screening to predict the presence of a deficit in general neurocognitive functioning at 12 months post-injury. This systematic review reflects the absence of robust prediction models for neurocognitive outcome of children with mTBI. The findings indicate that demographic factors, pre-morbid factors as well as acute and subacute clinical factors have relevance for neurocognitive outcome. Based on the available evidence, evaluation of demographic and pre-morbid risk factors in conjunction with a subacute neurocognitive screening may have the best potential to predict neurocognitive outcome in children with mTBI. The findings underline the importance of future research contributing to early identification of children at risk of persisting neurocognitive deficits.

The Underlying Mechanisms in the Association Between Traumatic Brain Injury in Childhood and Conduct Disorder Symptoms in Late Adolescence

The present study examined i) the direct association between traumatic brain injury (TBI) in childhood and conduct disorder symptoms in adolescence, ii) whether this effect is mediated by impulsivity and/or callous unemotional traits (CU traits), and iii) whether these indirect effects are moderated by childhood family adversity and adolescent substance use. Utilising data from the Avon Longitudinal Study of Parents and Children (ALSPAC), participants with head injury information up to 12 years (4.5 years, 5.4 years, 6.5 years, 8.6 years, 11.7 years) were identified and categorised into a TBI (n = 409), orthopaedic injury (n = 1469) or non-injury group (n = 5685). Psychosocial factors such as impulsivity at 13 years, CU traits at 13 years, childhood family adversity (between birth to 4 years) and substance use at 14 years were collated for moderated mediation analyses. Conduct disorder symptoms were assessed at 16 years of age. TBI and conduct disorder symptoms were positively associated, and this association was mediated by impulsivity but not CU traits. The indirect effects were higher in magnitude for individuals with higher levels of childhood family adversity. Adolescent substance use was not found to moderate the indirect effects between TBI and conduct disorder symptoms. These results were specific to TBI individuals, and not in participants with orthopaedic injury and no reported injuries. Targeting impulsivity and early family adversity may alleviate the risk of conduct disorder symptoms following TBI in childhood. These findings have important implications for informing neuro-rehabilitative and preventative measures in clinical and community settings.

Deficits in visuospatial attentional cueing following mild traumatic brain injury

Visual attentional deficits are frequently reported in patients with mild traumatic brain injury (TBI). In the present study, the ability to orient visual attention (i.e., the use of endogenous and exogenous visual cues) was investigated using a modified Posner visual search task, in which the participant was required to search for a target shape (radial frequency patterns) amongst distractor shapes. Participants were required to determine whether a target radial frequency pattern was present or absent from an array of distractors. Attention to the target location was cued using central or peripheral cueing procedures to investigate endogenous or exogenous attention allocation. Predictability was not manipulated between central and peripheral cues. Search difficulty was varied by systematically changing the radial frequency difference between target and distractors (and thereby shape difference), and cues could be valid or invalid in that they correctly or incorrectly indicated the position of the target shape. Both target discriminability (i.e., identifying the presence or absence of the target) and reaction times were measured. Thirteen patients with chronic mild TBI and 21 age-, sex-, and IQ -matched healthy controls participated in the study. For control participants, both discrimination accuracy and reaction times improved with visual search efficiency, and they were sensitive to the type of cue, with performance worst for cue invalid conditions than valid conditions. However, the results for TBI patients were strikingly different; we find that discrimination accuracy slightly improved with visual search difficulty (compared to controls), but not reaction times, and TBI patients were largely insensitive to the type of visual cue, and did not show a selective deficit for central or peripheral cues, suggesting an impairment in both endogenous and exogenous visual attention. In conclusion, patients with mild TBI exhibit a poor ability to orient visual attention.

The AMPK-SIRT1-FoxO1-NF-κB signaling pathway participates in hesperetin-mediated neuroprotective effects against traumatic brain injury via the NLRP3 inflammasome

BACKGROUND

Traumatic brain injury (TBI) induces inflammations that lead to secondary damage. Hesperetin (Hes) exerts anti-inflammatory activities against central nervous system (CNS) diseases. This article probes the possible neuroprotective effect and mechanism of Hes on TBI-induced acute cerebral damage.

