BACKGROUND: Symptoms reported by patients who sustain a concussion are non-specific. As such, clinicians are better able to manage patients when a standardized clinical exam is performed to sub-type the driver(s) of symptoms. Aerobic exercise and multimodal rehabilitation have consistently shown to be a possibly effective means to manage this population; however, the optimal training prescription is unclear. Thus, there is a need to further examine the effectiveness of personalized rehabilitative treatments. Our primary aim is to evaluate the response to personalized therapy on recovery, as measured by The Rivermead Post-concussion Symptoms Questionnaire (RPQ) when compared to an active control.
METHODS: We will conduct a multi-center 12-week case-crossover randomized controlled trial. 50 participants will be recruited from out-patient University Health Network clinics and community-based clinical practices around the greater Toronto area. Participants will be randomized at baseline to Group A: a personalized care program followed by an active control or Group B: an active control followed by a personalized care program. Participants will be included should they be 21 years of age and older and have symptoms that have persisted beyond 4 weeks but less than 1 year. Participants will undergo 6-weeks of care in their respective streams. After 6-weeks, participants will undergo a re-examination. They will then crossover and undertake the alternative treatment for 6 weeks. At the end of 12 weeks, participants will undertake the endpoint examinations. The primary outcome will be the Rivermead Postconcussion Questionnaire (RPQ). The secondary outcomes will be changes in standardized clinical examination, Neck Disability Index (NDI), Patient Health Questionnaire (PHQ-9) and an electroencephalography (EEG) via NeuroCatch™. The statistical analysis to be performed is composed of an adjusted model using an analysis of variance, specifically using an unpaired t-test to test for associations between variables and outcomes.
CONCLUSIONS: Given the recommendations from reviews on the topic of rehabilitation for adults with persistent concussion symptoms, we are undertaking a controlled trial. The documented high costs for patients seeking care for persistent symptoms necessitate the need to evaluate the effectiveness of a personalized rehabilitative program compared to the current standard of care.
BACKGROUND: ClinicalTrials.gov ID: NCT06069700.

OBJECTIVE: Postconcussive symptom questionnaires (PCSQs) are often used in concussion patient assessment, yet there is a lack of knowledge as to whether symptom subtype prevalence is dependent on the mechanism of injury (MOI). These subtypes can be defined as cognitive, atlanto-occipital/cervical spine, autonomic, balance, low energy/fatigue/sleep, emotional changes, eyes, and somatic. Using an institutional PCSQ that quantitatively addressed these subtypes, this retrospective study aimed to provide insight into differences in subtype symptomatology between sports-related (SR) and non-sports-related (NSR) injuries.
METHODS: Consecutive concussion patients with Glasgow Coma Scale (GCS) score ≥ 13 and ≥ 16 years of age who were treated at a concussion clinic affiliated with an academic level I trauma center in the United States between December 2009 and January 2020 were eligible for inclusion. The authors extracted data on MOI, comorbidities, habits, prior injuries, and PCSQ results. Multivariate analysis of covariance was then conducted to determine the correlations between subtype scores and MOI while considering covariates.
RESULTS: Of the 194 patients remaining after applying inclusion and exclusion criteria, analysis included 91 patients in the SR group consisting of 54 (59%) males with mean ± SD (range) age of 20.9 ± 7.3 (16-58) years and 103 patients in the NSR group consisting of 38 (37%) males with mean age of 39.2 ± 14.8 (17-71) years. Demographic characteristics differed significantly between groups. Estimated marginal mean scores were significantly lower in the SR injury group compared to the NSR injury group (with comparing main effects) for the cognitive (p < 0.001), autonomic (p < 0.000), balance (p < 0.025), energy (p < 0.006), emotional (p < 0.000), and total score (p < 0.001) subtypes. Multivariate tests identified three comorbidities that contributed to differences in subtype scores between groups: migraines (p < 0.012), vertigo (p < 0.004), and anxiety (p < 0.038). No significant results were found for the remaining comorbidities of (but not limited to) depression, neuropsychiatric disorders, seizures, syncope, sleep disorder, or none.
CONCLUSIONS: The findings indicate that patients who sustain a concussion via an NSR injury present with more severe symptoms but similar concussion subtype frequency as those presenting with SR concussion. This suggests that the MOI may correlate more closely to symptom severity than concussion subtype composition, although larger patient populations with more definitive control of MOI are needed to further elucidate these claims.

