Advancing Concussion Assessment in Pediatrics (A-CAP): a prospective, concurrent cohort, longitudinal study of mild traumatic brain injury in children: protocol study

Sex differences in maturational timing of amygdala and prefrontal cortex volumes and white matter tract microstructure

The developmental mismatch hypothesis (DMH) proposes that a mismatch in maturational timing of the amygdala and prefrontal cortex (PFC) drives adolescent sensation-seeking behaviour. While some studies provide support for the DMH, few have evaluated sex differences or examined both grey and white matter. Here, we used T1-weighted and diffusion-weighted magnetic resonance imaging (MRI) to examine amygdala and PFC macrostructure and amygdala-PFC white matter microstructure development across 606 MRI sessions from 148 typically developing children and adolescents (76 females) aged 1.95-17.71 years. Using generalized additive mixed effects models, we evaluated the maturational timing of amygdala volume, four PFC subregion volumes, and fractional anisotropy and mean diffusivity of the uncinate fasciculus and amygdala-PFC white matter tracts. Amygdala and PFC maturation was consistent with the DMH in males but less so in females. Relative to males, females exhibited less amygdala development and shorter periods of PFC development. In contrast to gray matter volumes, white matter changed continuously from early childhood to late adolescence, but ended earlier in females than in males. Our findings show different amygdala-PFC maturation patterns and that the amygdala-PFC neural system reaches maturity earlier in females than in males. These important differences may underlie sex differences in sensation-seeking behaviour.

Brain Network Functional Connectivity in Children With a Concussion

BACKGROUND AND OBJECTIVES

Pediatric concussion can disrupt functional brain network connectivity, but prospective longitudinal research is needed to clarify recovery and identify moderators of change. This study investigated network functional connectivity (FC) up to 6 months after pediatric concussion.

METHODS

This prospective longitudinal concurrent cohort observational study consecutively recruited children (aged 8 to 17 years) at 5 Canadian pediatric hospital emergency departments within 48 hours of sustaining a concussion or mild orthopaedic injury (OI). Children completed 3T MRI scanning postacutely (2 to 33 days) and at either 3 or 6 months after injury (randomly assigned at the postacute visit). Reliable change between retrospective preinjury (based on parent report) and 1-month postinjury symptom ratings based on parent and child report was used to classify concussion with or without persisting symptoms. Within-network and between-network FC was computed for 8 brain networks from resting-state fMRI scans and analyzed using linear mixed-effects models, with multiple comparison correction.

RESULTS

Groups (385 with concussion/198 with OI; 59% male; 69% White; age 12.42 ± 2.29 years) did not differ in within-network FC. Relative to OI, connectivity between the visual and ventral attention networks was lower after concussion, d (95% CI) = -0.46 (-0.79 to -0.14), across time. Connectivity between the visual and default mode networks was lower at 6 months after concussion, -0.60 (-0.92 to -0.27). At 3 months after concussion, connectivity between the frontoparietal and ventral attention networks was lower in younger children, -0.98 (-1.58 to -0.37), but higher in older children, 0.81 (0.20 to 1.42). For symptom groups based on parent report, connectivity between the dorsal and ventral attention networks was higher in female children at 3 months after concussion without persisting symptoms relative to concussion with persisting symptoms, 1.25 (2.05 to 0.46), and OI, 0.87 (0.25 to 1.49).

DISCUSSION

Time after injury, age at injury, biological sex, and persistent symptom status are important moderators of FC after pediatric concussion for children seen in emergency department settings. Postacute FC may not enhance clinical diagnosis. Although within-network connectivity is preserved, between-network connectivity differences emerge after most children clinically recover and persist up to 6 months after pediatric concussion, providing a potential objective biomarker for lasting changes in brain function.

Predictors of persisting symptoms after concussion in children following a traumatic brain injury: a longitudinal retrospective cohort study

OBJECTIVES

To identify predictors of persisting symptoms after concussion (PSaC) in children, following any medically attended traumatic brain injury (TBI).

DESIGN

Retrospective cohort study.

SETTING

Linked primary and secondary care data from UK Clinical Practice Research Datalink and Hospital Episode Statistics.

PARTICIPANTS

Children aged 1-17 years with a medically attended TBI between 2013 and 2017.

MAIN OUTCOME MEASURE

A binary indicator of PSaC or suspected PSaC, measured using either a clinical code for PSaC or medical attendances for one or more PSaC symptoms 3-12 months after TBI.

RESULTS

We identified 137 873 children with a TBI; 4620 (3.4%) had PSaC or suspected PSaC. More females (3.8%) had PSaC than males (3.1%). Those with PSaC were older at the time of TBI compared with those without PSaC (8 vs 5.5 years). In a multivariable logistic regression model, older age (OR =1.02 per year increase in age, 95% CI 1.01 to 1.03), female sex (OR=1.20, 95% CI 1.13 to 1.28), being Asian (OR=1.37, 95% CI 1.22 to 1.54) or mixed ethnicity (OR=1.18, 95% CI 1.01 to 1.37) (compared with white ethnicity), having a history of headaches (OR=3.52, 95% CI 3.13 to 3.95), learning disabilities (OR=2.06, 95% CI 1.69 to 2.52), ADHD (OR=2.41, 95% CI 1.91 to 3.04), anxiety (OR=2.58, 95% CI 2.18 to 3.05), depression (OR=4.00, 95% CI 3.28 to 4.89) or sleep disorders (OR=2.35, 95% CI 1.99 to 2.78) were associated with increased odds of PSaC.

CONCLUSIONS

These results may be used to identify children more likely to develop PSaC following a TBI and those who may benefit from targeted healthcare for PSaC symptoms. Identifying cases of PSaC in primary care data was challenging as perhaps many children do not attend services for suspected PSaC or, if they did, are not diagnosed with PSaC. Furthermore, the clinical predictors are a measure of healthcare access for these symptoms; thus, results could be influenced by patient or carer's health-seeking behaviour.

Association of Psychological Resilience, Cognitive Reserve, and Brain Reserve with Post-Concussive Symptoms in Children with Mild Traumatic Brain Injury and Orthopedic Injury: An A-CAP Study

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 (ps ≤ 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.

Optimal Recovery Following Pediatric Concussion

Importance

Pediatric concussion affects millions and results in heterogeneous outcomes and recovery trajectories. Given favorable outcome for most children, it is useful to understand characteristics of positive outcome to promote full recovery in all children.

Objective

To document the timeframe of recovery to optimal functioning, defined comprehensively across motor-physical, cognitive, socioemotional, and resilience-support domains, after concussion among children ages 8 to 16 years.

Design, Setting, and Participants

For this prospective cohort study, children ages 8 to 16.99 years with a concussion or orthopedic injury (OI) were recruited between September 2016 and July 2019 from 5 Pediatric Emergency Research Canada emergency departments and assessed approximately 10 days, 3 months, and 6 months after their injury. Data were analyzed from January 29, 2024, to January 11, 2025.

