Adult Outcomes of Pediatric Traumatic Brain Injury

Traumatic brain injury (TBI) is one of the most common causes of acquired disability during childhood. While the majority of such injuries are mild, and result in few, if any, functional sequelae, children sustaining more significant insults may experience permanent cognitive and behavioral deficits. Clinical reports indicate residual impairments in a range of skills, particularly information-processing, attention, memory, learning, social function and behavior. These deficits impact on a child\u27s capacity to interact with the environment effectively, resulting in lags in skill acquisition, and increasing gaps between injured children and their age peers, as they move through childhood and into adulthood. Secondary deficits may also emerge, relating to family stress and adjustment difficulties. Treatment and management of the child with TBI and family requires long-term involvement, where the role of the neuropsychologist is to understand the child\u27s difficulties, to inform parents and the wider community of their cognitive and behavioral implications, to liaise with teachers and rehabilitation workers, to design academic and vocational interventions and behavior-management programs, and to provide counseling with respect to adjustment issues for the child and family

L'apprentissage cognitif dans la maladie de Parkinson

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal

From early relationships to preacademic knowledge : a socio-cognitive developmental cascade to school readiness

This study aimed to test a four-wave sequential mediation model linking mother–child attachment to children’s school readiness through child executive functioning (EF) and prosociality in toddlerhood and the preschool years. Mother–child attachment security was assessed when children (N = 255) were aged 15 months and 2 years, child EF at age 2, prosocial behavior at age 4, and finally cognitive school readiness in kindergarten (age 6). The results revealed three indirect pathways linking attachment to school readiness: one through EF only, one through prosocial behavior only, and a last pathway involving both EF and prosocial behavior serially. These findings suggest that secure attachment may equip children with both cognitive and social skills that are instrumental to their preparedness for school

A secure base from which to regulate: Attachment security in toddlerhood as a predictor of executive functioning at school entry

In light of emerging evidence suggesting that the affective quality of parent-child relationships may relate to individual differences in young children's executive functioning (EF) skills, the aim of this study was to investigate the prospective associations between attachment security in toddlerhood and children's EF skills in kindergarten. Mother-child dyads (N = 105) participated in 2 toddlerhood visits in their homes, when children were 15 months and 2 years of age. Mother-child attachment security was assessed with the Attachment Q-Sort during both these visits. When children were in kindergarten (ages 5-6), they were administered a battery of EF tasks, and their teachers completed the Behavior Rating Inventory of Executive Function to assess children's EF problems. The results indicated that kindergarteners who were more securely attached to their mothers in toddlerhood showed better performance on all EF tasks, and were considered by their teachers to present fewer EF problems in everyday school situations. These results held above family socioeconomic status (SES) and child age, sex, and general cognitive functioning. The fact that early attachment security uniquely predicted both teacher reports and children's objective EF task performance suggests that parent-child attachment may be a promising factor to consider in the continuing search for the social antecedents of young children's EF

Age-related differences in inhibitory control in the early school years

The transition to school is associated with a greater requirement to inhibit irrelevant or inappropriate thought and behavior in order to concentrate on effective learning and to interact successfully with peers. Current knowledge of inhibitory control development in the early school years is limited due to a lack of normative data from age-appropriate, sensitive measures. In this study, three pictorial versions of the Stroop task were administered to investigate inhibitory control development in early school-aged children. Age-related trajectories of inhibition and effects of gender were examined in 80 children (42 boys) aged 5 to 8 years. All children were assessed with the Cognitive Assessment System Expressive Attention subtest (Big-Small Stroop), Fruit Stroop, and Boy-Girl Stroop. The Big-Small Stroop revealed substantial age-related improvement in inhibition from 5 to 7 years with a levelling of performance at 8 years of age, while the Fruit Stroop and Boy-Girl Stroop demonstrated clear but nonsignificant age trends. In particular, older children committed fewer errors and corrected their errors more frequently than younger children. Performance on all Stroop tasks correlated significantly, providing evidence that they tap similar cognitive abilities. Some gender differences were found. This study indicates that inhibitory skills develop rapidly in the early school years and suggests that error awareness may be a useful indicator of the development of cognitive inhibition for this age group

