Executive function mediates the prospective association between neurostructural differences within the central executive network and anti-social behavior after childhood traumatic brain injury

Delineating the impact of childhood traumatic brain injury (TBI) on long-term depressive symptom severity: Does sub-acute brain morphometry prospectively predict 2-year outcome?

Despite evidence of a link between childhood TBI and heightened risk for depressive symptoms, very few studies have examined early risk factors that predict the presence and severity of post-injury depression beyond 1-year post injury. This longitudinal prospective study examined the effect of mild-severe childhood TBI on depressive symptom severity at 2-years post-injury. It also evaluated the potential role of sub-acute brain morphometry and executive function (EF) in prospectively predicting these long-term outcomes. The study involved 81 children and adolescents with TBI, and 40 age-and-sex matched typically developing (TD) controls. Participants underwent high-resolution structural magnetic resonance imaging (MRI) sub-acutely at five weeks post-injury (M = 5.55; SD = 3.05 weeks) and EF assessments were completed at 6-months post-injury. Compared to TD controls, the TBI group had significantly higher overall internalizing symptoms and were significantly more likely to exhibit clinically significant depressive symptoms at 2-year follow-up. The TBI group also displayed significantly lower EF and altered sub-acute brain morphometry in EF-related brain networks, including the default-mode network (DMN), salience network (SN) and central executive network (CEN). Mediation analyses revealed significant indirect effects of CEN morphometry on depression symptom severity, such that lower EF mediated the prospective association between altered CEN morphometry and higher depression symptoms in the TBI group. Parallel mediation analyses including grey matter morphometry of a non-EF brain network (i.e., the mentalising network) were not statistically significant, suggesting some model specificity. The findings indicate that screening for early neurostructural and neurocognitive risk factors may help identify children at elevated risk of depressive symptoms following TBI. For instance, children at greatest risk of post-injury depression symptoms could be identified based in part on neuroimaging of networks implicated in EF and post-acute assessments of executive function, which could support more effective allocation of limited intervention resources.

Mediating effects of impulsivity and alexithymia in the association between traumatic brain injury and aggression in incarcerated males

Studies suggest both alexithymia and impulsivity (partially) explain aggressive behavior in traumatic brain injury (TBI) patients, but none of these studies use both questionnaire and performance-based measures as recommended, nor simultaneously investigate both impulsivity and alexithymia. The available studies therefore likely miss part of the constructs of alexithymia and impulsivity, and do not comprehensively assess the mediating effects of both constructs in the relationship between TBI and aggression. A sample of N = 281 incarcerated individuals were recruited from Dutch penitentiary institutions, and completed the Buss Perry Aggression Questionnaire (aggression), BIS-11 (impulsivity) and Toronto Alexithymia Scale-20 (alexithymia) questionnaires, as well as a stop-signal task and an emotion recognition paradigm. Several multiple mediation analyses were conducted using structural equation modelling, to assess the viability of a causal theoretical model of aggression. The final planned models were the original models with a good fit with the data (comparative fit index > 0.95, root mean square error of approximation and Standardized root mean square residual < 0.05), and results indicate that only questionnaire-based impulsivity mediated the relationship between TBI and aggression. TBI was unrelated to alexithymia, stop-signal or emotion recognition performance. Aggression was predicted by both alexithymia and impulsivity, but not by the performance measures. Post hoc analyses shows that alexithymia moderates the relationship between impulsivity and aggression. These results imply that aggressive incarcerated individuals showing impulsive behavior should be screened for TBI, since TBI is often overlooked or misdiagnosed, and indicate that both impulsivity and alexithymia are potential focus points for aggression reduction treatment in TBI patients.

In utero and post-natal opioid exposure followed by mild traumatic brain injury contributes to cortical neuroinflammation, mitochondrial dysfunction, and behavioral deficits in juvenile rats

Maternal opioid use poses a significant health concern not just to the expectant mother but also to the fetus. Notably, increasing numbers of children born suffering from neonatal opioid withdrawal syndrome (NOWS) further compounds the crisis. While epidemiological research has shown the heightened risk factors associated with NOWS, little research has investigated what molecular mechanisms underly the vulnerabilities these children carry throughout development and into later life. To understand the implications of in utero and post-natal opioid exposure on the developing brain, we sought to assess the response to one of the most common pediatric injuries: minor traumatic brain injury (mTBI). Using a rat model of in utero and post-natal oxycodone (IUO) exposure and a low force weight drop model of mTBI, we show that not only neonatal opioid exposure significantly affects neuroinflammation, brain metabolites, synaptic proteome, mitochondrial function, and altered behavior in juvenile rats, but also, in conjunction with mTBI these aberrations are further exacerbated. Specifically, we observed long term metabolic dysregulation, neuroinflammation, alterations in synaptic mitochondria, and impaired behavior were impacted severely by mTBI. Our research highlights the specific vulnerability caused by IUO exposure to a secondary stressor such as later life brain injury. In summary, we present a comprehensive study to highlight the damaging effects of prenatal opioid abuse in conjunction with mild brain injury on the developing brain.

