Uncovering cortico-striatal correlates of cognitive fatigue in pediatric acquired brain disorder: Evidence from traumatic brain injury

Biopsychosocial correlates of fatigue in young adult survivors of childhood traumatic brain injury: A prospective cohort study

This prospective cohort study aimed to evaluate the potential role of injury, socio-demographic and individual psychological factors in predicting long-term fatigue outcomes in young adult survivors of childhood TBI at 16-years post-injury. The study included 51 young adults diagnosed with childhood TBI from 2-12 years of age. Twenty age-and-sex-matched controls were included for comparison. Findings showed that almost one-in-four TBI participants (24%) endorsed clinically elevated fatigue at 16-years post-injury. Despite the relatively large proportion of TBI participants endorsing clinically significant fatigue, group comparisons revealed that the TBI and control groups did not significantly differ on fatigue symptom severity or rates of clinically elevated fatigue. For the TBI group, post-injury fatigue was significantly associated with socio-demographic and psychological factors, including lower educational level, higher depression symptom severity, and more frequent substance use. Higher fatigue was also associated with lower self-reported quality of life (QoL) in the physical, psychological, and environmental domains, even after controlling for depressive symptom severity, socio-demographic, and injury-related factors. Overall, findings show that a substantial proportion of young adults with a history of childhood TBI experience clinically elevated fatigue at 16-years post-injury. Identification and treatment of modifiable risk-factors (e.g. depression symptoms, substance use) has potential to reduce fatigue.

Neuroimaging Correlates of Functional Outcome Following Pediatric TBI

Neuroimaging plays an important role in assessing the consequences of TBI across the postinjury period. While identifying alterations to the brain is important, associating those changes to functional, cognitive, and behavioral outcomes is an essential step to establishing the value of advanced neuroimaging for pediatric TBI. Here we highlight research that has revealed links between advanced neuroimaging and outcome after TBI and point to opportunities where neuroimaging could expand our ability to prognosticate and potentially uncover opportunities to intervene.

Reflections on the physical, executive developmental and systems applied framework in child neuropsychological rehabilitation

This paper describes the influence of the Physical, Executive, Developmental and Systems (PEDS) framework on the delivery of community-based child neuropsychological rehabilitation and how it has been enhanced by the proliferation of neuroscientific, neuropsychological and psychosocial research and evidence-base in childhood brain injury and rehabilitation over the past decade. The paper signposts to some of the key models, theories and concepts currently shaping service delivery. Application of the PEDS framework in a clinical case is described.

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.

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

BACKGROUND

Despite increasing evidence of a link between early life brain injury and anti-social behavior, very few studies have assessed factors that explain this association in children with traumatic brain injury (TBI). One hypothesis suggests that childhood TBI elevates risk for anti-social behavior via disruption to anatomically distributed neural networks implicated in executive functioning (EF). In this longitudinal prospective study, we employed high-resolution structural neuroimaging to (a) evaluate the impact of childhood TBI on regional morphometry of the central executive network (CEN) and (b) evaluate the prediction that lower EF mediates the prospective relationship between structural differences within the CEN and postinjury anti-social behaviors.

METHODS

This study involved 155 children, including 112 consecutively recruited, hospital-confirmed cases of mild-severe TBI and 43 typically developing control (TDC) children. T1-weighted brain magnetic resonance imaging (MRI) sequences were acquired sub-acutely in a subset of 137 children [TBI: n = 103; TDC: n = 34]. All participants were evaluated using direct assessment of EF 6 months postinjury, and parents provided ratings of anti-social behavior 12 months postinjury.

RESULTS

Severe TBI was associated with postinjury volumetric differences within the CEN and its putative hub regions. When compared with TD controls, the TBI group had significantly worse EF, which was associated with more frequent anti-social behaviors and abnormal CEN morphometry. Mediation analysis indicated that reduced EF mediated the prospective association between postinjury volumetric differences within the CEN and more frequent anti-social behavior.