Mother–infant interaction and child brain morphology : a multidimensional approach to maternal sensitivity

Emerging research suggests that normative variation in parenting quality relates to children's brain development. However, although the young brain is presumed to be especially sensitive to environmental influence, to our knowledge only two studies have examined parenting quality with infants as it relates to indicators of brain development, and both were cross‐sectional. This longitudinal study investigated whether different components of maternal sensitivity in infancy predicted the volume of two brain structures presumed to be particularly sensitive to early experience, namely the amygdala and the hippocampus. Three dimensions of sensitivity (Cooperation/Attunement, Positivity, Accessibility/Availability) were observed in 33 mother–infant dyads at 1 year of age and children underwent structural magnetic resonance imaging at age 10. Higher maternal Accessibility/Availability during mother–infant interactions was found to be predictive of smaller right amygdala volume, while greater maternal positivity was predictive of smaller bilateral hippocampal volumes. These longitudinal findings extend those of previous cross‐sectional studies and suggest that a multidimensional approach to maternal behavior could be a fruitful way to further advance research in this area, given that different facets of parenting might be differentially predictive of distinct aspects of neurodevelopment

Visual Encoding of Social Cues Contributes to Moral Reasoning in Autism Spectrum Disorder: An Eye-Tracking Study

Eye-tracking studies suggest that visual encoding is important for social processes such as socio-moral reasoning. Alterations to the visual encoding of faces, for example, have been linked to the social phenotype of autism spectrum disorders (ASDs) and are associated with social and communication impairments. Yet, people with ASD often perform similarly to neurotypical participants on measures of moral reasoning, supporting the hypothesis of differential mechanisms of moral reasoning in ASD. The objective of this study was to document visual encoding and moral reasoning in ASD and neurotypical individuals using a visual, ecological, sociomoral reasoning paradigm paired with eye-tracking. Two groups (ASD, Control) matched for age and IQ completed the SoMoral task, a set of picture situations describing everyday moral dilemmas, while their eye movements and pupil dilation were recorded. Moral understanding, decision-making, and justification were recorded. Participants with ASD presented a longer time to first fixation on faces. They also understood fewer dilemmas and produced fewer socially adaptive responses. Despite a similar average level of moral maturity, the justifications produced by participants with ASD were not distributed in the same way as the neurotypical participants. Visual encoding was a significant predictor of moral decision-making and moral justification for both groups. The results are discussed in the context of alternative mechanisms of moral reasoning in ASD

Interleukin-8 predicts fatigue at 12 months post-injury in children with traumatic brain injury

Despite many children experiencing fatigue after childhood brain injury, little is known about the predictors of this complaint. To date, traditional indices of traumatic brain injury (TBI) severity have not reliably predicted persisting fatigue (up to 3 years post‐injury). This study aimed to establish if persisting fatigue is predicted by serum biomarker concentrations in child TBI. We examined if acute serum biomarker expression would improve prediction models of 12‐month fatigue based on injury severity. Blood samples were collected from 87 children (1 – 17 years at injury) sustaining mild to severe TBI (GCS range 3‐15; mean 12.43; classified as mild TBI (n=50, 57%) vs moderate/severe TBI n=37, 43%), and presenting to the Emergency Departments (ED) and Pediatric Intensive Care Units (PICU) at one of three tertiary pediatric hospitals (Royal Children’s Hospital (RCH); Hospital for Sick Children (HSC), Toronto St Justine Children’s Hospital (SJH), Montreal). Six serum biomarker concentrations were measured within 24 hours of injury [interleukin‐6 (IL‐6), interleukin‐8 (IL‐8), soluble vascular cell adhesion molecule (SVCAM), S100 calcium binding protein B (S100B), neuron specific enolase (NSE), and soluble neural cell adhesion molecule (sNCAM)]. Fatigue at 12 months post‐injury was measured using the Pediatric Quality of Life Inventory Multidimensional Fatigue Scale (parent report), classified as present/absent using previously derived cut‐points. At 12 months post‐injury, 22% of participants experienced fatigue. A model including interleukin‐8 (IL‐8) was the best serum biomarker for estimating the probability of children experiencing fatigue at 12 months post‐injury. IL‐8 also significantly improved predictive models of fatigue based on severity

