Abstracts of the 2nd Annual Meeting of the Canadian Concussion Network/Réseau Canadien des Commotions (CCN-RCC) : The Journal of Head Trauma Rehabilitation

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Abstract

Abstracts of the 2nd Annual Meeting of the Canadian Concussion Network/Réseau Canadien des Commotions (CCN-RCC)

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Journal of Head Trauma Rehabilitation: September/October 2022 - Volume 37 - Issue 5 - p E390-E427
doi: 10.1097/HTR.0000000000000810
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The following abstracts were presented at the 2nd Annual Meeting of the Canadian Concussion Network/Réseau Canadien des Commotions (CCN-RCC) in Montreal, Quebec, on June 4-6, 2022. Established in 2020, the CCN-RCC has a vision to establish and guide a coordinated national research and knowledge translation agenda in Canada. This agenda aims to reduce the risk of concussions and their consequences across 4 broad domains: prevention, detection/diagnosis, prognosis/modifiers, and treatment.

Exploring the Feasibility of Move&Connect: Experiences of Youth With Prolonged Postconcussion Symptoms and Their Parents With a Virtual Group-Based Interdisciplinary Intervention

Al-Hakeem Hiba1,2; Hickling Andrea1,3; Bardiko Tess1; Lam Brendan1; Duplessis Danielle1; Mallory Kylie1,4; Provvidenza Christine1; Lovell Andrew2; Miller Carlin2; Scratch Shannon1,4,5

1Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada; 2Faculty of Arts, Humanities and Social Sciences, University of Windsor, Windsor, Canada; 3Department of Occupational Science and Occupational Therapy, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; 4Rehabilitation Sciences Institute, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; 5Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada

Background

Youth with prolonged postconcussion symptoms (PPCS) can experience challenges in physical, social, and emotional domains. Youth and their caregivers' health are interconnected as caregivers of youth with PPCS can experience parental distress and report poor family functioning. Move&Connect is an interdisciplinary group-based intervention that provides skills training, social support, and psychoeducation to caregivers, and combines these elements with active rehabilitation for youth.

Objective

To explore the feasibility and acceptability of the virtual Move&Connect program.

Methods

Semistructured interviews were conducted with 9 parents (all mothers) and 10 youth (9 girls, 1 boy) who participated in Move&Connect. Youth participants ranged in age from 12 to 18 years (M = 14.5 years, SD = 1.58) and were 5 months to 4 years postinjury (M = 19.2 months, SD = 13.08). Move&Connect was delivered twice (2 youth groups, 2 parent groups). Interview questions focused on exploring youth and caregivers' experiences participating in Move&Connect, and interview transcripts were analyzed using qualitative content analysis.

Results

Experiences and perceptions of participants were captured in 3 categories: (1) program engagement, (2) perceived Move&Connect benefits, and (3) Move&Connect outcomes. Results demonstrate that youth and caregivers valued sharing and receiving advice from facilitators and other peers in the group. Specifically, caregivers appreciated the evidence-based psychoeducation and youth reported that the active rehabilitation exercises promoted fitness integration into their daily routines. The virtual format of Move&Connect was reported to be convenient, accessible, and a safe space to share personal experiences. Suggestions to improve Move&Connect included providing handouts, website resources, and adding new topics.

Conclusions

Move&Connect is a feasible and meaningful virtual intervention for youth with PPCS and their caregivers. The intervention merges the benefits of social support, concussion education, and physical activity to support youth with PPCS and their families.

Acknowledgments

This work was supported by the Centre for Leadership at Holland Bloorview Kids Rehabilitation Hospital and the Canadian Institutes of Health Research (#453794-463185). The authors thank the clients and families that participated in this study and made this research possible. The authors acknowledge the efforts of the members of the “Move&Connect Team” and the efforts of the members of the NOvEL Lab Team (Bloorview Research Institute).

Unraveling Molecular and Biochemical Signatures Underlying Traumatic Brain Injury Pathophysiology Using Light Sheet Microscopy and Spatial Transcriptomics

Anwer Mehwish1,2; Kraus Larissa3; Cheng Wai Hang1,2; Bristow Brianna3; McInnes Kurt A4; Fan Jianjia1,2; Cheung Honor1,2; Barron Carlos1; Cripton Peter A1,4; Rossi Fabio4; Cembrowski Mark S1,3; Wellington Cheryl L1,2

1Djavad Mowafaghian Centre for Brain Health, The University of British Columbia, Vancouver, Canada; 2Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver, Canada; 3Department of Cellular and Physiological Sciences, The University of British Columbia, Vancouver, Canada; 4School of Biomedical Engineering, The University of British Columbia, Vancouver, Canada

Background

Traumatic brain injury (TBI) induces white matter injury, inflammation, vascular damage, and altered neuronal activity. To understand underlying mechanisms, we are using the Closed Head Impact Model of Engineered Rotational Acceleration (CHIMERA) nonsurgical model of impact-acceleration injury.

Objectives

To identify molecular changes in murine brain after CHIMERA TBI using light sheet microscopy (LSM) and spatial transcriptomics.

Methods

cFosTRAP mice, which stably express neuronal cFos upon tamoxifen exposure, were randomly assigned to TBI or sham groups. Traumatic brain injury–induced acute neurological deficits were assessed by loss of righting reflex (LRR) and neurological severity scale (NSS) score. Brain tissue was harvested 6 hours postprocedure and cleared by the SHIELD technique prior to LSM. For spatial transcriptomics, 10-μm sections from sham and TBI brains were mounted onto 10x Visium slides. Immunohistochemical readouts were established to map expression profiles to glia and neurons. Sections underwent cDNA synthesis and library construction, followed by Illumina NextSeq500 sequencing. Reads were mapped and quantified via SpaceRanger and Seurat R package.

Results

Traumatic brain injury mice exhibited prolonged LRR and higher NSS score compared with shams. An LSM analysis pipeline, including stitching of volumetric images, 3D rendering, cell segmentation, and registration with Allen Mouse Brain Atlas, was established using ARIVIS and BrainQuant3D software. Whole-brain changes and region-specific changes in cFos+ cell counts in sham and TBI brains are ongoing. We obtained transcriptomic information for 55-μm circular regions tiling entire brain sections (2 sections/mouse; 4992 sequenced regions/section; ∼40 000 total RNA-seq data sets). We found strong replicate reproducibility for TBI and sham animals. The initial data set of >1B reads yielded cell clusters with dysregulated genes previously identified in TBI as well as novel differentially expressed genes that will be validated using in situ hybridization.

Conclusions

We established LSM and spatial transcriptomics as whole-brain methods to improve analysis of diffuse brain injury mechanisms and identify potential therapeutic targets.

To Disclose or Not to Disclose? A Grounded Theory of Sport Concussion Disclosure in University Athletes

Archambault William1,2, Ellemberg Dave1

1School of Kinesiology and Physical Activity, Faculty of Medicine, University of Montreal, Montreal, Canada; 2Ingram School of Nursing, Faculty of Medicine and Health Sciences, McGill University, Montreal, Canada

Background

Without reliable objective diagnostic tools, concussion diagnostics rely heavily on symptom disclosure. Yet, between 30% and 80% of athletes underreport their concussion symptoms. This means that many concussions remain undetected and athletes expose themselves to enhanced risks of prolonged and severe health consequences. To facilitate disclosure and prevent these negative health outcomes, a better understanding of which determinants of concussion disclosure matter and how they influence athletes' disclosure decision must be achieved.

Objectives

Identify intrapersonal and extrapersonal factors influencing the decision-making process of concussion disclosure in university athletes and describe their effects and interactions by integrating them into an explanatory theoretical model.

Methods

Qualitative semistructured interviews were conducted with 9 university athletes, aged 18 to 25 years, from 3 team sports (soccer, rugby, and cheerleading). Grounded Theory guided data collection, analysis, and integration.

Results

Twenty-four factors divided into 3 intrapersonal categories (Attitudes & Behaviors; Concussion Knowledge; and Subjective Injury Severity) and 2 extrapersonal categories (Socio-Cultural Pressures; and Contextual Incentives) were identified as determinants of concussion disclosure. Anchored around the core category Fear, these factors and categories were integrated into a grounded theory of concussion disclosure named Concussion Disclosure Theory (CDT). The CDT posits that disclosure decisions are determined by the relative weight of 2 competing aversions: presence-aversion and absence-aversion. Identified determinants of concussion disclosure would contribute to the decisional process by generating 1 or both types of aversion.

Conclusions

This work highlights the benefits of using qualitative approaches to the study of concussion disclosure and the importance of systematically investigating both intra- and extrapersonal factors. The CDT identifies key determinants of concussion disclosure and explains their effects on the process through a mechanism involving comparison of 2 competing aversions. The CDT can be used to generate future research hypotheses and help design interventions aimed at promoting concussion symptoms disclosure.

Cognitive Fatigue Is Associated With Cerebral Perfusion at 72 Hours PostConcussion

Béland Valérie; Sicard Veronik; Healey Katherine; Zemek Roger; Ledoux Andrée-Anne for the PedCARE Team

Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada; Department of Biology, University of Ottawa, Ottawa, Ontario, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada

Background

Cognitive fatigue associated with concussion may impact school functioning. Little evidence exists whether cognitive fatigue is associated with cerebral perfusion in pediatric concussion.

Objectives

(1) To investigate whether a concussion group reports increased cognitive fatigue at 72 hours postinjury compared with an orthopedic injury (OI) group. (2) To examine the association between perfusion and cognitive fatigue at 72 hours postinjury, and whether study group moderated this relationship.

Methods

This is a secondary analysis of a clinical randomized trial. Participants aged 10 to 17.99 years with a concussion or an OI were recruited from the emergency department within 48 hours of injury. Participants underwent arterial spin labeling magnetic resonance imaging and completed the PedsQL Multidimensional Fatigue Scale—Cognitive Fatigue Subscale (range: 0-100; lower scores indicate increased cognitive fatigue) within 72 hours postinjury. An independent-samples t test compared cognitive fatigue between the concussion and OI groups. Between and within-group analyses examined the association between perfusion and cognitive fatigue adjusting for motion.

Results

Sixty-eight participants with concussion (median age [interquartile range (IQR)] = 12.88 [11.68-14.36] years; 45.6% female) and 29 with OI (median age [IQR] = 12.05 [11.18-13.89] years; 41.4% females) were included in the study. The concussion group had increased cognitive fatigue (M [SD] = 65.01 [20.1]) at 72 hours relative to the OI group (M (SD) = 78.5 (18.9); P = .003]. In the concussion group, increased cognitive fatigue was significantly associated with hyperperfusion within the left cuneus (β = −.39, 95% confidence interval [CI: −0.57 to −0.21]; Pfwe <.05) and left precuneus (β = −.35, 95% CI [−0.52 to −0.18]; Pfwe <.05). In the OI group, regional perfusion was not associated with cognitive fatigue. The association between perfusion and cognitive fatigue was not moderated by group.

Conclusion

Concussion was associated with increased cognitive fatigue among youth aged 10 to 17.99 years compared with youth with an orthopedic injury. Acute cognitive fatigue postconcussion is associated with hyperperfusion in the left cuneus and precuneus. Future studies are needed to understand the clinical implications of this association.

Acknowledgments

This work was supported by the OSSU IMPACT Award; PSI Foundation Award.

Evaluating the Effect of the Concussion Awareness Training Tool for High-Performance Athletes on theoretical Behavioral Determinants of Appropriate Concussion Management Among Canadian Varsity Athletes

Black Amanda M1–4; Wetherell Aura1; Turcotte Kate5; Taylor Taryn6; Bruin Samantha5; Sadler Karen5; Karmali Shazya5; Babul Shelina5,7

1Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 2Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; 3Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 4O'Brien Institute for Public Health, University of Calgary, Calgary, Alberta, Canada; 5BC Injury Research and Prevention Unit, BC Children's Hospital, Vancouver, British Columbia, Canada; 6Carleton Sport Medicine Clinic, Carleton University, Ottawa, Ontario, Canada; 7Department of Pediatrics, The University of British Columbia, Vancouver, British Columbia, Canada

Background

The Concussion Awareness Training Tool for High-Performance Athletes (CATT-HPA) is a new online education program specifically designed to address Canadian varsity student-athlete knowledge and change concussion management. The CATT-HPA covers topics including concussion recognition, importance of reporting, recovering from concussion, coping, and supporting teammates. It was designed to influence 4 behaviors: (1) reporting symptoms, (2) seeking care, (3) encouraging teammates to report symptoms, and (4) supporting teammates. Evidence-based behavior change approaches were used, informed by the theoretical domains framework (TDF), and the Behaviour Change Theory and Technique Tool.

Objectives

To examine the immediate effects of the CATT-HPA on behavioral determinants of concussion management behavior within Canadian varsity athletes.

Methods

A pre-experimental study was used, in which university administrators and athletic therapists/physiotherapists at all 56 U SPORTS–affiliated institutions were provided a link to the CATT-HPA for their athletes, including a link to pre-post course assessments. The course assessments examined specific determinants of appropriate concussion management informed by the TDF hypothesized to be affected by exposure to the tool (ie, knowledge, skills, social roles/identity, beliefs about capabilities, beliefs about consequences, intentions to report, and emotions). We conducted a preliminary analysis using paired t tests to examine mean score differences (MD) with 95% confidence intervals (95% CI) of each behavioral determinant.

Results

A convenience sample of 257 student-athletes (99 males, 158 females; median age [range]: 20 [17-33] years) from 14 Canadian university institutions completed the pre-/postcourse assessments. Exposure to the CATT-HPA resulted in significant immediate increases in mean knowledge scores (MD: 0.88 [95% CI: 0.58-1.17]), skills (MD: 0.55 [95% CI: 0.41-0.68]), beliefs about capabilities (MD: 0.64 [95% CI: 0.50-0.78]), indirect and direct self-reporting intentions (MD: 0.26 [95% CI: 0.18-0.35], MD: 0.25 [95% CI: 0.16-0.33]), and direct teammate reporting intentions (MD: 0.24 [95% CI: 0.14-0.35]).

Conclusions

Student-athletes completing the CATT-HPA resulted in small but statistically significant positive changes in most behavioral determinants.

Acknowledgments

This project was funded by U SPORTS, the Canadian Academy of Sport and Exercise Medicine, the Canadian Athletic Therapists Association, Ontario Athletic Therapist Association, Atlantic Provinces Athletic Therapists' Association, and Brock University Faculty of Applied Health Sciences. The authors thank all of the athletic therapists, physiotherapists, athletic directors, administrators, physicians, and athletes who assisted with the development of the tool. They also thank John Jacob and his development team at the Digital Lab at the British Columbia Children Hospital for building the web-based platform.

There's an App for That: Individuals With an mTBI May Improve Their Symptoms by Using an App to Pace and Plan Their Activities

Bonn Marquise M1,2; Bloom Samantha1; Wolfe Dalton1,2; Graham Laura1–3

1Faculty of Health Sciences, Western University, London, Ontario, Canada; 2Lawson Health Research Institute, London, Ontario, Canada; 3Parkwood Institute, London, Ontario, Canada

Background

Managing daily activities and symptom exacerbation is difficult for many individuals following a mild traumatic brain injury (mTBI). Although many individuals with an mTBI seek care, waitlists for care can be several months. A mobile application, MyBrainPacerTM, was created to improve healthcare access and help these individuals pace and plan their days and track their symptoms.

Objectives

The purpose of this study was to evaluate whether individuals with an mTBI improved their symptoms and increased their number of daily activities while using the MyBrain PacerTM app.

Methods

Individuals with an mTBI used MyBrainPacerTM for a minimum of 8 weeks. Participants completed the Rivermead Post-Concussion Symptom Questionnaire (RPQ) when registering for the app and again every 4 weeks. Participants also completed a General Symptom Questionnaire every 2 weeks, in which they rated their average symptoms as much worse, somewhat worse, no difference, somewhat better, or much better. Participants were able to increase their number of daily activities as their symptoms improved. Visual inspection was used to identify trends according to baseline RPQ score and change in RPQ values from the first to last day of app use.

Results

Fifteen individuals (50.9 ± 12.3 years, 13 females) used MyBrainPacerTM for 203.7 ± 94.1 days following an mTBI. On average, participants decreased their RPQ score by 8.4 ± 10.4 points between their first and last day of use. Change in daily point value and General Symptom Questionnaire responses varied, and no trends were observed according to baseline or change in RPQ score.

Conclusions

Individuals with an mTBI may reduce the number and severity of their symptoms by using MyBrainPacerTM to pace and plan daily activities. However, individual responses varied, regardless of baseline or change in symptoms. Larger studies are needed to confirm these preliminary trends.

Acknowledgments

The authors thank St Joseph's Healthcare Foundation, Cowan Foundation, Siskins Law Firm, and everyone at Parkwood Institute who helped create and promote the MyBrainPacerTM app.

Concussion Knowledge and Patterns of Practice Among Ontario Medical Association Physicians: A Follow-up Study (2013-2022)

Boyd Annie1,2; Prasad Abhaya1; Przyslupski Ann-Marie1,2; Belton Kathy3; Hussain Wasif4; Mrazik Martin1,5; Taylor Taryn6; Jevremovic Tatiana7; Lebrun Constance1,2

1Glen Sather Sports Medicine Clinic, Edmonton, Alberta, Canada; 2Department of Family Medicine, University of Alberta, Edmonton, Alberta, Canada; 3Injury Prevention Centre, School of Public Health, University of Alberta, Edmonton, Alberta, Canada; 4Department of Medicine, Division of Neurology, University of Alberta, Edmonton, Alberta, Canada; 5Department of Educational Psychology, University of Alberta, Edmonton, Alberta, Canada; 6Carleton University, Ottawa, Ontario, Canada; 7Western University, London, Ontario, Canada

Background

Initiatives to educate physicians on concussion have been promoted in recent years but their effects remain largely unknown.

Objective

To assess the changes in physician concussion knowledge and patterns of practice over the past decade.

Methods

Cross-sectional online survey distributed in 2013 and 2022 to practicing physicians who see patients with concussion in the Ontario Medical Association sections of General and Family Practice 226/12,168 (1.9%) 2013, 221/15,674 (1.4%) 2022; and Sport and Exercise Medicine 84/594 (14.0%) 2013, 30/696 (4.3%) 2022.

Results

Physician nonreliance on published guidelines significantly decreased (29.9% 2013, 21.4% 2022; P = .022). The incidence of organized sport-related concussions significantly decreased (91.2% 2013, 83.7% 2022; P = .007), but injuries related to recreational activities (30.8% 2013, 51.2% 2022; P < .001), work (12.6% 2013, 25.0% 2022; P < .001), and motor vehicle accidents (22.3% 2013, 39.7% 2022; P < .001) significantly increased. For initial assessment, there was a significant reduction in use of the Standardized Assessment of Concussion (6.6% 2013, 2.0% 2022; P = .009) and clinical examination (93.7% 2013, 87.6% 2022; P = .011) but a significant uptake in the Sport Concussion Assessment Tool (SCAT) (43.7% 2013, 67.9% 2022; P < .001), and no differences for other commonly used initial assessment tools. For return-to-play (RTP) decision tools, there was an increase in SCAT use (38.4% 2013, 59.7% 2022; P < .001) but reduced balance testing (31.5% 2013, 23.0% 2022; P = .026), computerized neurocognitive testing (11.6% 2013, 4.8% 2022; P = .004), and player self-report (54.1% 2013, 38.3% 2022; P < .001), and no differences for other commonly used RTP tools.

Conclusions

Over the past decade there has been a shift in mechanism of injury, and physician uptake in the use of published guidelines and standardized concussion tools such as the SCAT. Results appear to reflect increased awareness and education, but conclusions are limited by the observational study design and low response rate.

Psychological Resilience and White Matter Microstructural Properties in the Subacute Phase of Pediatric Concussion

Brown Olivier; Fang Zhuo; Healey Katherine; Zemek Roger; Smith Andra; Ledoux Andrée-Anne

Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada; Department of Psychology, University of Ottawa, Ottawa, Ontario, Canada; Department of Cellular Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada; Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada; Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada

Purpose

Investigate the associations between psychological resilience and white matter microstructural properties in the subacute phase following pediatric concussion.

Methods

This was a substudy to a larger randomized controlled trial, PedCARE. Concussed children and orthopedic-injured children (control) were enrolled during their emergency department visit. All participants completed the Connor Davidson Resilience scale at 72 hours postinjury and underwent diffusion tensor imaging magnetic resonance imaging at 4 weeks postinjury. Permutation testing was applied to examine whether fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were associated with resilience by group. Adjusted analyses corrected for age, sex, 72 hours of scans, history of psychiatric illness, and history of concussion. Within-group analyses were conducted to determine whether resilience is associated with white matter microstructure in each group.