METHODS

Male C57BL/6J mice were subjected to controlled cortical impingement (CCI) and Hes (50 mg/kg) treatment after the surgery. Short-term neurological deficits were assessed with the modified neurological severity score (mNSS) and the Rota-rod test. The brain edema was tested by the wet/dry method. Neuron apoptosis was evaluated by Nissl staining and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining. The blood-brain barrier (BBB) integrity was measured by Evans' blue staining, and immunohistochemistry (IHC) was conducted to study BV2 microglial activation. BV2 microglia and HT22 neuronal cells were stimulated by oxygen-glucose deprivation followed by recovery (OGD/R) and processed with Hes. Quantitative real-time-polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) were implemented to gauge the expression of inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-β (IL-1-β) and interleukin-6 (IL-6). Western blot (WB) was performed to check AMPK-SIRT1-FoxO1 both in vitro and in vivo.

RESULTS

Hes eased neurological deficits, cerebral edema, and neuronal apoptosis in mice following TBI. Hes hampered microglial activation and pro-inflammatory cytokines production. Hes promoted AMPK and SIRT1 expression, whereas repressed the phosphorylation of FoxO1-NF-κB, and inhibited NLRP3 expression. The AMPK inhibitor Compound C markedly reversed Hes-mediated anti-inflammatory and neuron-protective effects.

CONCLUSION

Hes curbs microglial activation-mediated inflammation via the AMPK-SIRT1-FoxO1-NF-κB axis, thereby improving neurobehavioral function after TBI.

Effects of Pediatric Traumatic Brain Injury on Verbal IQ: A Systematic Review and Meta-Analysis

OBJECTIVES

To examine the effects of pediatric traumatic brain injury (TBI) on verbal IQ by severity and over time.

METHODS

A systematic review and subsequent meta-analysis of verbal IQ by TBI severity were conducted using a random effects model. Subgroup analysis included two epochs of time (e.g., <12 months postinjury and ≥12 months postinjury).

RESULTS

Nineteen articles met inclusion criteria after an extensive literature search in MEDLINE, PsycInfo, Embase, and CINAHL. Meta-analysis revealed negative effects of injury across severities for verbal IQ and at both time epochs except for mild TBI < 12 months postinjury. Statistical heterogeneity (i.e., between-study variability) stemmed from studies with inconsistent classification of mild TBI, small sample sizes, and in studies of mixed TBI severities, although not significant. Risk of bias on estimated effects was generally low (k = 15) except for studies with confounding bias (e.g., lack of group matching by socio-demographics; k = 2) and measurement bias (e.g., outdated measure at time of original study, translated measure; k = 2).

CONCLUSIONS

Children with TBI demonstrate long-term impairment in verbal IQ, regardless of severity. Future studies are encouraged to include scores from subtests within verbal IQ (e.g., vocabulary, similarities, comprehension) in addition to functional language measures (e.g., narrative discourse, reading comprehension, verbal reasoning) to elucidate higher-level language difficulties experienced in this population.

Resting-state network organisation in children with traumatic brain injury

Children with traumatic brain injury are at risk of neurocognitive and behavioural impairment. Although there is evidence for abnormal brain activity in resting-state networks after TBI, the role of resting-state network organisation in paediatric TBI outcome remains poorly understood. This study is the first to investigate the impact of paediatric TBI on resting-state network organisation using graph theory, and its relevance for functional outcome. Participants were 8-14 years and included children with (i) mild TBI and risk factors for complicated TBI (mild^RF+, n = 20), (ii) moderate/severe TBI (n = 15), and (iii) trauma control injuries (n = 27). Children underwent resting-state functional magnetic resonance imaging (fMRI), neurocognitive testing, and behavioural assessment at 2.8 years post-injury. Graph theory was applied to fMRI timeseries to evaluate the impact of TBI on global and local organisation of the resting-state network, and relevance for neurocognitive and behavioural functioning. Children with TBI showed atypical global network organisation as compared to the trauma control group, reflected by lower modularity (mild^RF + TBI and moderate/severe TBI), higher smallworldness (mild^RF + TBI) and lower assortativity (moderate/severe TBI ps < .04, Cohen's ds: > .6). Regarding local network organisation, the relative importance of hub regions in the network did not differ between groups. Regression analyses showed relationships between global as well as local network parameters with neurocognitive functioning (i.e., working memory, memory encoding; R² = 23.3 - 38.5%) and behavioural functioning (i.e., externalising problems, R² = 36.1%). Findings indicate the impact of TBI on global functional network organisation, and the relevance of both global and local network organisation for long-term neurocognitive and behavioural outcome after paediatric TBI. The results suggest potential prognostic value of resting-state network organisation for outcome after paediatric TBI.