OBJECTIVE: This study aimed to determine the validity of quantitative pupillometry to predict the length of time for return to full activity/duty after a mild traumatic brain injury (mTBI) in a cohort of injured cadets at West Point.
METHODS: Each subject received baseline (T0) quantitative pupillometry, in addition to evaluation with the Balance Error Scoring System (BESS), Standardized Assessment of Concussion (SAC), and Sport Concussion Assessment Tool 5th Edition Symptom Survey (SCAT5). Repeat assessments using the same parameters were conducted within 48 hours of injury (T1), at the beginning of progressive return to activity (T2), and at the completion of progressive return to activity protocols (T3). Pupillary metrics were compared on the basis of length of time to return to full play/duty and the clinical scores.
RESULTS: The authors\' statistical analyses found correlations between pupillometry measures at T1, including end-initial diameter and maximum constriction velocity, with larger change and faster constriction predicting earlier return to play. There was also an association with maximum constriction velocity at baseline (T0), predicting faster return to play.
CONCLUSIONS: The authors conclude that that pupillometry may be a valuable tool for assessing time to return to duty from mTBI by providing a measure of baseline resiliency to mTBI and/or autonomic dysfunction in the acute phase after mTBI.

OBJECTIVE: Epidemiology provides fundamental opportunities to protect student-athlete health. The goal of this study was to describe the epidemiology of sport-related concussion (SRC) across 8 years (2015/2016-2022/2023) and compare boys\' and girls\' sports for SRC incidence and SRC mechanisms.
METHODS: This was a retrospective cohort study performed using a statewide high school head injury surveillance system of high school student-athletes (n = 2,182,128; boys, n = 1,267,389; girls, n = 914,739). Exposures of interest included study year and boys and girls in comparable sports. Clinical incidence was calculated by dividing SRC counts in each sport by the number of participants per 100 player-seasons and presented with 95% CIs. The 2019/2020 and 2020/2021 data were included in the analysis, however caution is warranted due to the COVID-19 pandemic. Clinical incidence ratios (CIRs) were estimated for sex-comparable sports, and significance was determined if 95% CIs excluded 1.00. The authors compared mechanism of injury in boys\' and girls\' comparable sports with chi-square analyses (p < 0.05).
RESULTS: Among 25,482 total SRCs, the overall clinical incidence of SRC for all boys and girls was 1.17 (95% CI 1.15-1.18) per 100 player-seasons across all years. Across all years, the overall clinical incidence in boys\' sports was 1.34 (95% CI 1.32-1.36) per 100 player-seasons, and 0.93 (95% CI 0.91-0.95) per 100 player-seasons in girls\' sports. Boys\' sports with the highest clinical incidence included football, ice hockey, and wrestling. Girls\' sports with the highest clinical incidence included basketball, soccer, lacrosse, competitive cheer, and gymnastics. Girls consistently had higher SRC rates relative to boys for baseball/softball, basketball, and soccer (CIR range 1.65 [95% CI 1.41-1.93] to 3.32 [95% CI 2.67-4.16]). Girls had lower SRC in lacrosse in 2015/2016 (CIR 0.63, 95% CI 0.40-0.97); no difference in 2016/2017-2020/2021, but had higher clinical incidence in 2021/2022 (CIR 1.69, 95% CI 1.18-2.44) relative to boys. In boys the most common mechanism of SRC occurred from person-to-person contact (n = 8752, 62.8%), whereas girls commonly sustained SRC from person-to-object contact (n = 2369, 33.4%) and from person-to-person contact (n = 2368, 33.4%). There were significant associations between boys\' versus girls\' sports and mechanism of injury within baseball/softball (χ2 = 12.71, p = 0.005); basketball (χ2 = 36.47, p < 0.001); lacrosse (χ2 = 185.15, p < 0.001); and soccer (χ2 = 122.70, p < 0.001).
CONCLUSIONS: These findings can help understand the potential impact of interventions aimed at preventing or reducing SRC. Including girls\' sports within this study extends research for a largely underrepresented group.

