Search

While cognitive skill learning is normally acquired implicitly through frontostriatal circuitry in healthy individuals, neuroimaging studies suggest that patients with Parkinson's disease (PD) do so by activating alternate, intact brain areas associated with explicit memory processing. To further test this hypothesis, 10 patients with PD and 12 healthy controls were tested on a modified, learning version of the Tower of London task while undergoing positron emission tomography at four different time points over the course of learning. Despite having less accurate problem solving abilities than controls, PD patients were able to acquire the skill learning task. However, as compared to controls, they maintained higher levels of cerebral blood flow activity in the dorsolateral prefrontal cortex and hippocampus and showed an increase in activity in the frontopolar cortex and posterior cingulate over the course of learning. These findings reflect a shift to the explicit memory system in PD patients, enabling them to learn this cognitive skill, which is normally acquired by control subjects using implicit learning strategies and frontostriatal circuitry. [ABSTRACT FROM AUTHOR]

Protective factors, including psychological resilience, cognitive reserve, and brain reserve, may be positively associated with recovery after pediatric mild traumatic brain injury (mTBI) but are yet to be studied concurrently. We sought to examine these factors as moderators of post-concussive symptoms (PCS) in pediatric mTBI compared with mild orthopedic injury (OI). Participants included 967 children (633 mTBI, 334 OI) aged 8-16.99 years, recruited from 5 Canadian pediatric emergency departments as part of a prospective longitudinal cohort study. At 10 days post-injury, psychological resilience was measured using the Connor-Davidson Resilience Scale and brain reserve was measured using total brain volume derived from structural magnetic resonance imaging. Cognitive reserve was measured at 3 months post-injury using IQ scores from the Wechsler Abbreviated Scale of Intelligence-Second Edition. Cognitive and somatic PCS were measured using child and parent ratings on the Health and Behavior Inventory, completed weekly for 3 months and biweekly to 6 months. Analyses involved generalized least-squares regression models using restricted cubic splines. Covariates included age at injury, sex, racialized identity, material and social deprivation, pre-injury migraine and concussion history, and retrospective pre-injury PCS. Psychological resilience moderated group differences in parent-reported PCS. At 30 days post-injury, estimated group differences in parent-reported cognitive and somatic PCS (mTBI > OI) were larger at higher (75th percentile) resilience scores ( Est = 2.25 [0.87, 3.64] and Est = 2.38 [1.76, 3.00], respectively) than at lower (25th percentile) resilience scores ( Est = 1.44 [0.01, 2.86] and Est = 2.08 [1.45, 2.71], respectively). Resilience did not moderate group differences in child-reported PCS but was negatively associated with child-reported PCS in both groups ( p s ≤ 0.001). Brain reserve (i.e., total brain volume [TBV]) also moderated group differences, but only for parent-reported somatic PCS ( p = 0.018). Group difference (mTBI > OI) at 30 days was larger at smaller (25th percentile) TBV ( Est = 2.78 [2.17, 3.38]) than at larger (75th percentile) TBV ( Est = 1.95 [1.31, 2.59]). TBV was not associated with parent-reported cognitive PCS or child-reported PCS. IQ did not moderate PCS in either group but had a significant non-linear association in both groups with child-reported somatic PCS ( p = 0.018) and parent-reported PCS ( p < 0.001), with higher PCS scores at both lower and higher IQs. These findings suggest that higher resilience predicts fewer PCS, but less strongly after mTBI than OI; greater brain reserve may reduce the effect of mTBI on somatic PCS; and cognitive reserve has an unexpected curvilinear association with PCS across injury types. The results highlight the importance of protective factors as predictors of recovery and potential targets for intervention following pediatric mTBI.

Background: Predicting recovery following pediatric mild traumatic brain injury (mTBI) remains challenging. The identification of objective biomarkers for prognostic purposes could improve clinical outcomes. Telomere length (TL) has previously been used as a prognostic marker of cellular health in the context of mTBI and other neurobiological conditions. While psychosocial and environmental factors are associated with recovery outcomes following pediatric mTBI, the relationship between these factors and TL has not been investigated. This study sought to examine the relationships between TL and psychosocial and environmental factors, in a cohort of Canadian children with mTBI or orthopedic injury (OI)., Methods: Saliva was collected at a postacute (median 7 days) timepoint following injury to assess TL from a prospective longitudinal cohort of children aged 8 to 17 years with either mTBI (n = 202) or OI (n = 90), recruited from 3 Canadian sites. Questionnaires regarding psychosocial and environmental factors were obtained at a postacute follow-up visit and injury outcomes were assessed at a 3-month visit. Univariable associations between TL and psychosocial, environmental, and outcome variables were assessed using Spearman's correlation. Further adjusted analyses of these associations were performed by including injury group, age, sex, and site as covariates in multivariable generalized linear models with a Poisson family, log link function, and robust variance estimates., Results: After adjusting for age, sex, and site, TL in participants with OI was 7% shorter than those with mTBI (adjusted mean ratio = 0.93; 95% confidence interval, 0.89-0.98; P = .003). As expected, increasing age was negatively associated with TL (Spearman's r = -0.14, P = .016). Sleep hygiene at 3 months was positively associated with TL (adjusted mean ratio = 1.010; 95% confidence interval, 1.001-1.020; P = .039)., Conclusion: The relationships between TL and psychosocial and environmental factors in pediatric mTBI and OI are complex. TL may provide information regarding sleep quality in children recovering from mTBI or OI; however, further investigation into TL biomarker validity should employ a noninjured comparison group., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 The Authors. Published by Wolters Kluwer Health, Inc.)

Background: Developmental Coordination Disorder (DCD) is a condition characterized by difficulties in motor planning and coordination and affects 5 to 6% of all school-aged children. Children with DCD frequently present with difficulties with academic activities such as handwriting. However, no study to date has comprehensively described mathematical capacity and its potential associated factors in this high-risk group., Aims: We aimed to describe the frequency and nature of mathematical difficulties of school-aged children with DCD and to evaluate potential factors associated with mathematical performance., Methods: A total of 55 elementary school-aged children with DCD underwent comprehensive standardized assessments of mathematical, visuoperceptual (VP), attentional, visual-motor integration (VMI), and motor skills. The contribution of each factor to mathematical capacity was established using hierarchical multivariate linear regression models., Results: Children with DCD (9.1 ± 1.5 years, 44 males) had lower overall mathematical capacity compared to normative data (-0.59 SD) on the KeyMath 3rd edition, with poorer performance in basic concepts and problem-solving. Thirty-eight percent of the sample performed below the 15th percentile in overall mathematical skills. VP skills were the most important factors associated with most mathematical domains. Thirty-four percent of the variance of overall mathematical capacity was explained by VP skills, inattention, VMI and motor impairments while controlling for household income (F [5,49]=5.029, p < .0001)., Conclusion: Children with DCD present with mathematical difficulties in basic concepts and problem-solving, which are partially explained by VP skills. Our findings stress the important of systematically assessing mathematical difficulties children with DCD to ensure they receive the necessary support that leads to academic success., Competing Interests: Declaration of Competing Interest None., (Crown Copyright © 2024. Published by Elsevier Ltd. All rights reserved.)