Intelligence outcome of pediatric intensive care unit survivors: a systematic meta-analysis and meta-regression

BACKGROUND

Long-term morbidity after pediatric intensive care unit (PICU) admission is a growing concern. Both critical illness and accompanying PICU treatments may impact neurocognitive development as assessed by its gold standard measure; intelligence. This meta-analysis and meta-regression quantifies intelligence outcome after PICU admission and explores risk factors for poor intelligence outcome.

METHODS

PubMed, Embase, CINAHL and PsycINFO were searched for relevant studies, published from database inception until September 7, 2021. Using random-effects meta-analysis, we calculated the standardized mean difference in full-scale intelligence quotient (FSIQ) between PICU survivors and controls across all included studies and additionally distinguishing between PICU subgroups based on indications for admission. Relation between demographic and clinical risk factors and study's FSIQ effect sizes was investigated using random-effects meta-regression analysis.

RESULTS

A total of 123 articles was included, published between 1973 and 2021, including 8,119 PICU survivors and 1,757 controls. We found 0.47 SD (7.1 IQ-points) lower FSIQ scores in PICU survivors compared to controls (95%CI -0.55 to -0.40, p < .001). All studied PICU subgroups had lower FSIQ compared to controls (range 0.38-0.88 SD). Later year of PICU admission (range 1972-2016) and longer PICU stay were related to greater FSIQ impairment (R² = 21%, 95%CI -0.021 to -0.007, p < .001 and R² = 2%, 95%CI -0.027 to -0.002, p = .03, respectively), whereas male sex and higher rate of survivors were related to smaller FSIQ impairment (R² = 5%, 95%CI 0.001 to 0.014, p = .03 and R² = 11%, 95%CI 0.006 to 0.022, p < .001, respectively). Meta-regression in PICU subgroups showed that later year of PICU admission was related to greater FSIQ impairment in children admitted after cardiac surgery and heart- or heart-lung transplantation. Male sex was related to smaller FSIQ impairment in children admitted after cardiac surgery. Older age at PICU admission and older age at follow-up were related to smaller FSIQ impairment in children admitted after heart- or heart-lung transplantation.

CONCLUSIONS

PICU survivors, distinguished in a wide range of subgroups, are at risk of intelligence impairment. Length of PICU stay, female sex and lower rate of survivors were related to greater intelligence impairment. Intelligence outcome has worsened over the years, potentially reflecting the increasing percentage of children surviving PICU admission.

Serum sulfonylurea receptor-1 as a biomarker of clinical severity and prognosis in patients with traumatic brain injury

BACKGROUND

Sulfonylurea receptor-1 (Sur1) plays an important role in acute brain injury. We determine whether serum Sur1 concentrations are associated with traumatic severity and clinical outcome after traumatic brain injury (TBI).

METHODS

Serum Sur1 concentrations were measured in 100 healthy controls and 138 patients with moderate to severe TBI. Glasgow coma scale (GCS) and Rotterdam computed tomography (CT) classification were recorded to assess traumatic severity. Glasgow outcome scale (GOS) score of 1-3 at posttraumatic 3 months was defined as an unfavorable outcome.

RESULTS

Serum Sur1 concentrations were markedly higher in patients than in controls. Serum Sur1 concentrations of patients were highly correlated with GCS score, Rotterdam CT classification and GOS score. Patients with unfavorable outcome displayed markedly higher serum Sur1 concentrations than those presenting with favorable outcome. Under receiver operating characteristic curve, serum Sur1 concentrations significantly distinguished patients at risk of unfavorable outcome. Serum Sur1 emerged as an independent predictor for unfavorable outcome.