Background: Understanding the behavioral and neural underpinnings of the post-concussion recovery of working memory function is critically important for improving clinical outcomes and adequately planning return-to-activity decisions. Previous studies provided inconsistent results due to small sample sizes and the use of a mixed population of participants who were at different post-injury time points. We aimed to examine working memory recovery during the first 6 months post-concussion in adolescents. Methods: We used functional magnetic resonance imaging (fMRI) to scan 45 concussed adolescents [CONCs] at baseline (<10 days post-concussion) and at 6 months post-concussion. Healthy control adolescents [HCs; n = 32] without a history of concussion were scanned once. During the scans, participants performed one-back and two-back working memory tasks with letters as the stimuli and angry, happy, neutral, and sad faces as distractors. Results: All affected adolescents were asymptomatic and cleared to return to activity 6 months after concussion. Working memory recovery was associated with faster and more accurate responses at 6 months vs. baseline (p-values < 0.05). It was also characterized by significant difficulty-related activation increases in the left inferior frontal gyrus (LIFG) and the left orbitofrontal cortex (LOFC) at 6 months vs. baseline. Although the activation differences between one-back and two-back were comparable between HCs and CONCs at 6 months, HCs had more pronounced activation in the LIFG than concussed adolescents. Conclusions: Post-concussion recovery is associated with significant performance improvements in speed and accuracy, as well as the normalization of brain responses in the LIFG and LOFC during the n-back task. The observed patterns of LOFC activation might reflect compensatory strategies to distribute neural processing and reduce neural fatigue post-concussion.

UNASSIGNED: Treatment for post-traumatic greater occipital neuralgia (GON) includes serial injections of steroid/anesthetic. While these injections can alleviate pain, effects can be transient, frequently lasting only 1 month. As a potential alternative, platelet-rich plasma (PRP) injections are an emerging biological treatment with beneficial effects in peripheral nerve disorders. We investigated the feasibility, safety, and effectiveness of a single PRP injection for post-traumatic GON in comparison to saline or steroid/anesthetic injection.
UNASSIGNED: In this pilot randomized, double-blinded, placebo-controlled trial, 32 adults with post-traumatic GON were allocated 1:1:1 to receive a single ultrasound-guided injection of (1) autologous PRP (2) steroid/anesthetic or (3) normal saline. Our primary outcome was feasibility (recruitment, attendance, retention) and safety (adverse events). Exploratory measures included headache intensity and frequency (daily headache diaries) and additional questionnaires (headache impact, and quality of life) assessed at pre-injection, 1 week, 1 month, and 3 months post-injection.
UNASSIGNED: We screened 67 individuals, 55% were eligible and 95% of those participated. Over 80% of daily headache diaries were completed with 91% of participants completing the 3-month outcome questionnaires. No serious adverse events were reported. There were no significant differences between groups for headache intensity or frequency. Headache impact on function test-6 scores improved at 3 month in the PRP (β = -9.7, 95% CI [-15.6, -3.74], p = 0.002) and saline (β = -6.7 [-12.7, -0.57], p = 0.033) groups but not steroid/anesthetic group (p = 0.135).
UNASSIGNED: PRP is a feasible and safe method for treating post-traumatic GON with comparable results to saline and steroid/anaesthetic. Further trials with larger sample sizes are required.Clinical trial registration:https://clinicaltrials.gov/, identifier NCT04051203.