Objective: To examine preinjury life events as moderators of postconcussive symptoms (PCS) and quality of life (QoL) in children with pediatric mild traumatic brain injury (mTBI) versus orthopedic injury (OI)., Methods: Participants were 633 children with mTBI and 334 with OI, ages 8-16.99, recruited from 5 pediatric emergency departments and followed for 6 months postinjury as part of a prospective cohort study. Preinjury life events were measured retrospectively using the Child and Adolescent Survey of Experiences, PCS using the Health and Behavior Inventory (HBI) and Post-Concussion Symptom Interview (PCS-I), and QoL using the Pediatric Quality of Life Inventory (PedsQL). Analyses involved longitudinal regression using restricted cubic splines, with group, positive and negative life events, and time as primary predictors. Covariates included age, sex, race, socioeconomic status, preinjury history (i.e., headache, migraine, previous concussion), and parent-rated retrospective PCS-I, HBI, and PedsQL scores., Results: PCS and QoL were worse after mTBI than OI, but group differences declined with time (all p < .001). Group differences in PCS were larger at higher levels of positive life events, which predicted lower PCS (p= .03 to p < .001) and higher QoL (p = .048) after OI but not after mTBI. Negative life events predicted worse PCS and QoL in both groups (p = .002 to p < .001)., Conclusions: Preinjury positive life events moderate outcomes after pediatric injury, with a protective effect seen in OI but not in mTBI. Negative life events are consistently associated with worse outcomes regardless of injury type., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Importance: Research on postconcussive symptoms (PCS) following early childhood concussion has been hindered by a lack of measures suitable for this age group, resulting in a limited understanding of their evolution in young children., Objective: To document PCS in the first 3 months after early childhood concussion using a developmentally appropriate measure., Design, Setting, and Participants: This cohort study used data collected at 3 Canadian and 1 US urban pediatric emergency departments (EDs) and 8 Canadian daycares from December 2018 to December 2022 as part of the Kids' Outcomes and Long-Term Abilities (KOALA) project, a prospective, multicenter, longitudinal cohort study. Participants included children aged 6 to 72 months with early childhood concussion or orthopedic injury (OI) or uninjured children from the community to serve as controls. Data were analyzed from March 2023 to January 2024., Exposure: Concussion sustained between ages 6 and 72 months., Main Outcomes and Measures: Primary outcomes were cognitive, physical, behavioral and total PCS assessed prior to injury (retrospectively), acutely (within 48 hours), and at 10 days, 1 month, and 3 months after injury or recruitment through caregiver observations using the Report of Early Childhood Traumatic Injury Observations & Symptoms inventory. Group comparisons were analyzed using ordinal regression models., Results: The study included 303 children (mean [SD] age, 35.8 [20.2] months; 152 [50.2%] male). Of these, 174 children had a concussion (mean [SD] age,  33.3 [19.9] months), 60 children had an OI (mean [SD] age, 38.4 [19.8] months) and 69 children were uninjured controls (mean [SD] age, 39.7 [20.8] months). No meaningful differences were found between the concussion and comparison groups in retrospective preinjury PCS. Significant group differences were found for total PCS at the initial ED visit (concussion vs OI: odds ratio [OR], 4.33 [95% CI, 2.44-7.69]; concussion vs control: OR, 7.28 [95% CI, 3.80-13.93]), 10 days (concussion vs OI: OR, 4.44 [95% CI, 2.17-9.06]; concussion vs control: OR, 5.94 [95% CI, 3.22-10.94]), 1 month (concussion vs OI: OR, 2.70 [95% CI, 1.56-4.68]; concussion vs control: OR, 4.32 [95% CI, 2.36-7.92]), and 3 months (concussion vs OI: OR, 2.61 [95% CI, 1.30-5.25]; concussion vs control: OR, 2.40 [95% CI, 1.36-4.24]). Significant group differences were also found for domain-level scores (cognitive, physical, behavioral) at various time points., Conclusions and Relevance: In this early childhood cohort study, concussion was associated with more PCS than OIs or typical development up to 3 months after injury. Given the limited verbal and cognitive abilities typical of early childhood, using developmentally appropriate manifestations and behaviors is a valuable way of tracking PCS and could aid in concussion diagnosis in young children.

Advanced magnetic resonance imaging (MRI) techniques indicate that concussion (i.e., mild traumatic brain injury) disrupts brain structure and function in children. However, the functional connectivity of brain regions within global and local networks (i.e., functional connectome) is poorly understood in pediatric concussion. This prospective, longitudinal study addressed this gap using data from the largest neuroimaging study of pediatric concussion to date to study the functional connectome longitudinally after concussion as compared with mild orthopedic injury (OI). Children and adolescents ( n  = 967) 8-16.99 years with concussion or mild OI were recruited from pediatric emergency departments within 48 h post-injury. Pre-injury and 1-month post-injury symptom ratings were used to classify concussion with or without persistent symptoms based on reliable change. Subjects completed a post-acute (2-33 days) and chronic (3 or 6 months via random assignment) MRI scan. Graph theory metrics were derived from 918 resting-state functional MRI scans in 585 children (386 concussion/199 OI). Linear mixed-effects modeling was performed to assess group differences over time, correcting for multiple comparisons. Relative to OI, the global clustering coefficient was reduced at 3 months post-injury in older children with concussion and in females with concussion and persistent symptoms. Time post-injury and sex moderated group differences in local (regional) network metrics of several brain regions, including degree centrality, efficiency, and clustering coefficient of the angular gyrus, calcarine fissure, cuneus, and inferior occipital, lingual, middle occipital, post-central, and superior occipital gyrus. Relative to OI, degree centrality and nodal efficiency were reduced post-acutely, and nodal efficiency and clustering coefficient were reduced chronically after concussion (i.e., at 3 and 6 months post-injury in females; at 6 months post-injury in males). Functional network alterations were more robust and widespread chronically as opposed to post-acutely after concussion, and varied by sex, age, and symptom recovery at 1-month post-injury. Local network segregation reductions emerged globally (across the whole brain network) in older children and in females with poor recovery chronically after concussion. Reduced functioning between neighboring regions could negatively disrupt specialized information processing. Local network metric alterations were demonstrated in several posterior regions that are involved in vision and attention after concussion relative to OI. This indicates that functioning of superior parietal and occipital regions could be particularly susceptibile to the effects of concussion. Moreover, those regional alterations were especially apparent at later time periods post-injury, emerging after post-concussive symptoms resolved in most and persisted up to 6 months post-injury, and differed by biological sex. This indicates that neurobiological changes continue to occur up to 6 months after pediatric concussion, although changes emerge earlier in females than in males. Changes could reflect neural compensation mechanisms.

Background: Paediatric acquired brain injury is a life-long condition which impacts on all facets of the individual's lived experience. The existing evidence base continues to expand and new fields of enquiry are established as clinicians and researchers uncover the extent of these impacts., Primary Objective: To add to recommendations described in the International Paediatric Brain Injury Society's 2016 paper on post-acute care for children with acquired brain injury and highlight new areas of enquiry., Review of Information: Recommendations were made based on the opinions of a group of experienced international clinicians and researchers who are current or past members of the board of directors of the International Paediatric Brain Injury Society. The importance of each recommendation was agreed upon by means of group consensus., Outcomes: This update gives new consideration to areas of study including injuries which occur in pre-school children, young people in the military, medical referral, young offenders and the use of technology in rehabilitation.

Concussion is commonly characterized by a cascade of neurometabolic changes following injury. Magnetic Resonance Spectroscopy (MRS) can be used to quantify neurometabolites non-invasively. Longitudinal changes in neurometabolites have rarely been studied in pediatric concussion, and fewer studies consider symptoms. This study examines longitudinal changes of neurometabolites in pediatric concussion and associations between neurometabolites and symptom burden. Participants who presented with concussion or orthopedic injury (OI, comparison group) were recruited. The first timepoint for MRS data collection was at a mean of 12 days post-injury (n = 545). Participants were then randomized to 3 (n = 243) or 6 (n = 215) months for MRS follow-up. Parents completed symptom questionnaires to quantify somatic and cognitive symptoms at multiple timepoints following injury. There were no significant changes in neurometabolites over time in the concussion group and neurometabolite trajectories did not differ between asymptomatic concussion, symptomatic concussion, and OI groups. Cross-sectionally, Choline was significantly lower in those with persistent somatic symptoms compared to OI controls at 3 months post-injury. Lower Choline was also significantly associated with higher somatic symptoms. Although overall neurometabolites do not change over time, choline differences that appear at 3 months and is related to somatic symptoms., (© 2024. The Author(s).)

Objectives: Symptoms and cognition are both utilized as indicators of recovery following pediatric concussion, yet their interrelationship is not well understood. This study aimed to investigate: 1) the association of post-concussion symptom burden and cognitive outcomes (processing speed and executive functioning [EF]) at 4 and 12 weeks after pediatric concussion, and 2) the moderating effect of sex on this association., Methods: This prospective, multicenter cohort study included participants aged 5.00-17.99 years with acute concussion presenting to four Emergency Departments of the Pediatric Emergency Research Canada network. Five processing speed and EF tasks and the Post-Concussion Symptom Inventory (PCSI; symptom burden, defined as the difference between post-injury and retrospective [pre-injury] scores) were administered at 4 and 12 weeks post-concussion. Generalized least squares models were conducted with task performances as dependent variables and PCSI and PCSI*sex interaction as the main predictors, with important pre-injury demographic and injury characteristics as covariates., Results: 311 children (65.0% males; median age = 11.92 [IQR = 9.14-14.21 years]) were included in the analysis. After adjusting for covariates, higher symptom burden was associated with lower Backward Digit Span (χ 2 = 9.85, p = .043) and Verbal Fluency scores (χ 2 = 10.48, p = .033) across time points; these associations were not moderated by sex, ps ≥ .20. Symptom burden was not associated with performance on the Coding, Continuous Performance Test, and Color-Word Interference scores, ps ≥ .17., Conclusions: Higher symptom burden is associated with lower working memory and cognitive flexibility following pediatric concussion, yet these associations were not moderated by sex. Findings may inform concussion management by emphasizing the importance of multifaceted assessments of EF.