CONCLUSIONS

Rising serum Sur1 concentrations are highly correlated with traumatic severity and are independently associated with poor prognosis after TBI, indicating that serum Sur1 may have the potential to be a useful prognostic biomarker of TBI.

Quality of family environment predicts child perceptions of competence 12 months after pediatric traumatic brain injury

BACKGROUND

. Demographic and environmental factors can affect child recovery after traumatic brain injury (TBI); however, little is known about their role in predicting child perceptions of competence (i.e., subjective judgments of ability or a sense of adequacy).

OBJECTIVES

. This prospective, cohort study examined the contribution of participant sex, age at assessment, socioeconomic status, parent-reported change in academic performance post-injury, and the quality of a child's relationship with their family (i.e., family affective involvement, intimacy, integration, and the nature of family roles) to child perceptions of global and academic competence 12 months after pediatric TBI.

METHODS

. Participants included 127 children, 84 with a TBI (53 mild, 31 moderate-severe TBI; injury age: 5-15 years) and 43 age-matched typically developing (TD) controls. Children rated their perceptions of global and academic competence and degree of family intimacy and integration. Parents completed questionnaires measuring socioeconomic status, family affective involvement, and the nature of family roles. Parents also indicated whether they perceived a change in their child's post-injury academic performance.

RESULTS

. Child perceptions of academic competence were significantly lower for children with moderate-severe TBI relative to TD children. In contrast, child perceptions of global competence were comparable between TBI and TD control groups. Socioeconomic status, age at assessment, parent-reported relative change in academic performance post-TBI, and family roles were associated with child perceptions of academic competence. Degree of family integration was the sole predictor of child perceptions of global competence.

CONCLUSIONS

. Child perceptions of academic competence are vulnerable to the effects of moderate-severe TBI, particularly among older children and those from low socioeconomic backgrounds. Well-defined family roles for handling family functions and greater integration of family units might enhance perceptions of global and academic competence in children with TBI.

Expression of Urea Transporter B in Normal and Injured Brain

Urea transporter B (UT-B) is a membrane channel protein widely distributed in mammals, and plays a significant physiological role by regulating urea and water transportation in different tissues. More and more studies have found that UT-B is related to neurological diseases, including myelinopathy and depression. When urea accumulates in the brains of UT-B knockout mice, the synaptic plasticity of neurons is reduced, and the morphology and function of glial cells are also changed. However, the distribution and expression change of UT-B remain unclear. The purpose of this study is to determine the expression characteristics of UT-B in the brain. Through single-cell RNA sequencing, UT-B was found to express universally and substantially throughout the various cells in the central nervous system except for endothelial and smooth muscle cells. UT-B was detected in the third cerebral ventricular wall, granule cell layer of the dentate gyrus, and other parts of the hippocampal, cerebral cortex, substantia nigra, habenular, and lateral hypothalamic nucleus by immunohistochemistry. Compared with the membrane expression of UT-B in glial cells, the subcellular localization of UT-B is in the Golgi apparatus of neurons. Further, the expression of UT-B was regulated by osmotic pressure in vitro. In the experimental traumatic brain injury model (TBI), the number of UT-B positive neurons near the ipsilateral cerebral cortex increased first and then decreased over time, peaking at the 24 h. We inferred that change in UT-B expression after the TBI was an adaptation to changed urea levels. The experimental data suggest that the UT-B may be a potential target for the treatment of TBI and white matter edema.