Results

Sixty-six concussed children (median age = 12.88 [interquartile range (IQR): 11.82-14.35]; 47% female) and 29 orthopedic-injured children (median age = 12.49 [IQR: 11.18-14.00]; 41% female) were included. Associations between resilience and FA were greater in concussed children relative to orthopedic-injured children (P < .005, uncorrected). Contrarily, associations between resilience and both MD and RD were greater in orthopedic-injured children relative to concussed children. These interactions were common along the anterior thalamic radiation, forceps major, forceps minor, cingulum, and inferior fronto-occipital fasciculus. Within-group analyses found no significant associations between resilience and white matter in concussed children, but such associations were observed within orthopedic-injured children.

Conclusions

Our results suggest that white matter correlates of resilience dissipate in the subacute phase of concussion. In nonconcussed children, resilience was associated with white matter microstructure, but no such associations were observed in concussed children. Resilience appears to be associated with fiber integrity only before sustaining a concussion, which may be considered when developing psychological-based interventions for pediatric concussion.

Acknowledgments

This work was supported by the OSSU IMPACT Award; PSI Foundation Award; Canada Graduate Scholarships—Master's (CGSM) competition.

Reduced Executive Function and Increased Functional Connectivity Between the DMN and SN in Acute Pediatric Concussion

Butterfield Lauren1,2; Sicard Veronik1; Healey Katherine1; Zemek Roger1; Ledoux Andrée-Anne1–3; for the PedCARE Team

1Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario; 2Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada; 3Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada

Background

Literature suggests that executive functioning is associated with altered functional connectivity (FC) between the default mode network (DMN) and salience network (SN) in adults within 7 days postconcussion.

Objective

To investigate the relationship between executive functioning and resting-state FC between the DMN and SN at 72 hours post–pediatric concussion compared with orthopedic injury (OI).

Methods

Secondary analysis of a clinical randomized trial. Participants aged 10 to 17.99 years were recruited within 48 hours of injury from the emergency department. Within 72 hours of injury, participants completed a resting-state functional MRI and an executive functioning assessment with the NIH Toolbox's Dimensional Change Card Sort (DCCS) Test. The DCCS age-corrected scores were compared between groups. An analysis of covariance (ANCOVA), with age, sex, handedness, and head motion as covariates, was conducted to compare the groups between-network FC. The FC results were Bonferroni corrected. Based on the FC results, an ANCOVA was performed to examine the interaction of groups between-network FC and DCCS scores. A multiple regression was performed to assess the association of within-group between-network FC and DCCS scores.

Results

Fifty-eight concussion participants (mean (SD) age = 13.3 (2.1) years; 43.1% female) and 24 OI participants (mean (SD) age = 13.1 (1.9) years; 41.7% female] were analyzed. The concussion group scored lower on the DCCS (median [IQR] = 90 [82.00-102.00]) than the OI group (median [IQR] = 105.50 [91.75-121.75], P = .002). Increased FC between the left frontoinsular cortex of the SN (seed region) and the left medial prefrontal cortex of the DMN (pFWE-corr = 0.002) was observed in the concussion group when compared with the OI group. No interaction of group SN-DMN FC*DCCS scores was found (PFWE-corr > .05). No within-group associations between SN-DMN FC and DCCS scores were found (PFWE-corr > .05).

Conclusion

Although youth with acute concussion exhibited decreased executive functioning compared with orthopedic-injured youth, lower executive functioning was not associated with an observed increased FC in the SN-DMN using advanced neuroimaging.

Acknowledgments

This research was supported by the OSSU IMPACT Award, PSI Foundation Award.

Which Factors Do Athletes, Coaches, and Sport Stakeholders Believe Are Involved in Returning to Sport Following a Concussion?

Cadotte Gabrielle1,2; Podlog Leslie3; Collict Cameron1,2; van Ierssel Jacqueline4; Caron Jeffrey G1,2

1Université de Montréal, Montreal, Québec, Canada; 2Centre for Interdisciplinary Research in Rehabilitation of Greater Montreal, Montreal, Québec, Canada; 3The University of Utah, Salt Lake City, Utah, United States; 4Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada

Background

A recent reviewing of the sport-related concussion (SRC) literature determined that fear, emotional factors (eg, depression, anxiety), and contextual factors (eg, social support, pressure) have been associated with athletes' return to sport experience (RTS; van Ierssel et al, 2022). However, these factors are currently not comprehensively assessed in the graduated RTS Strategy.

Objectives

To explore the factors that athletes, coaches, and healthcare professionals believe are involved in RTS following SRC.

Methods

Twenty-two participants (n = 13 females, 9 males), including 4 formerly concussed athletes, 5 coaches, 5 athletic therapists, 4 physiotherapists, 3 sport medicine doctors, and 1 nurse practitioner participated in this qualitative study. Participants were aged between 21 and 58 years and were involved in contact or collision sports at the high school, university, or professional level. We conducted 1 semistructured interview with each participant via Zoom and followed Braun and Clarke's (2021) recommendations for a coding reliability approach to thematic analysis.

Results

Participants described physical, behavioral, psychological, and social factors that they believed were involved in RTS following SRC. Physical factors included the different concussion symptoms that athletes experienced and the importance of returning to preinjury levels of fitness. Behavioral factors were described as instances in which athletes avoided contact or collisions, malingered, or played more passively upon their RTS. Psychological factors included cognitive appraisals (eg, confidence, contemplating retirement, emotions, internal pressures, motivation), individual factors (eg, attitude, athletic identity, adjusting expectations), and mental health (eg, anxiety/stress, depression/sadness). Finally, social factors included external pressures, isolation, social support, and interactions between healthcare professionals and coaches with concussed athletes.

Conclusions

Our results suggest that concussed athletes may experience a variety of biopsychosocial concerns during RTS following SRC—many of which do not appear to be assessed while completing the RTS strategy.

Screen Time and Concussion Recovery: Is Moderation the Best Policy?

Cairncross Molly1,2; Yeates Keith Owen3–5; Tang Ken6; Madigan Sheri3,4; Beauchamp Miriam7,8; Craig William9; Doan Quynh10,11; Zemek Roger12,13; Kowalski Kristina6; Silverberg Noah on behalf of the Pediatric Emergency Research Canada A-CAP Study Team2,14

1Department of Psychology, Simon Fraser University, Burnaby, British Columbia, Canada; 2Rehabilitation Research Program, Vancouver Coastal Health Research Institute, Vancouver, Canada; 3Department of Psychology, University of Calgary, Calgary, Alberta, Canada; 4Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada; 5Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 6Independent Consultant, Vancouver, British Columbia, Canada; 7Department of Psychology, University of Montreal, Montreal, Québec, Canada; 8Ste-Justine Hospital Research Center, Montreal, Quebec, Canada; 9Department of Pediatrics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada; 10Department of Pediatrics, The University of British Columbia, Vancouver, Canada; 11BC Children's Hospital Research Institute, Vancouver, Canada; 12Department of Pediatrics and Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada; 13Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada; 14Department of Psychology, The University of British Columbia, Vancouver, Canada

Background

The clinical recommendation to avoid screen time after a concussion has limited empirical justification.

Objectives

To determine whether screen time is detrimental to children with concussion, we measured the association between early screen time (7-10 days postinjury) and postconcussion symptom severity in children with concussion, compared with children with orthopedic injury (OI).

Methods

The study was a secondary analysis of a prospective longitudinal cohort study (A-CAP). A total of 633 children with acute concussion and 334 children with OI aged 8 to 16 years and their caregiver completed the Health and Behaviour Inventory at 7 to 10 days, weekly for 3 months, and biweekly from 3 to 6 months postinjury. The Healthy Lifestyle Behaviour Questionnaire was used to measure screen time and other health behaviors in the first 7 to 10 days postinjury. Generalized least squares models were t for each Health and Behaviour Inventory outcome (child- and parent-reported cognitive and somatic symptoms), with predictors including screen time, covariates associated with recovery, and two 3-way interactions (child- and parent-reported screen time with group and time postinjury).

Results

Screen time was a significant moderator of group differences in postconcussion symptom severity for 2 of 4 outcomes: parent-reported somatic (×2 = 10.82, df = 3, P = .013) and child-reported cognitive symptoms (×2 = 8.67, df = 3, P = .034). Both low and high screen time were associated with relatively more severe symptoms in the concussion group than in the OI group during the first 30 days postinjury. Screen time was not associated with symptom severity after 30 days. Other risk factors and health behaviors had larger associations with symptom severity than screen time.

Conclusions

Low and high screen time was associated with more symptoms in the concussion group up to 30 days postinjury, suggesting that moderation may be an important principle for acute clinical management. Screen time was not associated with worse long-term outcomes.

Acknowledgments

The authors thank the entire Pediatric Emergency Research Canada A-CAP study team.

Improving Pediatric Concussion Care in a Tertiary Centre Concussion Clinic: A Nursing-Led Multidisciplinary Initiative

Caron-Brulotte Erika-Pier1; Paquin Hugo2; Rached-d'Astous Soha2; Beauchamp Miriam3; Boissonneault Sophie1; Delisle Marie-Gabrielle1; Boutin Ariane2

1CHU Sainte-Justine, University of Montreal, Montreal, Quebec, Canada; 2Division of Pediatric Emergency Medicine, CHU Ste-Justine, Montreal, Quebec, Canada; 3Research Centre, CHU Sainte-Justine, Montreal, Canada; Department of Psychology, Université de Montréal, Montreal, Canada

Background

Effective intervention during the acute phase of pediatric concussion, including reassurance and education, is essential for management.

Aim

To evaluate whether an early nursing-led in-person information session optimizes care and improves resource utilization after concussion.

Methods

A pre-/postintervention retrospective chart review of a random sample of patients (6-17.5 years of age) diagnosed with concussion in the emergency department was conducted. The primary outcome was the proportion of concussed children who required a medical consultation with a concussion specialist physician as per the standardized pathway. Secondary outcomes included the total number of phone calls and medical follow-ups, as the proportion of patients requiring consultation with other professionals.

Results

A total of 331 patients were included (165 in the pre- and 166 in the postintervention group), with an overall median age of 12.6 years (interquartile range, 9.9-15.0). In the postintervention group, 24/159 (15%) patients required medical consultation compared with 35/159 (22%) in the preintervention group (crude odds ratio [OR]: 0.62, 95% confidence interval [CI]: 0.35-1.11). After adjusting for age, sex, number of days since injury to emergency department visit as a history of migraine, and past concussion, being in the postintervention group was associated with a 45% decrease in the odds of requiring medical consultation (OR: 0.55, 95% CI: 0.30-1.01) (P = .056) and a 54% decrease in the odds of requiring physiotherapy or psychological referral (OR: 0.46, 95% CI: 0.24-0.90) (P = .023). In those patients, the rate of medical visits was similar between the 2 groups (2.0 vs 1.9 visits). Overall, the rate of phone calls carried out by nurses in the postintervention group was 32% (95%CI: 20%-44%) (P < .001) lower than in the preintervention group.

Conclusions

The findings provide empirical support for the value and efficacy of this innovative nursing-led intervention in concussion management and could be applied to other clinics that may have more limited resources.

CHIMERA Traumatic Brain Injury in a Mouse Model of Tauopathy

Cheng Wai Hang1; Cheung Honor1; Kang Amy1; Fan Jianjia1; Barron Carlos1; Cooper Jennifer1; Wilkinson Anna1; Hu Grace1; Cripton Peter A2; Vocadlo David3; Wellington Cheryl L1

1Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver, Canada; 2Departments of Mechanical Engineering and Orthopaedics, The University of British Columbia, Vancouver, Canada, International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, Canada; 3Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada

Background

Traumatic brain injury (TBI) is a major cause of death and disability. A moderate-severe TBI may increase neurodegeneration risk. To study the long-term consequences of TBI, we previously designed an animal model of impact-acceleration TBI called Closed Head Injury Model of Engineered Rotational Acceleration (CHIMERA).

Objective

We induced a single high-energy impact TBI to rTg4510 mice, a tauopathy mouse model, to determine whether CHIMERA TBI exacerbates tau pathology.

Methods

Male rTg4510 mice were impacted at 4.0J at 4 months of age, using CHIMERA with impact interface. Sham controls received all procedures except for impact. Brain tissues were harvested at 2 months postinjury and analyzed using immunohistochemistry and Western blotting. Blood samples were collected biweekly.

Results

A 4.0J impact induced moderate-severe injury (immediate mortality: 7/15; 47%). At 2 months postinjury, surviving mice displayed significant microgliosis (Iba1) and axonal injury (Neurosilver) histologically. Western blotting showed that TBI mice had a reduced ratio of p-GSK-3β (S9) to GSK-3β (P = .0132), suggesting greater tau kinase activity. Plasma total tau in TBI mice showed a trend toward accelerated elevation (2 weeks). Brain tauopathy of surviving TBI mice showed a divergent response. Three of eight surviving TBI mice had very low tau level in lysates (lower than sham mice) and were thus analyzed separately from TBI mice that maintained the expected tau level. Compared with sham, TBI mice with normal total tau had increased p-tau (PHF1 and AT8) (P = .0217 and P = .0376, respectively), increased autophagolysosome accumulation (P62, Cathepsin D) (P = .0177 and P = .0460, respectively), and smaller hippocampus (P = .0480). These findings were not observed in TBI mice with very low total tau.

Conclusions

Our preliminary findings suggest that TBI may lead to chronic axonal injury and alteration in GSK-3β activity. Intriguingly, the postinjury total tau response was divergent, with increased p-tau and autophagolysosome accumulation observed only in TBI mice that maintained tau levels. The mechanism underlying reduced tau levels remains to be determined.

Using Light Sheet Microscopy to Investigate the Role of Apolipoprotein E4 in Traumatic Vascular Injury

Honor Cheung1,2*; Mehwish Anwer1,2*; Jianjia Fan1,2; Wai Hang Cheng1,2; Carlos Barron1,2; Cheryl Wellington1,2

1Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver, Canada; 2Djavad Mowafaghian Centre for Brain Health, The University of British Columbia, Vancouver, Canada. *Equal contribution

Background

Apolipoprotein E4 (APOE4) is the major genetic risk factor for sporadic Alzheimer disease (AD). Even in the absence of AD diagnosis, the APOE4 allele has emerged as a risk factor for small vessel disease and vascular cognitive impairment. The role of vascular injury sustained via traumatic brain injury (TBI) has been well established, where secondary pathways triggered upon traumatic vascular injury contribute to neuronal damage and subsequent cognitive decline. We are using the Closed-Head Impact Model of Engineered Rotational Acceleration (CHIMERA) to study APOE isoform effects on traumatic vascular injury. As CHIMERA is a nonsurgical model that produces diffuse brain injury, we have developed tissue-clearing methods to assess whole-brain traumatic vascular injury.

Aim

To test the hypothesis that APOE4 contributes to greater vascular damage compared with APOE3 controls in targeted replacement mice with and with no TBI.

Methods

Mice expressing human APOE4 and APOE3 (Cure Alzheimer Fund) are bred in-house and randomized to TBI or sham groups at 6 to 7 months of age. Traumatic brain injury animals receive a 3.0J impact; sham controls receive all procedures except for impact. To enable 3D mapping of vascular damage after TBI, mice are transcardially perfused with Alexa Fluor 594 conjugated wheat germ agglutin (WGA), and brain tissue is subsequently cleared using the SHIELD passive clearing protocol and imaged using light sheet microscopy.

Results

Pilot experiments with APOE3 mice revealed altered vascular anatomy 1 day after TBI, including hematoma and a disorganized cortical vascular network compared with sham controls. We have established an analytical pipeline for 3D quantification of vascular density and branching. We are currently expanding our colony to examine the effect of APOE genotype on traumatic vascular injury outcomes at acute and chronic time points.

Conclusions

Our preliminary findings establish tissue clearing as an efficient tool for the assessment of vascular injury sustained after TBI.

Acknowledgments

The presenters thank the Weston Brain Institute for their support of this research.

First-Half Versus Second-Half Head Impact Biomechanics in Canadian High School Football

Clermont Christian; Pavlovic Nina; Cairns Joshua; Williamson Rylen; Emery Carolyn A; Stefanyshyn Darren

Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada

Background

Football players experiencing fatigue over the course of a game may be at a greater risk of concussion as fatigue may decrease physical strength and tackling proficiency. With higher head impact magnitudes associated with concussion, monitoring the changes in head impact biomechanics over the course of a football game is needed.

Objectives

The objective of this study was to evaluate whether head impact biomechanics change throughout the course of a high school football game.

Methods

68 Canadian high school football players from 2 teams participated. All players wore an instrumented mouthguard (Prevent Biometrics) throughout the season to measure peak magnitudes of linear and angular acceleration and velocity for each head impact. Given potential redundancy of the biomechanical measures for each impact, a principal component analysis (PCA) was used to reduce the number of variables. Video recordings for the games were also collected (12 games total) and the data were time synchronized to determine whether an impact occurred during the first or second half of each game. A Mann-Whitney U nonparametric test was performed to determine whether the PC scores differed between the first half and the second half (P < .05).

Results

A total of 1534 head impacts were included in the analysis, with 869 occurring in the first half and 665 occurring in the second. One principal component (PC1) was retained from the PCA, with all 4 biomechanical variables loading positively on PC1, meaning that greater PC1 scores were associated with greater magnitudes of acceleration and velocity. PC1 scores during the second half were slightly lower than the first, but the Mann-Whitney U test indicated that this difference was not statistically significant (P = .098).

Conclusions

Head impact magnitudes remained consistent throughout the football game. Future studies should consider other risk factors for head impacts and acute concussion rates in youth players from a larger cohort of teams.

Acknowledgments

This work was supported by the Canadian Institutes of Health Research (postdoctoral fellowship) and the NSERC CREATE Wearable Technology Research and Collaboration (We-TRAC) Training Program (project no. CREATE/511166-2018). The Sport Injury Prevention Research Centre is one of the International Research Centres for Prevention of Injury and Protection of Athlete Health supported by the International Olympic Committee. The authors acknowledge funding from the National Football League Play Smart Play Safe Program. Dr Emery holds a Canada Research Chair in Concussion.

Interventions Used by Interprofessional Healthcare Teams to Treat Pediatric Concussions: A Scoping Review

Cogliano Alexandra1; Roman Alessia1; Hildebrand Danielle1; Mallory Kylie D2,3; Wilson Katherine E1; Hickling Andrea1,2; Reed Nick1–3

1Department of Occupational Science and Occupational Therapy, Faculty of Medicine, University of Toronto, Toronto, Canada; 2Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Canada; 3Rehabilitation Sciences Institute, Faculty of Medicine, University of Toronto, Toronto, Canada

Background

Concussion symptoms are classified as physical, cognitive, emotional, and sleep, which can limit children and youths' participation in school, work, and leisure activities. Given the wide range of concussion symptoms and functional difficulties, an interprofessional healthcare team consisting of a variety of healthcare professions is recommended to treat concussion. Although literature has highlighted benefits of an interprofessional approach to pediatric concussion care, a summary of this literature on the use interprofessional healthcare teams when treating pediatric concussion, along with specific interventions these teams might use, has yet to be published.

Objectives

To identify and summarize peer-reviewed literature on (1) interprofessional healthcare teams that treat pediatric concussion and (2) which interventions these teams use.

Methods

The methodological framework by Arksey and O'Malley informed this scoping review. Four databases were searched (MEDLINE, EMBASE, CINAHL Plus, and SPORTDiscus) until February 2021. Article screening and extraction were completed by two independent reviewers. A third reviewer resolved conflicts.

Results

Twenty-five studies were included in this review. The most common professions were physiotherapists (N = 16) and physicians (N = 22) and the number of professions included on teams ranged from 2 to 6. Physical activity (eg, active rehabilitation, return to play, and graded activity), education, and return-to-school guidelines were the most common interventions, with most teams using interventions in combination (eg, education and return-to-school strategies). Studies that implemented return-to-school and active rehabilitation interventions often followed similar protocols; however, education varied in content and delivery method. Mental health was addressed in less than half of the studies (N = 11) and family members were involved in concussion interventions in almost half of the studies (N = 12).

Conclusion

The variety of healthcare professions and interventions used to treat pediatric concussion aligns well with the breadth of concussion symptoms; however, there appears to be a gap in mental healthcare and standards for providing concussion education to patients.

