Concussion recovery time among high school and collegiate athletes: a systematic review and meta-analysis

Preparticipation Sports Physical Evaluation in Adolescents

The purpose of the preparticipation physical evaluation (PPE) is to promote safe participation in sport and to restrict participation only when necessary for the safety of the athlete. Based on expert opinion, this tool is considered standard of care. Six stakeholder professional societies collaboratively published the Preparticipation Physical Evaluation Monograph to guide a more useful experience for both examiners and athletes. The PPE uses systems-based history-taking and physical examinations to determine medical eligibility for participation in sport.

Impact of Sex and Pubertal Development on Anxiety in Adolescents After Concussion

Concussion often results in psychological symptoms, including anxiety. Post-concussion anxiety has been well documented, although much of this research has focused on collegiate athletes. The purpose of this study was to compare (1) anxiety symptoms in concussed and healthy controls over time and (2) to explore sex differences in post-concussion anxiety within the context of pubertal development. Participants (N = 126, mean age = 15.1 years old), including concussed (n = 86) and healthy adolescents (n = 40), completed the Pubertal Development Scale (PDS) and the Screen for Child Anxiety and Related Disorders (SCARED-C). The concussed groups completed SCARED-C at three visits (<10 days, 4 weeks, 3 months). Results of an analysis of covariance (ANCOVA) and multi-variate analysis of covariance (MANCOVA) found concussed adolescents reported higher SCARED-C total, generalized, and panic anxiety scores than healthy controls, after controlling for sex, age, and PDS score (PDSS). A three-way mixed ANCOVA examined the effects of sex, PDSS, time, and their interaction on SCARED-C total score in concussed adolescents while controlling for age. There was a significant three-way interaction between sex, age, and PDSS on SCARED-C total score while controlling for age. Overall, we observed increased anxiety in concussed adolescents, compared with controls, as well as greater post-concussion anxiety reported by females compared with males, including within PDSS groups. Concussion providers should be prepared to receive training to administer well-validated measures of psychopathology and should consider that female adolescents, compared with males, regardless of pubertal development, may be at greater risk for post-concussion anxiety.

Assessing Mild Traumatic Brain Injury-Associated Blood-Brain Barrier (BBB) Damage and Restoration Using Late-Phase Perfusion Analysis by 3D ASL MRI: Implications for Predicting Progressive Brain Injury in a Focused Review

Mild traumatic brain injury (mTBI) is a common occurrence around the world, associated with a variety of blunt force and torsion injuries affecting all age groups. Most never reach medical attention, and the identification of acute injury and later clearance to return to usual activities is relegated to clinical evaluation-particularly in sports injuries. Advanced structural imaging is rarely performed due to the usual absence of associated acute anatomic/hemorrhagic changes. This review targets physiologic imaging techniques available to identify subtle blood-brain barrier dysfunction and white matter tract shear injury and their association with chronic traumatic encephalopathy. These techniques provide needed objective measures to assure recovery from injury in those patients with persistent cognitive/emotional symptoms and in the face of repetitive mTBI.

American Headache Society white paper on treatment of post-traumatic headache from concussion in youth

OBJECTIVE

To provide healthcare professionals guidance on youth at risk for prolonged recovery and post-traumatic headache (PTH), and on pharmacologic and non-pharmacologic management of PTH due to concussion and mild traumatic brain injury.

BACKGROUND

Headache is the most common persistent post-concussive symptom affecting 8% of youth for >3 months after concussion. Over the past decade, many studies have explored the treatment of PTH in youth, but there are no established guidelines.

METHODS

This white paper is based on a synthesis of an updated systematic review of the literature on treatment of PTH and a narrative review of the literature on risk factors for prolonged recovery and health disparities. Results were interpreted by a group of expert providers in PTH in children and adolescents through collaboration of the PTH and pediatric special interest groups of the American Headache Society.

RESULTS

Factors that consistently were associated with prolonged recovery from concussion and persistent PTH included female sex, a high number of acute symptoms, and adolescent age. Social determinants of health also likely play an important role in PTH and deserve consideration in the clinical and research settings. A total of 33 studies met the criteria for inclusion in the systematic review of PTH treatment in youth, although most were retrospective and of fair-to-poor quality. Treatment strategies included acute and preventive pharmacologic management, procedures, neuro-modulatory devices, physical therapy, physical activity, and behavioral health support. A collaborative care approach that includes a thoughtful combination of these management strategies is likely most effective.

CONCLUSIONS

This white paper provides a roadmap for tailoring the treatment of PTH based on factors influencing prolonged headache, the timing of therapies, and therapies with the most evidence for treating PTH in youth. We also highlight research needed for developing more definitive guidelines on PTH management in youth.

HISTOLOGICAL COMPARISON OF REPEATED MILD WEIGHT DROP AND LATERAL FLUID PERCUSSION INJURY MODELS OF TRAUMATIC BRAIN INJURY IN FEMALE AND MALE RATS

ABSTRACT

In preclinical traumatic brain injury (TBI) research, the animal model should be selected based on the research question and outcome measures of interest. Direct side-by-side comparisons of different injury models are essential for informing such decisions. Here, we used immunohistochemistry to compare the outcomes from two common models of TBI, lateral fluid percussion (LFP) and repeated mild weight drop (rmWD) in adult female and male Wistar rats. Specifically, we measured the effects of LFP and rmWD on markers of cerebrovascular and tight junction disruption, neuroinflammation, mature neurons, and perineuronal nets in the cortical site of injury, cortex adjacent to injury, dentate gyrus, and the CA 2/3 area of the hippocampus. Animals were randomized into the LFP or rmWD group. On day 1, the LFP group received a craniotomy, and on day 4, injury (or sham procedure; randomly assigned). The rmWD animals underwent either injury or isoflurane only (randomly assigned) on each of those 4 days. Seven days after injury, brains were harvested for analysis. Overall, our observations revealed that the most significant disruptions were evident in response to LFP, followed by craniotomy only, whereas rmWD animals showed the least residual changes compared with isoflurane-only controls, supporting consideration of rmWD as a mild injury. LFP led to longer-lasting disruptions, perhaps more representative of moderate TBI. We also report that craniotomy and LFP produced greater disruptions in females relative to males. These findings will assist the field in the selection of animal models based on target severity of postinjury outcomes and support the inclusion of both sexes and appropriate control groups.

Identifying the Cerebral Physiologic Response to Aerobic Exercise Following Concussion: A Scoping Review

OBJECTIVE

The purpose of this study was to identify the cerebral physiologic response to aerobic exercise in individuals with a symptomatic concussion, highlighting available knowledge and knowledge gaps in the literature.

DESIGN

A systematic scoping review was conducted and reported in keeping with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews. A search of EMBASE, MEDLINE, SCOPUS, BIOSIS, and Cochrane libraries was conducted on June 15, 2023 (from database inception). An online systematic/scoping review management system was used to remove duplicates, and the remaining articles were screened for inclusion by 2 researchers. Inclusion criteria required articles to be original research published in peer-reviewed journals. Additionally, studies were required to have an aerobic exercise component, include a measure of cerebral physiology during a bout of aerobic exercise, exclude moderate and/or severe traumatic brain injury (TBI) populations, and be in the English language. Both human and animal studies were included, with participants of any age who were diagnosed with a mild TBI/concussion only (ie, Glasgow Coma Scale score ≥ 13). Studies could be of any design as long as a measure of cerebral physiologic response to a bout of aerobic exercise was included.

RESULTS

The search resulted in 1773 articles to be screened and data from 3 eligible studies were extracted.

CONCLUSIONS

There are currently too few studies investigating the cerebral physiologic response to aerobic exercise following concussion or mild TBI to draw definitive conclusions. Further research on this topic is necessary since understanding the cerebral physiologic response to aerobic exercise in the concussion and mild TBI populations could assist in optimizing exercise-based treatment prescription and identifying other targeted therapies.

A controlled early-exercise rehabilitation program commencing within 48 hours of a Sports-Related Concussion improves recovery in UK student-athletes: A prospective cohort study

OBJECTIVES

Explore if implementing an individualised Sub-Symptom Heart Rate Threshold (SSHeRT) rehabilitation program within 48 hours versus physical rest for 14 days affects recovery following SRC in university-aged student-athletes.

DESIGN

Prospective, observational cohort study.

METHODS

Two UK university-aged student-athlete rugby union cohorts were compared (Physical Rest Group (PRG), n = 140, July 2019-March 2020 and Controlled Early-Exercise Group (CEG), n = 167, July 2021-April 2023). Both groups completed the test battery (Post-Concussion Symptom Scale (PCSS), Immediate Post-Concussion and Cognitive Test (ImPACT), Vestibular-Ocular Motor Screening Tool (VOMS)) during pre-season to provide a baseline and within 48 hours, at 4, 8, 14-days post-SRC and at Return to Play (RTP). The PRG (n = 42) physically rested for 14 days as per the nationwide community guidelines. The CEG (n = 52) followed the SSHeRT rehabilitation program. Individual change to baseline was used in all analyses.