The Implications of Moral Neuroscience for Brain Disease: Review and Update

The last 2 decades have seen an explosion of neuroscience research on morality, with significant implications for brain disease. Many studies have proposed a neuromorality based on intuitive sentiments or emotions aimed at maintaining collaborative social groups. These moral emotions are normative, deontological, and action based, with a rapid evaluation of intentionality. The neuromoral circuitry interacts with the basic mechanisms of socioemotional cognition, including social perception, behavioral control, theory of mind, and social emotions such as empathy. Moral transgressions may result from primary disorders of moral intuitions, or they may be secondary moral impairments from disturbances in these other socioemotional cognitive mechanisms. The proposed neuromoral system for moral intuitions has its major hub in the ventromedial prefrontal cortex and engages other frontal regions as well as the anterior insulae, anterior temporal lobe structures, and right temporoparietal junction and adjacent posterior superior temporal sulcus. Brain diseases that affect these regions, such as behavioral variant frontotemporal dementia, may result in primary disturbances of moral behavior, including criminal behavior. Individuals with focal brain tumors and other lesions in the right temporal and medial frontal regions have committed moral violations. These transgressions can have social and legal consequences for the individuals and require increased awareness of neuromoral disturbances among such individuals with brain diseases.

Association of neurostructural biomarkers with secondary attention-deficit/hyperactivity disorder (ADHD) symptom severity in children with traumatic brain injury: a prospective cohort study

BACKGROUND

Despite a well-established link between childhood traumatic brain injury (TBI) and elevated secondary attention-deficit/hyperactivity disorder (s-ADHD) symptomology, the neurostructural correlates of these symptoms are largely unknown. Based on the influential 'triple-network model' of ADHD, this prospective longitudinal investigation aimed to (i) assess the effect of childhood TBI on brain morphometry of higher-order cognitive networks proposed to play a key role in ADHD pathophysiology, including the default-mode network (DMN), salience network (SN) and central executive network (CEN); and (ii) assess the independent prognostic value of DMN, SN and CEN morphometry in predicting s-ADHD symptom severity after childhood TBI.

METHODS

The study sample comprised 155 participants, including 112 children with medically confirmed mild-severe TBI ascertained from consecutive hospital admissions, and 43 typically developing (TD) children matched for age, sex and socio-economic status. High-resolution structural brain magnetic resonance imaging (MRI) sequences were acquired sub-acutely in a subset of 103 children with TBI and 34 TD children. Parents completed well-validated measures of ADHD symptom severity at 12-months post injury.

RESULTS

Relative to TD children and those with milder levels of TBI severity (mild, complicated mild, moderate), children with severe TBI showed altered brain morphometry within large-scale, higher-order cognitive networks, including significantly diminished grey matter volumes within the DMN, SN and CEN. When compared with the TD group, the TBI group showed significantly higher ADHD symptomatology and higher rates of clinically elevated symptoms. In multivariable models adjusted for other well-established risk factors, altered DMN morphometry independently predicted higher s-ADHD symptomatology at 12-months post-injury, whilst SN and CEN morphometry were not significant independent predictors.

CONCLUSIONS

Our prospective study findings suggest that neurostructural alterations within higher-order cognitive circuitry may represent a prospective risk factor for s-ADHD symptomatology at 12-months post-injury in children with TBI. High-resolution structural brain MRI has potential to provide early prognostic biomarkers that may help early identification of high-risk children with TBI who are likely to benefit from early surveillance and preventive measures to optimise long-term neuropsychiatric outcomes.