Exposure

Concussion.

Main Outcomes and Measures

Participants completed self-report and direct assessment measures of postconcussive symptoms, physical activity and function, balance, cognitive function, quality of life, resilience, and social support. The main outcome was optimal functioning, which was derived from 11 variables and criteria indicative of absence of impairment and average or above functioning in each domain (overall score, 0-11; higher score indicates better function). A longitudinal, multivariable, cumulative probability ordinal regression model was fitted to examine factors associated with optimal functioning.

Results

A total of 967 children (median [IQR] age, 12.3 [10.5-14.3] years; 562 [58.1%] male) were enrolled, including 633 children with a concussion and 334 children with an OI. The median (IQR) optimal functioning scores for the OI group were 6.0 (4.0-8.0) at 10 days, 7.0 (5.0-9.0) at 3 months, and 7 (5.0-9.0) at 6 months, compared with 4.0 (2.0-6.0) at 10 days, 6.0 (4.0-9.0) at 3 months, and 7.0 (4.0-9.0) at 6 months in the concussion group. The 3 main variables (time, sex, and group) were significantly associated with optimal functioning, as were all 2-way interactions. Time was the strongest factor associated with optimal functioning (Wald χ258 = 485.11; P < .001), followed by group (Wald χ26 = 95.10; P < .001), and sex (Wald χ26 = 23.19; P < .001). At the 10-day follow-up, concussion was associated with lower optimal functioning than OI among females (odds ratio [OR],  0.24 [95% CI, 0.16-0.36]) and males (OR, 0.37 [95% CI, 0.26-0.53]). This difference persisted for females at 3 months (OR, 0.57 [95% CI, 0.35-0.93]) but not for males. Optimal functioning was comparable at 6 months.

Conclusions and Relevance

In this prospective cohort study of children with concussion, achieving optimal functioning levels across physical, cognitive, socioemotional, and resilience domains took 3 months or more, especially for girls with concussion. Multiple domains of outcome need to be taken into account when considering full recovery and optimal function after pediatric concussion.

Shorter Telomere Length Is Associated With Older Age, Poor Sleep Hygiene, and Orthopedic Injury, but Not Mild Traumatic Brain Injury, in a Cohort of Canadian Children

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.

Cross-Lagged Associations Among Sleep, Headache, and Pain in Pediatric Mild Traumatic Brain Injury: An A-CAP Study

OBJECTIVE

To test cross-lagged associations among sleep, headache, and pain in pediatric mild traumatic brain injury (mTBI).

SETTING, PARTICIPANTS, DESIGN

Children and adolescents aged 8.0 to 16.9 years who sustained a mTBI and presented to 1 of 5 pediatric emergency departments across Canada completed assessments at 1-week, 3 months, and 6 months post-injury as part of a larger prospective cohort study.

MAIN MEASURES

Sleep disturbance was measured using 7 sleep items from the Child Behaviour Checklist. Sleep duration was measured using average weekday and weekend sleep from the Healthy Lifestyle Behaviours Questionnaire. Pain intensity was measured using an 11-point numerical rating scale. Headache severity and associated functional impairment were measured using the Headache Impact Test and 1 item from the Health and Behaviour Inventory. Analyses included trivariate-indicator random-intercept cross-lagged panel models.

RESULTS

Of 633 recruited children, 563 were included in the current study. Headache showed significant within-person, bidirectional, cross-lagged associations with sleep disturbance and duration, as well as with pain intensity. More specifically, worse headache predicted greater sleep disturbance (1-week to 3 months and 3 months to 6 months: Bs = .47, Ps ≤ .013) and shorter sleep duration (1-week to 3 months: B = -.21, P = .006), while greater sleep disturbance predicted worse headache (1-week to 3 months: B = .08, P = .001). Worse headache also predicted higher pain intensity (1-week to 3 months & 3 months to 6 months: Bs ≥ 1.27, P s < .001), while higher pain intensity predicted worse headache (3 months to 6 months: Bs ≥ .03, Ps ≤ .042). No cross-lagged associations involving sleep disturbance or duration with pain intensity were significant.

CONCLUSIONS

Significant bi-directional, cross-lagged associations exist between headache and both sleep and pain. The findings suggest that early intervention for headaches may help prevent later sleep disturbance and pain after pediatric mTBI.

Psychosocial Factors Associated With Time to Recovery After Concussion in Adolescent Ice Hockey Players

OBJECTIVE

To investigate the association between psychosocial factors and physician clearance to return to play (RTP) in youth ice hockey players after sport-related concussion.

DESIGN

Prospective cohort study, Safe to Play (2013-2018).

SETTING

Youth hockey leagues in Alberta and British Columbia, Canada.

PARTICIPANTS

Three hundred fifty-three ice hockey players (aged 11-18 years) who sustained a total of 397 physician-diagnosed concussions.

INDEPENDENT VARIABLES

Psychosocial variables.

MAIN OUTCOME MEASURES

Players and parents completed psychosocial questionnaires preinjury. Players with a suspected concussion were referred for a study physician visit, during which they completed the Sport Concussion Assessment Tool (SCAT3/SCAT5) and single question ratings of distress and expectations of recovery. Time to recovery (TTR) was measured as days between concussion and physician clearance to RTP. Accelerated failure time models estimated the association of psychosocial factors with TTR, summarized with time ratios (TRs). Covariates included age, sex, body checking policy, days from concussion to the initial physician visit, and symptom severity at the initial physician visit.

RESULTS

Self-report of increased peer-related problems on the Strengths and Difficulties Questionnaire (TR, 1.10 [95% CI, 1.02-1.19]), higher ratings of distress about concussion outcomes by participants (TR, 1.06 [95% CI, 1.01-1.11]) and parents (TR, 1.05 [95% CI, 1.01-1.09]), and higher parent ratings of distress about their child's well-being at the time of injury (TR, 1.06 [95% CI, 1.02-1.09]) were associated with longer recovery.

CONCLUSIONS

Greater pre-existing peer-related problems and acute distress about concussion outcomes and youth well-being predicted longer TTR. Treatment targeting these psychosocial factors after concussion may promote recovery.

Do preinjury life events moderate the outcomes of mild traumatic brain injuries in children? An A-CAP Study

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.

Longitudinal Functional Connectome in Pediatric Concussion: An Advancing Concussion Assessment in Pediatrics Study

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.

Longitudinal changes in brain metabolites following pediatric concussion

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.

Dynamic Relations Between Psychological Resilience and Post-Concussion Symptoms in Children With Mild Traumatic Brain Injury Versus Orthopedic Injury: An A-CAP Study

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.