RESULTS

The CEG performed better on ImPACT's verbal memory at 4 (PRG; -5.5 (-10.8-0.0), CEG; 1.0 (-2.0-10.5), p = 0.05) and 14 days (PRG; -2.0 (-10.0-3.0), CEG; 4.0 (-1.0-11.0), p = 0.05) and on the VOMS at 4 (PRG; 3.0 (0.0-12.0), CEG; 0.0 (0.0-5.0), p = 0.03, OR; 2.910) and 14-days post-SRC (PRG; 0.0 (0.0-1.0), CEG; 0.0 (0.0-0.0), OR; 5.914). Near point convergence was better at all time points for the CEG. The CEG was 26.7 % more likely to have RTP within 30 days, and 6.7 and 5.1 times more likely to have resumed non-contact and contact academic activities by 4 days.

CONCLUSIONS

SSHeRT is safe, can be used within 48 hours of a SRC and may hasten university-aged student-athletes recovery following an SRC.

Association of Auditory Interference and Ocular-Motor Response with Subconcussive Head Impacts in Adolescent Football Players

The aim of this study was to examine whether neuro-ophthalmological function, as assessed by the King-Devick test (KDT), alters during a high school football season and to explore the role of auditory interference on the sensitivity of KDT. During the 2021 and 2022 high school football seasons, football players' neuro-ophthalmological function was assessed at five time points (preseason, three in-season, postseason), whereas control athletes were assessed at preseason and postseason. Two-hundred ten football players and 80 control athletes participated in the study. The year 1 cohort (n = 94 football, n = 10 control) was tested with a conventional KDT, whereas the year 2 cohort (n = 116 football, n = 70 control) was tested with KDT while listening to loud traffic sounds to induce auditory interference. There were improvements in KDT during a season among football players, regardless of conventional KDT (preseason 53.4 ± 9.3 vs. postseason 46.4 ± 8.5 sec; β = -1.7, SE = 0.12, p < 0.01) or KDT with auditory interference (preseason 52.3 ± 11.5 vs. postseason 45.1 ± 9.5 sec; β = -1.7, SE = 0.11, p < 0.001). The degree of improvement was similar between the tests, with no significant group-by-time interaction (β = -0.08, SE = 0.17, p = 0.65). The control athletes also improved KDT performance at a similar degree as the football cohorts in both KDT conditions. Our data suggest that KDT performance improves during a season, regardless of auditory interference or head impact exposure. KDT performance was not impacted by a noisy environment, supporting its sideline utility for screening more severe forms of injury.

Factors Associated with Symptom Resolution after Aerobic Exercise Intervention in Adolescent and Young Adults with Concussion

BACKGROUND

Aerobic exercise facilitates postconcussion symptom resolution at the group level, but patient-level characteristics may affect the likelihood of treatment efficacy.

PURPOSE

This study aimed to investigate demographic and clinical characteristics, which differentiate postconcussion aerobic exercise treatment efficacy from nonefficacy in the intervention arm of a randomized clinical trial.

METHODS

Adolescent and young adult participants initiated a standardized aerobic exercise intervention within 14 d of concussion, consisting of self-selected exercise for 100 min·wk -1 at an individualized heart rate (80% of heart rate induced symptom exacerbation during graded exercise testing). Treatment efficacy was defined as symptom resolution within 28-d postconcussion. Treatment efficacy and nonefficacy groups were compared on demographics, clinical characteristics, intervention adherence, and persistent symptom risk using the Predicting Persistent Postconcussive Problems in Pediatrics (5P) clinical risk score.

RESULTS

A total of 27 participants (16.1 ± 2.3 yr old; range, 11-21 yr; 52% female) began the intervention, with a mean of 9.5 ± 3.7 d after concussion; half ( n = 13; 48%) demonstrated treatment efficacy (symptom resolution within 28 d postconcussion). Those whose symptoms resolved within 28 d had significantly lower preintervention postconcussion symptom inventory scores (21.2 ± 13.2 vs 41.4 ± 22.2; P < 0.01), greater adherence to the intervention (77% vs 36%; P = 0.05), and longer average exercise duration (median [interquartile range], 49.7 [36.8-68.6] vs 30.4 [20.7-34.7] min; P < 0.01) than those whose symptoms lasted more than 28 d. Groups were similar in age, sex, timing of intervention, and preintervention 5P risk score.

CONCLUSIONS

A standardized aerobic exercise intervention initiated within 14 d of concussion demonstrated efficacy for approximately half of participants, according to our definition of treatment efficacy. This multisite aerobic exercise intervention suggests that lower symptom severity, higher intervention adherence, and greater exercise duration are factors that increase the likelihood of symptoms resolving within 28 d of concussion.

Identifying delay in glymphatic clearance of labeled protons post-acute head trauma utilizing 3D ASL MRI (arterial spin labeling): a pilot study

This study correlated mild traumatic brain injury (mTBI) cognitive changes with ASL-MRI glymphatic clearance rates (GCRs) and recovery with GCR improvement. mTBI disrupts the blood brain barrier (BBB), reducing capillary mean transit time and GCRs. mTBI is clinically diagnosed utilizing history/examination findings with no physiologic biomarkers. 3D TGSE (turbo-gradient spin-echo) pulsed arterial spin-labeling 3T MRI with 7 long inversion times (TIs) assessed the signal clearance of labeled protons 2800-4000 ms postlabeling in bifrontal, bitemporal, and biparietal regions within 7 days of mTBI and once clinically cleared to resume activities. The Sport Concussion Assessment Tool Version 5 (SKAT5) and Brief Oculomotor/Vestibular Assessment evaluated injured athletes' cognitive function prior to MRIs. The pilot study demonstrated significant GCRs improvement (95% CI - 0.06 to - 0.03 acute phase; to CI-recovery CI 0.0772 to - 0.0497; P < 0.001 in frontal lobes; and parietal lobes (95% CI - 0.0584 to - 0.0251 acute; CI - 0.0727 to - 0.0392 recovery; P = 0.024) in 9 mTBI athletes (8 female, 1 male). Six age/activity-matched controls (4 females, 2 males) were also compared. mTBI disrupts the BBB, reducing GCR measured using the 3D ASL MRI technique. ASL MRI is a potential noninvasive biomarker of mTBI and subsequent recovery.

The Role of Puberty and Sex on Brain Structure in Adolescents With Anxiety Following Concussion

BACKGROUND

Adolescence represents a window of vulnerability for developing psychological symptoms following concussion, especially in girls. Concussion-related lesions in emotion regulation circuits may help explain these symptoms. However, the contribution of sex and pubertal maturation remains unclear. Using the neurite density index (NDI) in emotion regulation tracts (left/right cingulum bundle [CB], forceps minor [FMIN], and left/right uncinate fasciculus), we sought to elucidate these relationships.

METHODS

No adolescent had a history of anxiety and/or depression. The Screen for Child Anxiety Related Emotional Disorders and Children's Depression Rating Scale were used at scan to assess anxiety and depressive symptoms in 55 concussed adolescents (41.8% girls) and 50 control adolescents with no current/history of concussion (44% girls). We evaluated if a mediation-moderation model including the NDI (mediation) and sex or pubertal status (moderation) could help explain this relationship.

RESULTS

Relative to control adolescents, concussed adolescents showed higher anxiety (p = .003) and lower NDI, with those at more advanced pubertal maturation showing greater abnormalities in 4 clusters: the left CB frontal (p = .002), right CB frontal (p = .011), FMIN left-sided (p = .003), and FMIN right-sided (p = .003). Across all concussed adolescents, lower NDI in the left CB frontal and FMIN left-sided clusters partially mediated the association between concussion and anxiety, with the CB being specific to female adolescents. These effects did not explain depressive symptoms.

CONCLUSIONS

Our findings indicate that lower NDI in the CB and FMIN may help explain anxiety following concussion and that adolescents at more advanced (vs less advanced) status of pubertal maturation may be more vulnerable to concussion-related injuries, especially in girls.

The influence of ADHD on recovery from sport concussion among collegiate athletes in the United States: LIMBIC MATARS consortium investigation

OBJECTIVE

The present study aimed to assess the potential influence of a diagnosis of ADHD on concussion recovery among collegiate athletes.

DESIGN

Retrospective and cross-sectional.

METHODS

Data were extracted retrospectively from medical records across LIMBIC MATARS member institutions (n = 11), representing 1,044 concussion cases among collegiate athletes. After exclusions, 406 concussions were included in our analysis (ADHD: n = 38, age = 20.2 ± 1.67 years, 18.4% female; No ADHD: n = 368, age = 19.8 ± 1.39 years, 40.1% female). Mann-Whitney U tests were used to compare days from injury to diagnosis, symptom resolution, and return to sport among athletes with and without ADHD.