Higher psychological resilience is correlated with less severe post-concussion symptoms (PCS) after mild traumatic brain injury (mTBI) in children, but the directional nature of this relationship remains uncertain. Although traditionally regarded as a stable, trait-like construct, resilience may be malleable and potentially influenced by mTBI and post-concussive symptoms. The current study sought to examine the stability of resilience, elucidate the dynamic nature of the resilience-PCS relation, and determine whether resilience-symptom associations are specific to mTBI or applicable to traumatic injury in general. Participants were children aged 8-16.99 years with either mTBI ( n  = 633) or orthopedic injury (OI; n  = 334) recruited to participate in a prospective cohort study after presenting acutely to five Canadian pediatric emergency departments (EDs). Symptoms and psychological resilience were assessed at 1 week, 3 months, and 6 months post-injury. Group differences in resilience over time were examined using a mixed linear model, and associations between resilience and symptoms over time were examined using random intercepts cross-lagged panel modeling (RI-CLPM). The mTBI group reported significantly lower resilience than the OI group, but the difference was significantly larger 1 week post-injury ( d  = 0.50) than at 3 months ( d  = 0.08) and 6 months ( d  = 0.10). Cross-lagged panel models indicated that resilience had both stable and dynamic aspects, and both affected and was affected by PCS, although their association varied by time post-injury, symptom measure, and reporter (parent vs. child). Higher parent-reported cognitive symptom severity at 1 week was significantly associated with higher resilience at 3 months ( β  = 0.23, p  = 0.001). Higher resilience at 3 months was associated with lower levels of parent-reported somatic symptom severity ( β  = -0.14, p  = 0.004) and fewer total symptoms ( β  = -0.135, p  = 0.029) at 6 months. Higher resilience at 3 months was associated with fewer child-reported symptoms at 6 months ( β  = -0.11, p  = 0.030) and, reciprocally, fewer child-reported symptoms at 3 months were associated with higher resilience at 6 months ( β  = -0.22, p  = 0.001). Notably, injury group was not a significant moderator in cross-lagged models, suggesting that resilience-symptom associations are not specific to mTBI. Psychological resilience and symptoms have bidirectional relationships after injury. Interventions designed to foster resilience have the potential to promote recovery after mTBI specifically and injury more generally.

Objective: Little is known about the symptoms, signs, and management guidelines for children under the age of 6 years after they sustain a concussion. Caregivers of such young children may have unique concerns and encounter different challenges from those of school-age children given the distinctive developmental characteristics of the early childhood period. This study aimed to explore the experience of caregivers through semistructured interviews to inform clinical practice., Methods: Fifty caregivers of children aged 6 months to 5.99 years were interviewed 3 months postinjury for this qualitative study to document their experience in relation to their child's accident, recovery, and healthcare provisions., Results: Four main themes were identified: (1) visible changes associated with caregiver concerns, (2) a roller-coaster of emotions after the injury, (3) healthcare providers' role in addressing the need for reassurance, and (4) the need for better information after the injury., Conclusion: The findings provide critical insight into the unique experiences and information needs of caregivers of young children who sustain concussion. The challenges identified can inform healthcare professionals regarding the needs of caregivers after early concussion and contribute to building a knowledge base for the development of age-appropriate anticipatory guidance for caregiver mental health and child recovery., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Studies examining the associations between adolescent social media use and depression/anxiety symptoms show inconsistent results and do not elucidate the direction of associations. Differences in how studies operationalize social media use and consider potential moderating effects of sex and extraversion could contribute to inconsistencies. A distinction has been made between three types of social media use: passive, active and problematic. This study examined longitudinal associations between these types of adolescents' social media use and depression/anxiety symptoms and moderation effects of sex or extraversion. At ages 13 (T1) and 14 (T2), 257 adolescents completed an online questionnaire regarding their depression and anxiety symptoms and problematic social media use as well as three social media use diaries. Cross-lagged panel modeling (CLPM) revealed a positive association between problematic use and later anxiety symptoms (β = .16, p = .010). Extraversion moderated the association between active use and anxiety (β = -.14, p = .032). Specifically, active use predicted higher subsequent anxiety symptoms only in adolescents with low to moderate levels of extraversion. No sex moderation was found. While social media use (active or problematic) predicted later anxiety symptoms (but not depression), the reverse was not the case. However, highly extraverted individuals seem to be less vulnerable to potential negative effects of social media use., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Preschoolers and school-aged children with congenital heart disease (CHD) are at higher risk of attention deficit hyperactivity disorder (ADHD) compared with the general population. To this day, no randomised controlled trial (RCT) aiming to improve attention has been conducted in young children with CHD. There is emerging evidence indicating that parent-child yoga interventions improve attention and reduce ADHD symptoms in both typically developing and clinical populations., Methods and Analysis: This is a single-blind, two-centre, two-arm trial during which 24 children with CHD and their parents will be randomly assigned to (1) a parent-child yoga intervention in addition to standard clinical care or (2) standard clinical care alone. All participants will undergo standardised assessments: (1) at baseline, (2) immediately post-treatment and (3) 6 months post-treatment. Descriptive statistics will be used to estimate the feasibility and neurodevelopmental outcomes. This feasibility study will evaluate: (1) recruitment capacity; (2) retention, drop-out and withdrawal rates during the yoga programme and at the 6-month follow-up; (3) adherence to the intervention; (4) acceptability of the randomisation process by families; (5) heterogeneity in the delivery of the intervention between instructors and use of home-based exercises between participants; (6) proportion of missing data in the neurodevelopmental assessments and (7) SD of primary outcomes of the full RCT in order to determine the future appropriate sample size., Ethics and Dissemination: Ethical approval has been obtained by the Research Ethics Board of the Sainte-Justine University Hospital. The findings will be disseminated in peer-reviewed journals and conferences and presented to the Canadian paediatric grand round meetings., Trial Registration Number: NCT05997680., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: Socio-emotional skills, including social competence and social cognition, form the basis for robust relationships and wellbeing. Despite their importance, these skills are poorly defined and measured, particularly in children with developmental vulnerabilities. As a consequence, targets for effective management and treatment remain unclear. We aimed to i) phenotype social competence and social cognition in typically developing children (TDC) and in children with neurodevelopmental or mental health disorders (clinical groups) and ii) establish the relationships between these child-direct measures and parent ratings of social competence and behavior., Method: Using a multi-site, cross-sectional study design, we recruited 513 TDC and 136 children with neurodevelopmental (autism spectrum disorder [ASD], attention deficit hyperactivity disorder [ADHD]) or mental health (Anxiety Disorder [ANX]) diagnoses (age range 5-15 years). We administered the Paediatric Evaluation of Emotions, Relationships and Socialisation (PEERS) to children, and parents completed standardised questionnaires rating children's socio-emotional function., Results: Standardised parent questionnaires revealed a global pattern of everyday socio-emotional impairment that was common to all clinical groups, while PEERS identified disorder-specific socio-cognitive profiles for children with ASD, ADHD and ANX. Compared to TDCs, children with ASD demonstrated global socio-cognitive impairment. Children with ADHD were impulsive, demonstrating difficulties managing speed accuracy trade-offs. Children with ANX exhibited slowed social decision-making, but otherwise intact skills., Conclusions: Standardized parent questionnaires of child socio-emotional function reveal differences between children with typical and atypical development, but do not yield disorder-specific, socio-emotional profiles. In contrast, findings from the PEERS objective assessment suggest that that ASD, ADHD and ANX are associated with distinct socio-cognitive phenotypes, to more accurately guide and target management and treatment of impaired social competence., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Anderson et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The term concussion has permeated mainstream media and household vocabulary mainly due to awareness regarding the risks of concussion in professional contact sports, yet it occurs across a variety of settings and ages. Concussion is prevalent in infants, preschoolers, children, and adolescents, and is a common presentation or reason for referral to primary care providers, emergency departments, and specialised trauma clinics. Its broad range of symptoms and sequelae vary according to multiple individual, environmental, and clinical factors and can lead to health and economic burden. More than 20 years of research into risk factors and consequences of paediatric concussion has revealed as many questions as answers, and scientific work and clinical cases continue to expose its complexity and heterogeneity. In this Review, we present empirical evidence for improving outcome after paediatric concussion. We consider work pertaining to both sports and other injury mechanisms to provide a perspective that should be viewed as complementary to publications focused specifically on sports concussion. Contemporary challenges in prevention, diagnosis, prognosis, and intervention are discussed alongside pathways and future directions for improving outcome., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background and Objectives: This prospective, longitudinal cohort study examined trajectories of brain gray matter macrostructure after pediatric mild traumatic brain injury (mTBI)., Methods: Children aged 8-16.99 years with mTBI or mild orthopedic injury (OI) were recruited from 5 pediatric emergency departments. Reliable change between preinjury and 1 month postinjury symptom ratings was used to classify mTBI with or without persistent symptoms. Children completed postacute (2-33 days) and/or chronic (3 or 6 months) postinjury T1-weighted MRI, from which macrostructural metrics were derived using automated segmentation. Linear mixed-effects models were used, with multiple comparisons correction., Results: Groups ( N = 623; 407 mTBI/216 OI; 59% male; age mean = 12.03, SD = 2.38 years) did not differ in total brain, white, or gray matter volumes or regional subcortical gray matter volumes. However, time postinjury, age at injury, and biological sex-moderated differences among symptom groups in cortical thickness of the angular gyrus, basal forebrain, calcarine cortex, gyrus rectus, medial and posterior orbital gyrus, and the subcallosal area all corrected p < 0.05. Gray matter macrostructural metrics did not differ between groups postacutely. However, cortical thinning emerged chronically after mTBI relative to OI in the angular gyrus in older children ( d [95% confidence interval] = -0.61 [-1.15 to -0.08]); and in the basal forebrain (-0.47 [-0.94 to -0.01]), subcallosal area (-0.55 [-1.01 to -0.08]), and the posterior orbital gyrus (-0.55 [-1.02 to -0.08]) in females. Cortical thinning was demonstrated for frontal and occipital regions 3 months postinjury in males with mTBI with persistent symptoms vs without persistent symptoms (-0.80 [-1.55 to -0.05] to -0.83 [-1.56 to -0.10]) and 6 months postinjury in females and younger children with mTBI with persistent symptoms relative to mTBI without persistent symptoms and OI (-1.42 [-2.29 to -0.45] to -0.91 [-1.81 to -0.01])., Discussion: These findings signal little diagnostic and prognostic utility of postacute gray matter macrostructure in pediatric mTBI. However, mTBI altered the typical course of cortical gray matter thinning up to 6 months postinjury, even after symptoms typically abate in most children. Collapsing across symptom status obscured the neurobiological heterogeneity of discrete clinical outcomes after pediatric mTBI. The results illustrate the need to examine neurobiology in relation to clinical outcomes and within a neurodevelopmental framework., (© 2023 American Academy of Neurology.)