Assessment of Early, Preventive, and Multidimensional Telephone Intervention Following Mild Traumatic Brain Injury (SAAM): A Preliminary Study

Coll Sarah-Maude1,2; Audrit Hélène1,2; Denault Stéphany3; Laguë-Beauvais Maude3–5; Abouassaly Michel3; de Guise Elaine1–4

1Department of Psychology, University of Montreal, Montreal, Quebec, Canada; 2Centre de Recherche Interdisciplinaire en Réadaptation du Montréal Métropolitain (CRIR), Montréal, Québec, Canada; 3Traumatic Brain Injury Program, McGill University Health Centre, Montreal, Quebec, Canada; 4Research Institute of McGill University Health Centre, Montreal, Quebec, Canada; 5Neurology and Neurosurgery Department, Faculty of Medicine, McGill University, Montreal, Canada

Background

Individuals who sustain a mild traumatic brain injury (mTBI) usually experience a variety of postconcussion symptoms (PCS) that can slow their reintegration into socioprofessional activities. Although these symptoms resolve in most patients within days or weeks, 10% to 15% of people who have had an mTBI remain with persistent PCS. Notably, few studies have suggested that early interventions can counteract the longer-term development of PCS. A brief, multidimensional and psychoeducational intervention for adults with mTBI was developed to target PCS (SAAM Intervention). It focuses on the 4 most common interactional symptoms: sleep/fatigue, attention/concentration, anxiety/mood disorders, and memory/organization.

Objectives

(1) To assess the feasibility and tolerability of the SAAM intervention administered by phone and (2) to explore the treatment effect of this intervention on reducing PCS for patients with mTBI in the post–acute phase of recovery.

Methods

Using a repeated-measures design, we compared a group that received the intervention (n = 11) with a wait-list control group (n = 11). The experimental group received the intervention (1 session per week for 4 weeks) by telephone. Feasibility was measured in addition to tolerability, which is based on a 10-item satisfaction questionnaire. Main measure included the Rivermead Post-concussion Symptoms Questionnaire (RPQ); secondary measures included the Hospital Anxiety and Depression Scale, the Pittsburgh Sleep Quality Index, the Multidimensional Fatigue Inventory, and a neuropsychological battery.

Results

Rate of satisfaction and tolerability regarding the intervention was high and only 1 participant withdrew during the intervention. Exploratory results showed that the group × time interaction was not significant but had a moderate effect size for the RPQ (P = .17, η2 = 0.11). No significant interaction, nor large effect size was obtained for the secondary measures.

Conclusions

This telephone intervention delivered postacutely might reduce PCS; however, a larger-scale randomized controlled trial is recommended to confirm these results.

Acknowledgments

The authors thank the medical team for its collaboration in this project and all participants who took part in this study.

Sport-Related Concussions and Their Impact to the Identity Constructs of Elite Athletes: A Qualitative Multimethod Study

Collict Cameron B1,2; Benson Alex3; Schaefer Lee4; Caron Jeffrey G1,2

1Université de Montréal, Montreal, Québec, Canada; 2Centre for Interdisciplinary Research in Rehabilitation of Greater Montreal, Montreal, Québec, Canada; 3Western University, London, Ontario, Canada; 4University of Saskatchewan, Saskatoon, Saskatchewan, Canada

Background

Researchers have found that athletes may experience a disruption to their athletic identity following a sport-related concussion (SRC; Dean, 2019). To date, researchers have approached this topic through the lens of athletic identity, which fails to capture important identity constructs such as personal (eg, personality, emotions) and social identity (eg, family, student) and self-concept (ie, personal and social identity together).

Objective

Guided by the Social Identity Approach (Hogg, 2016), this qualitative, multimethod study explored the impact of elite athletes' SRC experiences on their identity constructs.

Methods

We studied 7 elite athletes' (n = 6 female, M = 25.1 years) perceptions of their identity constructs and SRC experience. The Participants competed as elite athletes for 1 season or longer and were medically diagnosed with an SRC lasting longer than 4 weeks as an elite athlete. Data collection occurred in 2 phases: (1) semistructured interview number 1 was conducted with each participant to understand his or her identity constructs during his or her SRC; (2) approximately 1 week later, each participant engaged in semistructured interview number 2, which centered around a discussion of the Social Identity Mapping Tool he or she completed, a comprehensive visual overview of his or her social identities. We used a 6-step reflexive thematic analysis to generate themes within the interview data (Braun & Clarke, 2021).

Results

Participants described prolonged identity disruption (months to years) that impacted perceptions of themselves (eg, self-worth) and within their social groups. The severity of identity disruption appeared to be impacted by social support received, with negative support furthering identity disruption. In addition, athletes said that they attempted to minimize identity disruption in 2 distinct ways, either (a) leaving sport to pursue other social identities (eg, school) or (b) further ingraining themselves within sport (eg, coaching).

Conclusion

Our results suggest that future SRC research should consider that identity disruption may extend beyond solely the athletic role.

A Multiparameter Approach to Neuroimaging of Acute Concussion for Early Identification of Persistent Postconcussion Symptoms

D'Souza Gina1,2; Churchill Nathan W2–4; Hunt Cindy2,5; Baker Andrew2,6; Schweizer Tom A2,3,7,8

1Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; 2Keenan Centre for Biomedical Research, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada; 3Neuroscience Research Program, St Michael's Hospital, Toronto, Ontario, Canada; 4Physics Department, Ryerson University, Toronto, Ontario, Canada; 5Head Injury Clinic, Trauma and Neurosurgery Program, St Michael's Hospital, Toronto, Ontario, Canada; 6Department of Critical Care, St Michael's Hospital, Toronto, Ontario, Canada; 7Faculty of Medicine (Neurosurgery) University of Toronto, Toronto, Ontario, Canada; 8The Institute of Biomaterials & Biomedical Engineering (IBBME) at the University of Toronto, Toronto, Ontario, Canada

Background

Concussions are a major public health concern, with 10% to 25% of adults experiencing persistent postconcussion symptoms (PPCS) that have negative social and economic impacts. Because of complex heterogeneous clinical and biological outcomes, the characterization and prediction of PPCS are limited. A holistic framework is needed to understand the relationship between clinical outcome and underlying neurobiology, beginning at acute injury, to better understand mechanisms giving rise to PPCS.

Objectives

This pilot study evaluated the feasibility of collecting multiparameter neuroimaging and clinical data for acutely concussed adults in an emergency department setting, beginning at clinical intake and with follow-up for more than a 12-week period to identify potential predictors of PPCS.

Methods

Sixteen patients with concussion who presented to St Michael's emergency department underwent a magnetic resonance imaging (MRI) battery within 48 hours postinjury, with a follow-up at 4 weeks postinjury. Each imaging session assessed cerebral blood flow (CBF), global functional connectivity (Gconn), white matter fractional anisotropy, and mean diffusivity (MD). All participants also underwent clinical assessments acutely, within 48 hours to 2 weeks, 4 weeks, and 12 weeks postinjury. Longitudinal change in symptoms and MRI measures were evaluated in a repeated-measures design, with bootstrapped confidence bounds. Significant brain regions were identified for MRI measures, thresholded at P = .005 voxelwise, followed by cluster-sized correction to P = .05.

Results

Our protocol identified longitudinal changes in both symptoms and MRI parameters. Both CBF and Gconn exhibited significant declines in frontal and occipital clusters during recovery. Fractional anisotropy displayed significant increases in the posterior corona radiata, while MD showed significant decreases in the genu of corpus callosum and longitudinal fasciculus. These changes were further associated with significant declines in postconcussion symptoms.

Conclusions

This pilot study has established the feasibility of acute imaging and multidimensional data collection following concussion, with robust measures of clinical and biological recovery. Expanding on these findings, we aim to increase recruitment and expand to additional sites.

Major Updates in the Living Guideline for Pediatric Concussion Care to Clinical Practice Recommendations for 2021

Dawson J1; Sampson M1; Ledoux AA1; Reed N2*; Zemek R1*; (cosenior authors) on behalf of the PedsConcussion Living Guidelines team

1Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada; 2University of Toronto, Toronto, Ontario, Canada

Background

The Living Guideline for Pediatric Concussion Care was developed to inform best practices for healthcare professionals diagnosing and managing pediatric patients who have or may have sustained concussion.

Objectives

Update guideline recommendations as part of the Living Guideline methodology.

Methods

A literature search was preformed that included primary research articles and systematic reviews published between May and November 2021. Investigators screened articles according to the guideline scoping review protocol using EppiReviewer. Population, intervention, comparison, and outcomes (PICO) data, level of evidence, and risk of bias were extracted from full texts. Articles were categorized on the basis of 15 guideline domains and associated with at least 1 of the clinical recommendations within the domains. Articles were annotated and shared with expert panel members. Consensus voting was conducted using REDCap following the Glaser method. A quorum of 75% of eligible expert panel members was required to vote on major guideline updates. Minor guideline changes were performed at the level of the domain group, and 75% consensus was required to implement guideline changes. Updates and the consensus process were shared on the living guideline website (www.pedsconcussion.com).

Results

A total of 341 new articles were retrieved in the literature search with 97 studies included. Eighty-five percent expert panel members voted (35/40) on 3 major and 9 minor updates. Major guideline updates addressed (1) aerobic exercise threshold testing and prescribed exercise: 91% (32/35) consensus; (2) recommending against complete absence from school for more than 1 week: 94%(33/35) consensus; and (3) early initiation of supportive care for those at high risk for a prolonged recovery: 94%(33/35) consensus.

Conclusions

The rapidly evolving published evidence base supports the living guideline approach. Dissemination and implementation of these 3 major updates to clinical practice are important to improve standard of care and reduce incidence of prolonged recovery in youth with concussion.

R2Play and End-User Needs: Understanding Clinician and Coach Priorities for a Novel Return-to-Play Assessment

DuPlessis Danielle1,2; Lam Emily1,3; Hotze Fanny1; Reed Nick2,4; Wright Virginia1,2,5; Biddiss– Elaine1–3; Scratch Shannon E1,2,6

1Bloorview Research Institute—Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada; 2Rehabilitation Sciences Institute—University of Toronto, Toronto, Ontario, Canada; 3Institute of Biomedical Engineering—University of Toronto, Toronto, Ontario, Canada; 4Department of Occupational Science & Occupational Therapy—University of Toronto, Toronto, Ontario, Canada; 5Department of Physical Therapy—University of Toronto, Toronto, Ontario, Canada; 6Department of Paediatrics—University of Toronto, Toronto, Ontario, Canada

Background

Following concussion, traditional return-to-play (RtoP) protocols rely on a battery of single-domain tasks and self-reporting of symptoms to discern whether the injury has resolved. Yet, single-domain assessments may fail to detect symptoms and changes that are elicited by the combined cognitive, physical, and emotional multidomain demands when an athlete returns to sport.

Objective

To support clinical decision making following pediatric concussion, our team at Holland Bloorview set out to create a novel multidomain RtoP assessment: R2Play. Our concept for the R2Play assessment was that youth athletes would run between buttons to connect a “trail” in ascending alphanumeric order, 1-A-2-B, and so forth. Their performance across a series of levels of increasing difficulty would be logged on a clinician tablet.

Methods

This concept was presented to 6 clinicians and 4 youth sports coaches, who provided feedback through semistructured interviews. Interviews began by exploring participants' experiences with return-to-play broadly and then shifted to focus on targeted feedback for the R2Play assessment. Interviews were transcribed and analyzed using qualitative content analysis. All feedback was organized in an itemized change table, and we brainstormed its implementation as a team.

Results

Clinicians provided rich feedback on R2Play, including suggestions to improve accessibility for youth with disabilities, bolster the ecological validity of our assessment through scaffolding tasks, and increase future uptake in practice by reducing assessment time. Coaches, on the other hand, focused on the sport-like nature of R2Play and contributed to a theoretical framework that captured areas of sport that we should aim to tax with our assessment.

Conclusions

Through this process, we collaboratively refined the R2Play assessment concept with clinician and coach stakeholders. This work highlights the value of integrating user feedback into the early stages of research and design, as it enabled us to ground our assessment in the needs of end users.

Acknowledgments

This work was supported by the Centre for Leadership at Holland Bloorview Kids Rehabilitation Hospital. The authors thank the clinicians and coaches who participated in this study and made this research possible. The authors acknowledge the efforts of the members of the “R2Play Team” and the members of the NOvEL Lab team (Bloorview Research Institute), specifically Hiba Al-Hakeem, Ajmal Khan, Andie Hickling, Stephanie McFarland, and Brendan Lam.

Highest Concussion Rates in Youth Ice Hockey Found in Females and Previously Concussed Players: Goalies and Players in Leagues Disallowing Body Checking Remain Protected

Eliason Paul1–4; Galarneau Jean-Michel1; Shill Isla1–4; Kolstad Ash1–4; Babul Shelina5; Mrazik Martin6; Lebrun Constance7; Hagel Brent1–3,8,9; Emery Carolyn1–4,8,9

1Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 2Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; 3O'Brien Institute for Public Health, University of Calgary, Calgary, Alberta, Canada; 4Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 5British Columbia Injury Research and Prevention Unit, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada; 6Faculty of Education, University of Alberta, Edmonton, Alberta, Canada; 7Family Medicine, Faculty of Medicine and Dentistry and Glen Sather Sport Medicine Clinic, University of Alberta, Edmonton, Alberta, Canada; 8Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 9Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada

Background

Factors associated with concussion in youth ice hockey have been identified previously; however, inconsistent evidence for some factors, including sex, required further study.

Objectives

To examine factors that influence game-related concussion rates in youth ice hockey players.

Methods

Safe2Play is a 5-year longitudinal prospective cohort study. In total, 4419 youth ice hockey players (aged: 10-18 years, 90% male, 9% female, all levels) were recruited (6585 player-seasons). All game-related concussions were identified using validated injury surveillance methodology. Players with a suspected concussion were referred to a study sport medicine physician for diagnosis and management. Multiple multilevel mixed-effects negative binomial regression analysis was performed, adjusted for a priori covariates suggested in the literature (body checking policy, age group, year of play, level of play, concussion history, sex, player weight, and position of play) and random effect at a team level (offset by game exposure hours), to estimate concussion incidence rate ratios (IRRs).

Results

A total of 554 game-related concussions (crude concussion rate adjusted for cluster by team = 3.08 concussions/1000 game hours [95% confidence interval (CI): 2.78-3.41]) were sustained for more than 5 years (median time loss = 14 days; interquartile range: 17; missing 1.91%). Based on complete case analysis of 4148 player-seasons, female players (IRR female/male = 1.69; 95% CI: 1.09-2.62) and players with a previous concussion history (IRR = 1.98; 95% CI: 1.58-2.47) had higher rates of game-related concussion. Policy disallowing body checking in games (IRR = 0.52; 95% CI: 0.35-0.76) and being a goaltender (IRR goaltenders/forwards = 0.54; 95% CI: 0.32-0.89) were protective against game-related concussion.

Conclusions

In youth ice hockey, female players (despite policy disallowing body checking) and players with a concussion history had higher rates of concussion. Goalies had a lower rate of concussion. Playing in leagues where policy disallowed body checking was associated with lower concussion rates in youth ice hockey and policy allowing body checking continues to be the most reported modifiable risk factor in youth ice hockey.

Acknowledgments

The Sport Injury Prevention Research Centre is one of the International Research Centres for Prevention of Injury and Protection of Athlete Health supported by the International Olympic Committee. The authors acknowledge funding from Canadian Institutes of Health Research, Alberta Innovates Health Solutions, Hotchkiss Brain Institute, and Alberta Children's Hospital Foundation (Integrated Concussion Research Program). Carolyn Emery holds a Canada Research Chair in Concussion. The authors acknowledge Hockey Canada, Hockey British Columbia, Hockey Edmonton, Airdrie Minor Hockey Association, Hockey Calgary, and all team safety designates, coaches, players, and parents involved for their time and support in completing this research project.

Distinct Blood Biomarker Profiles Induced After CHIMERA Traumatic Brain Injury in Mice

Fan Jianjia1,2; Cheng Wai Hang1,2; Cheung Honor1,2; Anwer Mehwish1,2; Barron Carlos1; Cripton Peter A1,3; Wellington Cheryl L1,2

1Djavad Mowafaghian Centre for Brain Health, The University of British Columbia, Vancouver, Canada; 2Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver, Canada; 3School of Biomedical Engineering, The University of British Columbia, Vancouver, Canada

Background

Neurofilament light chain (NF-L) and glial fibrillary acidic protein (GFAP) have emerged as promising clinical fluid biomarkers for traumatic brain injury (TBI). However, there is scant literature on their use in animals due to lack of reliable murine-reactive immunoassays. This is a research gap as animal models are invaluable study tools. Our nonsurgical model CHIMERA (Closed-Head Impact Model of Engineered Rotational Acceleration) replicates neuropathological features similar to human concussion cases in rodents. We recently refined CHIMERA to produce distinct injury subtypes depending on whether skull is directly impacted by piston or whether an “interface” is inserted between skull and piston to prevent the skull from fracturing at higher-energy impact. In addition to the development of a sensitive mouse GFAP immunoassay, we validated commercially available human NF-L assays on murine samples. This allows us to determine whether direct versus interfaced TBI leads to distinct patterns of biomarker changes in animals.

Objectives

To profile murine plasma NF-L and GFAP changes in direct versus interfaced TBI.

Methods

Mice at 4 months of age were subjected to sham, direct, or interfaced impact(s) using CHIMERA at various energy levels with the number of hits indicated in each study. Plasma samples were then collected for biomarker measures at 6 hours, 1 day, 2 days, 7 days, and 60 days post-TBI.

Results

We showed that direct and interfaced impacts produced distinct GFAP and NF-L signatures, with 1 × 2.1J impact triggering an acute spike of GFAP 6 hours after injury and a subtle NF-L response across 7 days, whereas double direct impacts at 0.7J had a mild GFAP response at 6 hours but a robust NF-L response at 1 to 2 days postinjury. Elevated plasma biomarkers by interfaced TBI seemed to correlate with impact energy.

Conclusions

Distinct profiles of biomarkers are produced by direct/interfaced CHIMERA TBI, supporting the hypothesis that CHIMERA can be used to produce distinct injury subtypes.

Personality Traits and Clinical Syndromes as Predictors of Persistent Postconcussive Symptoms and Outcome Following Mild TBI

Gagnon Catherine1; Trépanier Laurence1; Denault Stéphany1; Saluja Rajeet1,2; Abouassaly Michel3; de Guise Elaine4

1Centre de recherche interdisciplinaire en réadaptation du Montréal métropolitain, Institut Universitaire sur la réadaptation en déficience physique de Montréal, Montreal, Quebec, Canada; 2Department of Neurology & Neurosurgery, McGill University, Montreal, Quebec, Canada; 3Traumatic Brain Injury Program, McGill University Health Center, Montreal, Canada; 4Department of Psychology, University of Montréal, Montreal, Canada

Background

To date, very few studies exist on the links between personality traits and their impact on the development and persistence of postconcussion symptoms (PPCS) and on the quality of social reintegration after mild traumatic brain injury (mTBI). In fact, authors have mainly focused on the history of psychiatric disorders, such as anxiety and depression, or the presence of psychological consequences after mTBI as poor prognostic factors.

Objective

The aim of this study was to explore the predictive value of personality traits and clinical syndromes on PPCS and quality of social reintegration following mTBI.

Methods

This prospective longitudinal study included self-report of personality and psychiatric disorders in a total of 82 patients with mTBI. In the first 2 weeks following their injury, patients with mTBI completed the Million Clinical Multiaxial Inventory III (MCMI-III). Persistence of postconcussion symptoms and social reintegration were assessed at 3 months after mTBI using the Rivermead Post-Concussion Symptoms Questionnaire and the Mayo-Portland Adaptability Inventory (MPAI-4).

Results

Hierarchical linear regression analyses showed that the presence of depressive, schizotypal, and borderline personality traits alone predicted more than 25% of PPCS, whereas the presence of clinical syndromes such as anxiety, posttraumatic stress disorder (PTSD), and major depression predicted more than 36% of PPCS. Furthermore, the results showed that report of depressive and histrionic personality symptoms alone predicted nearly 24% of the social reintegration measure following an mTBI, whereas clinical syndromes such as anxiety, dysthymia, and PTSD predicted more than 38% of the social reintegration score.

Conclusion

These models illustrate the role of personality traits and clinical syndromes in mTBI recovery and suggest that it would be relevant to assess these variables as they are early reliable predictors of recovery.

Diffusion MRI Is Sensitive to Subtle Changes in the White Matter of Mice Following Mild TBI During Adolescence

Gazdzinski Lisa M1–3; Mak Jordan J1; Adel Seyed Amir Ali1; Papaioannou Christina1; Joghataie Goldin1; Sled John G2–4; Nieman Brian J2–4; Wheeler Anne L1,5

1Neurosciences and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada; 2Mouse Imaging Centre at The Centre for Phenogenomics, Toronto, Ontario, Canada; 3Translational Medicine, Hospital for Sick Children, Toronto, Ontario, Canada; 4Departments of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; 5Departments of Physiology, University of Toronto, Toronto, Ontario, Canada

Background

Adolescents are more likely to experience persistent symptoms after mild TBI than adults or younger children, possibly due to disruption to the ongoing development of white matter. Diffusion-weighted magnetic resonance imaging (dMRI) is sensitive to white matter microstructure and Neurite Orientation Dispersion and Density Imaging (NODDI) is a geometric model, which may provide greater sensitivity and specificity to tissue changes than diffusion tensor imaging (DTI).