Pediatric traumatic brain injury and abusive head trauma

Childhood traumatic brain injury (TBI) commonly occurs during brain development and can have direct, immediately observable neurologic, cognitive, and behavioral consequences. However, it can also disrupt subsequent brain development, and long-term outcomes are a combination of preinjury development and abilities, consequences of brain injury, as well as delayed impaired development of skills that were immature at the time of injury. There is a growing number of studies on mild TBI/sport-related concussions, describing initial symptoms and their evolution over time and providing guidelines for effective management of symptoms and return to activity/school/sports. Mild TBI usually does not lead to long-term cognitive or academic consequences, despite reports of behavioral/psychologic issues postinjury. Regarding moderate to severe TBI, injury to the brain is more severe, with evidence of a number of detrimental consequences in various domains. Patients can display neurologic impairments (e.g., motor deficits, signs of cerebellar disorder, posttraumatic epilepsy), medical problems (e.g., endocrine pituitary deficits, sleep-wake abnormalities), or sensory deficits (e.g., visual, olfactory deficits). The most commonly reported deficits are in the cognitive-behavioral field, which tend to be significantly disabling in the long-term, impacting the development of autonomy, socialization and academic achievement, participation, quality of life, and later, independence and ability to enter the workforce (e.g., intellectual deficits, slow processing speed, attention, memory, executive functions deficits, impulsivity, intolerance to frustration). A number of factors influence outcomes following pediatric TBI, including preinjury stage of development and abilities, brain injury severity, age at injury (with younger age at injury most often associated with worse outcomes), and a number of family/environment factors (e.g., parental education and occupation, family functioning, parenting style, warmth and responsiveness, access to rehabilitation and care). Interventions should identify and target these specific factors, given their major role in postinjury outcomes. Abusive head trauma (AHT) occurs in very young children (most often <6 months) and is a form of severe TBI, usually associated with delay before appropriate care is sought. Outcomes are systematically worse following AHT than following accidental TBI, even when controlling for age at injury and injury severity. Children with moderate to severe TBI and AHT usually require specific, coordinated, multidisciplinary, and long-term rehabilitation interventions and school adaptations, until transition to adult services. Interventions should be patient- and family-centered, focusing on specific goals, comprising education about TBI, and promoting optimal parenting, communication, and collaborative problem-solving.

Early coagulopathy in children with isolated blunt head injury is associated with mortality and poor neurological outcomes

OBJECTIVE

Traumatic brain injury (TBI) is the leading cause of long-term disability and death in children and adolescents globally. Long-term adverse outcomes, including physical, cognitive, and behavioral sequelae, have been reported after TBI in a significant number of pediatric patients. In this study the authors sought to investigate the epidemiology of TBI-associated coagulopathy and its association with mortality and poor neurological outcome in a pediatric population with isolated moderate to severe blunt head injury treated at the authors' institution.

METHODS

This retrospective study was conducted in the children's emergency department between January 2010 and December 2016. Children < 18 years old who presented with isolated moderate to severe blunt head injury were included in the study. The authors collected data on patient demographics, clinical presentation, and TBI management. Outcomes studied were death and poor neurological outcome defined by a score of < 7 (death, moderate to severe neurological disability) at 6 months postinjury on the pediatric version of the Glasgow Outcome Scale-Extended (GOS-E Peds).

RESULTS

In 155 pediatric patients who presented with isolated moderate to severe blunt head injury, early coagulopathy was observed in 33 (21.3%) patients during the initial blood investigations done in the emergency department. The mean (SD) age of the study group was 7.03 (5.08) years and the predominant mechanism of injury was fall from height (65.2%). The median Abbreviated Injury Scale of the head (AIS head) score was 4 and the median GCS score was 13 (IQR 12-15). TBI-associated coagulopathy was independently associated with GOS-E Peds score < 7 (p = 0.02, adjusted OR 6.07, 95% CI 1.32-27.83). The overall mortality rate was 5.8%. After adjusting for confounders, only AIS head score and hypotension at triage remained significantly associated with TBI-associated coagulopathy.

CONCLUSIONS

TBI-associated coagulopathy was independently associated with GOS-E Peds score < 7 at 6 months postinjury. Larger prospective studies are needed to investigate the use of TBI-associated coagulopathy to prognosticate these critical clinical outcomes.