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., (Copyright © 2023 by the American Academy of Pediatrics.)

Mentalizing is defined as the ability to attribute mental states to oneself and others. In the context of parental behavior, parents' tendency to comment on their child's mental activities refers to the concept of mind-mindedness (MM). MM has been positively associated with various developmental outcomes in children, notably their own ability to mentalize, known as theory of mind (ToM). Although parental (MM) and child (ToM) mentalizing have important implications during childhood, their associations with children's neural structures are largely unknown. Among 62 mother-child dyads, maternal MM was rated from free-play sequences when children were aged 1 year, child ToM was assessed using a first-order false-belief task at 4 years of age, and structural MRI images were acquired at 10 years of age. Maternal MM was positively associated with gray matter volumes (GMV) in the dorsal prefrontal cortex and the superior temporal pole. Child ToM abilities were positively associated with GMV in the ventromedial prefrontal cortex. Though cortical regions associated with MM and ToM showed no anatomical overlap, many are functionally connected through a neural network highly involved in self-referential strategies for mentalizing. These findings suggest that MM and ToM may contribute to distinct sub-processes that collectively support social cognition development.

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.

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.

Advanced diffusion-weighted imaging techniques have increased understanding of the neuropathology of paediatric mild traumatic brain injury (i.e. concussion). Most studies have examined discrete white-matter pathways, which may not capture the characteristically subtle, diffuse and heterogenous effects of paediatric concussion on brain microstructure. This study compared the structural connectome of children with concussion to those with mild orthopaedic injury to determine whether network metrics and their trajectories across time post-injury differentiate paediatric concussion from mild traumatic injury more generally. Data were drawn from of a large study of outcomes in paediatric concussion. Children aged 8-16.99 years were recruited from five paediatric emergency departments within 48 h of sustaining a concussion ( n = 360; 56% male) or mild orthopaedic injury ( n = 196; 62% male). A reliable change score was used to classify children with concussion into two groups: concussion with or without persistent symptoms. Children completed 3 T MRI at post-acute (2-33 days) and/or chronic (3 or 6 months, via random assignment) post-injury follow-ups. Diffusion-weighted images were used to calculate the diffusion tensor, conduct deterministic whole-brain fibre tractography and compute connectivity matrices in native (diffusion) space for 90 supratentorial regions. Weighted adjacency matrices were constructed using average fractional anisotropy and used to calculate global and local (regional) graph theory metrics. Linear mixed effects modelling was performed to compare groups, correcting for multiple comparisons. Groups did not differ in global network metrics. However, the clustering coefficient, betweenness centrality and efficiency of the insula, cingulate, parietal, occipital and subcortical regions differed among groups, with differences moderated by time (days) post-injury, biological sex and age at time of injury. Post-acute differences were minimal, whereas more robust alterations emerged at 3 and especially 6 months in children with concussion with persistent symptoms, albeit differently by sex and age. In the largest neuroimaging study to date, post-acute regional network metrics distinguished concussion from mild orthopaedic injury and predicted symptom recovery 1-month post-injury. Regional network parameters alterations were more robust and widespread at chronic timepoints than post-acutely after concussion. Results suggest that increased regional and local subnetwork segregation (modularity) and inefficiency occurs across time after concussion, emerging after post-concussive symptom resolve in most children. These differences persist up to 6 months after concussion, especially in children who showed persistent symptoms. While prognostic, the small to modest effect size of group differences and the moderating effects of sex likely would preclude effective clinical application in individual patients., Competing Interests: The authors report no competing interests., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Guarantors of Brain.)

Background: Mild traumatic brain injury (mTBI) sustained in early childhood affects the brain at a peak developmental period and may disrupt sensitive stages of skill acquisition, thereby compromising child functioning. However, due to the challenges of collecting non-sedated neuroimaging data in young children, the consequences of mTBI on young children's brains have not been systematically studied. In typically developing preschool children (of age 3-5years), a brief behavioral-play familiarization provides an effective alternative to sedation for acquiring awake magnetic resonance imaging (MRI) in a time- and resource-efficient manner. To date, no study has applied such an approach for acquiring non-sedated MRI in preschool children with mTBI who may present with additional MRI acquisition challenges such as agitation or anxiety., Objective: The present study aimed to compare the effectiveness of a brief behavioral-play familiarization for acquiring non-sedated MRI for research purposes between young children with and without mTBI, and to identify factors associated with successful MRI acquisition., Materials and Methods: Preschool children with mTBI (n=13) and typically developing children (n=24) underwent a 15-minutes behavioral-play MRI familiarization followed by a 35-minutes non-sedated MRI protocol. Success rate was compared between groups, MRI quality was assessed quantitatively, and factors predicting success were documented., Results: Among the 37 participants, 15 typically developing children (63%) and 10 mTBI (77%) reached the MRI acquisition success criteria (i.e., completing the two first sequences). The success rate was not significantly different between groups (p=.48; 95% CI [-0.36 14.08]; Cramer's V=.15). The images acquired were of high-quality in 100% (for both groups) of the structural images, and 60% (for both groups) of the diffusion images. Factors associated with success included older child age (Β=0.73, p=.007, exp(B)=3.11, 95% CI [1.36 7.08]) and fewer parental concerns (Β=-1.56, p=.02, exp(Β)=0.21, 95% CI [0.05 0.82]) about the MRI procedure., Conclusion: Using brief behavioral-play familiarization allows acquisition of high-quality non-sedated MRI in young children with mTBI with success rates comparable to those of non-injured peers., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: To validate the two-factor structure (i.e., cognitive and somatic) of the Health and Behaviour Inventory (HBI), a widely used post-concussive symptom (PCS) rating scale, through factor analyses using bifactor and correlated factor models and by examining measurement invariance (MI)., Methods: PCS ratings were obtained from children aged 8-16.99 years, who presented to the emergency department with concussion (n = 565) or orthopedic injury (OI) (n = 289), and their parents, at 10-days, 3-months, and 6-months post-injury. Item-level HBI ratings were analyzed separately for parents and children using exploratory and confirmatory factor analyses (CFAs). Bifactor and correlated models were compared using various fit indices and tested for MI across time post-injury, raters (parent vs. child), and groups (concussion vs. OI)., Results: CFAs showed good fit for both a three-factor bifactor model, consisting of a general factor with two subfactors (i.e., cognitive and somatic), and a correlated two-factor model with cognitive and somatic factors, at all time points for both raters. Some results suggested the possibility of a third factor involving fatigue. All models demonstrated strict invariance across raters and time. Group comparisons showed at least strong or strict invariance., Conclusions: The findings support the two symptom dimensions measured by the HBI. The three-factor bifactor model showed the best fit, suggesting that ratings on the HBI also can be captured by a general factor. Both correlated and bifactor models showed substantial MI. The results provide further validation of the HBI, supporting its use in childhood concussion research and clinical practice.