RESULTS

No differences were observed for days from concussion until diagnosis (z = -0.33, p = 0.74), until days to symptom resolution (z = -1.30, p = 0.19), or days until return to sport (z = -0.68, p = 0.49); among concussion cases with or without a previously reported diagnosis of ADHD.

CONCLUSION

Our findings further expand the literature that suggests ADHD is not strongly associated with recovery trajectory following sport concussion in collegiate athletes. Future research should extend these findings to be inclusive of additional preexisting health conditions and moderating effects related to medication usage among diverse athlete levels.

Histological comparison of repeated mild weight drop and lateral fluid percussion injury models of traumatic brain injury (TBI) in female and male rats

Traumatic brain injury (TBI) heterogeneity has led to the development of several preclinical models, each modeling a distinct subset of outcomes. Selection of an injury model should be guided by the research question and the specific outcome measures of interest. Consequently, there is a need for conducting direct comparisons of different TBI models. Here, we used immunohistochemistry to directly compare the outcomes from two common models, lateral fluid percussion (LFP) and repeat mild weight drop (rmWD), on neuropathology in adult female and male Wistar rats. Specifically, we used immunohistochemistry to measure the effects of LFP and rmWD on cerebrovascular and tight junction disruption, inflammatory markers, mature neurons and perineuronal nets in the cortical site of injury, cortex adjacent to injury, dentate gyrus, and the CA2/3 area of the hippocampus. Animals were randomized into either LFP or rmWD groups. The LFP group received a craniotomy prior to LFP (or corresponding sham procedure) three days later, while rmWD animals underwent either weight drop or sham (isoflurane only) on each of those four days. After a recovery period of 7 days, animals were euthanized, and brains were harvested for analysis of RECA-1, claudin-5, GFAP, Iba-1, CD-68, NeuN, and wisteria floribunda lectin. Overall, our observations revealed that the most significant disruptions were evident in response to LFP, followed by craniotomy-only, while rmWD animals showed the least residual changes compared to isoflurane-only controls. These findings support consideration of rmWD as a mild, transient injury. LFP leads to longer-lasting disruptions that are more closely associated with a moderate TBI. We further show that both craniotomy and LFP produced greater disruptions in females relative to males at 7 days post-injury. These findings support the inclusion of a time-matched experimentally-naïve or anesthesia-only control group in preclinical TBI research to enhance the validity of data interpretation and conclusions.

The Role of Level of Play in Concussions in High School Athletes

OBJECTIVES

To examine level of play (LOP) as a risk factor for concussion severity and recovery-related outcomes among high school athletes, stratified by sex, and among boys, by sport (football, non-football male sports).

DESIGN/SETTING

Secondary analysis of data collected through the High School Reporting Information Online surveillance system for academic years 2007-2008 through 2018-2019.

PARTICIPANTS

A total of 9916 concussions were reported between the academic years 2007-2008 and 2018-2019 from 9 sports (5189 from football; 2096 from non-football male sports; 2631 from female sports).

MAIN OUTCOME MEASURE

Examined the association between LOP (Freshman, Junior Varsity [JV], and Varsity teams) and concussion outcomes (number of concussion symptoms, symptom resolution time [SRT], and time to return to play [RTP]).

RESULTS

Compared with Varsity football athletes, concussed JV football athletes had on average 0.19 fewer concussion symptoms, longer SRT (>1 week vs <1 week: odds ratio [OR] = 1.3; 95% confidence interval [CI], 1.1-1.5), and longer RTP (1-3 weeks vs <1 week: OR = 1.5; 95% CI, 1.2-1.9; >3 weeks vs <1 week: OR = 1.6; 95% CI, 1.1-2.3). Compared with Varsity football athletes, Freshman football athletes had on average 0.48 fewer concussion symptoms, longer SRT (OR = 1.3; 95% CI, 1.1-1.5), and longer RTP (1-3 weeks vs <1 week: OR = 1.5; 95% CI, 1.1-2.0; >3 weeks vs <1 week: OR = 2.0; 95% CI, 1.3-3.0). Similarly, compared with female athletes on Varsity teams, concussed JV female athletes had longer RTP (1-3 weeks vs <1 week: OR = 1.8; 95% CI, 1.2-2.7). Trend analyses revealed an increase in the number of concussion symptoms between 2015-2016 and 2018-2019, a decrease between 2009-2010 and 2018-2019 for SRT of less than 1 week, and an increase between 2014-2015 and 2018-2019 for RTP of less than 1 week among Varsity football athletes. Among Varsity female athletes, there was a linear decrease during the study period for RTP of less than 1 week.

CONCLUSIONS

Despite a higher number of symptoms overall and in recent years, Varsity football players had shorter RTP than Freshman and JV athletes.

Sports-Related Concussion Affects Cognitive Function in Adolescents: A Systematic Review and Meta-analysis

BACKGROUND

Rates of sports-related concussion (SRC) are high in adolescents. Ambiguity exists regarding the effect of SRC on cognitive function in adolescents.

PURPOSE

To rigorously examine adolescents' cognitive function after SRC.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

Web of Science, Scopus, and PubMed were searched from database inception until September 2021. Studies were included if participants were adolescents aged 13 to 18 years, if the definition of SRC was fully consistent with the Berlin Consensus Statement on Concussion in Sport, if the study included a control group or in-group baseline test, and if the study reported cognitive outcomes (eg, visual memory, processing speed) that could be separately extracted.

RESULTS

A total of 47 studies were included in the systematic review, of which 31 were included in the meta-analysis, representing 8877 adolescents with SRC. Compared with individuals in the non-SRC group, individuals with SRC had worse performance in cognitive function and reported more symptoms not only in the acute phase but also in the prolonged phase (1-6 months after injury) (visual memory: d = -0.21, 95% CI, -0.37 to -0.05, P = .012; executive function: d = -0.56, 95% CI, -1.07 to -0.06, P = .028; and symptoms: d = 1.17, 95% CI, 0.13 to 2.22, P = .028). Lower scores in most of the outcomes of cognitive function were observed at <3 days and at 3 to 7 days, but higher scores for verbal memory (d = 0.10; 95% CI, 0.03 to 0.17; P = .008) and processing speed (d = 0.17; 95% CI, 0.10 to 0.24; P < .001) were observed at 7 to 14 days after SRC relative to baseline. The effects of SRC on cognitive function decreased over time (100% of the variance in reaction time, P < .001; 99.94% of the variance in verbal memory, P < .001; 99.88% of the variance in visual memory, P < .001; 39.84% of the variance in symptoms, P = .042) in control group studies. Study design, participant sex, measurement tools, and concussion history were found to be modulators of the relationship between cognitive function and SRC.

CONCLUSION

This study revealed that adolescent cognitive function is impaired by SRC even 1 to 6 months after injury. Results of this study point to the need for tools to measure cognitive function with multiple parallel versions that have demographically diversiform norms in adolescents. Effective prevention of SRC, appropriate treatment, and adequate evaluation of cognitive function before return to play are needed in adolescent SRC management. Moreover, caution is warranted when using the baseline-to-postconcussion paradigm in return-to-play decisions.

Temporal Network Analysis of Neurocognitive Functioning and Psychological Symptoms in Collegiate Athletes After Concussion

Sport-related concussion (SRC) is associated with several post-injury consequences, including neurocognitive decrements and psychological distress. Yet, how these clinical markers interact with each other, the magnitude of their interrelationships, and how they may vary over time following SRC are not well understood. Network analysis has been proposed as a statistical and psychometric method to conceptualize and map the complex interplay of interactions between observed variables (e.g., neurocognitive functioning and psychological symptoms). For each collegiate athlete with SRC (n = 565), we constructed a temporal network as a weighted graph, with nodes, edges, and the set of weights associated with each edge at three time-points (baseline, 24-48 h post-injury, and asymptomatic), that graphically depicts the interrelated nature of neurocognitive functioning and symptoms of psychological distress throughout the recovery process. This graph shows that the inter-group relationships between neurocognitive functioning and symptoms of psychological distress were stronger at the 24-48 h time-point than at baseline or at the asymptomatic time-point. Further, all symptoms of psychological distress and neurocognitive functioning significantly improved from the 24-48 h time-point to asymptomatic status. The effect sizes of these changes ranged from 0.126 (small) to 0.616 (medium). This research suggests that significant improvements in symptoms of psychological distress appear necessary to drive related improvements in neurocognitive functioning and vice versa. Therefore, clinical interventions should consider the importance of managing psychological distress during the acute care of individuals with SRC to help ameliorate negative outcomes.