Pediatric Sport-Related Concussion: Recommendations From the Amsterdam Consensus Statement 2023

The 6th International Consensus Conference on Concussion in Sport, Amsterdam 2022, addressed sport-related concussion (SRC) in adults, adolescents, and children. We highlight the updated evidence-base and recommendations regarding SRC in children (5-12 years) and adolescents (13-18 years). Prevention strategies demonstrate lower SRC rates with mouthguard use, policy disallowing bodychecking in ice hockey, and neuromuscular training in adolescent rugby. The Sport Concussion Assessment Tools (SCAT) demonstrate robustness with the parent and child symptom scales, with the best diagnostic discrimination within the first 72 hours postinjury. Subacute evaluation (>72 hours) requires a multimodal tool incorporating symptom scales, balance measures, cognitive, oculomotor and vestibular, mental health, and sleep assessment, to which end the Sport Concussion Office Assessment Tools (SCOAT6 [13+] and Child SCOAT6 [8-12]) were developed. Rather than strict rest, early return to light physical activity and reduced screen time facilitate recovery. Cervicovestibular rehabilitation is recommended for adolescents with dizziness, neck pain, and/or headaches for greater than 10 days. Active rehabilitation and collaborative care for adolescents with persisting symptoms for more than 30 days may decrease symptoms. No tests and measures other than standardized and validated symptom rating scales are valid for diagnosing persisting symptoms after concussion. Fluid and imaging biomarkers currently have limited clinical utility in diagnosing or assessing recovery from SRC. Improved paradigms for return to school were developed. The variable nature of disability and differences in evaluating para athletes and those of diverse ethnicity, sex, and gender are discussed, as are ethical considerations and future directions in pediatric SRC research.

Improving outcome after paediatric concussion: challenges and possibilities

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.

Fluid biomarkers and neuroimaging in mild traumatic brain injury: current uses and potential future directions for clinical use in emergency medicine

Mild traumatic brain injury is a common presentation to the emergency department, with current management often focusing on determining whether a patient requires a CT head scan and/or neurosurgical intervention. There is a growing appreciation that approximately 20%-40% of patients, including those with a negative (normal) CT, will develop ongoing symptoms for months to years, often termed post-concussion syndrome. Owing to the requirement for improved diagnostic and prognostic mechanisms, there has been increasing evidence concerning the utility of both imaging and blood biomarkers.Blood biomarkers offer the potential to better risk stratify patients for requirement of neuroimaging than current clinical decisions rules. However, improved assessment of the clinical utility is required prior to wide adoption. MRI, using clinical sequences and advanced quantitative methods, can detect lesions not visible on CT in up to 30% of patients that may explain, at least in part, some of the ongoing problems. The ability of an acute biomarker (be it imaging, blood or other) to highlight those patients at greater risk of ongoing deficits would allow for greater personalisation of follow-up care and resource allocation.We discuss here both the current evidence and the future potential clinical usage of blood biomarkers and advanced MRI to improve diagnostic pathways and outcome prediction following mild traumatic brain injury.

Longitudinal Gray Matter Trajectories in Pediatric Mild Traumatic Brain Injury

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.

IQ After Pediatric Concussion

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A Prospective Cohort Study of the Association Between Preinjury Psychosocial Function and Postconcussive Symptoms in Pediatric Mild Traumatic Brain Injury: An A-CAP Study

OBJECTIVE

We evaluated the moderating effect of preinjury psychosocial function on postconcussion symptoms for children with mild traumatic brain injury (mTBI).

DESIGN, SETTING, AND POPULATION

We conducted a prospective cohort study of children ages 8.0 to 16.9 years with mTBI ( n = 633) or orthopedic injury (OI; n = 334), recruited from 5 pediatric emergency departments from September 2016 to December 2018.

MAIN MEASURES

Participants completed baseline assessments within 48 hours of injury, and postconcussion symptoms assessments at 7 to 10 days, weekly to 3 months, and biweekly to 6 months post-injury. Preinjury psychosocial function was measured using parent ratings on the Pediatric Quality of Life Inventory (PedsQL) and the Strengths and Difficulties Questionnaire (SDQ), retrospectively evaluating their child's status prior to the injury. Parent and child ratings on the Health and Behavior Inventory (HBI) (cognitive and somatic subscales) and the Post-Concussion Symptom Interview (PCS-I) were used as measures of postconcussion symptoms. We fitted 6 longitudinal regression models, which included 747 to 764 participants, to evaluate potential interactions between preinjury psychosocial function and injury group as predictors of child- and parent-reported postconcussion symptoms.

RESULTS

Preinjury psychosocial function moderated group differences in postconcussion symptoms across the first 6 months post-injury. Higher emotional and conduct problems were significantly associated with more severe postconcussion symptoms among children with mTBI compared with OI. Wald's χ 2 for interaction terms (injury group × SDQ subscales) ranged from 6.3 to 10.6 ( P values <.001 to .043) across parent- and child-reported models. In contrast, larger group differences (mTBI > OI) in postconcussion symptoms were associated with milder hyperactivity (Wald's χ 2 : 15.3-43.0, all P < .001), milder peer problems (Wald's χ 2 : 11.51, P = .003), and higher social functioning (Wald's χ 2 : 12.435, P = .002).

CONCLUSIONS

Preinjury psychosocial function moderates postconcussion symptoms in pediatric mTBI, highlighting the importance of assessing preinjury psychosocial function in children with mTBI.

What tests and measures accurately diagnose persisting post-concussive symptoms in children, adolescents and adults following sport-related concussion? A systematic review

OBJECTIVE

To determine what tests and measures accurately diagnose persisting post-concussive symptoms (PPCS) in children, adolescents and adults following sport-related concussion (SRC).

DESIGN

A systematic literature review.

DATA SOURCES

MEDLINE, Embase, PsycINFO, Cochrane Central Register of Controlled Trials, CINAHL and SPORTDiscus through March 2022.

ELIGIBILITY CRITERIA

Original, empirical, peer-reviewed findings (cohort studies, case-control studies, cross-sectional studies and case series) published in English and focused on SRC. Studies needed to compare individuals with PPCS to a comparison group or their own baseline prior to concussion, on tests or measures potentially affected by concussion or associated with PPCS.

RESULTS

Of 3298 records screened, 26 articles were included in the qualitative synthesis, including 1016 participants with concussion and 531 in comparison groups; 7 studies involved adults, 8 involved children and adolescents and 11 spanned both age groups. No studies focused on diagnostic accuracy. Studies were heterogeneous in participant characteristics, definitions of concussion and PPCS, timing of assessment and the tests and measures examined. Some studies found differences between individuals with PPCS and comparison groups or their own pre-injury assessments, but definitive conclusions were not possible because most studies had small convenience samples, cross-sectional designs and were rated high risk of bias.

CONCLUSION

The diagnosis of PPCS continues to rely on symptom report, preferably using standardised symptom rating scales. The existing research does not indicate that any other specific tool or measure has satisfactory accuracy for clinical diagnosis. Future research drawing on prospective, longitudinal cohort studies could help inform clinical practice.