Introduction: The effects caused by differences in data acquisition can be substantial and may impact data interpretation in multi-site/scanner studies using magnetic resonance spectroscopy (MRS). Given the increasing use of multi-site studies, a better understanding of how to account for different scanners is needed. Using data from a concussion population, we compare ComBat harmonization with different statistical methods in controlling for site, vendor, and scanner as covariates to determine how to best control for multi-site data., Methods: The data for the current study included 545 MRS datasets to measure tNAA, tCr, tCho, Glx, and mI to study the pediatric concussion acquired across five sites, six scanners, and two different MRI vendors. For each metabolite, the site and vendor were accounted for in seven different models of general linear models (GLM) or mixed-effects models while testing for group differences between the concussion and orthopedic injury. Models 1 and 2 controlled for vendor and site. Models 3 and 4 controlled for scanner. Models 5 and 6 controlled for site applied to data harmonized by vendor using ComBat. Model 7 controlled for scanner applied to data harmonized by scanner using ComBat. All the models controlled for age and sex as covariates., Results: Models 1 and 2, controlling for site and vendor, showed no significant group effect in any metabolites, but the vendor and site were significant factors in the GLM. Model 3, which included a scanner, showed a significant group effect for tNAA and tCho, and the scanner was a significant factor. Model 4, controlling for the scanner, did not show a group effect in the mixed model. The data harmonized by the vendor using ComBat (Models 5 and 6) had no significant group effect in both the GLM and mixed models. Lastly, the data harmonized by the scanner using ComBat (Model 7) showed no significant group effect. The individual site data suggest there were no group differences., Conclusion: Using data from a large clinical concussion population, different analysis techniques to control for site, vendor, and scanner in MRS data yielded different results. The findings support the use of ComBat harmonization for clinical MRS data, as it removes the site and vendor effects., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The handling editor HZ declared a past co-authorship with the author AH., (Copyright © 2023 La, Bell, Craig, Doan, Beauchamp, Zemek, Yeates and Harris.)

Millions of children sustain a concussion annually. Concussion disrupts cellular signaling and neural pathways within the brain but the resulting metabolic disruptions are not well characterized. Magnetic resonance spectroscopy (MRS) can examine key brain metabolites (e.g., N-acetyl Aspartate (tNAA), glutamate (Glx), creatine (tCr), choline (tCho), and myo-Inositol (mI)) to better understand these disruptions. In this study, we used MRS to examine differences in brain metabolites between children and adolescents with concussion versus orthopedic injury. Children and adolescents with concussion (n = 361) or orthopedic injury (OI) (n = 184) aged 8 to 17 years were recruited from five emergency departments across Canada. MRS data were collected from the left dorsolateral prefrontal cortex (L-DLPFC) using point resolved spectroscopy (PRESS) at 3 T at a mean of 12 days post-injury (median 10 days post-injury, range 2-33 days). Univariate analyses for each metabolite found no statistically significant metabolite differences between groups. Within each analysis, several covariates were statistically significant. Follow-up analyses designed to account for possible confounding factors including age, site, scanner, vendor, time since injury, and tissue type (and interactions as appropriate) did not find any metabolite group differences. In the largest sample of pediatric concussion studied with MRS to date, we found no metabolite differences between concussion and OI groups in the L-DLPFC. We suggest that at 2 weeks post-injury in a general pediatric concussion population, brain metabolites in the L-DLPFC are not specifically affected by brain injury., (© 2023 The Authors. Human Brain Mapping published by Wiley Periodicals LLC.)

Early childhood experiences are considered to influence the strength and effectiveness of neural connections and thus the development of brain connectivity. As one of the most pervasive and potent early relational experiences, parent-child attachment is a prime candidate to account for experience-driven differences in brain development. Yet, knowledge of the effects of parent-child attachment on brain structure in typically developing children is scarce and largely limited to grey matter, whereas caregiving influences on white matter (i.e. neural connections) have seldom been explored. This study examined whether normative variation in mother-child attachment security predicts white matter microstructure in late childhood and explored associations with cognitive-inhibition. Mother-child attachment security was assessed using home observations when children ( N  = 32, 20 girls) were 15 and 26 months old. White matter microstructure was assessed using diffusion magnetic resonance imaging when children were 10 years old. Child cognitive-inhibition was tested when children were 11 years old. Results revealed a negative association between mother-toddler attachment security and child white matter microstructure organization, which in turn related to better child cognitive-inhibition. While preliminary given the sample size, these findings add to the growing literature that suggests that rich and positive experiences are likely to decelerate brain development.

Background: Brain injury during early childhood may disrupt key periods of neurodevelopment. Most research regarding mild traumatic brain injury (mTBI) has focused on school-age children. We sought to characterize the incidence and healthcare utilization for mTBI in young children presenting to U.S. emergency departments (ED)., Methods: The Nationwide Emergency Department Sample was queried for children age 0-6 years with mTBI from 2016 to 2019. Patients were excluded for focal or diffuse TBI, drowning or abuse mechanism, death in the ED or hospital, Injury Severity Score > 15, neurosurgical intervention, intubation, or blood product transfusion., Results: National estimates included 1,372,291 patient visits: 63.5% were two years or younger, 57.5% were male, and 69.4% were injured in falls. The most common head injury diagnosis was "unspecified injury of head" (83%); this diagnosis decreased in frequency as age increased, in favor of a concussion diagnosis. Most patients were seen at low pediatric volume EDs (64.5%) and non-children's hospital EDs (86.2%), and 64.9% were seen at a non-teaching hospital. Over 98% were treated in the ED and discharged home. Computed tomography of the head and cervical spine were performed in 18.7% and 1.6% of patients, respectively, less often at children's hospitals (OR = 0.55, 95%CI = 0.41-0.76 for head and OR = 0.19, 95%CI = 0.11-0.34 for cervical spine). ED charges resulted in $540-681 million annually, and more than half of patients utilized Medicaid., Conclusions: Early childhood mTBI is prevalent and results in high financial burden in the U.S. There is wide variation in diagnostic coding and computed tomography scanning amongst EDs. More focused research is needed to identify optimal diagnostic tools and management strategies., Competing Interests: Declaration of Competing Interest The authors report no conflicts of interest related to this article., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Quantitative susceptibility mapping (QSM) is an MRI technique that is a potential biomarker for concussion. We performed QSM in children following concussion or orthopaedic injury (OI), to assess QSM performance as a diagnostic and prognostic biomarker., Methods: Children aged 8-17 years with either concussion (N=255) or OI (N=116) were recruited from four Canadian paediatric emergency departments and underwent QSM postacutely (2-33 days postinjury) using 3 Tesla MRI. QSM Z-scores within nine regions of interest (ROI) were compared between groups. QSM Z-scores were also compared with the 5P score, the current clinical benchmark for predicting persistent postconcussion symptoms (PPCS), at 4 weeks postinjury, with PPCS defined using reliable change methods based on both participant and parent reports., Results: Concussion and OI groups did not differ significantly in QSM Z-scores for any ROI. Higher QSM Z-scores within frontal white matter (WM) independently predicted PPCS based on parent ratings of cognitive symptoms (p=0.001). The combination of frontal WM QSM Z-score and 5P score was better at predicting PPCS than 5P score alone (p=0.004). The area under the curve was 0.72 (95% CI 0.63 to 0.81) for frontal WM susceptibility, 0.69 (95% CI 0.59 to 0.79) for the 5P score and 0.74 (95% CI 0.65 to 0.83) for both., Conclusion: The findings suggest that QSM is a potential MRI biomarker that can help predict PPCS in children with concussion, over and above the current clinical benchmark, and thereby aid in clinical management. They also suggest a frontal lobe substrate for PPCS, highlighting the potential for QSM to clarify the neurophysiology of paediatric concussion., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Fatigue may be among the most profound and debilitating consequences of pediatric traumatic brain injury (TBI); however, neurostructural risk factors associated with post-injury fatigue remain elusive. This prospective study aimed to evaluate the independent value of susceptibility-weighted imaging (SWI) biomarkers, over-and-above known risk factors, to predict fatigue symptom severity in children with TBI. Forty-two children were examined with structural magnetic resonance imaging (sMRI), including a SWI sequence, within eight weeks post-injury. The PedsQL Multi-Dimensional Fatigue Scale (MFS) was administered 24 months post-injury. Compared with population expectations, the TBI group displayed significantly higher levels of general fatigue (Cohen d  = 0.44), cognitive fatigue (Cohen d  = 0.59), sleep/rest fatigue (Cohen d  = 0.37), and total fatigue (Cohen d  = 0.63). In multi-variate models adjusted for TBI severity, child demographic factors, and depression, we found that subacute volume of SWI lesions was independently associated with all fatigue symptom domains. The magnitude of the brain-behavior relationship varied by fatigue symptom domain, such that the strongest relationships were observed for the cognitive fatigue and total fatigue symptom scales. Overall, we found that total subacute volume of SWI lesions explained up to 24% additional variance in multi-dimensional fatigue, over-and-above known risk factors. The subacute SWI has potential to improve prediction of post-injury fatigue in children with TBI. Our preliminary findings suggest that volume of SWI lesions may represent a novel, independent biomarker of post-injury fatigue, which could help to identify high-risk children who are likely to benefit from targeted psychoeducation and/or preventive strategies to minimize risk of long-term post-injury fatigue.