Provision of Concussion Information From Coaches and the Presence of Athletic Trainers: Findings From the 2021 YouthStyles Survey

Coaches play an important role in concussion safety, and their views on concussion influence those of their athletes and the athletes' reporting behaviors. In this 2021 survey of youth, we examined how often coaches provide concussion safety information to their athletes and the association between coaches' provision of concussion information to athletes and the presence of athletic trainers (ATs) at a team's games and practices. More than 4 in 10 youth who played sports reported that their coaches did not provide any sort of concussion education or information to them in the past 12 months. Among those youth who always or sometimes had ATs at practices or games, 76.3% received some type of coach education on concussion in the past 12 months, compared with 31.9% of those who rarely or never had ATs at practices or games (P < .0001). Increasing access to ATs and adapting current concussion training and educational materials for coaches to increase coach-athlete communication may be beneficial.

Return to the Emergency Department Within 3 Months Following Pediatric Acute Concussion

OBJECTIVE

To determine the proportion of concussed children returning to the emergency department (ED) for a concussion-related reason within 3 months of initial presentation and to determine which clinical composite score (5P or Post-Concussion Symptom Inventory) best predicts a return visit.

SETTING, DESIGN, AND PARTICIPANTS

We combined a secondary analysis of data from the prospectively collected 5P study with a retrospective medical record review of children aged 5 to 18 years who returned to the Children's Hospital of Eastern Ontario (CHEO) ED for a concussion-related reason within 3 months of an acutely diagnosed concussion. Among 770 eligible participants, 632 children (median age: 11.8 [interquartile range (IQR), 9.0-14.5] years; 58.9% male) were included in the study.

MAIN MEASURES

The primary outcome was the number of patients who returned to CHEO ED for a concussion-related reason within 3 months of an acute concussion diagnosed at CHEO ED. The secondary outcome was number of patients who returned within 14 days.

RESULTS

Forty-seven children (7.4%; 95% confidence interval [CI]: 5.6-9.7) had a concussion-related return to the ED within 3 months, the majority of which occurred in the first 14 days (29/47; 61.7%; 95% CI: 47.4-74.2). History of migraines (21.3% vs 9.7%; P = .03) were more common in those with a return visit. Headache was the most frequently reported symptom (87.2%) on revisit. Females aged 13 to 18 years had the highest return rate (survival rate: 85.8% [95% CI: 79.8-92.3]) compared with males and younger age groups. In multivariable Cox hazards regression modeling, inclusion of risk scores improved prognostication (pseudo R2 = 8%). The difference in pseudo R2 between 5P and Post-Concussion Symptom Inventory is small.

CONCLUSION

Most children and adolescents do not return to the ED following an acute concussion. Female youth with medium to high 5P scores at the index concussion visit may benefit from early referral to interdisciplinary specialty concussion care to guide treatment in anticipation of prolonged symptoms. By identifying these risk factors at the initial ED visit, healthcare and patient burden may be reduced.

Potential Biomarkers in Experimental Animal Models for Traumatic Brain Injury

Traumatic brain injury (TBI) is a complex and multifaceted disorder that has become a significant public health concern worldwide due to its contribution to mortality and morbidity. This condition encompasses a spectrum of injuries, including axonal damage, contusions, edema, and hemorrhage. Unfortunately, specific effective therapeutic interventions to improve patient outcomes following TBI are currently lacking. Various experimental animal models have been developed to mimic TBI and evaluate potential therapeutic agents to address this issue. These models are designed to recapitulate different biomarkers and mechanisms involved in TBI. However, due to the heterogeneous nature of clinical TBI, no single experimental animal model can effectively mimic all aspects of human TBI. Accurate emulation of clinical TBI mechanisms is also tricky due to ethical considerations. Therefore, the continued study of TBI mechanisms and biomarkers, of the duration and severity of brain injury, treatment strategies, and animal model optimization is necessary. This review focuses on the pathophysiology of TBI, available experimental TBI animal models, and the range of biomarkers and detection methods for TBI. Overall, this review highlights the need for further research to improve patient outcomes and reduce the global burden of TBI.

Acute evaluation of sport-related concussion and implications for the Sport Concussion Assessment Tool (SCAT6) for adults, adolescents and children: a systematic review

OBJECTIVES

To systematically review the scientific literature regarding the acute assessment of sport-related concussion (SRC) and provide recommendations for improving the Sport Concussion Assessment Tool (SCAT6).

DATA SOURCES

Systematic searches of seven databases from 2001 to 2022 using key words and controlled vocabulary relevant to concussion, sports, SCAT, and acute evaluation.

ELIGIBILITY CRITERIA

(1) Original research articles, cohort studies, case-control studies, and case series with a sample of >10; (2) ≥80% SRC; and (3) studies using a screening tool/technology to assess SRC acutely (<7 days), and/or studies containing psychometric/normative data for common tools used to assess SRC.

DATA EXTRACTION

Separate reviews were conducted involving six subdomains: Cognition, Balance/Postural Stability, Oculomotor/Cervical/Vestibular, Emerging Technologies, and Neurological Examination/Autonomic Dysfunction. Paediatric/Child studies were included in each subdomain. Risk of Bias and study quality were rated by coauthors using a modified SIGN (Scottish Intercollegiate Guidelines Network) tool.

RESULTS

Out of 12 192 articles screened, 612 were included (189 normative data and 423 SRC assessment studies). Of these, 183 focused on cognition, 126 balance/postural stability, 76 oculomotor/cervical/vestibular, 142 emerging technologies, 13 neurological examination/autonomic dysfunction, and 23 paediatric/child SCAT. The SCAT discriminates between concussed and non-concussed athletes within 72 hours of injury with diminishing utility up to 7 days post injury. Ceiling effects were apparent on the 5-word list learning and concentration subtests. More challenging tests, including the 10-word list, were recommended. Test-retest data revealed limitations in temporal stability. Studies primarily originated in North America with scant data on children.

CONCLUSION

Support exists for using the SCAT within the acute phase of injury. Maximal utility occurs within the first 72 hours and then diminishes up to 7 days after injury. The SCAT has limited utility as a return to play tool beyond 7 days. Empirical data are limited in pre-adolescents, women, sport type, geographical and culturally diverse populations and para athletes.

PROSPERO REGISTRATION NUMBER

CRD42020154787.

Return to Learn After Traumatic Brain Injury

A successful return of youth back to school after traumatic brain injury (TBI) is an important aspect of post-injury management. Regardless of the severity of the injury, returning to school is an important aspect of improving recovery and outcomes. Often temporary informal school adjustments suffice in supporting children returning to school after concussion. For those with more a significant TBI, often formal school supports and interventions are important. Given the resiliency and recovery often seen after pediatric brain injury, close monitoring, serial evaluations, and fluid supports are important in accurately identifying what specific sequelae require support in the school setting.

Motor vehicle crash concussion mechanism displays a greater total number of symptoms and greater affective symptom severity but no neurocognitive differences compared with sport-related concussion mechanism

Previous research among adolescents has shown differences in symptoms and neurocognitive performance between sport-related (SRC) and motor vehicle crash (MVC) concussion mechanisms. Limited research has focused on young adults. The purpose of our study was to compare symptoms, balance, and neurocognitive performance between SRC and MVC mechanisms in young adults. Forty-three (58.1% female, age = 25.5 ± 3.2 years, days since concussion = 12.8 ± 12.7) and 26 (76.9% female, age = 24.1 ± 5.6 years, days since concussion = 12.6 ± 8.3) individuals with an SRC and MVC mechanism, respectively, participated. Primary outcome measures included the total number, severity, cluster (disorientation, migraine, lethargy, and affective) of post-concussion symptoms endorsed, Balance Error Scoring System (BESS), and CNS Vital Signs scores. Clusters are subgroups of symptoms used for targeted rehabilitation. We used independent t-tests and Mann-Whitney U tests to compare symptoms, BESS, and neurocognitive performance. Cliff's Delta effect size was interpreted as negligible (<0.15), small (0.15-0.33), medium (0.34-0.47), and large (≥0.48). There were no group differences for any demographic factors or preexisting conditions (p-range = 0.112-0.991). Participants with an MVC mechanism reported a greater number of total post-concussion symptoms (p = 0.025, Cliff's Delta = 0.32) and a more severe affective symptom cluster (p = 0.010, Cliff's Delta = 0.37). There were no group differences for BESS or neurocognitive performance after correcting for multiple comparisons. The MVC mechanism resulted in a greater total symptom burden relative to the SRC mechanism. Medical practitioners and individuals experiencing a concussion should know that concussions are heterogeneous within and across various mechanisms.