Altered longitudinal structural connectome in paediatric mild traumatic brain injury: an Advancing Concussion Assessment in Paediatrics study

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.

Brain metabolites measured with magnetic resonance spectroscopy in pediatric concussion and orthopedic injury: An Advancing Concussion Assessment in Pediatrics (A-CAP) study

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.

Can quantitative susceptibility mapping help diagnose and predict recovery of concussion in children? An A-CAP study

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.

Association of Posttraumatic Headache With Symptom Burden After Concussion in Children

Importance

Headache is the most common symptom after pediatric concussion.

Objectives

To examine whether posttraumatic headache phenotype is associated with symptom burden and quality of life 3 months after concussion.

Design, Setting, and Participants

This was a secondary analysis of the Advancing Concussion Assessment in Pediatrics (A-CAP) prospective cohort study, conducted September 2016 to July 2019 at 5 Pediatric Emergency Research Canada (PERC) network emergency departments. Children aged 8.0-16.99 years presenting with acute (<48 hours) concussion or orthopedic injury (OI) were included. Data were analyzed from April to December 2022.

Exposure

Posttraumatic headache was classified as migraine or nonmigraine headache, or no headache, using modified International Classification of Headache Disorders, 3rd edition, diagnostic criteria based on self-reported symptoms collected within 10 days of injury.

Main Outcomes and Measures

Self-reported postconcussion symptoms and quality-of-life were measured at 3 months after concussion using the validated Health and Behavior Inventory (HBI) and Pediatric Quality of Life Inventory-Version 4.0 (PedsQL-4.0). An initial multiple imputation approach was used to minimize potential biases due to missing data. Multivariable linear regression evaluated the association between headache phenotype and outcomes compared with the Predicting and Preventing Postconcussive Problems in Pediatrics (5P) clinical risk score and other covariates and confounders. Reliable change analyses examined clinical significance of findings.

Results

Of 967 enrolled children, 928 (median [IQR] age, 12.2 [10.5 to 14.3] years; 383 [41.3%] female) were included in analyses. HBI total score (adjusted) was significantly higher for children with migraine than children without headache (estimated mean difference [EMD], 3.36; 95% CI, 1.13 to 5.60) and children with OI (EMD, 3.10; 95% CI, 0.75 to 6.62), but not children with nonmigraine headache (EMD, 1.93; 95% CI, -0.33 to 4.19). Children with migraine were more likely to report reliable increases in total symptoms (odds ratio [OR], 2.13; 95% CI, 1.02 to 4.45) and somatic symptoms (OR, 2.70; 95% CI, 1.29 to 5.68) than those without headache. PedsQL-4.0 subscale scores were significantly lower for children with migraine than those without headache only for physical functioning (EMD, -4.67; 95% CI, -7.86 to -1.48).

Conclusions and Relevance

In this cohort study of children with concussion or OI, those with posttraumatic migraine symptoms after concussion had higher symptom burden and lower quality of life 3 months after injury than those with nonmigraine headache. Children without posttraumatic headache reported the lowest symptom burden and highest quality of life, comparable with children with OI. Further research is warranted to determine effective treatment strategies that consider headache phenotype.

The Role of Neuroimaging in Evolving TBI Research and Clinical Practice

Neuroimaging technologies such as computed tomography (CT) and magnetic resonance imaging (MRI) have been widely adopted in the clinical diagnosis and management of traumatic brain injury (TBI), particularly at the more acute and severe levels of injury. Additionally, a number of advanced applications of MRI have been employed in TBI-related clinical research with great promise, and researchers have used these techniques to better understand underlying mechanisms, progression of secondary injury and tissue perturbation over time, and relation of focal and diffuse injury to later outcome. However, the acquisition and analysis time, the cost of these and other imaging modalities, and the need for specialized expertise have represented historical barriers in extending these tools in clinical practice. While group studies are important in detecting patterns, heterogeneity among patient presentation and limited sample sizes from which to compare individual level data to well-developed normative data have also played a role in the limited translatability of imaging to wider clinical application. Fortunately, the field of TBI has benefitted from increased public and scientific awareness of the prevalence and impact of TBI, particularly in head injury related to recent military conflicts and sport-related concussion. This awareness parallels an increase in federal funding in the United States and other countries allocated to investigation in these areas. In this article we summarize funding and publication trends since the mainstream adoption of imaging in TBI to elucidate evolving trends and priorities in the application of different techniques and patient populations. We also review recent and ongoing efforts to advance the field through promoting reproducibility, data sharing, big data analytic methods, and team science. Finally, we discuss international collaborative efforts to combine and harmonize neuroimaging, cognitive, and clinical data, both prospectively and retrospectively. Each of these represent unique, but related, efforts that facilitate closing gaps between the use of advanced imaging solely as a research tool and the use of it in clinical diagnosis, prognosis, and treatment planning and monitoring.

Concurrent Psychosocial Concerns and Post-Concussive Symptoms Following Pediatric mTBI: An A-CAP Study

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.

Convergent Validity of Myheartsmap: A Pediatric Psychosocial Health Screening Tool

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.

Cerebral Hemodynamics and Microvasculature Changes in Relation to White Matter Microstructure After Pediatric Mild Traumatic Brain Injury: An A-CAP Pilot Study

Advanced neuroimaging techniques show promise as a biomarker for mild traumatic brain injury (mTBI). However, little research has evaluated cerebral hemodynamics or its relation to white matter microstructure post-mTBI in children. This novel pilot study examined differences in cerebral hemodynamics, as measured using functional near-infrared spectroscopy (fNIRS), and its association with diffusion tensor imaging (DTI) metrics in children with mTBI or mild orthopedic injury (OI) to address these gaps. Children 8.00-16.99 years of age with mTBI (n = 9) or OI (n = 6) were recruited in a pediatric emergency department, where acute injury characteristics were assessed. Participants completed DTI twice, post-acutely (2-33 days) and chronically (3 or 6 months), and fNIRS ∼1 month post-injury. Automated deterministic tractography was used to compute DTI metrics. There was reduced absolute phase globally and coherence in the dorsolateral pre-frontal cortex (DLPFC) after mTBI compared to the OI group. Coherence in the DLPFC and absolute phase globally showed distinct associations with fractional anisotropy in interhemispheric white matter pathways. Two fNIRS metrics (coherence and absolute phase) differentiated mTBI from OI in children. Variability in cerebral hemodynamics related to white matter microstructure. The results provide initial evidence that fNIRS may have utility as a clinical biomarker of pediatric mTBI.