Objectives: To measure the association between psychosocial problems and persistent post-concussive symptoms (PCS) in youth who were seen in the emergency department with mild traumatic brain injury (mTBI) or orthopedic injury (OI)., Methods: From a larger prospective cohort study, Advancing Concussion Assessment in Pediatrics (A-CAP), 122 child-guardian pairs who presented to the emergency department with mTBI (N = 70) or OI (N = 52) were recruited for this cross-sectional sub-study. Each pair completed 2 measures assessing PCS burden at 2 weeks, 3 months, and 6 months post-injury. At one visit, pairs concurrently completed MyHEARTSMAP, a comprehensive, psychosocial self-assessment tool to evaluate 4 domains of mental wellness., Results: When measured at the same visit, children who self-reported moderate or severe Psychiatry domain concerns concurrently experienced a greater burden of cognitive symptoms (β = 5.49; 0.93-10.05) and higher overall PCS count (β = 2.59; 0.70-4.48) after adjusting for covariables, including retrospective pre-injury symptoms and injury group. Additionally, reports indicating mild Function domain severity were associated with increased cognitive (β = 3.34; 95% CI: 0.69-5.99) and somatic symptoms (β = 6.79; 2.15-11.42) and total symptom count (β = 1.29; 0.18-2.39)., Conclusion: Increasing severity in multiple domains of mental health is associated with more PCS in youth. While the differences in PCS between the mTBI and OI groups appeared somewhat larger for children with more mental health concerns, the interaction was not statistically significant; larger sample sizes are needed to evaluate the moderating effect of psychosocial difficulties on post-concussion symptoms., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Recognition of pediatric mental health concerns often depends on assessment by parents, educators, and primary care professionals. Therefore, a psychosocial screening instrument suitable for routine use in schools and primary care is needed. The Pediatric Quality of Life (PedsQL) and the Strengths and Difficulties Questionnaire (SDQ) are widely used for screening but lack adolescent-specific mental health measures. MyHEARTSMAP is an instrument assessing aspects of youth psychosocial health via four domains: Psychiatry, Function, Social, and Youth Health. We evaluated MyHEARTSMAP convergent validity with PedsQL and SDQ among 122 child-parent dyads participating in a larger concussion study. Convergent validity was assessed via correlations: MyHEARTSMAP Psychiatry and Function domains correlated strongly (r ≥ 0.44) and Social domain correlated weakly (r ≤ 0.25) to corresponding PedsQL and SDQ subscales, while Youth Health domain correlated moderately (r ≥ 0.31) to the tools' total scales. In conclusion, MyHEARTSMAP converges with PedsQL and SDQ, and benefits from the inclusion of adolescent-specific psychosocial measures., (© 2021. Crown.)

Aims: Developmental Coordination Disorder (DCD) is a chronic condition affecting motor coordination in daily activities. While motor difficulties are well documented in this population, it is unclear how frequent and to what extent academic activities are affected. This systematic review aims to comprehensively summarize the knowledge regarding the prevalence and extent of academic difficulties in reading, writing and mathematics in school-aged children with DCD., Methods: Two independent reviewers analyzed original studies on academic difficulties in school-aged children with DCD. A binary random-effects model was used to calculate the pooled prevalence by academic difficulty. A random-effects model using standardized mean differences (g statistic) was calculated to estimate the extent of the academic difficulties., Results: Twenty-four studies were included. A pooled prevalence of 84% of handwriting difficulties and 89.5% of mathematical difficulties was reported. No pooled prevalence of difficulties could be calculated for the other academic outcomes. Children with DCD present with poorer performance in handwriting legibility (g = -1.312) and speed (g = -0.931), writing (g = -0.859), mathematics (g = -1.199) and reading (g = -1.193)., Conclusions: This review highlights the high frequency and severity of academic difficulties in children with DCD, specifically in mathematics, which stresses the importance of evaluating academic performance to target interventions to support optimal functioning in daily life.

Mild traumatic brain injuries (mTBI) are highly prevalent during early childhood and can lead to behavioral difficulties. Parent report questionnaires are widely used to assess children's behavior, but they are subject to parental bias. The aim of this study was to investigate parental discrepancies in internalized and externalized behavior ratings of children who sustain mTBI in early childhood (i.e., between 18 and 60 months) and to determine if parenting stress or family burden related to the injury contribute to parental discrepancies. Mothers and fathers of 85 children with mTBI, 58 orthopedic injured (OI), and 82 typically developing children (TDC) completed the Child Behavior Checklist 6 months after the injury. The primary caregiver completed the Parental Distress subscale of the Parenting Stress Index and the Family Burden of Injury Interview. Mothers reported more internalized and externalized behavior problems than fathers in the mTBI group. No group difference was found in the OI or TDC groups. Neither parenting stress nor family burden related to the injury predicted discrepancies in behavior ratings. Mothers' and fathers' perceptions of behavior after their young child sustains mTBI appear to differ, suggesting that both parents' views are useful in understanding outcome. This difference was not found in either of the comparison groups indicating that factors related to mTBI may underlie the rating discrepancies.

There is increasing empirical focus on the effects of early traumatic brain injuries (TBI; i.e., before the age of six years) on child development, but this literature has never been synthetized comprehensively. This systematic review aimed to document the cognitive, academic, behavioral, socio-affective, and adaptive consequences of early TBI. Four databases (Medline, PsycNET, CINAHL, PubMed) were systematically searched from 1990 to 2019 using key terms pertaining to TBI and early childhood. Of 12, 153 articles identified in the initial search, 43 were included. Children who sustain early TBI are at-risk for a range of difficulties, which are generally worse when injury is sustained at a younger age, injury severity is moderate to severe, and injury mechanisms are non-accidental. Early childhood is a sensitive period for the emergence and development of new skills and behaviors, and brain disruption during this time is not benign. Research, clinical management, intervention, and prevention efforts should be further developed with consideration of the unique characteristics of the early childhood period., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Adequate social functioning during childhood requires context-appropriate social decision-making. To make such decisions, children rely on their social norms, conceptualized as cognitive models of shared expectations. Since social norms are dynamic, children must adapt their models of shared expectations and modify their behavior in line with their social environment. This study aimed to investigate children's abilities to use social information to adapt their fairness norm and to identify the computational mechanism governing this process. Thirty children (7-11 years, M = 7.9 SD = 0.85, 11 girls) played the role of Responder in a modified version of the Ultimatum Game-a two-player game based on the fairness norm-in which they had to choose to accept or reject offers from different Proposers. Norm adaptation was assessed by comparing rejection rates before and after a conditioning block in which children received several low offers. Computational models were compared to test which best explains children's behavior during the game. Mean rejection rate decreased significantly after receiving several low offers suggesting that children have the ability to dynamically update their fairness norm and adapt to changing social environments. Model-based analyses suggest that this process involves the computation of norm-prediction errors. This is the first study on norm adaptation capacities in school-aged children that uses a computational approach. Children use implicit social information to adapt their fairness norm to changing environments and this process appears to be supported by a computational mechanism in which norm-prediction errors are used to update norms., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2022 Morasse et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