Kids' Outcomes And Long-term Abilities (KOALA): protocol for a prospective, longitudinal cohort study of mild traumatic brain injury in children 6 months to 6 years of age

Introduction: Mild traumatic brain injury (mTBI) is highly prevalent, especially in children under 6 years. However, little research focuses on the consequences of mTBI early in development. The objective of the Kids' Outcomes And Long-term Abilities (KOALA) study is to document the impact of early mTBI on children's motor, cognitive, social and behavioural functioning, as well as on quality of life, stress, sleep and brain integrity. Methods and analyses KOALA is a prospective, multicentre, longitudinal cohort study of children aged 6 months to 6 years at the time of injury/recruitment. Children who sustain mTBI (n=150) or an orthopaedic injury (n=75) will be recruited from three paediatric emergency departments (PEDs), and compared with typically developing children (community controls, n=75). A comprehensive battery of prognostic and outcome measures will be collected in the PED, at 10 days, 1, 3 and 12 months postinjury. Biological measures, including measures of brain structure and function (magnetic resonance imaging, MRI), stress (hair cortisol), sleep (actigraphy) and genetics (saliva), will complement direct testing of function using developmental and neuropsychological measures and parent questionnaires. Group comparisons and predictive models will test the a priori hypotheses that, compared with children from the community or with orthopaedic injuries, children with mTBI will (1) display more postconcussive symptoms and exhibit poorer motor, cognitive, social and behavioural functioning;(2) show evidence of altered brain structure and function, poorer sleep and higher levels of stress hormones. A combination of child, injury, socioenvironmental and psychobiological factors are expected to predict behaviour and quality of life at 1, 3 and 12 months postinjury. Ethics and dissemination The KOALA study is approved by the Sainte-Justine University Hospital, McGill University Health Centre and University of Calgary Conjoint Health Research Ethics Boards. Parents of participants will provide written consent. Dissemination will occur through peer-reviewed journals and an integrated knowledge translation plan

Theory of mind mediates the prospective relationship between abnormal social brain network morphology and chronic behavior problems after pediatric traumatic brain injury

Childhood and adolescence coincide with rapid maturation and synaptic reorganization of distributed neural networks that underlie complex cognitive-affective behaviors. These regions, referred to collectively as the ‘social brain network’ (SBN) are commonly vulnerable to disruption from pediatric traumatic brain injury (TBI); however, the mechanisms that link morphological changes in the SBN to behavior problems in this population remain unclear. In 98 children and adolescents with mild to severe TBI, we acquired 3D T1-weighted MRIs at 2–8 weeks post-injury. For comparison, 33 typically developing controls of similar age, sex and education were scanned. All participants were assessed on measures of Theory of Mind (ToM) at 6 months post-injury and parents provided ratings of behavior problems at 24-months post-injury. Severe TBI was associated with volumetric reductions in the overall SBN package, as well as regional gray matter structural change in multiple component regions of the SBN. When compared with TD controls and children with milder injuries, the severe TBI group had significantly poorer ToM, which was associated with more frequent behavior problems and abnormal SBN morphology. Mediation analysis indicated that impaired theory of mind mediated the prospective relationship between abnormal SBN morphology and more frequent chronic behavior problems. Our findings suggest that sub-acute alterations in SBN morphology indirectly contribute to long-term behavior problems via their influence on ToM. Volumetric change in the SBN and its putative hub regions may represent useful imaging biomarkers for prediction of post-acute social cognitive impairment, which may in turn elevate risk for chronic behavior problems