Harmonization of multi-scanner in vivo magnetic resonance spectroscopy: ENIGMA consortium task group considerations

Magnetic resonance spectroscopy is a powerful, non-invasive, quantitative imaging technique that allows for the measurement of brain metabolites that has demonstrated utility in diagnosing and characterizing a broad range of neurological diseases. Its impact, however, has been limited due to small sample sizes and methodological variability in addition to intrinsic limitations of the method itself such as its sensitivity to motion. The lack of standardization from a data acquisition and data processing perspective makes it difficult to pool multiple studies and/or conduct multisite studies that are necessary for supporting clinically relevant findings. Based on the experience of the ENIGMA MRS work group and a review of the literature, this manuscript provides an overview of the current state of MRS data harmonization. Key factors that need to be taken into consideration when conducting both retrospective and prospective studies are described. These include (1) MRS acquisition issues such as pulse sequence, RF and B0 calibrations, echo time, and SNR; (2) data processing issues such as pre-processing steps, modeling, and quantitation; and (3) biological factors such as voxel location, age, sex, and pathology. Various approaches to MRS data harmonization are then described including meta-analysis, mega-analysis, linear modeling, ComBat and artificial intelligence approaches. The goal is to provide both novice and experienced readers with the necessary knowledge for conducting MRS data harmonization studies.

Comparison of different approaches to manage multi-site magnetic resonance spectroscopy clinical data analysis

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.

Early Postinjury Screen Time and Concussion Recovery

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.

Longitudinal trends in incidence and health care use for pediatric concussion in Alberta, Canada

BACKGROUND

We described longitudinal trends in the incidence of episodes of care (EOC) and follow-up care for pediatric concussion in relation to age, sex, rurality of patient residence, point of care, and area-based socioeconomic status (SES) in Alberta, Canada.

METHODS

A retrospective population-based cohort study was conducted using linked, province-wide administrative health data for all patients <18 years of age who received a diagnosis of concussion, other specified injuries of head, unspecified injury of head, or post-concussion syndrome between April 1, 2004 and March 31, 2018. Data were geospatially mapped.

RESULTS

Concussion EOCs increased 2.2-fold over the study period, follow-up visits 5.1-fold. Care was increasingly received in physician office (PO) settings. Concussion diagnoses in rural and remote areas occurred in emergency department (ED) settings more often than in metro centres or urban areas (76%/75% vs. 52%/60%). Proportion of concussion diagnoses was positively related to SES and age. Diagnosis and point of care varied geographically.

CONCLUSIONS

The shift in care to PO settings, increased incidence of all diagnoses, and the higher use of the ED by some segments of the population all have important implications for appropriate clinical management and the efficient provision of health care for pediatric concussion.

IMPACT

This is the first study to use EOC to describe longitudinal trends in incidence and follow-up care for pediatric concussion in relation to age, sex, rurality, point of care, and area-based SES. We report increased incidence of concussion in both emergency and outpatient settings and the proportion of diagnoses was positively related to SES and age. Patients increasingly received care for concussion in PO over time. Geospatial mapping indicated that the incidence of concussion and unspecified injury of head varied geographically and temporally. Results have important implications for appropriate clinical management and efficient provision of health care following pediatric concussion.

Factor structure and measurement invariance of post-concussion symptom ratings on the Health and Behaviour Inventory across time, raters, and groups: An A-CAP study

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.

Family Burden in Adolescents With Refractory Postconcussion Symptoms

OBJECTIVE

A significant minority of adolescents will have persistent postconcussion symptoms after an injury, potentially having a negative impact on family functioning. However, the reasons for a family's negative impact are not clearly understood. The objective of this study was to determine whether preinjury/demographic factors, injury characteristics, and/or worse postinjury symptoms are associated with higher levels of family stress in youth with refractory postconcussion symptoms.

SETTING

Pediatric refractory concussion clinic in a tertiary care center.

PARTICIPANTS

A total of 121 adolescents (13-18 years old) who were 1 to 12 months postconcussion.

MEASURES

Primary outcome was the mean stress rating on the Family Burden of Injury Interview (FBII), a 27-item questionnaire rating the impact on a family as a result of an injury. Preinjury/demographic and injury details were collected. Youth and their parents also completed measures of postconcussion symptoms, depression, anxiety, and behavioral problems.

RESULTS

Participants had a mean age of 16.0 years (SD = 1.3), of which, 65% identified as female, and were on an average 5.2 months (SD = 2.4) postconcussion. FBII ratings were not significantly correlated with demographics, preinjury functioning, injury severity, duration of persistent postconcussion problems (ie, time since injury), or self-reported postconcussion symptoms. Greater family burden (higher FBII ratings) significantly correlated with worse parent-reported postconcussion symptoms, worse psychological functioning (self-reported depression, parent-reported anxiety, and depression), and worse behavioral functioning (parent-reported conduct problems and peer problems). A multiple linear regression model revealed that parent-perceived postconcussion cognitive symptoms (β = .292, t = 2.56, P = .012) and parent-perceived peer problems (β = .263, t = 2.59, P = .011) were significantly associated with family burden ( F8,105 = 6.53; P < .001; R2 = 0.35).

CONCLUSION

Families of youth with refractory postconcussion symptoms can experience a negative impact. The severity of reported family burden in those with slow recovery from concussion was significantly associated with parents' perception of their child's cognitive symptoms and peer problems. These results could provide support for family-based interventions in this population.

Multisite Harmonization of Structural DTI Networks in Children: An A-CAP Study

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.

Longitudinal white matter microstructural changes in pediatric mild traumatic brain injury: An A-CAP study

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.

Examining brain white matter after pediatric mild traumatic brain injury using neurite orientation dispersion and density imaging: An A-CAP study

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We examined white matter microstructure after pediatric mTBI using NODDI and DTI.

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Children with mTBI did not significantly differ from those with OI on any metrics.

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Minor alterations, if any, may be present in children at the post-acute stage after mTBI.

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Large longitudinal studies are needed to understand long-term brain changes post injury.

Background

Pediatric mild traumatic brain injury (mTBI) affects millions of children annually. Diffusion tensor imaging (DTI) is sensitive to axonal injuries and white matter microstructure and has been used to characterize the brain changes associated with mild traumatic brain injury (mTBI). Neurite orientation dispersion and density imaging (NODDI) is a diffusion model that can provide additional insight beyond traditional DTI metrics, but has not been examined in pediatric mTBI. The goal of this study was to employ DTI and NODDI to gain added insight into white matter alterations in children with mTBI compared to children with mild orthopedic injury (OI).

Methods

Children (mTBI n = 320, OI n = 176) aged 8–16.99 years (12.39 ± 2.32 years) were recruited from emergency departments at five hospitals across Canada and underwent 3 T MRI on average 11 days post-injury. DTI and NODDI metrics were calculated for seven major white matter tracts and compared between groups using univariate analysis of covariance controlling for age, sex, and scanner type. False discovery rate (FDR) was used to correct for multiple comparisons.

Results

Univariate analysis revealed no significant group main effects or interactions in DTI or NODDI metrics. Fractional anisotropy and neurite density index in all tracts exhibited a significant positive association with age and mean diffusivity in all tracts exhibited a significant negative association with age in the whole sample.