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 and greater integration of family units might enhance perceptions of global and academic competence in children with TBI., Competing Interests: Declaration of Competing Interests None declared., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Objectives: To determine the association between early screen time (7-10 days postinjury) and postconcussion symptom severity in children and adolescents with concussion, as compared to those with orthopedic injury (OI)., Methods: This was a planned secondary analysis of a prospective longitudinal cohort study. Participants were 633 children and adolescents with acute concussion and 334 with OI aged 8 to 16, recruited from 5 Canadian pediatric emergency departments. Postconcussion symptoms were measured using the Health and Behavior Inventory at 7 to 10 days, weekly for 3 months, and biweekly from 3 to 6 months postinjury. Screen time was measured by using the Healthy Lifestyle Behavior Questionnaire. Generalized least squares models were fit for 4 Health and Behavior Inventory outcomes (self- and parent-reported cognitive and somatic symptoms), with predictors including screen time, covariates associated with concussion recovery, and 2 3-way interactions (self- and parent-reported screen time with group and time postinjury)., Results: Screen time was a significant but nonlinear moderator of group differences in postconcussion symptom severity for parent-reported somatic (P = .01) and self-reported cognitive symptoms (P = .03). Low and high screen time were both associated with relatively more severe symptoms in the concussion group compared to the OI group during the first 30 days postinjury but not after 30 days. Other risk factors and health behaviors had stronger associations with symptom severity than screen time., Conclusions: The association of early screen time with postconcussion symptoms is not linear. Recommending moderation in screen time may be the best approach to clinical management.

Background: Good quality friendships and relationships are critical to the development of social competence and are associated with quality of life and mental health in childhood and adolescence. Through social distancing and isolation restrictions, the COVID-19 pandemic has had an impact on the way in which youth socialize and communicate with friends, peers, teachers and family on a daily basis. In order to understand children's social functioning during the pandemic, it is essential to gather information on their experiences and perceptions concerning the social changes unique to this period. The objective of this study was to document children and adolescents' perspectives regarding their social life and friendships during the COVID-19 pandemic, through qualitative interviews., Methods: Participants (N = 67, 5-14 years) were recruited in May and June 2020. Semi-structured interviews were conducted via a videoconferencing platform. A thematic qualitative analysis was conducted based on the transcribed and coded interviews (NVivo)., Results: The upheavals related to the pandemic provoked reflection among the participants according to three main themes, each of which included sub-themes: (1) the irreplaceable nature of friendship, (2) the unsuspected benefits of school for socialization and (3) the limits and possibilities of virtual socialization., Conclusions: The collection of rich, qualitative information on the perspectives of children and adolescents provides a deeper understanding of the consequences of the pandemic on their socialization and psychological health and contributes to our fundamental understanding of social competence in childhood., (© 2022 John Wiley & Sons Ltd.)

Sociomoral reasoning (SMR) is an essential component of social functioning allowing children to establish judgments based on moral criteria. The progressive emergence and complexification of SMR during childhood is thought to be underpinned by a range of characteristics and abilities present in the preschool years. Past studies have mostly examined concurrent associations between individual factors and SMR. Using a more comprehensive and predictive approach to identify early predictors of school-age SMR would contribute to a more complete picture of SMR development. This study aimed to investigate the contribution of four domains of preschool predictors to SMR at school-age: demographic (age, sex, parental education), cognitive (executive and sociocognitive functions), behavioral (internalizing and externalizing behaviors), and familial (parent-child interactions, parental stress) factors. Parents of 122 children 3 to 5 years (M = 3.70, SD = 0.66 years, 51% girls) completed questionnaires and children were administered executive and sociocognitive tasks. Parent-child interactions were assessed using an observational approach. SMR was measured four years later using the SoMoral task. A four-step hierarchical regression analysis revealed that executive functions and internalizing problems were significant independent predictors of SMR. These findings provide a more comprehensive understanding of the early precursors of SMR during childhood.

Background and Objectives: Depression has been associated with alterations in social functioning. Decoding and understanding others' mental states and adaptive reasoning are important for social functioning. This study examined theory of mind (ToM) and socio-moral reasoning (SMR) in adolescent girls with and without depression. Within the depression group, we examined associations between relevant clinical features (depression severity, anxiety symptoms and borderline personality traits) and ToM and SMR., Methods: A cross-sectional study was conducted, whereby 43 adolescent girls (mean age = 16.19, SD = 1.24) meeting full or subthreshold criteria for depression and 40 adolescent girls (mean age = 15.44, SD = 1.24) with no psychiatric diagnosis were recruited. ToM was assessed using the Movie for the Assessment of Social Cognition; SMR was evaluated via the Socio-Moral Reasoning Aptitude Level task., Results: Analyses of covariance indicated that adolescents with depression did not differ from controls in ToM abilities but showed lower socio-maturity scores on the SMR task. This difference disappeared after controlling for the number of words used to justify responses. Amongst adolescents with depression, multiple linear regression analyses revealed that higher levels of borderline personality traits were associated with lower levels of mentalization (ToM task), and more severe depressive symptoms were associated with lower socio-moral maturity stages (SMR task) LIMITATIONS: Directional associations were not studied, and the sample included only girls., Conclusions: Findings may help to explain clinical heterogeneity in social cognitive functioning observed in individuals with depression., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objective: Children born with congenital heart disease (CHD) are at an increased risk for various neurodevelopmental impairments. However, little is known regarding social outcomes associated with CHD, particularly during early childhood. The present study aimed to characterize the sociocognitive profile and to assess the contribution of language, executive functions (EF), and social cognition to social competence (SC) in preschoolers with CHD., Method: Five-year-old children with CHD ( n = 55) completed a standardized neuropsychological assessment. Performance on sociocognitive skills was compared to test norms using one-sample t tests. Hierarchical regression was conducted to examine the associations between language skills, affect recognition (AR), theory of mind (ToM), EF (performance-based and parent-rated), and social competence., Results: Children with CHD performed significantly worse than norms in language and ToM, whereas EF and social competence appeared generally preserved in our sample. In hierarchical regression analysis, cognitive functions (language score, AR, ToM, EF performance) accounted for a significant 24.3% of the variance. Parent-rated EF added another 24.8% to the total explained variance., Conclusions: These findings provide new evidence for understanding social cognition and competence among preschoolers with CHD, showing vulnerability in social cognition and language skills but not in social competence more generally. The model suggests a combined contribution of social cognition, language, and EF on social outcomes. Remedial programs addressing these intervention targets could be useful in promoting social development in this vulnerable population. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

In the largest sample studied to date, white matter microstructural trajectories and their relation to persistent symptoms were examined after pediatric mild traumatic brain injury (mTBI). This prospective, longitudinal cohort study recruited children aged 8-16.99 years with mTBI or mild orthopedic injury (OI) from five pediatric emergency departments. Children's pre-injury and 1-month post-injury symptom ratings were used to classify mTBI with or without persistent symptoms. Children completed diffusion-weighted imaging at post-acute (2-33 days post-injury) and chronic (3 or 6 months via random assignment) post-injury assessments. Mean diffusivity (MD) and fractional anisotropy (FA) were derived for 18 white matter tracts in 560 children (362 mTBI/198 OI), 407 with longitudinal data. Superior longitudinal fasciculus FA was higher in mTBI without persistent symptoms relative to OI, d (95% confidence interval) = 0.31 to 0.37 (0.02, 0.68), across time. In younger children, MD of the anterior thalamic radiations was higher in mTBI with persistent symptoms relative to both mTBI without persistent symptoms, 1.43 (0.59, 2.27), and OI, 1.94 (1.07, 2.81). MD of the arcuate fasciculus, -0.58 (-1.04, -0.11), and superior longitudinal fasciculus, -0.49 (-0.90, -0.09) was lower in mTBI without persistent symptoms relative to OI at 6 months post-injury. White matter microstructural changes suggesting neuroinflammation and axonal swelling occurred chronically and continued 6 months post injury in children with mTBI, especially in younger children with persistent symptoms, relative to OI. White matter microstructure appears more organized in children without persistent symptoms, consistent with their better clinical outcomes., (© 2022 The Authors. Human Brain Mapping published by Wiley Periodicals LLC.)