Post-traumatic Headache After Pediatric Traumatic Brain Injury: Prevalence, Risk Factors, and Association With Neurocognitive Outcomes

Post-traumatic headache is common after pediatric traumatic brain injury and affects thousands of children every year, but little is known about how headache affects recovery after traumatic brain injury in other symptom domains. We aimed to determine the association between headache and other common symptoms after pediatric traumatic brain injury and explore whether subjective complaints of headache are associated with objective deficits on specialized neurocognitive testing. We conducted a retrospective cohort study of children ages 3-19 years following traumatic brain injury with a completed Sports Concussion Assessment Tool (SCAT) questionnaire. Post-traumatic headache was defined by a score more than 2 on the SCAT question for headache and define headache groups for comparison. In our cohort, we analyzed data from the Delis-Kaplan Executive Function System and the Wechsler Abbreviated Scale of Intelligence, Second Edition (WASI-II). Headache was reported in 40 (33%) patients presenting for post-traumatic brain injury care among 121 pediatric traumatic brain injury patients and did not differ by injury severity. Median total SCAT symptom score in the headache group was 5-fold higher compared to patients without headache (median 45.5 vs 9; P < .001). Significantly lower-scaled scores in color naming, matrix reasoning, letter sequencing, and letter switching were also found in the headache group (all P ≤ .03). Our study shows that headache, as reported by patients on the SCAT, is associated with higher symptom scores in all other symptom domains, including sleep, mood, sensory, and cognitive. Headache was also associated with worse objective neurocognitive measures and may identify patients who could benefit from specialized follow-up care and management.

Changes over time in family members of adults with mild traumatic brain injury

Objective:

The impact of traumatic brain injury (TBI) extends beyond the person who was injured. Family caregivers of adults with moderate to severe TBI frequently report increased burden, stress and depression. Few studies have examined the well-being of family members in the mild TBI population despite the latter representing up to 95% of all TBIs.

Methods:

Five areas of well-being were examined in 99 family members (including parents, partners, siblings, other relatives, adult children, friends or neighbours) of adults (aged ≥16 years) with mild TBI. At 6- and 12-month post-injury, family members completed the Bakas Caregiver Outcomes Scale, Short Form-36 Health Survey, EQ-5D-3L, Hospital Anxiety and Depression Scale and the Pittsburgh Sleep Quality Index. Outcomes and change over time and associated factors were examined.

Results:

At 6 months, group mean scores for health-related quality of life for mental and physical components and overall health status were similar to the New Zealand (NZ) population. Mean scores for sleep, anxiety and depression were below clinically significant thresholds. From 6 to 12 months, there were significant improvements in Bakas Caregiver Outcomes Scale scores by 2.61 (95% confidence interval: 0.72–4.49), health-related quality of life (mental component) and EQ-5D-3L overall health (P= 0.01). Minimally clinically important differences were observed in overall health, anxiety, health-related quality of life and depression at 12 months. Female family members reported significant improvements in physical health over time, and more positive life changes were reported by those caring for males with TBI.

Conclusions:

The findings suggest diminished burden over time for family members of adults with mild TBI.

Effects and Mechanism of Action of Neonatal Versus Adult Astrocytes on Neural Stem Cell Proliferation After Traumatic Brain Injury

Due to the limited capacity of brain tissue to self-regenerate after traumatic brain injury (TBI), the mobilization of endogenous neural stem cells (NSCs) is a popular research topic. In the clinic, the neurogenic abilities of adults versus neonates vary greatly, which is likely related to functional differences in NSCs. Recent studies have demonstrated that the molecules secreted from astrocytes play important roles in NSC fate determination. In this study, conditioned media (CM) derived from neonatal or adult rat astrocytes, which were unstimulated or stimulated by lipopolysaccharide (LPS), were prepared to treat NSCs. Our results revealed that neonatal rat astrocytes can significantly promote the proliferation of NSCs, compared with adult rat astrocytes, regardless of whether or not they were stimulated by LPS. Furthermore, we used mass spectrometry to detect the constituents of the CM from each group. We analyzed and screened for a protein, Tenascin-C (TNC), which was highly expressed in the neonatal group but poorly expressed in the adult group. We found that TNC can bind to the NSC surface epidermal growth factor receptor and promote proliferation through the PI3K-AKT pathway in vitro. Additionally, we confirmed in vivo that TNC can promote damage repair in a rat model of TBI, through enhancing the proliferation of endogenous NSCs. We believe that these findings provide a mechanistic understanding of why neonates show better neuroregenerative abilities than adults. This also provides a potential future therapeutic target, TNC, for injury repair after TBI. Stem Cells 2019;37:1344-1356.