Efficacy of aerobic exercise following concussion: a narrative review

Concussion is a type of mild traumatic brain injury which results in symptoms within the physical, cognitive, emotional, and sleep domains. Historically, guidelines established by expert opinion have recommended rest during the initial stages of recovery following a concussion until symptom resolution. However, recent recommendations have shifted to advise an initial period of 24-48 h of rest immediately following concussion with the gradual introduction of light-to-moderate intensity aerobic exercise thereafter. Given the relatively recent transition in recommendations, the aim of this review is to provide an overview of the current literature on the efficacy of aerobic exercise following concussion. The current literature is limited to studies assessing the impact of standardized aerobic exercise following concussion. Upon review, literature suggests participating in aerobic exercise below the point of symptom exacerbation is safe in both the acute and chronic post-concussion symptom stages of recovery and does not delay time to medical clearance. Future large-scale randomized controlled trials assessing the impact of aerobic exercise and differences between males and females would help support the current evidence suggesting aerobic exercise could improve time to recovery following concussion and identify any sex differences in response. As well, future studies with the purpose of identifying optimal aerobic exercise volume and intensity in the treatment of concussion could improve the specificity of the current guidelines.

Concussion Recovery in Children and Adolescents: A Retrospective Study

Background

Concussion is a common injury among children and adolescents, with a growing body of literature supporting a variety of diagnostic and treatment modalities. Recovery is variable and depends on multiple factors that can be evaluated through a clinic visit: a thorough history, physical examination, and use of the Post-concussion Symptom Scale (PCSS).

Purpose/Hypothesis

The purpose of this study was to evaluate factors associated with overall recovery from concussion in children and adolescents in the clinical setting. It was hypothesized that the presence of 1 of a number of pre- or postinjury characteristics will be associated with poor concussion recovery.

Study Design

Case-control study; Level of evidence, 3.

Methods

We conducted a retrospective chart review of adolescents and children aged 6 to 17 years with a diagnosis of concussion who were evaluated at a single sports medicine center between January 2015 and December 2019. Cases were categorized into recovered (PCSS <7) and poorly recovered (PCSS ≥7) cohorts based on the last PCSS scores during clinical follow-ups for concussion management.

Results

Of the 162 charts reviewed, 110 cases met inclusion criteria. Significant statistical differences were found between the recovered and poorly recovered cohorts regarding mean days from injury to last clinic visit, previous migraine diagnosis, and emergency room (ER) visit before the first clinic visit (P < .01 for all). Binary logistic regression analysis revealed that the most predictive factors associated with poorer recovery were having an ER visit before the first clinic evaluation (P = .01) and previous migraine diagnosis (P = .04).

Conclusion

While many factors may contribute to overall recovery from concussion in pediatric populations, our study suggested that a history of migraine and an ER visit before clinic evaluation may be associated with poor recovery of concussive symptoms.

Greater Acute Concussion Symptoms Are Associated With Longer Recovery Times in Adolescents

We examined the association between the severity of acute concussion symptoms and time to return to school and to sports in adolescent student athletes. We hypothesized that there would be an association between the severity of acute symptoms experienced in the first 72 hours and functional recovery such that adolescents with the lowest burden of acute symptoms would have the fastest return to school and sports and those with the highest burden of symptoms would have the slowest return to school and sports. This injury surveillance cohort included 375 adolescent student athletes aged 14-19 years who sustained a sport-related concussion between 2014 and 2020. Athletic trainers documented time to return to school and to sports. A greater proportion of adolescents with the highest acute symptoms remained out of school at 3 (odds ratio [OR] = 2.5, 95% confidence interval [CI] 1.5-4.4), 5 (OR = 2.4, 95% CI 1.4-4.0), 7 (OR = 2.6, 95% CI 1.5-4.3), and 10 days (OR = 2.3, 95% CI 1.3-3.9) compared to those with the lowest acute symptoms. Similarly, a greater proportion of athletes with the highest acute symptoms remained out of sports at 7 (OR = 3.5, 95% CI 1.5-8.1), 10 (OR = 3.1, 95% CI 1.8-5.6), 14 (OR = 1.8, 95% CI 1.1-3.0), and 21 days (OR = 1.9, 95% CI 1.0-3.6) compared to those with the lowest acute symptoms. This study underscores the adverse effect of high acute symptom burden following concussion on return to school and to sports among adolescent student athletes. Conversely, student athletes with a low burden of acute symptoms have a faster return to school and to sports.

A Pilot Randomized Controlled Trial of Docosahexaenoic Acid for the Treatment of Sport-Related Concussion in Adolescents

The objective was to examine the use of docosahexaenoic acid (DHA) for the treatment of sport-related concussion (SRC) in adolescent athletes. We hypothesize that participants who intake 2 g of DHA daily will not experience differences in recovery compared with participants who take a placebo. This double-blind, randomized controlled pilot trial was performed in a tertiary pediatric sports medicine clinic from 2013 to 2017 in adolescents (14-18 years) presenting with diagnosed SRC within 4 days of injury. Forty participants were randomized into DHA or PLACEBO group and were instructed to take 2 capsules twice daily for 12 weeks. Participants in the DHA group were symptom-free earlier than the PLACEBO group (11.0 vs 16.0 days, P = .08) and were cleared to begin the Return to Sport progression (14.0 vs 19.5 days, P = .12) sooner. The use of 2 g/day of DHA was well-tolerated and did not significantly affect recovery times in adolescent athletes following SRC.Clinical Trial Registration: ClincalTrials.gov, NCT01903525.

Prevalence and correlates of self-reported cognitive difficulties in deployment-injured U.S. military personnel

Cognitive difficulties typically resolve within days to weeks following mild traumatic brain injury (mTBI); however, a sizable proportion of individuals continue to report cognitive symptoms months to years later that are often associated with posttraumatic stress disorder (PTSD) and depression to a greater degree than a history of mTBI. The current study sought to evaluate the prevalence of self-reported cognitive difficulties as well as the relative contributions of demographic, injury-related, and mental health variables in a large study of U.S. military personnel injured during deployment since 2001. Slightly fewer than half (42.0%) of participants reported elevated cognitive difficulties compared with a normative population; however, this was driven primarily by those who screened positive for PTSD or depression. Hierarchical linear regression revealed that various demographic and injury factors, including lower educational attainment, retired or separated military status, enlisted rank, and a history of deployment-related mTBI, were associated with more self-reported cognitive difficulties, f² = 0.07. Screening positive for PTSD or depression accounted for 32.1% of the variance in self-reported cognitive symptoms, f² = 0.63, whereas injury variables, including a history of deployment-related mTBI, albeit significant in the model, accounted for 1.6%. The current findings add to the growing body of literature underscoring the importance of screening for and treating mental health conditions in injured military personnel.

Concussion History and Heart Rate Variability During Bouts of Acute Stress

CONTEXT

After a sport-related concussion, many athletes experience persisting neurophysiological alterations. These alterations may be absent at rest but emerge during moments of physiological stress. Unnoticed and untreated neurophysiological dysfunction may negatively affect long-term neurologic health in adolescent athletes, as they are at a critical point in development.

OBJECTIVE

To assess cardio-autonomic functioning in athletes with and those without a history of concussion by quantifying measures of heart rate variability (HRV) during times of physical and mental exertion.

DESIGN

Case-control study.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Thirty-four male Hockey Quebec Midget-AAA hockey players were separated into those with (n = 16; age = 16.06 ± 0.73 years, body mass index = 23.29 ± 1.79) and those without (n = 18; age = 15.98 ± 0.62 years, body mass index = 23.60 ± 2.49) a history of concussion.

INTERVENTION(S)

All athletes underwent a series of HRV recording sessions (1) at rest, (2) while completing a cognitive task at rest, and (3) while completing a cognitive task after a bout of submaximal aerobic exercise.

MAIN OUTCOME MEASURE(S)

Time-domain measures of HRV, including mean NN intervals, SD of NN intervals, and root mean square of successive NN interval differences, were quantified for each assessment.

RESULTS

No differences in characteristics were evident between groups. No between-groups differences in HRV at rest were observed. However, during the cognitive task at rest and after aerobic exercise, athletes with a history of concussion demonstrated a higher SD of NN intervals (78.1 ± 4.3 versus 63.2 ± 4.1 milliseconds and 71.2 ± 4.3 versus 65.2 ± 3.8 milliseconds, respectively; F1,31 = 4.31, P = .046) and root mean square of successive NN interval differences (75.8 ± 6.0 versus 59.0 ± 5.6 milliseconds and 74.0 ± 5.5 versus 59.0 ± 5.2 milliseconds, respectively; F1,31 = 4.88, P = .04) than athletes without a history of concussion.

CONCLUSIONS

Concussive injuries may result in long-term cardio-autonomic dysfunction. These deficits may not be present at rest but may be triggered by physiological stress.

Exploring Vestibular/Ocular and Cognitive Dysfunction as Prognostic Factors for Protracted Recovery in Sports-Related Concussion Patients Aged 8 to 12 Years

OBJECTIVE

To explore the prognostic ability of the vestibular/ocular motor screening (VOMS), King-Devick (K-D) Test, and C3 Logix Trails A and B to identify protracted recovery from sports-related concussion (SRC) in patients aged 8 to 12 years.

DESIGN

Retrospective cohort analysis.

SETTING

Specialty pediatric sports concussion clinic.