Studies show robust links between disorganized attachment in infancy and socioemotional maladjustment in childhood. Little is known, however, about the links between disorganized attachment and brain development, and whether attachment-related differences in brain morphology translate into meaningful variations in child socioemotional functioning. This study examined the links between infants' disorganized attachment behaviors toward their mothers, whole-brain regional grey matter volume and thickness, and peer rejection in late childhood. Thirty-three children and their mothers took part in this study. The Strange Situation Procedure was used to assess mother-infant attachment when infants were 18 months old. Magnetic resonance imaging was performed when they were 10 years old to assess cortical thickness and grey matter volumes. Children and teachers reported on peer rejection 1 year later, as an indicator of socioemotional maladjustment. Results indicated that disorganized attachment was not associated with grey matter volumes. However, children who exhibited more disorganized attachment behaviors in infancy had significantly thicker cortices in bilateral middle and superior frontal gyri, and extending to the inferior frontal gyrus, as well as the orbitofrontal and insular cortices in the right hemisphere in late childhood. Moreover, children with thicker cortices in these regions experienced greater peer rejection, as rated by themselves and their teachers. Although preliminary, these results are the first to indicate that disorganized attachment may play a role in cortical thickness development and that changes in cortical thickness are associated with differences in child socioemotional functioning., (© 2022. The Psychonomic Society, Inc.)

Objective: To (1) determine the level of agreement between symptom provocation and performance-based tests of vestibulo-ocular reflex (VOR) function after pediatric mild traumatic brain injury (mTBI) and (2) describe the level of symptom provocation induced by a VOR task in individuals with and without cervical findings., Design: Cross-sectional., Setting: This study was conducted at a tertiary care pediatric hospital., Participants: A total of 101 participants (N=101) aged 6-18 years within 3 weeks of mTBI diagnosis were included (54.5% female; mean age, 13.92±2.63 years; mean time since injury at assessment, 18.26±6.16 days)., Interventions: None., Main Outcome Measures: Symptom provocation (Vestibular/Ocular Motor Screening tool), performance (clinician-observed VOR performance, head thrust test [HTT], computerized dynamic visual acuity test, video head impulse test), and c ervical impairment (cervical flexion-rotation test, range of motion test, self-reported neck pain). Agreement was evaluated using Cohen's κ statistic., Results: No outcomes demonstrated agreement with symptom provocation (κ=-0.15 to 0.14). Fair agreement demonstrated between clinician-observed VOR performance and HTT (κ=0.32), with little to no agreement demonstrated between other measures. Proportions reporting test-induced dizziness and headache were greater among individuals with cervical findings (29.1%-41.8%) than without (2.3%-6.8%)., Conclusions: Findings support that symptom provocation and performance-based tests measure different constructs and thus have distinct roles when assessing VOR function. Findings suggest results from measures of symptom provocation may be influenced by coexisting cervical impairments, underlining the value of assessing for cervical injury after pediatric mTBI., (© 2022 The Authors.)

Background: Impairments to oculomotor (OM) and vestibulo-ocular reflex (VOR) function following pediatric mTBI have been demonstrated but are poorly understood. Such impairments can be associated with more negative prognosis, affecting physical and mental wellbeing, emphasizing the need to more fully understand how these evolve., Objectives: to determine i) the extent to which performance on clinical and computerized tests of OM and VOR function varies over time in children and adolescents at 21 days, 3-, and 6-months post-mTBI; ii) the proportion of children and adolescents with mTBI presenting with abnormal scores on these tests at each timepoint., Design: Prospective longitudinal design., Setting: Tertiary care pediatric hospital., Participants: 36 participants with mTBI aged 6 to18., Procedures: Participants were assessed on a battery of OM and VOR tests within 21 days, at 3- and 6-months post injury., Outcome Measures: Clinical measures : Vestibular/ocular motor screening tool (VOMS) (symptom provocation and performance); Computerized measures: reflexive saccade test (response latency) , video head impulse test (VOR gain), and dynamic visual acuity test (LogMAR change)., Analysis: Generalized estimating equations (parameter estimates and odd ratios) estimated the effect of time. Proportions above and below normal cut-off values were determined., Results: Our sample consisted of 52.8% females [mean age 13.98 (2.4) years, assessed on average 19.07 (8-33) days post-injury]. Older children performed better on visual motion sensitivity (OR 1.43, p = 0.03) and female participants worse on near point of convergence (OR 0.19, p = 0.03). Change over time (toward recovery) was demonstrated by VOMS overall symptom provocation (OR 9.90, p = 0.012), vertical smooth pursuit (OR 4.04, p = 0.03), voluntary saccade performance (OR 6.06, p = 0.005) and right VOR gain (0.068, p = 0.013). Version performance and VOR symptom provocation showed high abnormal proportions at initial assessment., Discussion: Results indicate impairments to the VOR pathway may be present and driving symptom provocation. Vertical smooth pursuit and saccade findings underline the need to include these tasks in test batteries to comprehensively assess the integrity of OM and vestibular systems post-mTBI., Implications: Findings demonstrate 1) added value in including symptom and performance-based measures in when OM and VOR assessments; 2) the relative stability of constructs measured beyond 3 months post mTBI., (Copyright © 2022 Crampton, Schneider, Grilli, Chevignard, Katz-Leurer, Beauchamp, Debert and Gagnon.)

The analysis of large, multisite neuroimaging datasets provides a promising means for robust characterization of brain networks that can reduce false positives and improve reproducibility. However, the use of different MRI scanners introduces variability to the data. Managing those sources of variability is increasingly important for the generation of accurate group-level inferences. ComBat is one of the most promising tools for multisite (multiscanner) harmonization of structural neuroimaging data, but no study has examined its application to graph theory metrics derived from the structural brain connectome. The present work evaluates the use of ComBat for multisite harmonization in the context of structural network analysis of diffusion-weighted scans from the Advancing Concussion Assessment in Pediatrics (A-CAP) study. Scans were acquired on six different scanners from 484 children aged 8.00-16.99 years [Mean = 12.37 ± 2.34 years; 289 (59.7%) Male] ~10 days following mild traumatic brain injury ( n = 313) or orthopedic injury ( n = 171). Whole brain deterministic diffusion tensor tractography was conducted and used to construct a 90 x 90 weighted (average fractional anisotropy) adjacency matrix for each scan. ComBat harmonization was applied separately at one of two different stages during data processing, either on the (i) weighted adjacency matrices (matrix harmonization) or (ii) global network metrics derived using unharmonized weighted adjacency matrices (parameter harmonization). Global network metrics based on unharmonized adjacency matrices and each harmonization approach were derived. Robust scanner effects were found for unharmonized metrics. Some scanner effects remained significant for matrix harmonized metrics, but effect sizes were less robust. Parameter harmonized metrics did not differ by scanner. Intraclass correlations (ICC) indicated good to excellent within-scanner consistency between metrics calculated before and after both harmonization approaches. Age correlated with unharmonized network metrics, but was more strongly correlated with network metrics based on both harmonization approaches. Parameter harmonization successfully controlled for scanner variability while preserving network topology and connectivity weights, indicating that harmonization of global network parameters based on unharmonized adjacency matrices may provide optimal results. The current work supports the use of ComBat for removing multiscanner effects on global network topology., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Onicas, Ware, Harris, Beauchamp, Beaulieu, Craig, Doan, Freedman, Goodyear, Zemek, Yeates and Lebel.)

Objective: To report preliminary empirical data on a novel, developmentally appropriate, observational postconcussive symptoms inventory for infants, toddlers, and preschoolers., Setting: Emergency departments of 2 tertiary, urban pediatric hospitals., Participants: Ninety-eight children (0-8 years of age; mean age at injury = 33.00, SD = 24.7 months) with mild traumatic brain injury (concussion) divided into younger (0-2 years) and older (3-8 years) age groups., Design: Observational study., Main Measure: The Report of Early Childhood Traumatic Injury Observations & Symptoms (REACTIONS) documents 17 postconcussive symptoms representing observable manifestations thereof and was completed by parents in the acute (24-48 hours; n = 65), subacute (7-14 days; n = 78), and/or persistent phase (25-35 days; n = 72) post-mild traumatic brain injury., Results: Different patterns of postconcussive symptoms were reported by age group, with behavioral manifestations particularly salient in younger children. More children younger than 2 years had sleep and comfort-seeking symptoms at each of the 3 postinjury time points., Conclusion: Postconcussive symptoms may manifest differently after mild traumatic brain injury sustained during early childhood. To fully understand and address their presence and evolution, developmentally sound measures such as the REACTIONS inventory are required., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)