BACKGROUND: Recent scientific evidence has challenged the traditional \"rest-is-best\" approach for concussion management. It is now thought that \"exercise-is-medicine\" for concussion, owing to dozens of studies which demonstrate that sub-maximal, graded aerobic exercise can reduce symptom burden and time to symptom resolution. However, the primary neuropathology of concussion is altered functional brain activity. To date, no studies have examined the effects of sub-maximal aerobic exercise on resting state functional brain activity in pediatric concussion. In addition, although exercise is now more widely prescribed following concussion, its cardiopulmonary response is not yet well understood in this population. Our study has two main goals. The first is to understand whether there are exercise-induced resting state functional brain activity differences in children with concussion vs. healthy controls. The second is to profile the physiological response to exercise and understand whether it differs between groups.
METHODS: We will perform a single-center, controlled, prospective cohort study of pediatric concussion at a large, urban children\'s hospital and academic center. Children with sport-related concussion (aged 12-17 years) will be recruited within 4-weeks of injury by our clinical study team members. Key inclusion criteria include: medical clearance to exercise, no prior concussion or neurological history, and no implants that would preclude MRI. Age- and sex-matched healthy controls will be required to meet the same inclusion criteria and will be recruited through the community. The study will be performed over two visits separated by 24-48 h. Visit 1 involves exercise testing (following the current clinical standard for concussion) and breath-by-breath gas collection using a metabolic cart. Visit 2 involves two functional MRI (fMRI) scans interspersed by 10-minutes of treadmill walking at an intensity calibrated to Visit 1 findings. To address sub-objectives, all participants will be asked to self-report symptoms daily and wear a waist-worn tri-axial accelerometer for 28-days after Visit 2.
CONCLUSIONS: Our study will advance the growing exercise-concussion field by helping us understand whether exercise impacts outcomes beyond symptoms in pediatric concussion. We will also be able to profile the cardiopulmonary response to exercise, which may allow for further understanding (and eventual optimization) of exercise in concussion management.
BACKGROUND: Not applicable.

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

OBJECTIVE: Describe head acceleration events (HAEs) experienced by professional male rugby union players during tackle, ball-carry, and ruck events using instrumented mouthguards (iMGs).
METHODS: Prospective observational cohort.
METHODS: Players competing in the 2023 Currie Cup (141 players) and Super Rugby (66 players) seasons wore iMGs. The iMG-recorded peak linear acceleration (PLA) and peak angular acceleration (PAA) were used as in vivo HAE approximations and linked to contact-event data captured using video analysis. Using the maximum PLA and PAA per contact event (HAEmax), ordinal mixed-effects regression models estimated the probabilities of HAEmax magnitude ranges occurring, while accounting for the multilevel data structure.
RESULTS: As HAEmax magnitude increased the probability of occurrence decreased. The probability of a HAEmax ≥15g was 0.461 (0.435-0.488) (approximately 1 in every 2) and ≥45g was 0.031 (0.025-0.037) (1 in every 32) during ball carries. The probability of a HAEmax >15g was 0.381 (0.360-0.404) (1 in every 3) and >45g 0.019 (0.015-0.023) (1 in every 53) during tackles. The probability of higher magnitude HAEmax occurring was greatest during ball carries, followed by tackles, defensive rucks and attacking rucks, with some ruck types having similar profiles to tackles and ball carries. No clear differences between positions were observed.
CONCLUSIONS: Higher magnitude HAEmax were relatively infrequent in professional men\'s rugby union players. Contact events appear different, but no differences were found between positions. The occurrence of HAEmax was associated with roles players performed within contact events, not their actual playing position. Defending rucks may warrant greater consideration in injury prevention research.

BACKGROUND: Sustaining multiple concussions over one\'s lifetime may be associated with behavioral and mood changes beyond the acute phase of injury. The present cross-sectional study examined the relationship between concussion history, the incidence of current moderate-severe psychological distress, and lifetime adolescent hazardous gambling in high school students.
METHODS: Four-hundred fifty-nine high school students from southern Sweden (age: 16.81 ± 0.83, 58.2% male) completed a survey assessing concussion history (0,1,2…>8), psychological distress using the Kessler-6 scale, and lifetime hazardous gambling using the NODS-CLiP scale.
RESULTS: Participants who self-reported three or more concussions were more likely to endorse moderate-severe symptoms of psychological distress than those with no concussion history while controlling for covariates, OR = 2.71, 95% CI [1.19, 6.18]. In contrast, concussion history was not associated with hazardous gambling after controlling for confounding variables.
CONCLUSIONS: Self-reporting three or more concussions was associated with increased current psychological distress beyond the acute phase of injury among high school students. Adolescents who have sustained multiple concussions should undergo mental health evaluations beyond the acute phase of injury to identify and treat psychological distress, but probing for hazardous gambling may not be clinically relevant in this previously concussed adolescent population.