Objective

To characterize the effect of mild TBI in adolescence on white matter in a mouse model using dMRI and histology.

Methods

Five-week-old mice received a mild TBI (or sham procedure). Following behavioral testing, mice were perfusion-fixed at 1 or 4 weeks postinjury (N = 3-5 mice/sex/injury group/time point). The brains were imaged on a 7T MRI scanner with a multishell dMRI protocol. The images were processed to calculate NODDI and DTI measures and registered together to allow group comparisons. Based on our previous findings in adult mice, the analysis was restricted to the corpus callosum and the optic tracts. Histological processing is underway to evaluate the inflammatory response.

Results

Diffusivity was elevated in the optic tracts following mTBI (P < .1), particularly at 4 weeks (P < .05). At 4 weeks, the orientation dispersion index (ODI) appeared increased in mTBI females but not in males (P < .1), and the dot fraction appeared to be decreased in this structure (P < .05). No differences were observed in the corpus callosum and no behavioral deficits were observed.

Conclusions

The injury produced in this model resulted in no deficits in the behavioral tests performed and no measurable differences in the corpus callosum. Despite the mildness of the injury, subtle differences in diffusion measures were observed in the optic tracts, consistent with our previous study in adult mice. The increased ODI and decreased dot fraction 4 weeks postinjury may reflect cellular changes involved in the inflammatory response.

For Whom the Bell Rings: A Look at Gender Differences in Concussion Knowledge, Attitudes, and Reporting Behaviors Among University Student Athletes

Golshan Faly; Mickleborough Marla; Bains Sarah; Morrison Todd G; Daly Jenna

University of Saskatchewan, Saskatoon, Saskatchewan, Canada

Background

Concussion is a critical pathophysiological process that occurs as a result of a traumatic biomechanical force. Also known as an invisible injury, concussion is a common type of traumatic brain injury with symptoms that may be underestimated. This urges fundamental improvements in public knowledge specifically addressing young university athletes and different genders who represent an understudied population.

Objective

This cross-sectional study aimed to explore the possibility of gender differences with respect to university student athletes' concussion knowledge, attitude, and their reporting behavior. We hypothesized that there should be no significant difference in concussion knowledge among male and female student athletes; however, females would show a higher positive attitude and more reporting behaviors than male student athletes.

Methods

A total of 115 university athlete students (mean age = 22.25, years; 27 males and 83 females) completed a survey questionnaire including Rosenbaum Concussion Knowledge and Attitude Survey-student version (RoCKAS-ST). ROCKAC-ST is a 55-item questionnaire with an adequate internal consistency (Cohen α range = 0.59-0.72). This measurement had 33 questions on Composite Concussion Knowledge (CKI) index with fair test-retest reliability (r = 0.67) and 15 items on Concussion Attitude (CAI) index with satisfactory test-retest reliability (r = 0.79).

Results

Out of 16 given reasons for reporting a concussion, 55.6% of males and 24.1% of females with the experience of concussion said that they did not think that it was something serious. Our independent t test results showed that the concussion knowledge and attitude indices did not significantly differ across the 2 genders (P > .05); however, male athletes had higher scores of concussion attitude toward other teammates' reaction to a reporting behavior (P = .008, Cohen d = 0.60). In addition, male athletes provided more reasons for reporting a concussion when compared with female counterparts (P = .02, Cohen d = 0.82)

Conclusion

Our study indicated that concussion knowledge and attitude are not generally gender biased among university athletes; however, males tend to show a more positive attitude toward their teammates' reaction to concussion reports. More investigation is required to suggest how a diligent report of symptoms could be established among young athletes and whether genders tend to show different reactions to acute or long-term symptoms of concussion.

Altered Brain Network Functional Connectivity 1 Month Following Pediatric Concussion

Healey Katherine1,5; Fang Zhuo2; Smith Andra2; Zemek Roger1,3; Ledoux Andrée-Anne1,2,4,5

1Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada; 2Department of Psychology, University of Ottawa, Ottawa, Ontario, Canada; 3Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada; 4Department of Cellular Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada; 5Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada

Background

Concussion is a mild traumatic brain injury with increasing prevalence among children and adolescents. Functional connectivity (FC) within and between the default mode network (DMN), central executive network (CEN), and salience network (SN) has been shown to be altered postconcussion. Few studies have investigated connectivity within and between these 3 networks following a pediatric concussion.

Objectives

The present study explored whether within and between-network FC differs between a pediatric concussion and orthopedic injury (OI) group aged 10 to 18 years.

Methods

Participants underwent resting-state functional magnetic resonance imaging 4 weeks postinjury. One-way analysis of covariance analyses were conducted between groups with seed-based FC of the 3 networks. Seed regions included the posterior cingulate cortex (PCC) and medial prefrontal cortex (mPFC) (DMN), posterior parietal cortex (pPC) and dorsolateral prefrontal cortex (dlPFC) (CEN), and dorsal anterior cingulate cortex (dACC) and frontoinsular cortex (FIC) (SN). Age, sex, handedness, group, and composite diagnostic score (based on self-reported diagnoses of learning disability, attention deficit hyperactivity disorder, anxiety, depression, and previous concussions) were covaried.

Results

Fifty-five concussion (mean age [SD] = 13.19 [2.09]; 47.3% female) and 27 OI participants (mean age [SD] = 12.89 [1.90]; 37% female) were included. In the concussion group compared with the OI group, increased within-network FC was found between the right dlPFC and right pPC (CEN) and the right FIC and bilateral dACC (SN). Furthermore, increased between-network FC was found between the right FIC (SN) and bilateral PCC and mPFC (DMN), as well as the right FIC (SN) and bilateral dlPFC (CEN). Finally, decreased between-network FC was found in the concussion group compared with the OI group between the right dlPFC (CEN) and left PCC (DMN).

Conclusions

This study identified differential connectivity patterns following a pediatric concussion compared with an OI 4 weeks postinjury. These differences indicate potential adaptive brain mechanisms that may provide insight into recovery trajectories and appropriate treatment timing within the first month postconcussion.

Acknowledgments

This work was supported by the IMPACT OSSU Award; the PSI Foundation; and graduate student funding by the Canadian Institutes of Health Research (CIHR).

High Head Contact and Suspected Concussion Rates in Youth and University Ringette: A Video-Analysis Study

Heming Emily E1; Kolstad Ash T1; West Stephen W1,2; Williamson Rylen A1; Sobry Alexandra J1; Goulet Claude3; Russell Kelly4,5; Emery Carolyn A1,2,6–10

1Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 2O'Brien Institute for Public Health, University of Calgary, Calgary, Alberta, Canada; 3Department of Physical Education, Faculty of Education, Université Laval, Quebec City, Quebec, Canada; 4Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Manitoba, Canada; 5Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada; 6Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; 7Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 8McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, Alberta, Canada; 9Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 10Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada

Background

Ringette is a popular team ice sport among Canadian females with high rates of concussion, despite rules prohibiting body checking and head contacts (HC). Previous video analysis in university-level athletes showed that ringette players had a 68% higher rate of HC and a threefold higher rate of suspected injury when compared with female ice hockey players. It is unknown how physical contacts (PC) and HC differ between university and youth ringette.

Objective

To compare PC, HC, and suspected concussion incidence rates (IR) in university and youth ringette using video analysis.

Methods

This cross-sectional study included video from Canadian university ringette tournament games (2018-2019/2019-2020) and elite youth (U16AA level) regular season and tournament games (2021-2022). Dartfish 10 video analysis software was used to assess: PC type (trunk, limb/object), trunk PC intensity (5-point scale: 1 [very light] to 5 [excessive]), HC type (HC1 = direct player to player, HC2 = indirect with environment), and suspected concussion, using previously validated criteria. Univariate Poisson regression analyses (adjusted for cluster by team, o set by game-minutes) were used to estimate PC, HC, and suspected concussion IRs and incidence rate ratios (IRRs) comparing university to youth gameplay.

Results

Analyses of 34 team-games (n [university] = 18, n [youth] = 16) revealed that total PCs in university (IR = 310.38 PC/100 team-minutes, 95% confidence interval [CI]: 285.40-337.54) and youth (IR = 330.46 PC/100 team-minutes, 95% CI: 289.86-376.75) did not differ (incidence rate ratio [IRR] = 1.06, 95% CI: 0.91-1.24). Total HCs in university (IR = 17.92 HC/100 team-minutes, 95% CI: 14.71-21.83) and youth (IR = 24.74 HC/100 team-minutes, 95% CI: 17.59-34.80) also did not differ (IRR = 1.38, 95%CI: 0.94-2.03). There was a 79% higher HC1 rate (IRR = 1.79, 95% CI: 1.22-2.61) in youth ringette (IR = 18.74 HC/100 team-minutes, 95% CI: 13.07-26.89) compared with university (IR = 10.49 HC/100 team-minutes, 95% CI: 9.14-12.04). The suspected concussion IR in youth (IR = 0.60 concussions/100 team-minutes, 95% CI: 0.20-1.84) was not significantly different than university (IR = 0.87 concussions/100 team-minutes, 95% CI: 0.34-2.24) (IRR = 0.69, 95% CI: 0.16-2.89).

Conclusions

Total PCs and HCs were high in both university and youth ringette; however, HC1 rates in youth were 79% higher than university. These findings inform future research evaluating injury prevention strategies in ringette targeting a reduction in head impacts and concussions.

Acknowledgments

The Sport Injury Prevention Research Centre is one of the International Research Centres for Prevention of Injury and Protection of Athlete Health supported by the International Olympic Committee. The authors acknowledge funding from the National Football League Play Smart Play Safe Program. Dr Emery holds a Canada Research Chair in Concussion.

Machine Learning and Deep Learning Techniques for Classification of Youth Ice Hockey Players With and Without a Previous History of Concussion in Robotic Testing of Sensory, Motor, and Cognitive Function

Hossain Delowar1; Kolstad Ash2; Emery Carolyn2; Scott Stephen H3; Dukelow Sean P1; Clu Tyler2

1Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 2Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 3Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada

Background

Concussion is a potential health problem in youth ice hockey players. Better tools are needed for early diagnosis and management. The purpose of this study was to determine whether machine learning and deep learning techniques could classify clinically asymptomatic participants with and without a history of concussion. Classification was based on performance in upper extremity robotic tasks.

Methods

Five robotic tasks were used to assess sensory, motor, and cognitive functions: visually guided reaching, arm position matching, object hit, object hit and avoid, and trail making B. Seventy-nine performance parameters were reported across all tasks. We examined the efficacy of 7 classification algorithms based on Machine Learning (ie, Logistic Regression, Decision Tree, Random Forest, Random Forest with Hyperparameters Tuning, Support Vector Machine, and K-Nearest Neighbors) and Deep Learning (ie, Deep Neural Network) to classify participants with and without a history of concussion.

Results

Three hundred twenty ice hockey players (aged 10-12 years) participated. Although all were clinically asymptomatic at the time of robotic assessment, 101 had a remote history of concussion (median: 702 days; range: 33-3610). Machine Learning and Deep Learning models correctly classified participants having a previous concussion or not with an average accuracy of 63.7%. The average area under the curve (AUC) for the Precision-Recall curve (summarizing the true positive rate and the true predictive value) was 0.69 and receiver operating characteristic (ROC) curve was 0.513.

Conclusion

Machine Learning and Deep Learning models performed better than chance when considering accuracy and the Precision-Recall curve but not with ROC analysis. The challenge in classifying may be related to participants with remote concussion history being clinically asymptomatic at the time of testing. Future studies conducted immediately following concussion will better inform on the ability of machine learning and deep learning algorithms to detect changes in performance associated with concussion.

Acknowledgments

The Sport Injury Prevention Research Centre is one of the International Research Centres for Prevention of Injury and Protection of Athlete Health supported by the International Olympic Committee. The authors acknowledge funding from the Canadian Institutes of Health Research and Hotchkiss Brain Institute. Dr Emery holds a Canada Research Chair in Concussion.

Examining the Comprehensiveness of Ontario High School Concussion Policies: The Development of a Rating Index

Ippolito Christina1; Paoli Victoria1; Lim Vanessa1; Mallory Kylie2,3; Wilson Katherine1; Kerr Brynna2; Reed Nick1–3

1Department of Occupational Science and Occupational Therapy, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; 2Rehabilitation Sciences Institute, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; 3Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada

Background

Amendments to the Ontario Education Act in September 2019 in compliance with Rowan's Law outline minimum requirements for school board concussion policies across Ontario, Canada. There is variability among existing concussion policies and no method to assess their comprehensiveness.

Objective

To develop, pilot test, and utilize a rating index to assess the comprehensiveness of Ontario high school board concussion policies. A “comprehensive policy” includes all mandates outlined by Ontario legislation, in addition to best practice recommendations by concussion literature.

Methods

Phase 1: A descriptive content analysis of Rowan's Law, Ontario Education Act Policy/Program Memorandum 158 and the concussion literature was conducted to inform mandatory components and suggested recommendations, resulting in a 75-point index (52 components, 23 recommendations) with 6 domains: Concussion Education, Code of Conduct, Removal from Play, Return-to-School, Return-to-Sport, and Concussion Tracking. Each included index item was awarded a score (included = 1; not included = 0). Phase 2: The index was pilot tested on 10 random Ontario school board concussion policies by 3 raters to establish interrater reliability. Phase 3: All Ontario school board concussion policies meeting the inclusion criteria (N = 55) were rated by 2 raters. Open access policies from publicly funded, English-speaking Ontario high schools boards were included.

Results

Pilot testing indicated excellent interrater reliability (ICC = 0.98). On average, only 57% of mandatory components were included in the 55 policies and only 28% of the recommended items. Two policies (3.6%) met all components and were deemed comprehensive. The index demonstrated excellent and good internal consistency for components (α = .97) and recommendations (α = .88), respectively.

Conclusions

The developed rating index identified that the majority of Ontario school board concussion policies fall below legislated provincial expectations. This study highlights areas of improvement and provides a rating tool to enable Ontario school boards to best support their students' successful return to school after a concussion.

Regional Blood Flow Alterations Following Pediatric Concussion: A PedCARE + MRI Substudy

Kardish R1,2; Healey K1,2; Sicard V1; Fang Z3; Smith A3; Cron G O4; Abdeen N1; Yeates K O5–7; Goldfield G1; Reed N8; Zemek R1,9; Ledoux AA1–3,10

1Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada; 2Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada; 3School of Psychology, Faculty of Social Sciences, University of Ottawa, Ottawa, Ontario, Canada; 4Department of Neurology, Stanford University; 5Department of Psychology, University of Calgary, Calgary, Alberta, Canada; 6Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; 7Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 8Department of Occupational Science & Occupational Therapy, University of Toronto, Toronto, Ontario, Canada; 9Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada; 10Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada

Background

Cerebral blood flow (CBF) may be a useful biomarker for concussion recovery, but no studies have examined whether acute CBF predicts 4-week symptom burden in pediatric concussion.

Objectives

(1) To examine whether CBF measured at 72 hours and 4 weeks postinjury differs between children with concussion versus orthopedic injury (OI), and (2) To determine whether 72-hour CBF predicts concussion symptoms at 4 weeks.

Methods

Children aged 10 to 18 years were enrolled from CHEO's Emergency Department from 2018 to 2020. Arterial spin labeling was used to measure CBF at 72 hours and 4 weeks. A mixed analysis of variance, adjusted for age, sex, and motion, was conducted to assess CBF differences between groups and time points. Regression analyses examined the relationship between regional CBF and symptoms measured with the Health and Behaviour Inventory, and the moderating effect of group.

Results

Seventy participants with concussion (Mage = 13.05 ± 2.02, 47% female) and 29 with OI (Mage = 12.59 ± 1.97, 41% female) were included in this study. A significant group × time interaction was found in the anterior cingulate/medial frontal cortex (ACC_MFC, P = .004) and right middle frontal gyrus (R_MFG, P = .017). In both regions, CBF increased from 72 hours to 4 weeks in children with concussion (P ≤ .001), but CBF did not differ between time points for the OI group. In the ACC_MFC, the concussion group showed increased CBF compared with the OI group at both time points (P < .001). In the R_MFG, CBF was increased compared with the OI group at 4 weeks (P < .001) but not 72 hours, despite a similar direction of effect. There was no relationship between ACC_MFC and R_MFG CBF and 4-week symptoms and no moderating effect of group.

Conclusions

Regional differences in CBF were found between children with concussion versus OI but were unrelated to symptom burden. However, these results indicate that CBF alterations may be important for understanding persistent neurobiological deficits after concussion.

Using the Closed-Head Impact Model of Engineered Rotational Acceleration to Study Co-occurring Traumatic Brain and Spinal Cord Injury

Kondiles BK*1,2; Anwer M2*; Cheng WH2; Fan J2; Barron JC2; McIness K1; Cheung H2; Earle JF1; Cripton PA1,2; Wellington C**1,2; Tetzlaff W**1,2

1International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada; 2The University of British Columbia, Vancouver, Canada

Background

Estimates of traumatic brain injury (TBI) in spinal cord injury (SCI) patients in North America range from 10% to 74%. Accurate diagnosis of concurrent injuries is necessary for appropriate treatments. Therefore, biomarkers capable of discerning co-occurring TBI and SCI (cTS) and injury severity would be a powerful diagnostic tool. There are mixed reports regarding outcomes following cTS, and there are no animal models of cTS. The Closed-Head Impact Model of Engineered Rotational Acceleration (CHIMERA) is a validated model of mouse TBI used around the world to cause consistent and repeatable injuries.

Objectives

Develop and characterize a cTS model using CHIMERA to enable investigation of biomarkers, recovery courses, and therapeutics for this common but poorly understood clinical condition.

Methods

Traumatic brain injury occurs when an impactor strikes an anesthetized mouse's head at the head's center of mass. To induce concurrent SCI, we adjusted the position of the head above the piston to cause extra rotation at the cervical spine. Time to wake from anesthesia was monitored. Blood levels of glial fibrillary acidic protein (GFAP) and neurofilament light were analyzed. Animals' scores on the neurological severity scale were assessed. Cell markers of inflammation and injury were assessed by histology in the spinal cord.

Results

High-speed videography confirmed cervical hyperextension with the novel head positions. Animals with CHIMERA impact with hyperextension took longer to wake from anesthesia. Plasma levels of GFAP were significantly elevated in animals with a CHIMERA impact with hyperextension. Neurological severity scale varied but trended toward worse severity in cTS animals. Staining for Iba1 in the cervical cord revealed that some cTS animals exhibited microglial morphology consistent with reactivity.

Conclusions

Initial results show that cervical hyperextension during CHIMERA TBI produces a behavioral and morphological phenotype consistent with concomitant SCI. Blood biomarkers are elevated in animals with cTS. Future work will further characterize the model and detail how cTS impacts behavioral recoveries.

Acknowledgments

ICORD Seed Funding made possible by the Rick Hansen Foundation US Department of Defense.

Responsiveness of the Postconcussion Symptoms Scale to Monitor Clinical Recovery Following Concussion/Mild Traumatic Brain Injury

Langevin P1,3; Frémont P1; Fait P2; Roy JS1,3

1Université Laval, Québec, Canada; 2UQTR, Québec, Canada; 3CIRRIS, Quebec City, Quebec, Canada

Background

The Post-Concussion Symptom Scale (PCSS) is used to assess the number and intensity of symptoms following a concussion/mild traumatic brain injury. However, its responsiveness to monitor clinical recovery has yet to be determined.

Purpose

To evaluate the responsiveness to change and longitudinal validity of the PCSS in patients with persistent post-concussive symptoms. Responsiveness of other clinical outcome measures to monitor recovery of patients with persistent postconcussive symptoms was also explored.

Study Design

Prospective cohort clinimetric study.

Methods

Patients with persistent symptoms following a concussion (n = 109) were evaluated using self-reported questionnaires at baseline and after a 6-week rehabilitation program. The program consisted of an individualized symptom-limited aerobic exercise program combined with education. Questionnaires included the PCSS, Neck Disability Index (NDI), Headache Disability Inventory (HDI), Dizziness Handicap Inventory (DHI), and Numerical Pain Rating Scales (NPRS) related to neck pain and headache. Internal responsiveness was evaluated using the Effect Size (ES) and Standardized Response Mean (SRM). External responsiveness was determined with the Minimal Clinical Important Difference (MCID) calculated with a receiver operating characteristic (ROC) curve method. The global rating of change was used as the external criterion. Pearson correlations were used to determine the longitudinal validity.

Results

The PCSS is highly responsive (ES and SRM > 1.3) and has an MCID of 26.5 out of 132 for total score and 5.5 out of 22 for number of symptoms. For longitudinal validity, low to moderate correlations were found between changes in PCSS and changes in NDI, HDI, and DHI. The NDI, HDI, DHI, and NPRS are also highly responsive (ES and SRM > 0.8).