Conclusions

Overall, there were no significant differences between mTBI and OI groups in brain white matter microstructure from either DTI or NODDI in the seven tracts. This indicates that mTBI is associated with relatively minor white matter differences, if any, at the post-acute stage. Brain differences may evolve at later stages of injury, so longitudinal studies with long-term follow-up are needed.

Structural connectome differences in pediatric mild traumatic brain and orthopedic injury

Sophisticated network‐based approaches such as structural connectomics may help to detect a biomarker of mild traumatic brain injury (mTBI) in children. This study compared the structural connectome of children with mTBI or mild orthopedic injury (OI) to that of typically developing (TD) children. Children aged 8–16.99 years with mTBI (n = 83) or OI (n = 37) were recruited from the emergency department and completed 3T diffusion MRI 2–20 days postinjury. TD children (n = 39) were recruited from the community and completed diffusion MRI. Graph theory metrics were calculated for the binarized average fractional anisotropy among 90 regions. Multivariable linear regression and linear mixed effects models were used to compare groups, with covariates age, hemisphere, and sex, correcting for multiple comparisons. The two injury groups did not differ on graph theory metrics, but both differed from TD children in global metrics (local network efficiency: TD > OI, mTBI, d = 0.49; clustering coefficient: TD < OI, mTBI, d = 0.49) and regional metrics for the fusiform gyrus (lower degree centrality and nodal efficiency: TD > OI, mTBI, d = 0.80 to 0.96; characteristic path length: TD < OI, mTBI, d = −0.75 to −0.90) and in the superior and middle orbital frontal gyrus, paracentral lobule, insula, and thalamus (clustering coefficient: TD > OI, mTBI, d = 0.66 to 0.68). Both mTBI and OI demonstrated reduced global and regional network efficiency and segregation as compared to TD children. Findings suggest a general effect of childhood injury that could reflect pre‐ and postinjury factors that can alter brain structure. An OI group provides a more conservative comparison group than TD children for structural neuroimaging research in pediatric mTBI.

Participant factors that contribute to magnetic resonance imaging motion artifacts in children with mild traumatic brain injury or orthopedic injury

Motion can compromise image quality and confound results, especially in pediatric research. This study evaluated qualitative and quantitative approaches to motion artifacts detection and correction, and whether motion artifacts relate to injury history, age, or sex in children with mild traumatic brain injury or orthopedic injury relative to typically developing children. The concordance between qualitative and quantitative motion ratings was also examined. Children aged 8-16 years with mild traumatic brain injury (n = 141) or orthopedic injury (n = 73) were recruited from the emergency department and completed an MRI scan roughly 2 weeks post-injury. Typically developing children (n = 41) completed a single MRI scan. T1- and diffusion-weighted images were visually inspected and rated for motion artifacts by trained examiners. Quantitative estimates of motion artifacts were derived from FreeSurfer and FSL. Age (younger > older) and sex (boys > girls) were significantly associated with motion artifacts on both T1- and diffusion-weighted images. Children with mild traumatic brain or orthopedic injury had significantly more motion-corrupted diffusion-weighted volumes than typically developing children, but mild traumatic brain injury and orthopedic injury groups did not differ from each other. The exclusion of motion-corrupted volumes did not significantly change diffusion tensor imaging metrics. Results indicate that automated quantitative estimates of motion artifacts, which are less labour-intensive than manual methods, are appropriate. Results have implications for the reliability of structural MRI research and highlight the importance of considering motion artifacts in studies of pediatric mild traumatic brain injury.

Normative and Psychometric Characteristics of the Health and Behavior Inventory Among Children With Mild Orthopedic Injury Presenting to the Emergency Department: Implications for Assessing Postconcussive Symptoms Using the Child Sport Concussion Assessment Tool 5th Edition (Child SCAT5)

OBJECTIVE

The study sought to present normative and psychometric data and reliable change formulas for the Health and Behavior Inventory (HBI), a postconcussive symptom rating scale embedded in the Child Sport Concussion Assessment Tool 5th edition (Child SCAT5).

DESIGN

Prospective cohort study with longitudinal follow-up.

SETTING

Pediatric emergency departments (EDs).

PARTICIPANTS

As part of 3 studies conducted in the United States and Canada between 2001 and 2019, 450 children aged 8 to 16 years with mild orthopedic injuries were recruited during ED visits and assessed postacutely (M = 9.38 days, SD = 3.31) and 1 month and 3 months postinjury. Independent variables were rater (child vs parent), sex, and age at injury.

MAIN OUTCOME MEASURE

HBI ratings.

METHODS

Children and parents rated children's symptoms at each time point; parents also rated children's preinjury symptoms retrospectively. Normative data (mean, SD, skewness, kurtosis, and percentiles) were computed for child and parent ratings. Internal consistency was assessed using Cronbach alpha (α), and test-retest reliability and interrater agreement were assessed with intraclass correlations (ICCs). Reliable change formulas were computed using linear regression and mixed models.

RESULTS

HBI ratings were positively skewed. Mean ratings and percentiles were stable over time. Child and parent ratings demonstrated good-to-excellent internal consistency (α 0.76-0.94) and moderate-to-good test-retest reliability (ICC 0.51-0.76 between adjacent assessments). However, parent-child agreement was poor to moderate (ICC 0.31-0.69).

CONCLUSIONS

The HBI demonstrates acceptable normative and psychometric characteristics. Modest parent-child agreement highlights the importance of multiple informants when assessing postconcussive symptoms. The results will facilitate the use of the HBI in research and clinical practice.

The clinical utility of proton magnetic resonance spectroscopy in traumatic brain injury: recommendations from the ENIGMA MRS working group

Proton (1H) magnetic resonance spectroscopy provides a non-invasive and quantitative measure of brain metabolites. Traumatic brain injury impacts cerebral metabolism and a number of research groups have successfully used this technique as a biomarker of injury and/or outcome in both pediatric and adult TBI populations. However, this technique is underutilized, with studies being performed primarily at centers with access to MR research support. In this paper we present a technical introduction to the acquisition and analysis of in vivo 1H magnetic resonance spectroscopy and review 1H magnetic resonance spectroscopy findings in different injury populations. In addition, we propose a basic 1H magnetic resonance spectroscopy data acquisition scheme (Supplemental Information) that can be added to any imaging protocol, regardless of clinical magnetic resonance platform. We outline a number of considerations for study design as a way of encouraging the use of 1H magnetic resonance spectroscopy in the study of traumatic brain injury, as well as recommendations to improve data harmonization across groups already using this technique.