Executive Function Profiles in Pediatric Traumatic Brain Injury

Traumatic brain injury (TBI) results in heterogeneous patterns of neuropsychological impairment. This study investigated heterogeneity in executive function (EF) using the Comprehensive Trail Making Test (CTMT) to evaluate 121 children and adolescents with TBI and 121 matched normal controls. The TBI group performed approximately two standard deviations below controls. Cluster analyses indicated that a three-cluster solution best classified the TBI group and a four-cluster solution best classified controls. Greater impairment in EF was associated with lower intellectual, achievement, and neuropsychological test performance in the TBI group. Results suggest that EF deficits reflected in CTMT performance may be useful for classifying severity of TBI.

Intelligence across the seventh decade in patients with brain injuries acquired in young adulthood

In this longitudinal study, we examined intelligence in a group of Vietnam veterans in their 60 s who suffered combat-related penetrating traumatic brain injuries (pTBI) in their 20 s (n = 120), as well as matched veterans with no brain damage (n = 33). Intelligence was evaluated using the Armed Forces Qualification Test (AFQT) administered before the injury occurred and then again at three points in time over the following 45 years. We tested for potential predictors and correlates of late midlife intelligence score, as well as the recent change in score over the seventh decade. The pTBI group had lower intelligence scores than the control group when currently evaluated. Pre-injury intelligence and the presence of a pTBI were the most consistent predictors of current intelligence scores. While exacerbated intellectual decline occurs following a young-adulthood pTBI and affects everyday life, no evidence for late midlife accelerated cognitive decline or dementia was found.

Interactive iBook-Based Patient Education in a NeuroTrauma Clinic

BACKGROUND

Traumatic brain injury (TBI) is a leading cause of death and disability in the United States. Educational interventions may alleviate the burden of TBI for patients and their families. Interactive modalities that involve engagement with the educational material may enhance patient knowledge acquisition when compared to static text-based educational material.

OBJECTIVE

To determine the effects of educational interventions in the outpatient setting on self-reported patient knowledge, with a focus on iPad-based (Apple, Cupertino, California) interactive modules.

METHODS

Patients and family members presenting to a NeuroTrauma clinic at a tertiary care academic medical center completed a presurvey assessing baseline knowledge of TBI or concussion, depending on the diagnosis. Subjects then received either an interactive iBook (Apple) on TBI or concussion, or an informative pamphlet with identical information in text format. Subjects then completed a postsurvey prior to seeing the neurosurgeon.

RESULTS

All subjects (n = 152) significantly improved on self-reported knowledge measures following administration of either an iBook (Apple) or pamphlet (P < .01, 95% confidence interval [CI]). Subjects receiving the iBook (n = 122) performed significantly better on the postsurvey (P < .01, 95% CI), despite equivalent presurvey scores, when compared to those receiving pamphlets (n = 30). Lastly, patients preferred the iBook to pamphlets (P < .01, 95% CI).

CONCLUSION

Educational interventions in the outpatient NeuroTrauma setting led to significant improvement in self-reported measures of patient and family knowledge. This improved understanding may increase compliance with the neurosurgeon's recommendations and may help reduce the potential anxiety and complications that arise following a TBI.

Traumatic brain injury and alcohol/substance abuse: A Bayesian meta-analysis comparing the outcomes of people with and without a history of abuse

Alcohol and substance (drugs and/or alcohol) abuse are major risk factors for traumatic brain injury (TBI); however, it remains unclear whether outcomes differ for those with and without a history of preinjury abuse. A meta-analysis was performed to examine this issue. The PubMed, Embase, and PsycINFO databases were searched for research that compared the neuroradiological, cognitive, or psychological outcomes of adults with and without a documented history of alcohol and/or substance abuse who sustained nonpenetrating TBIs. Data from 22 studies were analyzed using a random-effects model: Hedges's g effect sizes measured the mean difference in outcomes of individuals with/without a history of preinjury abuse, and Bayes factors assessed the probability that the outcomes differed. Patients with a history of alcohol and/or substance abuse had poorer neuroradiological outcomes, including reduced hippocampal (g = -0.82) and gray matter volumes (g = -0.46 to -0.82), and enlarged cerebral ventricles (g = -0.73 to -0.80). There were limited differences in cognitive outcomes: Executive functioning (g = -0.51) and memory (g = -0.39 to -0.43) were moderately affected, but attention and reasoning were not. The findings for fine motor ability, construction, perception, general cognition, and language were inconclusive. Postinjury substance and alcohol use (g = -0.97 to -1.07) and emotional functioning (g = -0.29 to -0.44) were worse in those with a history of alcohol and/or substance abuse (psychological outcomes). This study highlighted the type and extent of post-TBI differences between persons with and without a history of alcohol or substance abuse, many of which may hamper recovery. However, variation in the criteria for premorbid abuse, limited information regarding the history of abuse, and an absence of preinjury baseline data prevented an assessment of whether the differences predated the TBI, occurred as a result of ongoing alcohol/substance abuse, or reflected the cumulative impact of alcohol/substance abuse and TBI.