Conclusion

All questionnaires including the PCSS are highly responsive and can be used with confidence by clinicians and researchers to evaluate change over time in a concussion population with persistent symptoms.

Cervicovestibular Rehabilitation in Adults With Mild Traumatic Brain Injury: A Randomized Clinical Trial

Langevin Pierre1–3; Frémont Pierre2; Fait Philippe1,3–5; Dubé Marc-Olivier1–3; Bertrand-Charette Michaël1–3; Roy Jean-Sébastien2,3

1Clinique Cortex and Physio Interactive, Québec, Canada; 2Department of Rehabilitation, Faculty of Medicine, Université Laval, Pavillon Ferdinand-Vandry, Quebec City, Canada; 3Centre for Interdisciplinary Research in Rehabilitation and Social Integration, Quebec Rehabilitation Institute (CIRRIS), Quebec City, Canada; 4Department of Human Kinetics, Université du Québec à Trois-Rivières, Quebec City, Canada; 5Research Centerin Neuropsychology and Cognition (CERNEC), Montreal, Quebec City, Canada

Background

Up to 25% of adult with concussion/mild traumatic brain injury (mTBI) present persistent symptoms such as headache and/or dizziness. The Berlin 2016 consensus statement recommends the addition of individualized rehabilitation programs for mTBI with persistent symptoms based on limited scientific evidence. Such intervention should therefore be further investigated.

Objective

The objective of this study was to compare the effects of a cervicovestibular rehabilitation program combined with symptom-limited aerobic exercise (SLAE) program to a SLAE program alone in adults with persistent symptoms following mTBI on severity of symptoms and other indicators of clinical recovery.

Methods

In this single-blind, parallel-group randomized controlled trial, 60 adults with persistent symptoms following mTBI were randomly assigned to (1) a 6-week SLAE program or (2) a 6-week cervicovestibular rehabilitation program combined with SLAE program. All participants took part in 4 evaluation sessions (baseline, week 6, 12, and 26) performed by a blinded evaluator. The primary outcome was the Post-Concussion Symptoms Scale (PCSS). The secondary outcomes were Numerical Pain Rating Scale (NPRS), Neck Disability Index (NDI), Headache Disability Inventory (HDI), Dizziness Handicap Inventory (DHI), time to return to function, and physical cervical and vestibular measures. Nonparametric analysis for longitudinal data was used to evaluate the effect of interventions on outcomes.

Results

For PCSS, NPRS, NDI, HDI, DHI, and return to function, there were no group-by-time interactions at any time points follow-up (P > .05); clinically significant time effects were, however, observed (P < .05). There were group-by-time interactions at weeks 6 and 12 for vestibulo-ocular reflex (P < .003) and the craniovertebral mobility (P < .001) measures in favor of the cervicovestibular rehabilitation group.

Conclusions

The study indicates that a cervicovestibular rehabilitation program combined with SLAE was not superior to a SLAE program alone in term of symptoms and functional level improvement but resulted in improved physical cervical and vestibular function.

Frontal EEG Coherence as a Predictor of Contact-Sport Exposure

Lapointe Andrew P; Dunn Jeff F

University of Calgary, Calgary, Alberta, Canada

Background

Electroencephalography (EEG) has shown promise as a measure of concussion. However, the majority of studies have utilized frequency-based methods where EEG activity is categorized into different bands of activity from slowest (delta) to fastest (gamma).

Objectives

We investigate the utility of coherence-based EEG metrics utilizing electrodes in the frontal region.

Methods

Ten males and 10 females were recruited and daily consecutive qEEG measurements (M = 20.33+/−0.519 years) were taken for 7 days. Participants were excluded if they had suffered a concussion within the past 12 months. Participants filled a brief survey on their lifetime exposure to contact sports and concussion history. Average coherence over the 7 days of testing was calculated for every possibility of 7 frontal electrodes (Fp1, Fp2, F3, F4, F7, F8, and Fz). Both, self-reported contact-sport exposure and concussion history were used as independent variables.

Results

Concussion history failed to demonstrate any significant effect on coherence measures. However, a significant relationship between frontal coherence between left frontal regions was observed with contact-sport exposure. These were most prominent in Fp2, F1,16 = 7.456, P = .015, η = 0.318 and F8, F1,16 = 8.983, P < .01, η = 0.360.

Conclusions

The EEG coherence is impacted by contact sport history. This observation supports the use of EEG-based metrics beyond traditional frequency-based band power measures. Upcoming research will evaluate these changes in larger sample using brain activity over the whole-scalp region to discern whether the changes reported here can be observed in other brain regions.

Psychosocial Factors Involved in Readiness to Return to Sport After a Concussion

Lassman Matthew E1,2; Rathwell Scott3; Normandin Béatrice4; Black Amanda M5–8; Caron Jeffrey G1,2

1School of Kinesiology and Physical Activity Sciences, Université de Montréal, Montreal, Québec, Canada; 2Centre for Interdisciplinary Research in Rehabilitation of Greater Montreal, Montreal, Québec, Canada; 3Department of Kinesiology and Physical Education, University of Lethbridge, Lethbridge, Alberta, Canada; 4Department of Psychology, Université de Montréal, Montreal, Québec, Canada; 5Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 6Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; 7Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 8O'Brien Institute for Public Health, University of Calgary, Calgary, Alberta, Canada

Background

The graduated return to sport (RTS) schedule emphasizes physical readiness; however, psychosocial readiness is not comprehensively assessed among athletes with sport-related concussion (SRC). This is unfortunate, given that psychological symptoms comprise the primary symptoms in 30% of concussed athletes (Kontos et al, 2019), and athletes have expressed psychosocial concerns during RTS (Caron et al, 2021).

Objectives

To qualitatively explore formerly concussed athletes' perceptions of the psychosocial factors involved in feeling ready to RTS following SRC.

Methods

The participants were 12 university student athletes (n = 6 females, 6 males), between 19 and 25 years of age, whose SRC recovery ranged from 6 weeks to 2 years. They participated in American football, artistic swimming, basketball, cycling, ice hockey, ringette, sailing, synchronized ice skating, and swimming. Two semistructured interviews were held with each athlete, which explored their SRC and RTS experience (interview 1) as well as their reflections and advice to others in a similar situation (interview 2). We used a thematic narrative analysis to explore patterns within and across the interview data.

Results

Participants described the role of confidence, fear, and pressure in relation to feeling ready to RTS following SRC. Athletes knew that they were confident to RTS when they felt like the same person and athlete they were before their concussion. Participants described several aspects of fear in relation to their RTS experience, including fears about sustaining another injury, having setbacks, and their long-term brain health, as well as expressing self-presentation concerns. Athletes also spoke about the internal (ie, self-imposed) and external (ie, from others) real or perceived pressures they encountered during RTS.

Conclusions

Results from this study provide further evidence of the types of psychosocial factors that can be facilitative or debilitative among formerly concussed athletes during RTS. Future research should determine how psychosocial factors could be assessed during RTS decision making.

Preseason Performance of Youth on the Sport Concussion Assessment Tool 5: A Multisport Cohort Study

Leggett B1–3; Syrydiuk R1–3; Sick S1–3; Eliason P1–3; Schneider KJ1–4; Emery CA1–5

1Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 2Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; 3Hotchkiss Brain Institute, University of Calgary, Alberta, Canada; 4Sport Medicine Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 5Departments of Pediatrics and Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada

Objective

To examine youth sport participants' SCAT5 symptom evaluation (total number of symptoms [TS] and symptom severity [SS] score) and sex, age, number of previous concussions, collision versus noncollision sport, and self-reported medical diagnoses.

Design

Cohort study.

Participants

A total of 2606 youth sport participants (aged 11-19 years).

Assessment of Risk Factors

SCAT5 TS(/22) and SS(/132) were assessed by sex (male/female), age, number of previous concussions (0/1/2/3+), participation in collision/noncollision sport, and self-reported medical diagnoses (ie, attention-deficit/attention deficit hyperactivity disorder [ADD/ADHD], headache/migraine disorder, learning disability, and psychiatric disorder [anxiety/depression]).

Outcome Measures

In-person or virtual video administration of the SCAT5 was completed preseason. Primary outcomes included TS and SS. Kruskal-Wallis and post hoc Dunn multiple comparison tests with Bonferroni corrections were used to assess differences existing between independent variables and the SCAT5 TS and SS.

Results

The most frequently reported symptoms were “difficulty concentrating” (44.0%) and “fatigue/low energy” (40.9%) in males and “nervous/anxious” (57.7%) and “fatigue/low energy” (54.9%) for females. Females reported higher TS (H(2) = 101.257, P = .0001) and SS scores (H(1) = 101.713, P = .0001) than males. Females reporting 3+ previous concussions reported higher TS (P = .0002) and SS scores (P = .0014) compared with those with no concussion history. Only males reported lower TS (H(1) = 5.412, P = .0200) and SS (H(1) = 6.241, P = .0125) for collision compared with noncollision sport. Compared with youth with no such medical diagnosis, males and females with a self-reported medical diagnosis reported higher TS and SS scores for ADD/ADHD, headache/migraine, and psychiatric disorder (P < .05). Males with a learning disability compared with those without reported higher TS and SS scores with no differences found for females. No TS or SS differences were found comparing male or female age (P > .05).

Conclusion

Females reported higher TS and SS than males. Self-reported medical diagnoses of interest increased TS/SS scores except for learning disorder for all youth. Sex, age, concussion history, and medical diagnoses may be important considerations for interpretation of SCAT5 performance.

Acknowledgments

The Sport Injury Prevention Research Centre is one of the International Research Centres for Prevention of Injury and Protection of Athlete Health supported by the International Olympic Committee. The authors acknowledge funding from the National Football League Play Smart Play Safe Program. Dr Emery holds a Canada Research Chair in Concussion.

Investigating Tauopathy in Military Occupational Blast: A [18F]flortaucipir Positron Emission Tomography Study in Canadian Armed Forces Members

Lora Shamantha J1,2,5; Watling Sarah E1,2,5; Warsh Jerry1–5; Tartaglia Carmela6; Vartanian Oshin7; Vallée Isabelle8; Vergie Iain8; McCluskey Tina1,2; Vasdev Neil1,5,9; Rhind Shawn G7; Boileau Isabelle1–3,5

1Brain Health Imaging Centre and; 2Campbell Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; 3Department of Psychiatry; 4Pharmacology and Toxicology, and; 5Institute of Medical Sciences, Toronto, Ontario, Canada; 6Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada; 7Defence Research and Development Canada, Toronto Research Centre, Toronto, Ontario, Canada; 8Canadian Special Operations Forces Command, Ottawa, Ontario, Canada; 9Azrieli Centre for Neuro-Radiochemistry, Centre for Addiction and Mental Health, Toronto, Ontario, Canada

Background

Neurological damage, including long-term chronic traumatic encephalopathy (CTE)—a progressive neurodegenerative disorder resulting from repeated brain trauma—is suspected to occur as a result of repetitive subconcussive exposure to low-intensity occupational blast overpressure during military training and operations. The pathobiological changes underlying this phenomenon are not well understood. Aggregation of tau neurofibrillary tangles (tauopathy) is a key neuropathological feature of CTE and has been linked with memory loss, cognitive impairment, and mood changes. Although animal models putatively link low-level blast exposure with persistent neurological effects and accelerated tau aggregation, studies in humans exposed to blast are limited.

Objectives

The aim of this study was to evaluate the use of positron emission tomography (PET) imaging of [18F]flortaucipir (aka [18F]TAUVID™, [18F]AV-1451; [18F]T807) to detect in vivo brain levels of tau in a sample of Canadian Armed Forces (CAF) members with significant career exposure to blast overpressure.

Materials and Methods

Twenty four (n = 24) CAF members (male; 43.8 ± 6.1 years of age) exposed to repetitive low-intensity blast (ie, breaching and heavy weapons systems) completed a PET scan following the injection of [18F]flortaucipir. A magnetic resonance image was acquired for brain regions of interest (ROIs) delineation. Standardized Uptake Value ratio (SUVr) was calculated with the cerebellum as reference tissue. Participants performed a test of executive function (Stroop) and completed mood and clinical questionnaires.

Results

[18F]flortaucipir uptake was highest in midbrain/substantia nigra, basal ganglia, and temporal and frontal cortices. [18F]flortaucipir SUVr values (in seven brain ROIs, including temporal and frontal cortices) were positively correlated to years of breaching (r = 0.9; P uncorrected <.05). Greater [18F]flortaucipir SUVr values in prefrontal regions were related to poorer performance on the Stroop test of executive function (r = .7; P < .05). [18F]flortaucipir SUVr did not correlate with mood or clinical symptoms.

Conclusion

In line with an earlier PET study linking tau deposition with cumulative dose exposure to blast (Robinson et al, 2019), our study finds a positive correlation between repeated blast exposure and tau deposition, further suggesting that greater exposure could potentially increase long-term risk of tauopathy. Studies in a larger cohort of at-risk individuals should aim to model tau in order to better understand the pathobiological significance and what constitutes safe exposure limits to military occupational blast.

Acknowledgments

This work was funded by the Canadian Institute for Military and Veteran Health Research (CIMVHR) and Canadian Department of National Defence (DND).

Psychosocial Factors Associated With Time to Recovery From Concussion in Youth Ice Hockey Players

Luszawski CA1; Plourde V2; Sick SR3; Galarneau JM3; Yeates KO4; Emery CA5

1University of Calgary Department of Psychology and Alberta Children's Hospital Research Institute, Alberta, Canada; 2School of Psychology, Université de Moncton, New Brunswick, Canada; Centre de formation médicale du Nouveau-Brunswick, Université de Sherbrooke, New Brunswick, Canada, Faculté Saint-Jean, University of Alberta, Alberta, Canada; 3Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 4University of Calgary Department of Psychology, Alberta, Canada; Children's Hospital Research Institute, Departments of Pediatrics and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 5Sport Injury Prevention Research Centre, Faculty of Kinesiology and Departments of Pediatrics and Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada

Background

The identification of psychosocial factors associated with recovery time following concussion is important to identify potential targets for intervention for youth participating in high contact sports.

Objectives

To investigate the association of psychosocial factors preinjury (quality of life, emotional adjustment, resilience, perfectionism, parental involvement) and post–acute injury (acute distress and expectations of recovery) with time to recovery (TTR) in youth ice hockey players following concussion.

Methods

This is a planned substudy within a longitudinal cohort study, Safe-to-Play (2013-2018). Participants were 350 ice hockey players (aged 11-18 years; 87% males) who sustained a physician-diagnosed concussion. Players and parents completed preseason questionnaires (Pediatric Quality of Life, Strengths and Difficulties [SDQ], Connor-Davidson Resilience Scale 10, Sport Multidimensional Perfectionism Scale, and Parent Involvement in Sport Questionnaire). Players with a suspected concussion were referred for a study physician visit, during which they completed the sport concussion assessment tool (SCAT3/SCAT5) and ratings of distress and expectations of recovery. Time to recovery was based on time between concussion and physician clearance to return to play. Separate accelerated failure time models were computed to estimate psychosocial factors associated with TTR. Covariates included age, sex, body-checking policy, days from concussion to physician visit, and symptom severity at physician visit.

Results

Self-report of more peer problems on the SDQ (time ratio [TR], 1.10 [95% confidence interval (CI), 1.02-1.19]), higher ratings of distress about concussion outcomes through self-report (TR, 1.06 [95% CI, 1.01-1.11]) and parent-report (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 problems with peers and distress about concussion outcomes and youth well-being were psychosocial factors associated with time to recovery in youth ice hockey players following concussion. Targeting these psychosocial factors for intervention may promote recovery.

Acknowledgments

The Sport Injury Prevention Research Centre is one of the International Research Centres for Prevention of Injury and Protection of Athlete Health supported by the International Olympic Committee. The authors acknowledge funding from the Canadian Institutes of Health Research and Hotchkiss Brain Institute. Dr Yeates holds the Ronald and Irene Ward Chair in Pediatric Brain Injury. Dr Emery holds a Canada Research Chair in Concussion.

Biomarkers for Diagnosis and Prognostication of Mild Traumatic Brain Injury in Children: A Systematic Review

Malhotra Armaan K1; Ide Kentaro2; Salaheen Zaid3; Mahood Quenby4; Guerguerian Anne-Marie5–7; Hutchison Jamie5–7

1Division of Neurosurgery, University of Toronto, Toronto, Ontario, Canada; 2Department of Critical Care and Anesthesia, The National Center for Child Health and Development, Tokyo, Japan; 3Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; 4Reference Librarian, The Hospital for Sick Children, Toronto, Ontario, Canada; 5Department of Critical Care Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada; 6Neuroscience and Mental Health, The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada; 7Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada

Background

Mild traumatic brain injury (mTBI) in children can be misdiagnosed and is often associated with postconcussive symptoms that can negatively affect quality of life. Immediately following injury, we are unable to accurately predict which children will recover and which children will have long-term sequelae. This often leads to inadequate follow-up and management. Blood biomarkers hold tremendous potential to improve the accuracy of diagnosis and prognostication in children with mTBI.

Objectives

Assess the diagnostic and prognostic utility of fluid biomarkers in children following acute mTBI by systematically reviewing available literature.

Methods

We used Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology to conduct a systematic review using MEDLINE, EMBASE, and Cochrane Central Registry of Controlled Trials databases. We included studies of fluid biomarkers for diagnosis and prognosis in children with mTBI.

Results

There were 11 172 articles screened and 26 were included: 19 studies were diagnostic and 7 were prognostic. There were 8 diagnostic studies that reported on S100 calcium binding protein B (S100B) to predict abnormal computed tomographic scans with blood cutoff levels ranging from 0.02 to 0.18 ng/mL in children older than 24 months, and area under the curve (AUC) was between 0.67 and 0.998. Glial fibrillary acidic protein (GFAP) was included in 4 diagnostic studies and the AUC ranged from 0.73 to 0.85. Ubiquitin C-terminal hydrolase (UCH- L1) was reported in 4 studies with AUC of 0.59 to 0.83. Seven prognostic studies reported on 13 different blood biomarkers. The outcome of postconcussion syndrome (PCS) at 0.5 to 4 months postinjury was assessed in 5 studies, and 1 study assessed cognition and post-TBI fatigue, respectively, at 12 months postinjury.

Conclusions

There is highly heterogenous data demonstrating the accuracy and utility of various blood biomarkers in pediatric mTBI. We recommend studies with larger sample sizes and better methods to ensure follow-up to validate blood biomarkers for clinical use in children with mTBI.

Canadian High School Students' Intentions to Provide Social Support to a Peer With a Concussion

Mallory Kylie1,2; Wilson Katherine3; Hickling Andrea2,3; Ippolito Christina3; Reed Nick1–3

1Rehabilitation Sciences Institute, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; 2Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada; 3Department of Occupational Science and Occupational Therapy, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada

Background

The provision of social support after a concussion has been shown to mitigate the psychosocial impacts of a concussion such as feelings of isolation and loneliness. Little is known about high school students' intentions to provide social support to a peer with a concussion as well as factors that may influence these intentions.

Objectives

To deliver a survey based on the Theory of Planned Behaviour (TPB) to Canadian high school students to (1) investigate relationships between demographic variables, concussion knowledge, and TPB constructs (attitudes, subjective norms, self-efficacy, and intentions to provide social support to a peer with a concussion); and (2) explore whether intentions to provide social support to a peer with a concussion differ by school or province.

Methods

All students attending 9 high schools across 4 provinces were invited to complete an online survey that contained 7 sections with up to 44 questions. Relationships between variables were explored using Wilcoxon rank sum tests, Spearman rank-order correlation coefficients, and Kruskal-Wallis rank sum tests with follow-up Dunn's tests. The false discovery rate was controlled by adjusting P values using the Benjamini-Hochberg correction.

Results

A total of 1330 high school students (M = 15.31 years, SD = 1.32 years) completed the survey. Students who were older (ρ = 0.12, P ≤ .001), female (W = 1527, P ≤ .001), had higher concussion knowledge (ρ = 0.16, P ≤ .001), and did not play high-risk sports (W = 8590, P ≤ .001) had more favorable intentions to provide social support. Intentions to provide social support were significantly different between schools (H(8) = 17.94, P < .05), with follow-up tests finding this difference between only 2 schools (P < .05). Intentions to provide social support were not significantly different by province.

Conclusions

This study identifies high school students who may be more likely to provide social support to a peer with a concussion and highlights opportunities to deliver concussion education in high schools to enhance the provision of social support.

Acknowledgments

This work was funded by the Canadian Institutes of Health Research (#153025). The authors thank participating schools and students for their involvement in this research. They acknowledge the efforts of the members of the “Youth Concussion Awareness Network” (You-CAN) team, the OAK Concussion Lab (University of Toronto), and the Bloorview Research Institute. This research was undertaken, in part, thanks to funding from the Canada Research Chairs Program.