PARTICIPANTS

A total of 114 youth athletes aged 8 to 12 years who were diagnosed with an SRC within 7 days of injury.

INDEPENDENT VARIABLES

A positive screen on the VOMS, K-D, and C3 Logix Trails A and Trails B. Combined positive screens on multiple tests (ie, 2, 3, or all 4 positive screens of 4 possible).

MAIN OUTCOME MEASURES

Recovery time in days and protracted recovery (recovery time ≥30-days) were the primary outcomes of interest.

RESULTS

A positive VOMS screen was associated with 1.31 greater days to SRC recovery ( P = 0.02) than a negative VOMS screen. The K-D and C3 Logix tests were not significantly associated with recovery time, nor were any combinations of tests ( P > 0.05). The VOMS demonstrated moderate prognostic ability to predict normal recovery (negative predictive value = 80.78% [95% CI = 63.73-90.95]). Overall predictive accuracy of normal versus protracted recovery was strongest when a participant screened positive on all 4 tests (Accuracy = 76.32% [95% CI = 67.45-83.78]).

CONCLUSIONS

The VOMS was associated with overall recovery time and proved to be a useful test to identify those who would experience a normal recovery time. Combining the 4 tests improved the prognostic accuracy of the protocol in predicting protracted versus normal recovery. These findings suggest that combining multiple, varied assessments of cognition and vestibular/ocular functions may better explain factors contributing to protracted recovery.

Postconcussion Dizziness Severity Predicts Daily Step Count during Recovery among Adolescent Athletes

PURPOSE

Physical activity (PA) after concussion is an important aspect of appropriate clinical management. However, symptoms or functional deficits may reduce patient propensity toward PA, thereby negatively affecting recovery. Our purpose was to examine whether postconcussion dizziness, total symptom severity, or postural stability predicts PA level in the 2 wk after initial evaluation.

METHODS

We evaluated adolescent athletes within 14 d of concussion on assessments of symptoms, dizziness, and postural stability. Athletes were provided an activity monitor to track PA for 2 wk after the evaluation. Our primary outcome was step count (mean steps per day). Potential predictor variables included sex, Post-Concussion Symptom Inventory (PCSI) total symptom severity, individual PCSI ratings of dizziness and balance impairment, and postural stability assessments (single- and dual-task tandem gait, modified Balance Error Scoring System). To examine predictors of PA, we calculated correlation coefficients between steps per day and each potential predictor and included significantly correlated variables in a multivariable regression model.

RESULTS

Participants were ages 12-18 yr (n = 35, 15.2 ± 1.7 yr, 49% female) and initially evaluated 7.3 ± 3.0 d after concussion. Upon univariable evaluation, PCSI dizziness rating (Pearson R = -0.49, P = 0.003) and sex (mean difference, 2449 steps per day; P = 0.05) were associated with steps per day. Within the multivariable regression analysis, PCSI dizziness rating (β = -1035; 95% confidence interval, -191 to -1880; P = 0.018), but not sex, predicted average steps per day in the 2 wk after initial evaluation.

CONCLUSIONS

Self-reported dizziness, but not overall symptom severity or postural stability, assessed within 14 d of concussion predicted daily step count in the subsequent 2 wk. Given the importance of PA for concussion recovery, treating acute postconcussion dizziness can potentially reduce a barrier to PA and improve recovery trajectories.

Recovery of symptoms, neurocognitive and vestibular-ocular-motor function and academic ability after sports-related concussion (SRC) in university-aged student-athletes: a systematic review

BACKGROUND

Physiological differences between a maturing and matured brain alters how Sports-Related Concussion (SRC) affects different age groups; therefore, a review specific to university-aged student-athletes is needed.

OBJECTIVES

Determine time to recovery for symptom burden, neurocognitive and Vestibular-Ocular-Motor (VOM) function and academic impact in university-aged student-athletes.

METHODS

Searches were conducted in PubMed, SpringerLink, PsycINFO, Science Direct, Scopus, Cochrane, Web of Science and EMBASE. Articles were included if they contained original data collected within 30 days in university-aged student-athletes, analysed SRC associated symptoms, neurocognitive or VOM function or academic ability and published in English. Two reviewers independently reviewed sources, using the Oxford Classification of Evidence-Based Medicine (CEBM) and the Downs and Black checklist, and independently extracting data before achieving consensus.

RESULTS

58 articles met the inclusion criteria. Recovery of symptoms occurred by 7 and 3-5.3 days for neurocognition. The evidence base did not allow for a conclusion on recovery time for VOM function or academic ability. Few papers investigated recovery times at specified re-assessment time-points and have used vastly differing methodologies.

CONCLUSIONS

To fully understand the implication of SRC on the university-aged student-athlete' studies using a multi-faceted approach at specific re-assessments time points are required.Systematic review registration number: CRD42019130685.

Psychoeducational Interventions and Postconcussive Recovery in Children and Adolescents: A Rapid Systematic Review

OBJECTIVE

The purpose of this rapid systematic review was to identify and synthesize results of empirical studies that have examined psychoeducational interventions provided to children and adolescents aged 5-19 recovering from a concussion and their families.

METHODS

This study followed the PRISMA guidelines adjusted for a rapid systematic review. We searched three databases (EMBASE, PsycInfo and MEDLINE) with key terms for concussion (or mild traumatic brain injury - mTBI), the intervention (psychoeducation, instructions, and reassurance) and the target population (children and adolescents aged 5 to 19). Our search strategy generated 2225 unique records and seven were included. We performed a quality appraisal on the included studies using the Mixed Methods Appraisal Tool (MMAT).

RESULTS

Results indicated that psychoeducational interventions had satisfactory feasibility results. Caregivers generally found the intervention to be useful to determine return to play (n=2) and understand consequences following a concussion (n=1). However, results from studies on post-concussive symptom improvement (n=4) and post-intervention concussion knowledge (n=2) showed variability and mixed findings. Methodological quality was low for most studies.

CONCLUSIONS

This present review shows that there are very few published studies on psychoeducational interventions offered to children, adolescents, and families for the post-concussion management. Current evidence suggests that those interventions are useful in guiding caregivers during their child's recovery. However, the impact of psychoeducational interventions on post-concussive recovery seems to be less clear.

Greater Acute Concussion Symptoms Are Associated With Longer Recovery Times in NCAA Division III Collegiate Athletes

We examined the association between the severity of acute concussion symptoms and time to return to school and to sports in National Collegiate Athletic Association (NCAA) Division III collegiate athletes. We hypothesized that students with the lowest burden of acute symptoms, measured in the first 72 h, would have the fastest return to school and sports and those with the highest burden of symptoms would have the slowest return to school and sports. This injury surveillance cohort included 808 athletes from 11 NCAA Division III colleges who sustained a concussion between 2014 and 2019. Athletic trainers documented time to return to school and to sports. Kruskal-Wallis tests with post-hoc planned comparison Mann-Whitney U tests were used to assess whether athletes took longer to return based on their acute symptom burden (Low, Medium, or High). Survival analysis (Kaplan Meier with log rank tests) was used to compare the recovery times based on acute symptom burden (censored at 28 days). Chi-square tests compared the proportion of those who had not yet returned to school or sports at various recovery benchmarks (i.e., 1 week, 10 days, 2 weeks, 3 weeks, 4 weeks) based on acute symptom burden. Women (median = 5 days) took slightly longer than men (median = 4 days) to return to school (p = 0.001; r = −0.11, small effect). Women and men did not differ on time to return to sports (p = 0.32, r = −0.04). A greater proportion with high acute symptoms remained out of school at 5 (odds ratio, OR = 4.53), 7 (OR = 4.98), and 10 (OR = 4.80) days compared to those with low acute symptoms. A greater proportion with high acute symptoms remained out of sports at 10 (OR = 4.11), 14 (OR = 3.46), and 21 (OR = 3.01) days compared to those with low acute symptoms. This study shows a strong association between having a high burden of acute post-concussion symptoms and having a slower return to school and sports in Division III collegiate athletes. Moreover, it also illustrates the converse: that those athletes with a low burden of acute symptoms have a faster return to school and sports.

A Routine Electroencephalography Monitoring System for Automated Sports-Related Concussion Detection

Cases of concussions in the United States keep increasing and are now up to 2 million to 3 million incidents per year. Although concussions are recoverable and usually not life-threatening, the degree and rate of recovery may vary depending on age, severity of the injury, and past concussion history. A subsequent concussion before full recovery may lead to more-severe brain damage and poorer outcomes. Electroencephalography (EEG) recordings can identify brain dysfunctionality and abnormalities, such as after a concussion. Routine EEG monitoring can be a convenient method for reducing unreported injuries and preventing long-term damage, especially among groups with a greater risk of experiencing a concussion, such as athletes participating in contact sports. Because of the relative availability of EEG compared to other brain-imaging techniques (e.g., functional magnetic resonance imaging), the use of EEG monitoring is growing for various neurological disorders. In this longitudinal study, EEG was analyzed from 4 football athletes before their athletic season and also within 7 days of concussion. Compared to a control group of 4 additional athletes, a concussion was detected with up to 99.5% accuracy using EEG recordings in the Theta-Alpha band. Classifiers that use data from only a subset of the EEG electrodes providing reliable detection are also proposed. The most effective classifiers used EEG recordings from the Central scalp region in the Beta band and over the Temporal scalp region using the Theta-Alpha band. This proof-of-concept study and preliminary findings suggest that EEG monitoring may be used to identify a sports-related concussion occurrence with a high level of accuracy and thus reduce the chance of unreported concussion.