Traumatic brain injury in individuals at clinical high risk for psychosis

BACKGROUND

Recent research suggests that a traumatic brain injury (TBI) can significantly increase the risk of later development of psychosis. However, it is unknown whether people at clinical high risk (CHR) of psychosis have experienced TBI at higher rates, compared to otherwise healthy individuals. This study evaluated the prevalence of mild TBI, whether it was related to past trauma and the relationship of mild TBI to later transition to psychosis.

METHODS

Seven-hundred forty-seven CHR and 278 healthy controls (HC) were assessed on past history of mild TBI, age at first and last injury, severity of worst injury and number of injuries using the Traumatic Brain Injury Interview. Attenuated psychotic symptoms were assessed with the Scale of Psychosis-risk Symptoms. IQ was estimated using the Wechsler Abbreviated Scale of Intelligence and past trauma and bullying were recorded using the Childhood Trauma and Abuse Scale.

RESULTS

CHR participants experienced a mild TBI more often than the HC group. CHR participants who had experienced a mild TBI reported greater total trauma and bullying scores than those who had not, and those who experienced a mild TBI and later made the transition to psychosis were significantly younger at the age at first and most recent injury than those who did not.

CONCLUSION

A history of mild TBI is more frequently observed in CHR individuals than in HC. Inclusion or study of CHR youth with more severe TBI may provide additional insights on the relationship between TBI and later transition to psychosis in CHR individuals.

Impaired Visual Integration in Children with Traumatic Brain Injury: An Observational Study

Background

Axonal injury after traumatic brain injury (TBI) may cause impaired sensory integration. We aim to determine the effects of childhood TBI on visual integration in relation to general neurocognitive functioning.

Methods

We compared children aged 6–13 diagnosed with TBI (n = 103; M = 1.7 years post-injury) to children with traumatic control (TC) injury (n = 44). Three TBI severity groups were distinguished: mild TBI without risk factors for complicated TBI (mild^RF- TBI, n = 22), mild TBI with ≥1 risk factor (mild^RF+ TBI, n = 46) or moderate/severe TBI (n = 35). An experimental paradigm measured speed and accuracy of goal-directed behavior depending on: (1) visual identification; (2) visual localization; or (3) both, measuring visual integration. Group-differences on reaction time (RT) or accuracy were tracked down to task strategy, visual processing efficiency and extra-decisional processes (e.g. response execution) using diffusion model analysis. General neurocognitive functioning was measured by a Wechsler Intelligence Scale short form.

Results

The TBI group had poorer accuracy of visual identification and visual integration than the TC group (Ps ≤ .03; ds ≤ -0.40). Analyses differentiating TBI severity revealed that visual identification accuracy was impaired in the moderate/severe TBI group (P = .05, d = -0.50) and that visual integration accuracy was impaired in the mild^RF+ TBI group and moderate/severe TBI group (Ps < .02, ds ≤ -0.56). Diffusion model analyses tracked impaired visual integration accuracy down to lower visual integration efficiency in the mild^RF+ TBI group and moderate/severe TBI group (Ps < .001, ds ≤ -0.73). Importantly, intelligence impairments observed in the TBI group (P = .009, d = -0.48) were statistically explained by visual integration efficiency (P = .002).

Conclusions

Children with mild^RF+ TBI or moderate/severe TBI have impaired visual integration efficiency, which may contribute to poorer general neurocognitive functioning.