Incidence of Posttraumatic Headache After Pediatric Mild Traumatic Brain Injury

Marbil Mica Gabrielle1; Ware Ashley L1–4; Galarneau Jean-Michel1; Minich Nori Mercuri5,6; Hershey Andrew D7; Orr Serena L2; Defta Dana M8; Taylor H Gerry9; Bigler Erin D4,10; Cohen Daniel M9; Mihalov Leslie K9; Bacevice Ann5; Bangert Barbara A5; Yeates Keith Owen1–3

1Department of Psychology, University of Calgary, Calgary, Alberta, Canada; 2Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; 3Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 4Department of Neurology, University of Utah, Salt Lake City, Utah, United States; 5Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio, United States; 6Rainbow Babies & Children's Hospital, University Hospitals Cleveland Medical Center, Cleveland, Ohio, United States; 7Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States; 8Department of Neurological Surgery, University Hospitals Cleveland Medical Center, Cleveland, Ohio, United States; 9Abigail Wexner Research Institute at Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States; 10Department of Psychology, Brigham Young University, Provo, Utah, United States

Background

Annually, millions of children in North America sustain mild traumatic brain injury (mTBI), often experiencing posttraumatic headache (PTH). Research on factors associated with PTH is limited.

Objectives

This prospective, longitudinal cohort study examined PTH incidence, risk factors, and characteristics after pediatric mTBI and orthopedic injury (OI).

Methods

Children (N = 213) aged 8 to 16.99 years (M = 12.50, SD = 2.53) were recruited from 2 pediatric emergency departments within 24 hours of sustaining mTBI or OI and returned for assessments at ∼10 days, 3 months, and 6 months postinjury. At each time point, parents completed a standardized questionnaire that was used to characterize headaches and classify them as migraine, tension-type headache, or not otherwise classified, according to International Classification of Headache Disorders 3rd edition criteria. Mixed-effects logistic regression models examined group differences in PTH over time postinjury, adjusting for premorbid headache, age, sex, and site.

Results

The PTH incidence was greater after mTBI than OI (odds ratio [OR] = 482.69, P < .001), particularly at 10 days (OR = 197.41, P < .001) relative to 3 (OR = 3.50, P = .030) and 6 months postinjury (OR = 2.72, P = .101) and in children without premorbid headache (OR = 42.03, P < .001). The PTH frequency was higher after mTBI than OI (β = .80, P = .038) and declined over time in both groups. Groups did not differ on headache duration or severity, headache type, or proportion with worsening headache. Premorbid headache was associated with longer and more severe PTH.

Conclusions

Our results suggest that PTH is specific to mTBI, especially early after injury and in children without premorbid headache. No specific PTH phenotype was associated with mTBI. Future research should examine PTH alongside other mTBI outcomes, including other postconcussive symptoms.

Acknowledgments

This study was supported by the National Institutes of Health and the Eunice Kennedy Shriver National Institute of Child Health and Human Development (Predicting Outcomes in Children with Mild Traumatic Brain Injury; R01HD076885). Dr Yeates is the Ronald and Irene Ward Chair in Pediatric Brain Injury. Dr Ware is supported by the Harley N. Hotchkiss-Samuel Weiss and Killam Postdoctoral Fellowship. Ms Marbil is the recipient of a MITACS Research Training Award.

Development and Face Validation of an Acute Posttraumatic Headache Questionnaire

Marshall Alison1,2; Orr Serena L1,2; Lun Victor3; Debert Chantel4,5; Emery Carolyn5–7; Schneider Geoff8; Subramanium Suresh4; Yeates Keith8; Holte Kirsten6; Chadder Michaela6; Schneider Kathryn5–7

1Departments of Pediatrics, Community Health Sciences, and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 2Section of Neurology, Alberta Children's Hospital, Calgary, Alberta, Canada; 3Sport Medicine Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 4Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 5Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 6Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 7Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; 8Faculty of Arts, University of Calgary, Calgary, Alberta, Canada

Background

Concussions are among the most common sports-related injuries. Headaches are the most consistently reported symptom following concussion. Different headache subtypes may respond to different treatments. A standardized questionnaire that healthcare professionals can use to identify headache subtypes and direct management is needed.

Objectives

To develop and face validate a questionnaire for reporting and classifying posttraumatic headaches.

Methods

A questionnaire based on the International Classification of Headache Disorders (ICHD-3) was developed to identify the most common acute posttraumatic headache (PTH) subtypes that are reported in the literature, which include migraine with/without aura, tension type, cervicogenic, and occipital neuralgia. The initial version was sent to 6 physicians with expertise in PTHs and 6 individuals who had experienced a PTH. Each participant provided open feedback and answered standard questions about the questionnaire. The questionnaire was modified on the basis of feedback and paper and electronic versions were constructed.

Results

Six physicians (aged 36-47 years; 3 males, 3 females; 4-18 years of experience) with expertise in acute and persistent headaches following concussion and 6 individuals (1 youth, 5 adults; aged 13-31 years; 3 males, 3 females) who had a PTH at some point in their life participated in face validation. The questionnaire was viewed positively by all participants and was modified according to their feedback. Common feedback from physicians was that additional questions were needed to aid subtyping and clarify wording. Common feedback from participants with lived experience was to enlarge font size, allow for multiple headache types, simplify questions, and improve wording. Average time to completion was 14.7 minutes (range: 5-30 minutes, median: 15 minutes).

Conclusions

An acute posttraumatic headache questionnaire based on ICHD-3 criteria was viewed positively by physicians and participants with lived experience and evolved following face validation. Further research to validate the PTH questionnaire is required.

Prevalence of Sleep Disturbances Following Mild Traumatic Brain Injury: A Pilot Cross-sectional Survey

Martens Géraldine; Kaux Jean-François; Lejeune Nicolas; Thibaut Aurore

University of Liège, Liège, Belgium

Introduction

Patients who underwent a mild traumatic brain injury, or concussion, may present chronic symptoms such as headaches, attentional disorders, or sleep disturbances that can last for months. Although sleep is a key factor for recovery, it is still poorly investigated in the literature.

Methods

We developed an online survey to evaluate the prevalence of sleep disturbances in patients who had suffered from at least 1 concussion based on validated questionnaires (ie, Pittsburgh Sleep Quality Index—PSQI and Epworth Sleepiness Scale—ESS). The Rivermead Post-Concussion Symptoms Questionnaire, demographic data and additional clinical information were also collected (eg, number of concussions, concussion management, treatments).

Results

Out of 230 participants who started the survey, 89 (39%) completed it and their answers were analyzed. A total of 59/89 (66%) respondents were women. Sixty-one percent of respondents had a PSQI above 5 and 33% an ESS above 10, corresponding to the presence of sleep disturbances and daytime sleepiness. Fifty-eight percent of respondents reported 1 concussion, 24% reported 2, 11% reported 3, and 7% reported more than 3 concussions; 17% had their (last) concussion less than a year ago and 83% between 1 and 5 years. The main postconcussion symptoms were sleep disturbances (61%), troubles to stay focused (54%), light sensitivity (48%), irritability (47%), headaches (42%), and memory impairments (42%). Fifty-seven percent received pharmacological treatments and 25% received nonpharmacological interventions (eg, neuropsychology) following their concussion.

Conclusion

These preliminary data highlight a majority proportion of self-reported sleep disturbances in concussed patients. Prospective longitudinal studies should be conducted to confirm this finding and optimize patients' management.

Prevention and Management of Sport-Related Concussions: Current Knowledge and Practices Among Eld Stakeholders of the French-Speaking IOC Research Centre (ReFORM)

Martens Géraldine1; Kaux Jean-François1,2; Thibaut Aurore3; Urhausen Axel4; Le Garrec Sébastien5; Tscholl Philippe6; Leclerc Suzanne7

1ReFORM (Réseau Francophone Olympique de Recherche en Médecine du Sport—IOC Research Centre for Prevention of Injury and Protection of Athlete Health), University Hospital of Liège, Liège, Belgium; 2Physical Medicine and Sport Traumatology Department, SportS2, FIFA Medical Centre of Excellence and FIMS Collaborative Centre of Sports Medicine, University Hospital of Liège, Liège, Belgium; 3Coma Science Group & Brain2 Clinic, University and University Hospital of Liège, Liège, Belgium; 4Clinique du sport, Centre Hospitalier de Luxembourg, Luxembourg; Luxembourg Institute of Research in Orthopedics, Sport Medicine and Science, Luxembourg; 5Institut National du Sport, de l'Expertise, et de la Performance (INSEP), Paris, France; 6Department of Orthopaedic Surgery, Geneva University Hospitals, Geneva, Switzerland; 7Institut National du Sport du Quebec (INS Quebec), Montreal, Canada

Background

Sport-related concussions (SRC) impact the practice of numerous athletes. Their appropriate management involves education and prevention among all eld stakeholders including physicians, coaches, and athletes themselves.

Objective

To assess the current state of knowledge and practice regarding SRC (diagnosis, treatment, return to play) within the French-speaking sports community in order to tailor the prevention approaches.

Methods

A multicentric online anonymous survey (∼15 minutes completion time) was sent through mailing lists and social networks to athletes, sports healthcare professionals, and coaches through the ReFORM network. The survey was available for 3 months and monthly reminders were sent. It included between 25 and 33 questions about SRC knowledge, prevention and management practices, and access to educational resources. For the preliminary analysis, the main outcome measures were the reported level of knowledge regarding SRC and the current access to educational resources.

Results

A total of 2072 participants took part in the survey and 1704 finished it (completion rate: 82%). The sample included 48% of athletes, 33% of coaches, and 19% of healthcare professionals. The main countries represented were France (35%), Canada (32%), and Belgium (12%). The preliminary analyses reported an SRC knowledge self- assessment as “good” or “excellent” in 87% of healthcare professionals and 69% of coaches; while more than 40% of athletes rated their knowledge as “poor” or “none.” Only 17% of athletes reported knowing about an SRC education program in their setting against 63% for healthcare professionals and 45% for coaches. Regarding coaches, 54% do not feel having sufficient professional resources to correctly manage an SRC over the return to sports continuum.

Conclusions

There is an inhomogeneous distribution of SRC knowledge across sports stakeholders. This could be partly explained by different levels of access to educational resources and requires tailored interventions.

An Exploration Into Perceived Concussion Management Practices Within a Varsity Athletic Setting

Merilainen Emilie E; King Colin D

Acadia University, Wolfville, Nova Scotia, Canada

Background

Previous research has identified concussion stigma, including underreported and undiagnosed concussions as a major issue in sports medicine. Concussion tools and protocols are continuously being updated, but efficacy is impacted by unique perceptions, behaviors, and attitudes toward concussions. Effective concussion management systems should involve internal investigations of multiple stakeholder groups to explore complex socioecological networks, factors, and problematic areas to help implement fundamental change. Therefore, the purpose of this study was to investigate various attitudes, behaviors, and knowledge about concussions in a single varsity athletics setting.

Methods

Eight collision sport varsity athletes (22 ± 2.14; 4 males, 4 females), 3 collision sport varsity coaches, and 8 student athletic therapists (20.74 ± 0.71; 6 females, 2 males) participated in semistructured individual interviews, which explored the experiences and perceptions of sports-related concussions and concussion management within the varsity setting. A grounded theory methodology was employed to code all data and identify emerging themes.

Results

Regardless of concussion knowledge, factors within the intrapersonal, interpersonal, and cultural networks of athletes were found to negatively affect institutional concussion policies and protocols. Psychological factors and the culture of sport (ie, internal/external pressures, social/academic isolation) were found to negatively affect concussion protocol efficacy. Concussion nondisclosure may be increased because of internalized values such as commitment to sport, mental/physical toughness, and normality of “getting your bell rung.” Participants advocated for increased social, psychological, and academic support during concussion management. Participants proposed that management strategies should directly address dangerous perceptions, attitudes, and behaviors through improved concussion education and increased conversation within all stakeholder groups to help reinforce positive concussion intentions.

Conclusions

The findings from this study identified important factors that positively and negatively impacted concussion culture within a varsity athletics setting. These findings could be used by academics and health professionals within the institution to make meaningful changes to current concussion management.

Premature White Matter Microstructure in Female Children With a History of Concussion

Nishat Eman1,2; Stojanovski Sonja1,2; Scratch Shannon E3–5; Ameis Stephanie H6,7; Wheeler Anne L1,2

1Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; 2Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada; 3Department of Paediatrics, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; 4Rehabilitation Sciences Institute, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; 5Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada; 6Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; 7Cundill Centre for Child and Youth Depression, Margaret and Wallace McCain Centre for Child, Youth and Family Mental Health, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada

Background

Concussions can interfere with development and influence emerging cognitive abilities. Females are more likely to have persistent problems, yet sex-specific effects of concussions on brain microstructure in childhood are not well understood.

Objectives

(1) Investigate sex-specific differences in brain microstructure between children with and with no concussion. (2) Examine relationship between altered brain microstructure and cognition.

Methods

Neurite density (ND) measures from diffusion weighted magnetic resonance imaging were examined in children (9-10 years of age) in the Adolescent Brain Cognitive Development Study with (n = 336) and with no (n = 7368) concussion. (1) Multivariate regression was used to analyze relationships between concussion history, sex, and age in deep and superficial white matter, subcortical structures, and cortex. (2) Principal component analysis was performed on ND and components were examined in relation to performance on attention and processing speed tests and scores on the Child Behaviour Checklist.

Results

All tissue types had higher ND with age reflecting brain maturation. (1) Females with concussion had higher ND in deep (β = .004, P = .027) and superficial white matter (β = .007, P = .001). (2) Higher ND in superficial white matter beneath the frontal and temporal cortices was associated with worse processing speed performance in females with concussion (β = −4.435, P = .024), and better performance in males with concussion (β = 3.974, P = .004).

Conclusion

Higher ND in white matter of female children with a history of concussion may reflect premature maturation of or injury-induced changes in axons and myelin structure with a possible influence on processing speed. These sex-specific effects may contribute to the enhanced vulnerability to persistent symptoms after concussion in females.

Differences in Head Impact Biomechanics Between Playing Positions in Canadian High School Football Players

Pavlovic Nina; Clermont Christian; Cairns Joshua; Williamson Rylen; Emery Carolyn A; Stefanyshyn Darren

Faculty of Kinesiology, University of Calgary, Calgary, Canada Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Canada

Background

Head impact magnitudes and frequencies have been shown to vary among different playing positions in professional football. Linemen typically experience high-frequency, low-magnitude head impacts, whereas speed players experience low-frequency, high-magnitude impacts (Karton et al, 2020). It is unknown whether these same trends are seen in Canadian youth football.

Objectives

The purpose of this study was to compare head impact magnitudes and time between head impacts among positions in Canadian high school football.

Methods

Sixty-eight high school football players participated from 2 teams and were assigned a position pro le: Pro le 1 (quarterback, receiver, defensive back), Pro le 2 (linebacker, running back), and Pro le 3 (linemen). Each player wore an instrumented mouthguard (Prevent Biometrics), which measured peak magnitudes of linear and angular acceleration and velocity for each head impact throughout the season. In total, 2565 impacts were analyzed. A principal component analysis reduced the dimensionality of biomechanical variables, resulting in a PC1 score assigned to every impact. Time between impacts was calculated by subtracting the time stamps of subsequent head impacts within a session. Kruskal-Wallis H tests with post hoc comparisons were used to compare PC1 scores and time between impacts between position pro les.

Results

There were significant differences in PC1 scores and time between impacts among all playing position profiles (P values <.001). Post hoc comparisons determined that PC1 was greatest in Pro le 2, followed by Pro les 1 and 3. The time between impacts was lowest in Pro le 3, followed by Pro les 1 and 2.

Conclusion

The findings are consistent with previous work, in which head impact magnitudes and frequency differ between position pro les. Linemen experienced lower magnitudes but shorter time between impacts compared with the other positions. This study suggests that different players experience different magnitudes and frequencies of head impacts, which is important for monitoring concussion and repetitive head impact exposure.

Acknowledgments

The Sport Injury Prevention Research Centre is one of the International Research Centres for Prevention of Injury and Protection of Athlete Health supported by the International Olympic Committee. The authors acknowledge funding from the National Football League Play Smart Play Safe Program. Dr Emery holds a Canada Research Chair in Concussion.

Effects of Interval Exercise on Commonly Studied Fluid Biomarkers for Sport-Related Concussion

Penner Linden C1,2; Tabor Jason B1,2,4; Burma Joel1–4; Godfrey Heather2,3; Galarneau Jean-Michel1–4; Cooper Jennifer9; Ghodsi Mohammad9; Debert Chantel T2–7; Wellington Cheryl L9; Emery Carolyn A1–8; Smirl Jonathan D1–4

1Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 2Integrated Concussion Research Program, University of Calgary, Calgary, Alberta, Canada; 3Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; 4Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 5O'Brien Institute for Public Health, University of Calgary, Calgary, Alberta, Canada; 6Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 7Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 8McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, Alberta, Canada; 9Djavad Mowafaghian Centre for Brain Health, International Collaboration on Repair Discoveries, School of Biomedical Engineering, Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver, British Columbia, Canada

Background

Interval exercise has shown to elevate concentrations of CNS blood biomarkers for sport-related concussion (SRC). Given exercise is implicit in sport, this association requires further investigation before clinical validation of these biomarkers can be utilized as objective measures for SRC.

Objective

Examine levels of plasma t-tau, neurofilament light, and glial fibrillary acidic protein (GFAP) between varying exercise intensities across serial time points in healthy young adults, considering age, sex, and sleep.

Methods

A randomized-crossover cohort design, 10 healthy participants without concussion history (aged 19-26 years; 7 females, 3 males) completed 3 separate intensity exercise conditions (control, moderate intensity interval training [MIIT], high-intensity interval training [HIIT]). Blood samples were drawn before, during, and after each condition (0, 1, 2, 4, 6, 8, 24, and 48 hours). Plasma was analyzed for t-tau, NFL, and GFAP on SIMOA platform. ActiGraphs measured participant's total sleep (minutes) the night before each condition. Friedman test was used to examine differences in biomarker concentrations across time points by conditions and constrained baseline mixed-effects models to assess the influence of age, sex, and sleep (α = .05).

Results

Compared with control, NFL and GFAP decreased immediately following completion of MIIT (NFL; β = −1.002, 95% confidence interval [CI]: −1.852 to −0.152, P = .021. GFAP; β = −14.750, 95% CI: −27.154 to −2.345, P = .020) and HIIT (NFL; β = −1.414, 95% CI: −2.263 to −0.564, P = .001. GFAP; β = −20.956, 95% CI: −33.358 to −8.554, P = .001). There were no significant effects of age, sex, or sleep time for GFAP (P > .05). More sleep was associated with significant decreases in NFL (β = −.003, 95% CI: −0.005 to −0.001, P = .012); however, age or sex was not (P > .05).

Conclusions

Plasma t-tau appears unaffected by MIIT and HIIT. Short-lived decreases in NFL and GFAP suggest that the influence of exercise should be considered before the clinical validation of acute SRC blood biomarkers. Future studies are warranted to examine the influence of sleep patterns on biomarker concentrations.

Acknowledgments

The Sport Injury Prevention Research Centre is one of the International Research Centres for Prevention of Injury and Protection of Athlete Health, supported by the International Olympic Committee. The authors acknowledge funding from the National Football League Play Smart Play Safe Program for the SHRed Concussions project, as well as funding from the National Sciences and Engineering Research Council (NSERC: RGPIN-2020-04057). C Emery is supported by a Canada Research Chair (Tier 1) in Concussion.

Graded Exposure Therapy for Adults With Persistent Postconcussion Symptoms: A Historical Controlled Trial

Rioux Mathilde1; McKeown Gabriel1; Brasher Penelope2; Yeates Keith Owen3; Vranceanu Ana-Maria4,5; Snell Deborah L6,7; Cairncross Molly1,8; Panenka William J9–11; Debert Chantal T12; Bayley Mark T13; Hunt Cindy14,15; Burke Matthew J5,16,17; Baker Andrew14; Silverberg Noah D1,8

1Department of Psychology, University of British Columbia, Vancouver, British Columbia, Canada; 2Centre for Clinical Epidemiology and Evaluation, Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada; 3Department of Psychology, University of Calgary, Calgary, Alberta, Canada; 4Integrated Brain Health Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital, Boston, Massachusetts, United States; 5Harvard Medical School, Boston, Massachusetts, United States; 6Concussion Clinic, Canterbury District Health Board, Christchurch, New Zealand; 7Department of Orthopedic Surgery and Musculoskeletal Medicine, University of Otago, Dunedin, New Zealand; 8Rehabilitation Research Program, Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada; 9British Columbia Neuropsychiatry Program, Vancouver, British Columbia, Canada; 10BC Mental Health and Substance Use Research Institute, Vancouver, British Columbia, Canada; 11Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada; 12Department of Clinical Neurosciences, Division of Physical Medicine and Rehabilitation, University of Calgary, Calgary, Alberta, Canada; 13Toronto Rehabilitation Institute, University Health Network, Toronto, Ontario, Canada; 14Head Injury Clinic, Trauma and Neurosurgery Program, St. Michael's Hospital, Toronto, Ontario, Canada; 15Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; 16Neuropsychiatry Program, Department of Psychiatry and Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada; 17Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, Ontario, Canada

Background

Excessive avoidance of situations and activities feared to trigger symptom exacerbation is associated with slow recovery from concussion. By targeting fear avoidance behavior, a psychological risk factor, graded exposure therapy (GET) may improve concussion outcomes.