Association between white matter organization and cognitive performance in athletes with a history of sport-related concussion

INTRODUCTION

Impairments in cognitive performance after sport-related concussion (SRC) typically resolve within weeks of the injury, whereas alterations to white matter (WM) organization have been found to persist longer into the chronic injury stage. However, longer-term associations between cognition and WM organization following SRC have not been studied. The objective of this study was to compare WM organization and cognitive performance in collegiate athletes an average of almost 4 years post-SRC to athletes with no history of SRC.

METHOD

National Collegiate Athletic Association Division III athletes (n = 71, age = 19.3 ± 1.2; 14 with self-reported SRC) completed a neurocognitive assessment and diffusion tensor imaging (DTI). WM organization was assessed by extracting measures of fractional anisotropy (FA), mean diffusivity (MD), and radial diffusivity (RD) from 20 WM regions of interest (ROIs). Multivariate partial least squares analyses were used to compare athletes with and without a history of SRC and assess relationships between DTI-derived metrics of WM organization and cognitive measures.

RESULTS

Cognitive performance and ROI metrics did not differ between athletes with and without prior SRC. However, among athletes with a history of SRC, better executive function, processing speed, and memory but worse choice reaction time were associated with higher FA and lower MD and RD in several WM tracts.

CONCLUSION

Athletes with a history of SRC demonstrated greater associations between cognitive performance and WM organization, but also variability in the domains showing associations. Taken together, the findings demonstrate the importance of examining brain-behavior relationships several years after SRC to better gauge how WM organization supports cognition.

Using a Likelihood Heuristic to Summarize Conflicting Literature on Predictors of Clinical Outcome Following Sport-Related Concussion

OBJECTIVE

To introduce a new methodology for summarizing the results from systematic reviews-a likelihood heuristic-to the field of sport-related concussion.

DATA SOURCES

We applied the likelihood heuristic to the results of a systematic review published by Iverson et al (2017), containing 101 studies, on the predictors of worse clinical outcome following sport-related concussion.

STUDY SELECTION

We re-examined 5 individual prognostic factors that are of clinical interest and for which there is conflicting literature (female sex = 44 studies, prior concussion history = 41 studies, loss of consciousness = 31 studies, post-traumatic amnesia = 25 studies, and retrograde amnesia = 10 studies).

DATA EXTRACTION

For each prognostic factor, likelihood ratios were generated using the (1) number of significant and nonsignificant studies, (2) study power, (3) alpha level, and (4) prior probability that the alternative hypothesis was true.

DATA SYNTHESIS

Assuming each study had 80% power and an alpha level of 5%, observing the reported number of conflicting studies for female sex, prior concussion history, and retrograde amnesia is substantially more likely if each prognostic factor is associated with worse clinical outcome following sport-related concussion. For loss of consciousness, the observed number of conflicting studies is more likely if loss of consciousness is not associated with worse clinical outcome following sport-related concussion. A secondary analysis incorporating potentially more realistic study parameters of statistical power (45%) and alpha level (25%) generates weaker likelihood evidence that the observed numbers of studies for each prognostic factor are associated with worse clinical outcome following sport-related concussion than they are not.

CONCLUSIONS

Using a likelihood heuristic with 80% power and 5% alpha level, there is very strong likelihood evidence that female sex, prior concussion history, and retrograde amnesia are associated with worse clinical outcome following sport-related concussion. The strength of likelihood evidence that prognostic factors are associated with worse clinical outcome reduces when statistical power is lower and alpha level is inflated.

Prospective study with specific Re-Assessment time points to determine time to recovery following a Sports-Related Concussion in university-aged student-athletes

BACKGROUND

Time to recovery for symptom burden and neurocognition following a Sports-Related Concussion (SRC) has previously been determined by consolidating varying re-assessment time points into a singular point, and has not been established for Vestibular-Ocular-Motor (VOM) function or academic ability.

OBJECTIVES

Establish when recovery of symptom burden, neurocognition, VOM function, and academic ability occurs in university-aged student-athletes.

METHODS

Student-athletes completed an assessment battery (Post-Concussion Symptom Scale (PCSS), Immediate Post-Concussion Assessment and Cognitive Test (ImPACT), Vestibular Ocular-Motor Screening (VOMS), Perceived Academic Impairment Tool (PAIT)) during pre-season (n = 140), within 48 hours, 4, 8 and 14 days post-SRC and prior to Return To Play (RTP) and were managed according to the Rugby Football Union' community pathway (n = 42). Student-athletes were deemed recovered or impaired according to Reliable Change Index' (RCI) or compared to their individual baseline.

RESULTS

Symptom burden recovers by four days post-SRC on RCI and to baseline by eight days. VOM function and academic ability recovers by 8 days. Some student-athletes demonstrated worse performance at RTP on all tests by RCI and to baseline, except for on VOMS score and near point convergence by RCI change.

CONCLUSIONS

Variation in individual university-aged student-athletes requires a multi-faceted approach to establish what dysfunctions post-SRC exist and when recovery occurs.

Post-Concussion Dizziness, Sleep Quality, and Postural Instability: A Cross-Sectional Investigation

CONTEXT

Dizziness, postural instability, and poor sleep quality are all commonly reported post-concussion and individually relate to poor outcomes.

OBJECTIVE

To examine sleep quality and postural stability among adolescents who did and did not report dizziness within two weeks of concussion.

DESIGN

Cross-sectional study.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Participants ages 12-18 years within 14 days of concussion (n=58, 15.2±1.8 years; 50% female; 7.1±3.1 days post-injury) and uninjured controls (n=73; 15.8±1.3 years; 42% female).

MAIN OUTCOME MEASURES

Participants completed pre-injury and current dizziness ratings on the Post-Concussion Symptom Inventory (PCSI) and current sleep quality on the Pittsburgh Sleep Quality Index (PSQI). Participants also completed postural stability assessments (single/dual-task tandem gait and modified Balance Error Scoring System [mBESS]).

RESULTS

We grouped concussion patients into dizzy (n=21) or not dizzy (n=37) groups based on PCSI dizziness ratings: difference between current and pre-injury dizziness rating >3=dizzy; difference <3=not dizzy. The dizzy and not dizzy groups both reported significantly worse sleep quality than the control group (PSQI score: mean=9.6±3.7 vs 7.2±3.5 vs 4.3±2.6; p<0.001) upon univariable comparison. Similarly, the dizzy group performed slowest on single and dual-task tandem gait, followed by the not dizzy group, then the control group (single-task TG: mean= 27.2±11.7 sec vs 21.2±6.3 vs 14.7±3.6; p<0.001); (dual-task TG: mean=38.4±16.2 sec vs 29.9±7.2 vs 21.6±7.5; p<0.001). Both concussion groups demonstrated significantly more errors than the control group on the mBESS (mean=9.8±5.1 vs 6.9±5.8 vs 3.8±3.5; p<0.001). After controlling for total symptom severity in the multivariable model, tandem gait, but not mBESS or sleep quality, was associated with dizziness.

CONCLUSION

Individuals with post-concussion dizziness also demonstrated impaired tandem gait performance, while poor sleep quality was associated with total symptom severity. Identifying and treating the underlying dysfunction contributing to dizziness and postural instability may guide individualized rehabilitation strategies and facilitate recovery.

Reevaluating clinical assessment outcomes after unrestricted return to play following sport-related concussion

PRIMARY OBJECTIVE

The objective of this study was to examine neurocognition, postural control, and symptomology at multiple timepoints following concussion. We hypothesized that collegiate athletes would perform similar to or better than their baseline in terms of each outcome at both timepoints.

RESEARCH DESIGN

This was a retrospective study of 71 collegiate athletes (18.3 ± 0.89 years old; 182.2 ± 10.05 cm; 84.2 ± 20.07 kg) to observe changes in outcomes from a previously established clinical protocol.

METHODS AND PROCEDURES

Participants were administered ImPACT™, the Sensory Organization Test (SOT), and the revised head injury scale (HIS-r) prior to their seasons (baseline); upon reporting symptom-free following concussion (post-injury); and approximately 8-months after return-to-play to establish a new baseline.