CONCLUSIONS

Our longitudinal prospective findings suggest that detection of neurostructural abnormalities within the CEN may aid in the early identification of children at elevated risk for postinjury executive dysfunction, which may in turn contribute to chronic anti-social behaviors after early life brain injury. Findings underscore the potential value of early surveillance and preventive measures for children presenting with neurostructural and/or neurocognitive risk factors.

Pretend play ability in preschool-aged children with an acquired brain injury

INTRODUCTION

This study compares the self-initiated pretend play abilities of preschool-aged children with an acquired brain injury, with the self-initiated pretend play ability of their neurotypical peers.

METHOD

A non-experimental group comparison was conducted between 22 preschool-aged neurotypical children (M = 52.8 months, SD = 7.1 months) and 21 children with an acquired brain injury (ABI, M = 50.5 months, SD = 11.9 months), who had been discharged from inpatient rehabilitation and who were able to engage in a play session. The children were assessed individually using the Child-Initiated Pretend Play Assessment (ChIPPA).

RESULTS

The children with an ABI had significantly lower scores in pretend play ability than their neurotypical peers as measured by the percentage of elaborate play actions in both the conventional (P < .000) and symbolic (P < .000) sections of the ChIPPA, as well as the number of object substitutions (P < .000). The children with an ABI completed significantly less of the play time required compared with their neurotypical peers (P = .001); 66% could not play for the required time. There was no significant difference in the ChIPPA scores of the children with an ABI injured before and after the age of 18 months, nor between children with a severe or moderate injury.

CONCLUSION

The quality and the quantity of pretend play of preschool-aged children with an ABI are significantly below that of their neurotypical peers. Assessment of pretend play ability and direct intervention in ABI rehabilitation by occupational therapists is essential to enable children with an ABI to participate in pretend play and garner the developmental benefit this affords.

Cognitive Fatigue in Pediatric Traumatic Brain Injury: A Meta-Analysis and Scoping Review

OBJECTIVE

To review the evidence available on cognitive fatigue (ie, increase in mental exhaustion after prolonged cognitive activity) in childhood traumatic brain injury (TBI), including rates, associated factors and effects, and management strategies.

METHODS

A meta-analysis and scoping review of the literature were conducted following the PRISMA guidelines. Terms were searched in relevant databases and through hand-searching. Articles were included and excluded based on specific criteria and methods were evaluated for risk of bias.

RESULTS

Of 2579 initially eligible articles, 4 studies with 6 effect sizes (due to reporting of data by group in 2 studies) were included for a meta-analysis and 11 for a scoping review. Cognitive fatigue was a common symptom in children after TBI of varying severities and times post-injury. Few studies investigated factors or effects associated with cognitive fatigue, although emerging evidence indicates some relations with family and injury factors and postinjury functioning. Active rehabilitation was investigated by 2 studies and could be a safe management strategy for cognitive fatigue, but additional investigation is needed on this and other possible assessment and treatment approaches.

CONCLUSIONS

Cognitive fatigue is a common symptom in children who experience a TBI of any severity. Additional research is needed to determine the course of cognitive fatigue, elucidate the relations between cognitive fatigue and secondary factors, and to build clinically useful assessment and treatment methods.

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.

Reward presentation reduces on-task fatigue in traumatic brain injury

While cognitive fatigue is experienced by up to 80% of individuals with traumatic brain injury (TBI), little is known about its neural underpinnings. We previously hypothesized that presentation of rewarding outcomes leads to cognitive fatigue reduction and activation of the striatum, a brain region shown to be associated with cognitive fatigue in clinical populations and processing of rewarding outcomes. We have demonstrated this in individuals with multiple sclerosis. Here, we tested this hypothesis in individuals with TBI. Twenty-one individuals with TBI and 24 healthy participants underwent functional magnetic resonance imaging. Participants performed a task during which they were presented with 1) the Outcome condition where they were exposed to monetary rewards, and 2) the No Outcome condition that served as the control condition and was not associated with monetary rewards. In accordance with our hypothesis, results showed that attainment of rewarding outcomes leads to cognitive fatigue reduction in individuals with TBI, as well as activation of the striatum. Specifically, we observed a significant group by condition interaction on fatigue scores driven by the TBI group reporting lower levels of fatigue after the Outcome condition. fMRI data revealed a significant main-effect of condition in regions previously implicated in outcome processing, while a significant group by condition interaction was observed in the left ventral striatum as revealed by a priori region of interest analysis. Results suggest that a salient motivator can significantly reduce fatigue and that outcome presentation leads to increased activation of the ventral striatum in TBI. These findings can inform the development of future non-pharmacological cognitive fatigue treatment methods and contribute to the growing body of evidence showing the association between cognitive fatigue and the striatum.