Objectives

To determine whether GET is more effective than usual care at reducing postconcussion symptoms (PCS) and disability following concussion.

Methods

In a historical controlled design, we compared 2 cohorts drawn from independent studies. Only participants with complete outcome data were included. All participants were recruited from the same adult concussion clinics in Greater Vancouver, Canada. Participants receiving GET (N = 30; 63% women) were recruited from 2019 to 2020 (Silverberg et al, 2021). Graded exposure therapy was delivered over 16 videoconference sessions. The comparison group (N = 62; 58% women) was recruited from 2017 to 2018 and received usual care only (Silverberg et al, 2020). Participants rated PCS severity (Rivermead Post Concussion Symptoms Questionnaire; RPQ) and disability (World Health Organization Disability Assessment Schedule; WHODAS 2.0 12-item) twice at clinic intake (median = 2.6 months postinjury) and again median = 2.3 months later.

Results

Mean raw RPQ change was −15.0 (SD = 10.9) for the GET group and −5.3 (SD = 11.5) for the comparison group, standardized mean difference = −0.87 (95% confidence interval [CI] = −1.33 to −0.39). On the WHODAS, mean change was −5.2 (SD = 4.2) Rasch points for the GET group and −3.4 (SD = 5.1) for the comparison group, standardized mean difference = 0.39 (95% CI = −0.83 to 0.08). Repeated-measures analyses of variance to adjust for differences between the 2 cohorts in time since injury and time between assessments yielded similar estimates. There was a main effect of time on the RPQ (P = .006) and WHODAS (P = .017), but the time-by-group interaction was significant only for the RPQ (P < .001).

Conclusions

Postconcussion symptoms improved over time but more so for participants receiving GET compared with usual care. A similar, although weaker, pattern was apparent for disability. This nonrandomized study supports GET as a potentially effective treatment for persistent postconcussion symptoms.

Cognitive Outcomes in Pediatric Mild Traumatic Brain Injuries: Family Matters

Schmidtler Hayley E1; Yeates Keith O1; Beauchamp Miriam2; Craig William3; Doan Quynh4; Zemek Roger5

1University of Calgary (Alberta Children's Hospital), Calgary, Alberta, Canada; 2University of Montreal (Ste Justine Hospital), Montreal, Québec, Canada; 3University of Alberta (Stollery Children's Hospital), Edmonton, Alberta; 4The University of British Columbia (BC Children's Hospital), Vancouver, Canada; 5University of Ottawa (Children's Hospital of Eastern Ontario), Ottawa, Ontario, Canada

Background and Objective

The family environment has previously been proposed to moderate the outcomes of pediatric traumatic brain injury (TBI). Nevertheless, little is known about whether the family environment moderates the outcomes of mild TBI in children. The aim of the current study is to examine whether parent and family functioning moderates postacute cognitive outcomes in children who have experienced a mild TBI versus a comparison group of children with orthopedic injuries (OI).

Methods

The present study draws on data from a longitudinal, prospective cohort study, Advancing Concussion Assessment in Pediatrics (A-CAP). A total of 633 children with mTBI and 334 children with OI between the ages of 8 and 16.99 years were recruited from 5 Canadian emergency departments. Children's cognitive outcomes were assessed using 3 subtests from the CNS Vital Signs to provide measures of reaction time, cognitive flexibility, and visual memory. Parents completed the K6, which measures parent psychological distress, and the General Functioning Scale of the McMaster Family Assessment Device, which measures family functioning.

Results

Analyses of covariance, controlling for age, sex, race, and parent education showed that the mTBI group differed significantly from the OI group on measures of executive functioning (estimated mean difference = −2.56, 95% confidence interval [CI]: −4.89 to −0.23), visual memory (estimated mean difference = −3.38, 95% CI: −5.93 to −0.82), and reaction time (estimated mean difference = −5.35, 95% CI: −8.32 to −2.39) 10 days after injury. Findings did not show significant effects of family environment on children's scores after injury as main effects or as a moderator of group differences.

Conclusion

The findings suggest that though children with mTBI do demonstrate post–acute cognitive deficits, parent and family functioning do not play a role in moderating those deficits. These results will help further clarify the function of family environment as a target of intervention to improve cognitive outcomes following pediatric mTBI.

A Scoping Review on the Magnetic Resonance Modalities Used in Detection of Persistent Postconcussion Symptoms (PPCS) in Pediatric Populations

Sheldrake E1,2; Lam B1; Al-Hakeem H1; Wheeler AL3,4; Goldstein BI5–7; Dunkley BT3,8; Ameis S5,7; Reed N2; Scratch SE1,2,9

1Bloorview Research Institute, Toronto, Ontario, Canada; 2Rehabilitation Sciences Institute, University of Toronto, Toronto, Ontario, Canada; 3Neuroscience and Mental Health Program, Hospital for Sick Children, Toronto, Ontario, Canada; 4Department of Physiology, University of Toronto, Toronto, Ontario, Canada; 5Centre for Addiction and Mental Health, Toronto, Ontario, Canada; 6Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada; 7Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; 8Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; 9Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada

Background

Children and youth are vulnerable to the effects of mild traumatic brain injury, or concussion. Although most youth recover quickly, up to 30% can experience persistent postconcussion symptoms (PPCS) lasting for 4 weeks or longer, which can significantly impact quality of life. Magnetic reasoning imaging (MRI) has the potential to improve concussion detection and management. However, there are no clear preferred modalities to assist in detecting PPCS among children.

Objectives

The objective of this scoping review is to synthesize published findings on utilization of MRI among children and youth with PPCS and to summarize progress and limitations within the eld of concussion detection.

Methods

Thirty-seven studies were included from 4907 identified papers, from 4 databases (Ovid MEDLINE, CINAHL, EMBASE, and PsycINFO).

Results

The charting of studies was organized by modality. Many studies utilized more than 1 MRI modality, including (1) structural MRI (n = 27) such as T1- and T2-weighted imaging, diffusion weighted imaging (DWI), and susceptibility weighted imaging (SWI); (2) functional MRI (BOLD fMRI; n = 23; task-based and resting-state) and perfusion weighted imaging (PWI); and (3) magnetic resonance spectroscopy (MRS; n = 4). Significant findings were heterogeneous among modalities, with some trends favoring fMRI. Across all 37 studies in this review, no brain-based biomarker for PPCS in children was consistently identified, and a small majority utilized whole-brain analysis rather than localized regions of interest.

Conclusions

There remains a lack of consensus on which MRI modalities prove most beneficial when detecting PPCS in pediatric populations, although DWI, fMRI, and MRS appear to be most promising. Future research in this eld would also benefit from the consideration of MRI modalities, which might predict PPCS following concussion, and the integration of sensitive MRI modalities that could supplement a biopsychosocial approach to PPCS.

Acknowledgments

The authors acknowledge the efforts of the members of the NOvEL lab (Bloorview Research Institute), specifically Andrea Hickling, for her support and facilitation of manuscript preparation. The authors also acknowledge Kaitlin Fuller, Education & Liaison Librarian at Gerstein Library (University of Toronto, Faculty of Medicine), for her time, knowledge, and dedication to assisting in search formulation and queries.

Video Analysis Informs High Suspected Concussion and Head Impact Rates in Varsity Female Rugby: An Opportunity for Concussion Prevention

Shill Isla J1,2; West Stephen W1,3; Sutter Bonnie4,5; George Jonathan6; Ainsworth Nicola7–9; Wiley J Preston4,10; Patricios Jon11; Emery Carolyn A1–3,12–14

1Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 2Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 3O'Brien Institute of Public Health, University of Calgary, Calgary, Alberta, Canada; 4University of Calgary Sport Medicine Centre, Faculty of Kinesiology, Calgary, Alberta, Canada; 5Dino's Athletics, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 6Saracens Rugby Football Union, London, England, United Kingdom; 7Rugby Alberta, Alberta, Canada; 8Calgary 1 Rugby Union, Calgary, Alberta, Canada; 9Calgary Canadian Irish Athletic Association, Calgary, Alberta, Canada; 10Department of Family Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 11Wits Sport and Health (WiSH), School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; 12Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; 13Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 14Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada

Background

Video analysis is a valuable tool used in male rugby to identify mechanisms of concussion and tackle characteristics. The female game has not had such evaluations to date.

Objective

To describe the rate of suspected concussion, mechanisms, and head impact type and intensity in varsity female rugby.

Methods

This cross-sectional video analysis study includes 48 women's varsity rugby matches over 3 seasons. A suspected concussion was identified on the basis of combined criteria from 4 tools (ie, World Rugby's Head Injury Assessment protocol, concussion recognition tool 5, World Rugby's concussion guidance document, and the 2019 consensus definitions of video signs of concussion in professional sport), which were content validated by 6 experienced rugby clinicians. Two independent coders assessed head contact type (eg, head-to-player, head-to-ground in close quarters or during an uncontrolled fall) and head impact intensity (4-point Likert scale).

Results

Of 225 suspected injuries (117.5 injuries/1000 match-hours, 95% confidence interval [CI]: 102.6-133.9), 59 (26%) were suspected concussions (30.8/1000 match-hours, 95% CI: 23.5-39.7). Of all players with a suspected concussion, 39% were removed from play. The tackle accounted for 78% of suspected concussions (54% to the ball-carrier, 46% to the tackler). Of these, the most common head impact was direct head-to-player contact (39%). For tacklers, 62% of suspected concussive head impacts were head-to-player. For ball carriers, 44% of concussive head impact mechanisms were unknown and 32% were head to ground during an uncontrolled fall. The median head impact intensity score for an observable head impact resulting in a suspected concussion for both tacklers and ball carriers was 3/4 (moderate to heavy contact with significant head deviation).

Conclusions

Suspected injury and concussion rates in female varsity rugby are high. A greater understanding of concussion mechanisms for female tacklers and ball carriers is needed to inform future prevention interventions including tackle training programs or tackle law changes.

Acknowledgments

The Sport Injury Prevention Research Centre is one of the International Olympic Committee Research Centers for the Prevention of Injury and Protection of Athlete Health. The authors acknowledge the support of the CanWest league as well as the University of Calgary Dinos Athletics for their permission to use these videos for the purpose of informing a safer game.

Examining Cerebellum Volume and Postural Stability After Pediatric Mild Traumatic Brain Injury

Shukla Ayushi1; Ware Ashley L2,3; Goodyear Bradley4–6; Stang Antonia S7; Freedman Stephen B7; Yeates Keith O2,3; Lebel Catherine3,8

1Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 2Department of Psychology, University of Calgary, Calgary, Alberta, Canada; 3Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 4Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, Alberta, Canada; 5Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 6Departments of Radiology and Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada; 7Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada; 8Department of Radiology, University of Calgary, Calgary, Alberta, Canada

Introduction

Postural instability and balance problems are often reported after pediatric mild traumatic brain injury (mTBI). The cerebellum is involved in the regulation of postural control and gait. Yet, no studies have investigated the relation between balance and cerebellar gray matter volumes or differences in cerebellar gray matter volumes in children with mTBI or orthopedic injury (OI) relative to typically developing (TD) children.

Methods

Children (mTBI: n = 65, OI: n = 36, TD: n = 23) aged 8 to 16.99 years (M/SD = 12.96/2.34) were recruited from the emergency department and returned for MRI approximately 9 days postinjury. Voxel-based morphometry provided gray matter volume for 10 cerebellar parcellations; balance was assessed using the Balance Error Scoring System (BESS) for injury groups (mTBI, OI). Univariate analysis of variance and linear regressions were used to examine group differences in gray matter volumes and relations of gray matter volume with BESS, respectively, with age and sex as covariates.

Results

Cerebellar gray matter volume was significantly larger in injury groups than in TD children in lobe I IV and V, vermis crus I and II, and vermis VI and VIIb. Multiple linear regressions revealed significant group by cerebellar gray matter volume interactions in all lobules when examining the relation of cerebellar volume with BESS tandem stance scores. Follow-up revealed that volume of all regions was negatively associated with tandem stance scores in children with mTBI, but there were no significant associations between BESS scores and cerebellar volumes in the OI group.

Discussion

Higher cerebellar gray matter volume in injury groups may reflect a neuroinflammatory response at the post–acute stage of injury. The inverse relation of cerebellar volume with BESS tandem stance in children with mTBI indicates the importance of the cerebellum in postural control and gait, specifically after mTBI. More research regarding the cerebellum could foster diagnostic and prognostic understanding of mTBI.

The Association of Post-Concussive Symptoms and Executive Functioning at 4- and 12-Week Following Pediatric Concussion

Sicard Veronik1; Ledoux Andrée-Anne1,2; Tang Ken1; Yeates Keith Owen3–5; Brooks Brian4,6,7; Anderson Peter1,8; Keightley Michelle9,10; Desire Naddley11; Beauchamp Miriam12,13; Zemek Roger1,14; 5P PERC Neuropsych team

1Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada; 2Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada; 3Department of Psychology, University of Calgary, Calgary, Alberta, Canada; 4Department of Pediatrics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; 5Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 6Department of Psychology, Pediatrics, and Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada; 7Neuropsychological Service, Alberta Children's Hospital, Calgary, Alberta, Canada; 8Behavioral Neurosciences and Consultation-Liaison Program, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada; 9Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada; 10Departments of Occupational Science and Occupational Therapy and Rehabilitation Sciences Institute, University of Toronto, Toronto, Ontario, Canada; 11Department of Psychology, The Hospital for Sick Children, Toronto, Ontario, Canada; 12Department of Psychology, University of Montreal, Montreal, Quebec, Canada; 13Ste-Justine Hospital Research Center, Montreal, Quebec, Canada; 14Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada

Background

One-third of pediatric concussions result in persistent symptoms (physical, somatic, affective, cognitive, behavioral) lasting more than 1 month. Yet, few comprehensive studies have addressed the association between postconcussive symptoms (PCS) and cognitive impairment.

Objectives

(1) To investigate the association of PCS and executive functioning (EF) at 4 and 12 weeks following a pediatric concussion. (2) To investigate the effect of age and sex on the association of PCS and EF.

Methods

The study is a prospective, multicenter cohort study of participants aged 5.00 to 17.99 years with acute concussion presenting to 4 pediatric emergency departments in Canada. Five EF constructs (processing speed, attentional control, working memory, and cognitive flexibility) and symptoms (using the Post-Concussion Symptom Inventory; PCSI) were assessed at 4 weeks and 12 weeks postinjury. Symptoms were defined as the difference between current self-reported PCSI ratings and those from the retrospective ratings (ie, delta score). Linear mixed models were conducted with EF constructs as dependent variables in their separate models (5 total) and PCSI delta score as the main predictor, with age, sex, time, and PCSI × sex as covariates.

Results

A total of 311 children (65.0% males; median age = 11.92 [interquartile range = 9.14-14.21 years]) were included in the analysis. The PCSI delta score was significantly associated with cognitive flexibility (χ2 = 11.40, P = .022), with higher symptoms associated with lower cognitive flexibility scores. The relationship between PCSI and cognitive flexibility did not vary by sex or age. The PCSI was not associated with processing speed (P =. 639), attentional control (P = .417), working memory (P = .089), and inhibition (P = .580).

Conclusions

The findings provide evidence of an association between PCS and cognitive functioning. A better understanding of the cognitive pro le of individuals with prolonged symptom recovery provides an improved standard of care and targeted management strategies. Findings may inform the development of batteries to assess the chronic effects of concussion.

Acceptability, Usability, and Credibility of an Early Mindfulness-Based Intervention Delivered via a Mobile App for Pediatric Concussion

Sicard Veronik1; Brown Olivier1; Butterfield Lauren1; Kardish Rachel1; Healey Katherine1; O'Kane Kiarah2; Choi Esther3; Silverberg Noah2; Smith Andra4; Goldfield Gary1; Zemek Roger1,5; Cairncross Molly*6; Ledoux Andrée-Anne*1,4,7

1Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada; 2Department of Psychology, The University of British Columbia, Vancouver, British Columbia, Canada; 3Vancouver Coastal Health Research Institute, British Columbia, Canada; 4School of Psychology, Faculty of Social Sciences, University of Ottawa, Ottawa, Ontario, Canada; 5Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada; 6Department of Psychology, Simon Fraser University, Burnaby, British Columbia, Canada; 7Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada. * Cosenior authors

Background

The ability to adapt to a pediatric concussion and regulate emotions and stress is important to reduce the risk of prolonged symptoms. Early psychological interventions, such as mindfulness-based interventions (MBIs), might be key to managing concussions.

Objectives

This open-label pilot study assessed the acceptability, usability, and credibility of an MBI delivered through a smartphone app for acute pediatric concussion.

Methods

Participants, aged 12 to 18 years, were recruited from the CHEO Emergency Department within 48 hours of concussion. Participants were required to complete a novel 4-week MBI program (AmDTx app by Mobio Interactive, customized for the present study) for 10 to 15 min/day, minimum 4 d/wk. At 2 weeks postinjury, the participants completed a credibility and expectancy questionnaire. At 4 weeks, the participants completed questionnaires assessing satisfaction, usability, working alliance, and a semistructured phone interview.

Results

Seven of 10 participants (5 females; median [interquartile range (IQR)] age = 14.73 [13.94,16.94] years) completed the study outcomes. The app was considered usable (median = 62.50 [47.50,82.50], maximum possible = 100.00) and treatment was perceived as credible (median = 7.00 [6.33,9.00], maximum possible = 9.00). Participants indicated that they were very satisfied with the app (median = 29.00 [27.00,30.00], maximum possible = 32.00) and developed a good therapeutic working alliance with the mindfulness guides (median = 4.08 [3.75,4.42], maximum possible = 5.00). Four themes were identified from the qualitative data: positive attributes (including accessibility, ease of use, intervention effectiveness, variety of features, meditation guides), negative attributes (technical issues that acted as a barrier to use, and sounds and lights that were triggering headaches for 1 participant), ideas for modifications, and technical issues.

Conclusions

Results have informed us of required modifications to the app, instructions, and intervention, and ways to increase adherence by leveraging the positive attributes. A future randomized controlled trial will assess the effectiveness of the MBI to promote cognitive and neural recovery from pediatric concussion with the goal of decreasing the risk for persistent symptoms.

Impact of Moderate to Vigorous Physical Activity While Symptomatic on Cerebral Perfusion: A PedCARE Substudy

Sicard Veronik1; Healey Katherine1; Fang Zhuo2; Smith Andra2; Abdeen Nishard1; Cron Gregory3; Yeates Keith Owen4–6; Goldfield Gary1; Reed Nick7; Zemek Roger1,8; Ledoux Andrée-Anne1,2,9

1Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada; 2School of Psychology, Faculty of Social Sciences, University of Ottawa, Ottawa, Ontario, Canada; 3Department of Neurology, Stanford University, Stanford, California, United States; 4Department of Psychology, University of Calgary, Calgary, Alberta, Canada; 5Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; 6Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 7Department of Occupational Science & Occupational Therapy, University of Toronto, Toronto, Ontario, Canada; 8Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada; 9Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada

Background

Prolonged rest after a pediatric concussion may lead to increased symptoms and exacerbate cerebrovascular dysregulation. Little is known regarding the association between moderate to vigorous physical activity (MVPA) and brain perfusion after a pediatric concussion.

Objectives

(1) Determine whether brain perfusion is increased at 4 weeks after concussion compared with orthopedic injury (OI). (2) Investigate the association between the amount of MVPA within 2 weeks of a pediatric concussion and brain perfusion at 4 weeks postinjury.

Methods

Children aged 10 to 17.99 years with a concussion or OI were recruited from the emergency department (ED) within 48 hours of injury. Concussion participants wore an accelerometer for 14 consecutive days (24 h/d). Both groups underwent continuous arterial spin labeling magnetic resonance imaging at 4 week postinjury. An analysis of covariance examined the difference in perfusion between concussion and OI groups, adjusting for head motion and global average gray matter perfusion. A general linear model investigated the association between MVPA across the first 2 weeks postinjury and brain perfusion at 4 weeks for the concussion group, covarying for age, sex, head motion, and global average gray matter perfusion.