Culpability for offenses in frontotemporal dementia and other brain disorders

The responsibility of persons with brain disorders who commit offenses may depend on how their disorders alter brain mechanisms for culpability. Criminal behavior can result from brain disorders that alter social cognition including a neuromoral system of intuitive moral emotions that are absolute (deontological) normative codes and that includes an emotion-mediated evaluation of intentionality. This neuromoral system has its hub in the ventromedial prefrontal cortex (VMPFC) with other frontal, anterior temporal-amygdalar, insular, and right temporoparietal connections. Among brain disorders, investigators report offenses in persons with brain tumors, epilepsy, and traumatic brain injury, but it is those with a form of dementia with VMPFC pathology, behavioral variant frontotemporal dementia (bvFTD), who are most prone to criminal behavior. This review presents four new patients with bvFTD who were interviewed after committing offenses. These patients knew the nature of their acts and the wrongness of the type of action but lacked substantial capacity to experience the criminality of their conduct at the intuitive, deontological, moral emotional level. Disease in VMPFC and its amygdalar connections may impair moral emotions in these patients. These findings recommend evaluation for the experience of moral emotions and VMPFC-amygdala dysfunction among persons with antisocial behavior, with or without brain disease.

What predicts persisting social impairment following pediatric traumatic brain injury: contribution of a biopsychosocial approach

BACKGROUND

Psychosocial deficits, such as emotional, behavioral and social problems, reflect the most common and disabling consequences of pediatric traumatic brain injury (TBI). Their causes and recovery likely differ from physical and cognitive skills, due to disruption to developing brain networks and the influence of the child's environment. Despite increasing recognition of post-injury behavioral and social problems, there exists a paucity of research regarding the incidence of social impairment, and factors predicting risk and resilience in the social domain over time since injury.

METHODS

Using a prospective, longitudinal design, and a bio-psychosocial framework, we studied children with TBI (n = 107) at baseline (pre-injury function), 6 months, 1 and 2-years post-injury. We assessed intellectual ability, attention/executive function, social cognition, social communication and socio-emotional function. Children underwent structural magnetic resonance imaging (MRI) at 2-8 weeks post-injury. Parents rated their child's socio-emotional function and their own mental health, family function and perceived burden.

RESULTS

We distinguished five social recovery profiles, characterized by a complex interplay between environment and pre- and post-TBI factors, with injury factors playing a lesser role. Resilience in social competence was linked to intact family and parent function, intact pre-injury adaptive abilities, post-TBI cognition and social participation. Vulnerability in the social domain was related to poor pre- and post-injury adaptive abilities, greater behavioral concerns, and poorer pre- and post-injury parent health and family function.

CONCLUSIONS

We identified five distinct social recovery trajectories post-child-TBI, each characterized by a unique biopsychosocial profile, highlighting the importance of comprehensive social assessment and understanding of factors contributing to social impairment, to target resources and interventions to children at highest risk.

Predicting motor and cognitive outcomes from MRIs of brain structure in children with acquired brain injury: A pilot study

BACKGROUND

Acquired Brain Injury (ABI) describes a range of brain injuries occurring after birth, including tumor, traumatic brain injury or stroke. Although MRIs are routinely used for diagnosis, prediction of outcome following brain injury is challenging. Quantitative structural information from brain images may provide an opportunity to predict patient outcomes; however, due to the high prevalence of severe pathology in children with ABI, quantitative approaches must be robust to injury severity.

METHODS

In this pilot cross-sectional study, automated quantitative measures were extracted from the MRIs of a cohort of children with ABI (n = 30, 8-16 years, follow up MRI taken 1.8-13.4 years after time of injury) as well as 36 typically developing controls with no brain injury (7-17 years) using a pathology-robust technique. Measures of brain volume, lesion volume and cortical morphology were associated with concurrent motor, behavioral, visual and communicative function using Least Absolute Shrinkage and Selection Operator (LASSO) regression.

RESULTS

These regression models were validated on a separate test set (n = 8 of the ABI cohort), which revealed significant correlations between measures of brain structure with motor, cognitive, visual and communicative function (r = 0.65-0.85, all p < 0.01). Furthermore, comparisons of the structural measures to the typically developing cohort revealed overall reductions in global grey matter volume among the ABI cohort, as well as cortical thinning in several cortical areas.

CONCLUSIONS

These preliminary associations reveal that motor and behavioral function can be estimated from MRI alone, highlighting the potential utility of the proposed pathology-robust MRI quantification tools to provide estimates of long-term clinical prognosis of children with ABI following injury.

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

OBJECTIVE

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

METHODS AND PROCEDURES

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

OUTCOMES AND RESULTS

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

CONCLUSIONS AND IMPLICATIONS

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