Fatigue, Sleep, and Autoimmune and Related Disorders

Profound and debilitating fatigue is the most common complaint reported among individuals with autoimmune disease, such as systemic lupus erythematosus, multiple sclerosis, type 1 diabetes, celiac disease, chronic fatigue syndrome, and rheumatoid arthritis. Fatigue is multi-faceted and broadly defined, which makes understanding the cause of its manifestations especially difficult in conditions with diverse pathology including autoimmune diseases. In general, fatigue is defined by debilitating periods of exhaustion that interfere with normal activities. The severity and duration of fatigue episodes vary, but fatigue can cause difficulty for even simple tasks like climbing stairs or crossing the room. The exact mechanisms of fatigue are not well-understood, perhaps due to its broad definition. Nevertheless, physiological processes known to play a role in fatigue include oxygen/nutrient supply, metabolism, mood, motivation, and sleepiness-all which are affected by inflammation. Additionally, an important contributing element to fatigue is the central nervous system-a region impacted either directly or indirectly in numerous autoimmune and related disorders. This review describes how inflammation and the central nervous system contribute to fatigue and suggests potential mechanisms involved in fatigue that are likely exhibited in autoimmune and related diseases.

A systematic review of cross-sectional differences and longitudinal changes to the morphometry of the brain following paediatric traumatic brain injury

Paediatric traumatic brain injury (pTBI) is a leading cause of disability for children and young adults. Children are a uniquely vulnerable group with the disease process that occurs following a pTBI interacting with the trajectory of normal brain development. Quantitative MRI post-injury has suggested a long-term, neurodegenerative effect of TBI on the morphometry of the brain, in both adult and childhood TBI. Changes to the brain beyond that of anticipated, age-dependant differences may allow us to estimate the state of the brain post-injury and produce clinically relevant predictions for long-term outcome. The current review synthesises the existing literature to assess whether, following pTBI, the morphology of the brain exhibits either i) longitudinal change and/or ii) differences compared to healthy controls and outcomes. The current literature suggests that morphometric differences from controls are apparent cross-sectionally at both acute and late-chronic timepoints post-injury, thus suggesting a non-transient effect of injury. Developmental trajectories of morphometry are altered in TBI groups compared to patients, and it is unlikely that typical maturation overcomes damage post-injury, or even 'catches up' with that of typically-developing peers. However, there is limited evidence for diverted developmental trajectories being associated with cognitive impairment post-injury. The current review also highlights the apparent challenges to the existing literature and potential methods by which these can be addressed.

Cognitive fatigue in individuals with traumatic brain injury is associated with caudate activation

We investigated differences in brain activation associated with cognitive fatigue between persons with traumatic brain injury (TBI) and healthy controls (HCs). Twenty-two participants with moderate-severe TBI and 20 HCs performed four blocks of a difficult working memory task and four blocks of a control task during fMRI imaging. Cognitive fatigue, assessed before and after each block, was used as a covariate to assess fatigue-related brain activation. The TBI group reported more fatigue than the HCs, though their performance was comparable. Regarding brain activation, the TBI group showed a Task X Fatigue interaction in the caudate tail resulting from a positive correlation between fatigue and brain activation for the difficult task and a negative relationship for the control task. The HC group showed the same Task X Fatigue interaction in the caudate head. Because we had prior hypotheses about the caudate, we performed a confirmatory analysis of a separate dataset in which the same subjects performed a processing speed task. A relationship between Fatigue and brain activation was evident in the caudate for this task as well. These results underscore the importance of the caudate nucleus in relation to cognitive fatigue.