Results

Seventy children with concussion (median [interquartile range (IQR)] age = 12.70 [11.67,14.35] years, 47.1% females) and 29 with OI (age = 12.05 [11.18,13.77], 41.4% females) were included in this study. The concussion group showed greater perfusion within the left anterior cingulate cortex (ACC; pcluster-FWE = 0.001) and right middle frontal gyrus (rMFG; pcluster-FWE = 0.029) compared with the OI group. Of these, 52 children with a concussion had valid accelerometer data (at least 10 h/d for 4 days) (mean [SD] MVPA = 30.26 [18.41] min/d). Whole-brain analysis revealed a negative association between MVPA and perfusion in the precuneus (pcluster-FDR = 0.046). No associations between MVPA and perfusion in ACC and rMFG were found.

Conclusions

Findings provide evidence for differential brain perfusion profile at 4 weeks postinjury between children with concussion and OI. Increased physical activity might reduce perfusion in regions related to affective response to pain.

Using NeuroTracker to Determine How Concussion Status and Age Affect Perceptual Cognitive Functioning

Snowden Taylor; Skaug Emma; Christie Brian

University of Victoria, Victoria, British Columbia, Canada

Background

Concussion assessment and treatment are challenging for practitioners because of the plethora of symptoms patients can present with and the subjective measures used to diagnose these invisible injuries. NeuroTracker (NT) is a 3-dimensional multiple-object tracking test that objectively quantifies perceptual-cognitive processing and shows promise as an assessment tool for concussions.

Objectives

We aimed to create a set of normalized NT scores based on age, sex, and concussion status that could be used for concussion assessment. Furthermore, we explored whether sex, age, and concussion-related variables can predict NT performance.

Methods

The NT scores were categorized according to sex, concussion status, and age. Normative measures of NT scores were created by calculating Z-scores and analyzed by plotting standard normal curves. Independent mean difference and Hedges' g were used to assess effect sizes. Two-tailed t tests were used to assess the significance of concussion status on NT scores within age groups and sex. Linear and multiple regressions and linear correlation were used to assess the relationship between NT scores and concussion-related variables.

Results

A total of 1251 individuals participated in this study. Medium to large effect sizes were observed between concussed and nonconcussed participants in the following groups: males aged 13 to 24 years and 55 to 64 years and females aged 19 to 24 years and 45 to 54 years. Furthermore, NT scores increase from ages 5 to 18 years, peak between 19 and 34 years, and then decrease with age. King-Devick scores, number of symptoms, symptom severity, and immediate memory had the largest predictive power on NT scores. Approximately 22.42% of the variation in NT scores was accounted for in the multiple regression model.

Conclusions

NeuroTracker is sensitive to the cognitive processing effects of concussion across the life span and shows promise to evaluate the effects of age on cognition. We present a range of NT scores specific to age group, sex, and concussion status that may be useful for detecting concussions.

SHINE a Light on Concussion Awareness: Is There a Need for a Youth Neuroeducation Program?

Snowden Taylor1; Morrison Jamie1,2*; Yanish Madison1*; Mayoh Briar1; Bosdachin Emily1; Skaug Emma1; Bermeo Ian2; Prewett Pam2; Christie Brian1; *These authors contributed equally to this work

1University of Victoria, Victoria, British Columbia, Canada; 2Victoria Brain Injury Society, Victoria, British Columbia, Canada

Background

Approximately 1 in 10 Canadian youth sustained a concussion within the past year. Despite youth experiencing these injuries, it is estimated that 80% of Canadian youth have little to no knowledge about concussions. Engaged education is a promising secondary strategy to prevent concussions in this population.

Objectives

This study aimed to test the efficacy of a concussion education presentation to high school students in the Greater Victoria Area (GVA). Furthermore, this study aimed to classify the program's efficacy in relation to students' grade, gender, history of concussion, and experience with contact sports.

Methods

The SHINE (Student Head Injury Neuro Education) sessions were developed on the basis of the Concussion Awareness Training Tool modules and the Victoria Brain Injury Society pillars. Students (N = 100) from grades 9 to 12 in the GVA were tested on their concussion knowledge before and after the 45-minute interactive SHINE presentation.

Results

At baseline, students scored 19.14 (SD: 3.28) out of 26 on the knowledge quiz. Surprisingly, no student scored 100%, indicating a need for concussion education in this population. There were no significant differences in baseline scores between grade, gender, concussion history, and participation in contact sports. After the education session, the mean score rose to 22.1 (SD: 2.81). A paired samples t test found a significant mean difference of P < 2.2 × 10 to 16 between the pre- and posteducation scores, with a mean difference of 3.02 (95% confidence interval: 2.16-3.83). Grade, gender, history of concussion, and participation in contact sports explained little variability in improvement, indicating that these sessions are practical for a wide range of high school students.

Conclusions

Concussion knowledge among teens in the GVA is lacking. One 45-minute SHINE session improved student knowledge of concussions by 15%. Given the program's efficacy, the Victoria Brain Injury Society aims to educate all students in the GVA about concussions through SHINE.

Acknowledgments

The authors thank the GVA teachers and students, who welcomed them into their classrooms and enthusiastically engaged with SHINE. This project was funded by the Telus Friendly Future Foundation.

Local Network Architecture in Children With Mild TBI

Stojanovski Sonja1; Guberman Guido2; Nishat Eman1,3; Houde Jean-Christophe4; Descoteaux Maxime4,5; Wheeler Anne L1,3

1University of Toronto, Toronto, Ontario, Canada; 2Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada; 3Université de Sherbrooke, Sherbrooke, Quebec, Canada; 4Department of Computer Science, Université de Sherbrooke, Sherbrooke, Quebec, Canada; 5Imeka Solutions Inc, Sherbrooke, Quebec, Canada

Background

Attention problems are common sequelae of concussion in children. Short superficial white matter (SWM) fibers in the brain are particularly vulnerable to concussion in children due to their protracted myelination and location at the gray-white matter interface.

Objective

To describe alterations in the SWM in children with concussion and their impact on network community and attention.

Methods

Children (9-10 years of age) with concussion (N = 324) were matched to children with no concussion (N = 339) from the Adolescent Brain Cognitive Development Study. Particle filtering tractography was applied to multishell diffusion magnetic resonance imaging data to generate matrices weighted by fractional anisotropy (FA), fiber density (AFD), and fiber orientations (NuFO). Superficial white matter was derived via length thresholding (<85 mm), while measures of local community (modularity, mean clustering coefficient [mCC]) were calculated from matrices not thresholded by length. Attention was assessed with the Child Behavior Checklist attention problem scale.

Results

Linear mixed-effects models indicated that children with concussion had more clinically significant attention syndrome scores (P = 4.9 × 10-6). Concussed children had elevated FA (P = 2.0 × 10-16), AFD (P = 4.9 × 10-8), and NuFO (P = 2.3 × 10-16) in SWM and lower modularity (P = 2.0 × 10-16) and mCC (P = 2.0 × 10-16) compared with controls. Interactions between FA (P = .002) and NUFO (P = .03) and age showed that in younger concussed children, lower values were associated with better attention.

Conclusions

Maturation of SWM fibers may be altered by concussion and impair attention.

Determining the Best Practices in Concussion Management for Para Athletes With Vision Impairment: Preliminary Results From a Delphi Study

Teodoro Juliette; Dalton Kristine; Irving Elizabeth

School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada

Background and Objectives

There is a lack of clinical practice guidelines specific to concussion management for para athletes, including athletes with vision impairment (VI). This project aimed to understand how concussion is currently managed in elite para athletes with VI to inform the development of evidence-based best practice guidelines and improve concussion management in para sport.

Methods

The study used the Delphi survey technique, and the second-round survey results are presented here. Data were collected through web-based surveys using REDCap. The survey consisted of 43 Likert-scale statements grouped into 3 topic areas: clinical practice guidelines, experience working with athletes with VI, and future research priorities. Agreement of 80% or greater between experts was defined as consensus.

Results

Seven healthcare professionals with expertise in concussion management of athletes with VI completed the survey. Experts unanimously agreed that preseason baseline testing is necessary for these athletes. Eighty-six percent of experts agreed that apart from adaptations for the athlete's VI, concussion management strategies are similar for athletes with VI and sighted athletes. Consensus was not obtained regarding whether athletes with VI were thought to be underreporting concussion symptoms or had different attitudes to risk than sighted athletes. Validation of existing concussion assessment, management, and return-to-play protocols was highlighted as an important research priority (≥86% consensus). Consensus was not obtained regarding the need to develop new assessment, management, or return-to-play protocols.

Conclusions

Experts consider baseline testing to be important for concussion management in athletes with VI. More research is needed to understand what baseline testing should consist of and how current management strategies are being adapted for athletes with VI. Deeper understanding of how athletes with VI experience concussion is also needed. The third-round Delphi survey will be completed to explore these issues and will include input from athletes with VI and coaches.

Acknowledgments

This study was funded by an internal seed funding grant from the School of Optometry and Vision Science at the University of Waterloo. Juliette Teodoro was also supported by a CGS-M Scholarship from the Social Sciences and Humanities Research Council.

What Is the level of Agreement and the Nature of Disagreements Between the Detection of Suspected Concussions in the Eld and Initial Medical Diagnosis?

Tremblay Amélie1; Goulet Claude2; Schneider Kathryn3–5; Emery Carolyn A3–6; Sick Stacy3; Lun Victor7; Frémont Pierre1

1Department of Rehabilitation, Faculty of Medicine, Université Laval, Québec, Canada; 2Department of Physical Education, Faculty of Education, Université Laval, Québec, Canada; 3Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 4Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 5Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada; 6Departments of Pediatrics and Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 7University of Calgary Sport Medicine Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada

Background

Following the detection of a possible concussion, it is currently recommended to obtain a medical diagnosis. The objectives of this study were (1) to determine the level of agreement between the detection of a suspected concussion and subsequent initial medical diagnosis, and (2) to assess the level of risk associated with situations of disagreement.

Methods

This study is part of the SHRed Concussions project. This preliminary report is based on concussions documented as of February 28, 2022. A Cohen κ was used to determine agreement between the detection of suspected concussion in sport settings and the initial medical diagnosis. For cases in which other diagnoses were identified, the nature and risk of medical complications were described.

Results

Out of 168 cases, 164 concussion diagnoses were confirmed upon initial medical assessment (probability of agreement: 0.976, 95% confidence interval: 0.953-0.999; κ = 0.952). Other diagnoses were identified in 6 cases; 3 were head or neck injury other than concussion (“traumatic neck pain”, “possible whiplash,” and “pressure from helmet”), 2 were concussions with an additional diagnosis (“oculomotor dysfunction” and “query whiplash”), and 1 was a “red flag” (increasing headache), leading to brain imaging. Of these 6 cases, 5 were considered at low risk of complication once concussion management was initiated and 1 presented a higher risk of more severe outcome since brain imaging was required.

Conclusions

A high level of agreement between detection and initial medical diagnosis was observed. Only 1 situation associated with a higher risk of more severe brain injury was found to be related to the terminology of the SCAT5 linking the “red flags” to the notion of “immediate or on-field” assessment. This led us to prompt the review of the “red flags” for all initial assessments following an injury. This incident might inform future modifications to the SCAT5 terminology.

Acknowledgments

The Sport Injury Prevention Research Centre is one of the International Research Centres for Prevention of Injury and Protection of Athlete Health, supported by the International Olympic Committee. The authors acknowledge funding from the National Football League Play Smart Play Safe Program for the SHRed Concussions project. C Emery is supported by a Canada Research Chair (Tier 1) in Concussion.

Effect of Traumatic Brain Injury and Cortical Spreading Depolarization on Mitochondrial Function

van Hameren Gerben1; Aboghazleh Refat1,2; Friedman Alon1–3

1Dalhousie University, Halifax, Canada; 2Al-Balqa Applied University, Al-Salt, Jordan; 3Ben-Gurion University of the Negev, Beer-Sheva, Israel

Background

Despite the potentially devastating consequences of traumatic brain injury (TBI), the neural network changes in the minutes following TBI that could underlie long-term complications are still unclear. Spreading depolarization (SD) is a main electrophysiological event thought to be associated with TBI, which involves a near-complete depolarization of the cell membrane, resulting in temporary suppression of brain activity. Restoration of the ion gradients is energy demanding, thus healthy neurovascular and mitochondrial function is essential to avoid further brain damage.

Objectives

(1) Characterize the electrocorticographical changes in the minutes following TBI. (2) Investigate the effects of SD on the brain vasculature and mitochondria.

Methods

We used a closed head injury rat model to characterize early electrocorticographical changes following TBI in cortex and brain stem. We also triggered spreading depolarizations and measured vascular and mitochondrial morphology and function using a cranial window, fluorescence imaging, oxygen microelectrode recordings, and electron microscopy.

Results

We identified SD and nonspreading depression of activity as the most common electrocorticographical events after TBI. During SD, hemodynamic changes that are characteristic for neurovascular coupling occur, including vasodilation and changes in oxygen levels. Mitochondrial calcium and reactive oxygen species production increase during SD. The mitochondrial and vascular functional changes during SD are linked to structural damage in the days following SD. In addition, ROS levels in the rat cortex are increased and the antioxidant defense is compromised after TBI.

Conclusions

Our results suggest a vulnerable state of the brain after TBI, during which brain damage can be exacerbated and blood-brain barrier permeability increased after additional challenges, such as SD.

Time to Tackle Concussion in Youth Rugby: A Systematic Review Examining Rates, Risk Factors, and Prevention Strategies

West Stephen W1,2; Shill Isla J1,3; Bailey Stuart4; Syrydiuk Reid A1,5; Hayden K. Alix6; Palmer Debbie7,8; Black Amanda M1–3,5; Hagel Brent E1,2,5,12,13; Stokes Keith A9,10; Emery Carolyn A1–3,5,11–13

1Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 2O'Brien Institute of Public Health, University of Calgary, Calgary, Alberta, Canada; 3Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; 4Sport, Exercise and Health Science Research Group, Edinburgh Napier University, Scotland; 5Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; 6Libraries and Cultural Resources, University of Calgary, Calgary, Alberta, Canada; 7Edinburgh Sports Medicine Research Network, Institute for Sport, PE and Health Sciences, University of Edinburgh, Scotland; 8Division of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, Nottingham, United Kingdom; 9Department for Health, University of Bath, Bath, United Kingdom; 10Rugby Football Union, Twickenham, London, United Kingdom; 11Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; 12Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 13Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada

Background

The concussion rate in youth rugby has been described as the highest among youth sports. Identification of concussion risk factors and prevention strategies is a key priority.

Objective

To describe concussion rates, risk factors, and prevention strategies associated with male and female youth rugby union.

Methods

A systematic search of 9 databases included studies written in English with no publication date limitations set (conducted in January 2022). Concussion rates reported were included in meta-analyses using a DerSimonian Laird random effects model. Details of the search strategy and inclusion/exclusion criteria are published (Prospero Ref: CRD42017065645).

Results

Of 64 studies including injury rates, 54 concussion rates were reported. The overall match concussion rates (24-hour time loss) were 6.1/1000 match-hours (95% confidence interval [CI]: 5.0-7.2) in males and 33.9/1000 match-hours (95% CI: 24.1-43.7) in females. The concussion rate was higher (nonsignificantly) in 15- to 18-year-old males (6.8/1000 match-hours [95% CI: 5.2-8.4]) compared with males 12- to 14-year-olds (3.7/1000 match-hours [95% CI: 0.7-38.0]). No age group comparisons could be made in females. Only 1 study examined risk factors for concussion, which demonstrated that U12 players reported a nonstatistically significant higher concussion rate compared with older age groups. Five studies evaluated concussion prevention strategies. The use of headgear was not protective of concussion. The use of mouthguards showed mixed effects on concussion risk. The single study in rugby examining neuromuscular training (NMT) programs demonstrated a statistically significant 59% reduction in concussion in male youth when NMT was completed 3 times per week.

Conclusions

Although there are very few female-specific youth rugby epidemiology studies, this review has uncovered concerningly high concussion rates in female youth rugby. Given the high concussion rates reported in the female game, evaluation of concussion prevention strategies is critical. The NMT programs targeting concussion prevention are promising and require further evaluation. Other targets for prevention may include tackle training, laws, and equipment.

Acknowledgments

The Sport Injury Prevention Research Centre is one of the International Research Centres for Prevention of Injury and Protection of Athlete Health supported by the International Olympic Committee. The authors acknowledge the funding from the O'Brien Institute, Canadian Institutes of Health Research and Hotchkiss Brain Institute for their funding for this study.

Implementation of the Youth Concussion Awareness Network (You-CAN) in Canadian High Schools: School Staff Experiences

Wilson Katherine1; Hickling Andrea1,2; Mallory Kylie2,3; Walker Meaghan2; Reed Nick1–3

1Department of Occupational Science and Occupational Therapy, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; 2Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada; 3Rehabilitation Sciences Institute, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada

Background

Concussion education can improve youth's intended concussion behaviors, which may prevent negative health outcomes, such as prolonged recovery and mental health challenges. The Youth Concussion Awareness Network (You-CAN) has been developed as the first school-based peer-led concussion education program in which high school students teach their peers about concussions with support from school staff.

Objective

To examine the experiences of school staff with the implementation of the You-CAN program within Canadian high schools.

Methods

Semistructured interviews were conducted with 9 high school staff who participated in You-CAN. Interviews took place virtually in June 2020. Interview questions were centered on participants' experience supervising youth leaders in the creation of a concussion awareness campaign for their peers. Transcriptions were coded and analyzed using deductive thematic analysis. Furthermore, deductive sorting was completed using the constructs from the Consolidated Framework of Implementation Research (CFIR).

Results

Two overarching themes were found: (1) impact of culture, and (2) individualized approach to implementation. Impact of culture included participant's shared beliefs surrounding concussion (lack of understanding, invisible injury), newly formed culture within the student group (shared experiences, diversity), and pre-existing school culture (supportive administration, school size). The individualized approach to implementation included the program's adaptability (timing, school needs), implementation supports (simple messaging, videoconferencing), and staff's belief and actions as facilitators for student leadership (open-ended, student driven).

Conclusion

School culture affected program implementation and laid the foundation for program delivery. Participating schools had their own approaches to implementing the program, but the core components were similar and program goals were well known among stakeholders. The strength of the You-CAN intervention was its ability to meet the needs of each school, and staff relied on the flexibility. The school staff played an important role in the ease of implementation and their beliefs and actions influenced the level of student leadership.

Acknowledgments

This work was funded by the Canadian Institutes of Health Research (#153025). The authors acknowledge the support from the “Youth Concussion Awareness Network” (You-CAN) team, the OAK Concussion Lab (University of Toronto), and the Bloorview Research Institute, as well as the participants for their involvement in this research. In addition, this research was undertaken, in part, thanks to funding from the Canada Research Chairs Program.

Comparing the Optometric Management Between Concussed and Nonconcussed Individuals

Yeboah Anne Marie; Dalton Kristine; Irving Elizabeth

University of Waterloo, Waterloo, Ontario, Canada

Background

Worldwide, an estimated 42 million individuals annually experience mild traumatic brain injury or concussion. Many develop visual issues, such as convergence insufficiency, accommodative insufficiency, and refractive changes (Gardner and Yaffe, 2015; Leslie, 2009; Master et al, 2016). Optometrists play a prominent role in managing persistent concussion–associated vision deficits, but there is no optometric standard of care for these injuries.

Objectives

This study examined optometric assessment and management for concussed versus nonconcussed individuals with the aim of informing standard of care development.

Methods

A retrospective health record review was conducted at an academic university optometry clinic. Data were collected from individuals with concussion or persistent concussive symptoms (n = 119) and nonconcussed (n = 119) individuals. The nonconcussed cohort was age and sex matched to the concussed group. Group differences in frequency of vision assessments and management strategies were determined using χ2 tests.

Results

Frequency of vision therapy χ2 (1, N = 238) = 197.72, P < .00001, oculomotor control (fixations, saccades, and pursuits), χ2 (1, N = 238) = 129.82, P < .00001, and vergence assessment, χ2 (1, N = 238) = 106.97, P < .00001 were more common in the concussed cohort. Structural assessments, including posterior segment, χ2 (1, N = 238) = 157.05, P < .00001, anterior segment, χ2 (1, N = 238) = 129.82, P < .00001, and confrontation visual eld, χ2 (1, N = 238) = 89.93, P < .00001 were more commonly conducted in the nonconcussed group. All nonconcussed participants and 39% of concussed individuals had full eye examinations at the academic clinic. The remaining 61% of concussed individuals were referred from external clinics that did not always specify all tests conducted likely accounting for the differences in structural assessment frequency.

Conclusions

Concussed and nonconcussed individuals were assessed and managed differently. Functional assessments and treatment were prioritized in concussed individuals while structural assessments were more common in the nonconcussed individuals. The differences highlight the need for an optometric standard of care for individuals with concussion.

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