Challenges and opportunities for neuroimaging in young patients with traumatic brain injury: a coordinated effort towards advancing discovery from the ENIGMA pediatric moderate/severe TBI group

Traumatic brain injury (TBI) is a major cause of death and disability in children in both developed and developing nations. Children and adolescents suffer from TBI at a higher rate than the general population, and specific developmental issues require a unique context since findings from adult research do not necessarily directly translate to children. Findings in pediatric cohorts tend to lag behind those in adult samples. This may be due, in part, both to the smaller number of investigators engaged in research with this population and may also be related to changes in safety laws and clinical practice that have altered length of hospital stays, treatment, and access to this population. The ENIGMA (Enhancing NeuroImaging Genetics through Meta-Analysis) Pediatric Moderate/Severe TBI (msTBI) group aims to advance research in this area through global collaborative meta-analysis of neuroimaging data. In this paper, we discuss important challenges in pediatric TBI research and opportunities that we believe the ENIGMA Pediatric msTBI group can provide to address them. With the paucity of research studies examining neuroimaging biomarkers in pediatric patients with TBI and the challenges of recruiting large numbers of participants, collaborating to improve statistical power and to address technical challenges like lesions will significantly advance the field. We conclude with recommendations for future research in this field of study.

Cortical Volume and Thickness in Youth Several Years After Concussion

OBJECTIVE

The long-term effects of pediatric concussion on brain morphometry remain poorly delineated. This study used magnetic resonance imaging (MRI) to investigate cortical volume and thickness in youth several years after concussion.

METHODS

Participants aged 8-19 years old with a history of concussion (n = 37) or orthopedic injury (n = 20) underwent MRI, rated their postconcussion symptoms, and completed cognitive testing on average 2.6 years (SD = 1.6) after injury. FreeSurfer was used to obtain cortical volume and thickness measurements as well as determine any significant correlations between brain morphometry, postconcussion symptoms (parent and self-report), and cognitive functioning.

RESULTS

No significant group differences were found for either cortical volume or thickness. Youth with a history of concussion had higher postconcussion symptom scores (both parent and self-report Postconcussion Symptom Inventory) than the orthopedic injury group, but symptom ratings did not significantly correlate with cortical volume or thickness. Across both groups, faster reaction time on a computerized neurocognitive test battery (CNS Vital Signs) was associated with a thinner cortex in the left pars triangularis of the inferior frontal gyrus and the left caudal anterior cingulate. Better verbal memory was associated with a thinner cortex in the left rostral middle frontal gyrus.

CONCLUSION

Findings do not support differences in cortical volume or thickness approximately 2.5 years postconcussion in youth, suggesting either long-term cortical recovery or no cortical differences as a result of injury. Further research using a longitudinal study design and larger samples is needed.

Neuroimaging in paediatric mild traumatic brain injury: a systematic review

Neuroimaging is being increasingly applied to the study of paediatric mild traumatic brain injury (mTBI) to uncover the neurobiological correlates of delayed recovery post-injury. The aims of this systematic review were to: (i) evaluate the neuroimaging research investigating neuropathology post-mTBI in children and adolescents from 0-18 years, (ii) assess the relationship between advanced neuroimaging abnormalities and PCS in children, (iii) assess the quality of the evidence by evaluating study methodology and reporting against best practice guidelines, and (iv) provide directions for future research. A literature search of MEDLINE, PsycINFO, EMBASE, and PubMed was conducted. Abstracts and titles were screened, followed by full review of remaining articles where specific eligibility criteria were applied. This systematic review identified 58 imaging studies which met criteria. Based on several factors including methodological heterogeneity and relatively small sample sizes, the literature currently provides insufficient evidence to draw meaningful conclusions about the relationship between MRI findings and clinical outcomes. Future research is needed which incorporates prospective, longitudinal designs, minimises potential confounds and utilises multimodal imaging techniques.

Pediatric traumatic brain injury and abusive head trauma

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

Ability of the PILOT score to predict 6-month functional outcome in pediatric patients with moderate-severe traumatic brain injury

PURPOSE

To assess the Pediatric Intensity Level of Therapy (PILOT) score alone and in combination with Emergency Department (ED) GCS and Rotterdam score of initial head CT to predict functional outcomes in children with traumatic brain injury (TBI).

METHODS

Children (n=108) aged 31months-15years with moderate to severe TBI were prospectively enrolled at two sites. The ability of PILOT, ED GCS, and Rotterdam scores to predict the 6-month Pediatric Injury Functional Outcome Scale (PIFOS) was evaluated using multivariable regression models with enrollment site, age, and sex as covariates.

RESULTS

PILOT total (sum) score was more predictive of PIFOS (R²=0.23) compared to mean (R² = 0.20) or peak daily PILOT scores (R²=0.11). PILOT total score predicted PIFOS better than ED GCS (R²=0.01) or Rotterdam score (R²=0.06) and was similar to PILOT, ED GCS, and Rotterdam score combined. PILOT total score performed better in patients with intracranial pressure monitors (n=30, R²=0.28, slope=0.30) than without (n=78, R²=0.09, slope=0.36).

CONCLUSIONS

The PILOT score correlated moderately with functional outcome following TBI and outperformed other common predictors. PILOT may be a useful predictor or moderator of functional outcomes.

LEVEL OF EVIDENCE

Prognosis study, Level II.

Post-acute white matter microstructure predicts post-acute and chronic post-concussive symptom severity following mild traumatic brain injury in children

INTRODUCTION

Mild traumatic brain injury (TBI) is a global public health concern that affects millions of children annually. Mild TBI tends to result in subtle and diffuse alterations in brain tissue, which challenges accurate clinical detection and prognostication. Diffusion tensor imaging (DTI) holds promise as a diagnostic and prognostic tool, but little research has examined DTI in post-acute mild TBI. The current study compared post-acute white matter microstructure in children with mild TBI versus those with mild orthopedic injury (OI), and examined whether post-acute DTI metrics can predict post-acute and chronic post-concussive symptoms (PCS).

MATERIALS AND METHODS

Children aged 8-16.99 years with mild TBI (n = 132) or OI (n = 69) were recruited at emergency department visits to two children's hospitals, during which parents rated children's pre-injury symptoms retrospectively. Children completed a post-acute (<2 weeks post-injury) assessment, which included a 3T MRI, and 3- and 6-month post-injury assessments. Parents and children rated PCS at each assessment. Mean diffusivity (MD) and fractional anisotropy (FA) were derived from diffusion-weighted MRI using Automatic Fiber Quantification software. Multiple multivariable linear and negative binomial regression models were used to test study aims, with False Discovery Rate (FDR) correction for multiple comparisons.

RESULTS

No significant group differences were found in any of the 20 white matter tracts after FDR correction. DTI metrics varied by age and sex, and site was a significant covariate. No interactions involving group, age, and sex were significant. DTI metrics in several tracts robustly predicted PCS ratings at 3- and 6-months post-injury, but only corpus callosum genu MD was significantly associated with post-acute PCS after FDR correction. Significant group by DTI metric interactions on chronic PCS ratings indicated that left cingulum hippocampus and thalamic radiation MD was positively associated with 3-month PCS in the OI group, but not in the mild TBI group.

CONCLUSIONS

Post-acute white matter microstructure did not differ for children with mild TBI versus OI after correcting for multiple comparisons, but was predictive of post-acute and chronic PCS in both injury groups. These findings support the potential prognostic utility of this advanced DTI technique.

Practice Patterns in Pharmacological and Non-Pharmacological Therapies for Children with Mild Traumatic Brain Injury: A Survey of 15 Canadian and United States Centers

Given the lack of evidence regarding effective pharmacological and non-pharmacological interventions for pediatric mild traumatic brain injury (mTBI) and the resultant lack of treatment recommendations reflected in consensus guidelines, variation in the management of pediatric mTBI is to be expected. We therefore surveyed practitioners across 15 centers in the United States and Canada who care for children with pediatric mTBI to evaluate common-practice variation in the management of pediatric mTBI. The survey, developed by a panel of pediatric mTBI experts, consisted of a 10-item survey instrument regarding providers' perception of common pediatric mTBI symptoms and mTBI interventions. Surveys were distributed electronically to a convenience sample of local experts at each center. Frequencies and percentages (with confidence intervals [CI]) were determined for survey responses. One hundred and seven respondents (71% response rate) included specialists in pediatric Emergency Medicine, Sports Medicine, Neurology, Neurosurgery, Neuropsychology, Neuropsychiatry, Physical and Occupational Therapy, Physiatry/Rehabilitation, and General Pediatrics. Respondents rated headache as the most prevalently reported symptom after pediatric mTBI, followed by cognitive problems, dizziness, and irritability. Of the 65 (61%; [95% CI: 51,70]) respondents able to prescribe medications, non-steroidal anti-inflammatory medications (55%; [95% CI: 42,68]) and acetaminophen (59%; [95% CI: 46,71]) were most commonly recommended. One in five respondents reported prescribing amitriptyline for headache management after pediatric mTBI, whereas topiramate (8%; [95% CI: 3,17]) was less commonly reported. For cognitive problems, methylphenidate (11%; [95% CI: 4,21]) was used more commonly than amantadine (2%; [95% CI: 0,8]). The most common non-pharmacological interventions were rest ("always" or "often" recommended by 83% [95% CI: 63,92] of the 107 respondents), exercise (59%; [95%CI: 49,69]), vestibular therapy (42% [95%CI: 33,53]) and cervical spine exercises (29% [95%CI: 21,39]). Self-reported utilization for common pediatric mTBI interventions varied widely across our Canadian and United States consortium. Future effectiveness studies for pediatric mTBI are urgently needed to advance the evidence-based care.

Protocol for a prospective, longitudinal, cohort study of recovery pathways, acute biomarkers and cost for children with persistent postconcussion symptoms: the Take CARe Biomarkers study

INTRODUCTION

The majority of children who sustain a concussion will recover quickly, but a significant minority will experience ongoing postconcussive symptoms, known as postconcussion syndrome (PCS). These symptoms include emotional, behavioural, cognitive and physical symptoms and can lead to considerable disability. The neurobiological underpinnings of PCS are poorly understood, limiting potential clinical interventions. As such, patients and families frequently re-present to clinical services, who are often ill equipped to address the multifactorial nature of PCS. This contributes to the high cost of concussion management and the disability of children experiencing PCS. The aims of the present study are: (1) to plot and contrast recovery pathways for children with concussion from time of injury to 3 months postinjury, (ii) evaluate the contribution of acute biomarkers (ie, blood, MRI) to delayed recovery postconcussion and (3) estimate financial costs of child concussion to patients attending the emergency department (ED) of a tertiary children's hospital and factors predicting high cost.

METHODS AND ANALYSIS

Take C.A.Re is a prospective, longitudinal study at a tertiary children's hospital, recruiting and assessing 525 patients aged 5-<18 years (400 concussion, 125 orthopaedic injury) who present to the ED with a concussion and following them at 1-4 days, 2 weeks, 1 month and 3 months postinjury. Multiple domains are assessed: preinjury and postinjury, clinical, MRI, blood samples, neuropsychological, psychological and economic. PCS is defined as the presence of ≥2 symptoms on the Post Concussive Symptoms Inventory rated as worse compared with baseline 1 month postinjury. Main analyses comprise longitudinal Generalised Estimating Equation models and regression analyses of predictors of recovery and factors predicting high economic costs.

ETHICS AND DISSEMINATION

Ethical approval has been obtained through the Royal Children's Hospital Melbourne Human Research Ethics Committee (33122). We aim to disseminate the findings through international conferences, international peer-reviewed journals and social media.

TRIAL REGISTRATION NUMBER

ACTRN12615000316505; Results.

Brain MRI in Children with Mild Traumatic Brain Injury and Persistent Symptoms in Both Sports- and Non-sports-related Concussion

Aim: To evaluate the utility of magnetic resonance imaging (MRI) in children with mild traumatic brain injury (mTBI), persistent post-concussive syndrome (PPCS), and normal neurologic examination.

Materials and methods: This was a retrospective review of pediatric patients, who were evaluated in a Pediatric Concussion Clinic between August 2013 and November 2018, with documented persistent post-concussive symptoms, normal neurological examination, and available brain MRI.

Results: In our analysis of 86 cases we found seven MRI studies with abnormal findings, but none were clinically significant.

Conclusion: We conclude that MRI has a low diagnostic yield in this population, and based on these results we recommend that clinicians should avoid ordering MRI studies in this group. Further research is necessary to validate these results in larger and prospective studies.

Concussion in adolescent rugby union players: comprehensive acute assessment protocol and development of the SSC concussion passport to monitor long-term health

Introduction

Sports-related concussion (SRC) can be challenging to diagnose, assess and manage. Much of the SRC research is conducted on adults. The assessment of SRC should aim to identify deficits using a detailed multimodal assessment; however, most studies investigating the effects of SRC use diagnostic tools in isolation. It is likely that a combination of diagnostic tests will improve diagnostic accuracy. In this study, we aim to investigate how concussion affects adolescent rugby players and how a variety of diagnostic tools interact with each other as participants recover from their injury. The study will also determine the logistics of recording an individual’s concussion history on a virtual ‘Concussion Passport’ that would remain with the individual throughout their sporting career to allow monitoring of long-term health.

Methods and analysis

All rugby players (n=211) from the Senior Cup Teams of five schools in Dublin, Ireland will be invited to participate in the study. Baseline testing will be performed at the Sports Surgery Clinic, Dublin (SSC) before the rugby season commences. Participants will be followed up over the course of the rugby season. At baseline and at each postconcussion visit, participants will complete the following: Questionnaire, Sports Concussion Assessment Tool 3, Balance Error Scoring System, Computerised Neurocognitive Testing, Vestibulo-ocular assessment, King Devick test, Graded exercise test, Blood tests, Neck strength, FitBit.

Ethics and dissemination

Ethical approval was obtained from the Sports Surgery Clinic Research Ethics Committee (Approval number: SSC 0020). On completion of the study, further papers will be written and published to present the results of the various tests.

Trial registration number

NCT03624634.