MAIN OUTCOMES AND RESULTS

There were no changes in ImPACT scores or HIS-r reporting over time. ImPACT total symptom score (TSS) decreased over time (p = .002, η_p² = 0.08). Significant main effects occurred for the SOT equilibrium score (p < .01, η_p² = 0.34) and Vestibular sensory ratio (p < .001, η_p² = 0.22).

CONCLUSIONS

Our data suggest no decline in neurocognition, balance, or symptom burden approximately eight months post-injury. As clinicians continue to explore "best practices" for concussion management and potential long-term implications of these injuries it is important to monitor outcome measures longitudinally.

Daily Morning Blue Light Therapy Improves Daytime Sleepiness, Sleep Quality, and Quality of Life Following a Mild Traumatic Brain Injury

OBJECTIVE

Identify the treatment effects of 6 weeks of daily 30-minute sessions of morning blue light therapy compared with placebo amber light therapy in the treatment of sleep disruption following mild traumatic brain injury.

DESIGN

Placebo-controlled randomized trial.

PARTICIPANTS

Adults aged 18 to 45 years with a mild traumatic brain injury within the past 18 months (n = 35).

MAIN OUTCOME MEASURES

Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, Beck Depression Inventory II, Rivermead Post-concussion Symptom Questionnaire, Functional Outcomes of Sleep Questionnaire, and actigraphy-derived sleep measures.

RESULTS

Following treatment, moderate to large improvements were observed with individuals in the blue light therapy group reporting lower Epworth Sleepiness Scale (Hedges' g = 0.882), Beck Depression Inventory II (g = 0.684), Rivermead Post-concussion Symptom Questionnaire chronic (g = 0.611), and somatic (g = 0.597) symptoms, and experiencing lower normalized wake after sleep onset (g = 0.667) than those in the amber light therapy group. In addition, individuals in the blue light therapy group experienced greater total sleep time (g = 0.529) and reported improved Functional Outcomes of Sleep Questionnaire scores (g = 0.929) than those in the amber light therapy group.

CONCLUSION

Daytime sleepiness, fatigue, and sleep disruption are common following a mild traumatic brain injury. These findings further substantiate blue light therapy as a promising nonpharmacological approach to improve these sleep-related complaints with the added benefit of improved postconcussion symptoms and depression severity.

Laboratory Validation of Instrumented Mouthguard for Use in Sport

Concussion is an inherent risk of participating in contact, combat, or collision sports, within which head impacts are numerous. Kinematic parameters such as peak linear and rotational acceleration represent primary measures of concussive head impacts. The ability to accurately measure and categorise such impact parameters in real time is important in health and sports performance contexts. The purpose of this study was to assess the accuracy of the latest HitIQ Nexus A9 instrumented mouthguard (HitIQ Pty. Ltd. Melbourne Australia) against reference sensors in an aluminium headform. The headform underwent drop testing at various impact intensities across the NOCSAE-defined impact locations, comparing the peak linear and rotational acceleration (PLA and PRA) as well as the shapes of the acceleration time-series traces for each impact. Mouthguard PLA and PRA measurements strongly correlated with (R² = 0.996 and 0.994 respectively), and strongly agreed with (LCCC = 0.997) the reference sensors. The root mean square error between the measurement devices was 1 ± 0.6g for linear acceleration and 47.4 ± 35 rad/s² for rotational acceleration. A Bland-Altman analysis found a systematic bias of 1% for PRA, with no significant bias for PLA. The instrumented mouthguard displayed high accuracy when measuring head impact kinematics in a laboratory setting.

The Natural History of Sport-Related Concussion in Collegiate Athletes: Findings from the NCAA-DoD CARE Consortium

BACKGROUND

Sport-related concussion is recognized as a significant injury with variable recovery rates.

OBJECTIVE

This study defined the acute natural history of sport concussion in male and female collegiate athletes participating in a broad array of sports.

METHODS

We conducted a prospective, longitudinal investigation among collegiate student athletes (n = 34,709) from 30 academic institutions. Primary outcomes included the time (days) from injury until initiation of a return to participation (RTP) protocol and time from injury until medical clearance for unrestricted RTP.

RESULTS

Concussed athletes (n = 1751, 19.2 years, 63.2% male) participating in 22 different sports began the RTP protocol in a median 6.4 (IQR 3.7-11.8) days. Time to initiate the RTP protocol was lengthened by less frequent post-injury assessments, greater initial post-injury symptom severity, limited contact sports participation, practice/training injuries, and three or more prior concussions. The median total RTP duration was 12.8 (IQR 8.7-20.1) days. Total RTP duration was shorter with ADHD medication usage, males, and greater assessment frequency; while greater initial post-injury symptom severity, practice-/training-related injuries, and three or more prior concussions had longer recoveries.

CONCLUSION

Although median recovery times are consistent with previous guidelines, it was not until 1 month post-injury that a preponderance of collegiate athletes were cleared to begin the RTP protocol (92%) or cleared for unrestricted sport participation (85%). Intrinsic and extrinsic factors had a small effect, altering recovery trajectories by up to 2 days, suggesting a largely unified approach to post-injury monitoring and management across all athletes. These data represent a shift from previous classification parameters of normal clinical recovery.

Neurocognitive correlates of persisting concussion symptoms in youth

Many patients that experience a concussion have impairing symptoms that persist beyond typical recovery timeframes. Concussion symptoms often remit within a month, but persisting impairments are difficult to characterize and attribute to concussion given the poorly defined diagnostic criteria of post-concussion syndrome and inadequate understanding of the cognitive symptoms associated with this condition. The current study aims to clarify the cognitive profiles of school-aged concussion patients (n = 21; N = 36; 64% male) that have persisting symptoms to improve the clinical identification methods for this condition. Logistic regression was used to explore the importance of cognitive processing speed and working memory for identifying patients with persisting concussion symptoms (PCS). Additional exploratory analyses were conducted to clarify cognitive domains that may be impacted by having PCS. Findings indicate processing speed and working memory abilities alone are not adequate to identify patients with PCS. Further, measures of processing speed, fluid reasoning, working memory, and long-term retrieval together were found to be necessary to identify those who had a prior concussion with PCS. These findings indicate clinical neuropsychological batteries must include measures of these four cognitive domains when assessing school-aged patients with chronic symptoms that extend beyond three months following injury.

Injury Reduction Programs for Reducing the Incidence of Sport-Related Head and Neck Injuries Including Concussion: A Systematic Review

BACKGROUND

Sport-related head and neck injuries, including concussion, are a growing global public health concern with a need to explore injury risk reduction strategies such as neck exercises.

OBJECTIVES

To systematically review the literature to investigate: (1) the relationship between neck strength and sport-related head and neck injuries (including sport-related concussion (SRC); and (2) whether neck exercise programs can reduce the incidence of (a) sport-related head and neck injuries; and (b) SRC.

METHODS

Five databases (Ovid MEDLINE, CINAHL, EMBASE, SPORTDiscus, and Web of Science) and research lists of included studies were searched using a combination of medical subject headings and keywords to locate original studies which reported the association between incidence of head and/or neck injury and neck strength data, or included a neck exercise intervention either in isolation or as part of a more comprehensive exercise program.

RESULTS

From an initial search of 593 studies, six were included in this review. A narrative synthesis was performed due to the heterogeneity of the included studies. The results of two observational studies reported that higher neck strength, but not deep neck flexor endurance, is associated with a lower risk of sustaining a SRC. Four intervention studies demonstrated that injury reduction programs that included neck exercises can reduce the incidence of sport-related head and neck injuries including SRC.

CONCLUSION

Consideration should be given towards incorporating neck exercises into injury reduction exercise programs to reduce the incidence of sport-related head and neck injuries, including SRC.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (registration number: 194217).

Omega-3 Fatty Acids and Vitamin D Decrease Plasma T-Tau, GFAP, and UCH-L1 in Experimental Traumatic Brain Injury

Traumatic brain injury (TBI) results in neuronal, axonal and glial damage. Interventions targeting neuroinflammation to enhance recovery from TBI are needed. Exercise is known to improve cognitive function in TBI patients. Omega-3 fatty acids and vitamin D reportedly reduce inflammation, and in combination, might improve TBI outcomes. This study examined how an anti-inflammatory diet affected plasma TBI biomarkers, voluntary exercise and behaviors following exposure to mild TBI (mTBI). Adult, male rats were individually housed in cages fitted with running wheels and daily running distance was recorded throughout the study. A modified weight drop method induced mTBI, and during 30 days post-injury, rats were fed diets supplemented with omega-3 fatty acids and vitamin D₃ (AIDM diet), or non-supplemented AIN-76A diets (CON diet). Behavioral tests were periodically conducted to assess functional deficits. Plasma levels of Total tau (T-tau), glial fibrillary acidic protein (GFAP), ubiquitin c-terminal hydrolase L1 (UCH-L1) and neurofilament light chain (NF-L) were measured at 48 h, 14 days, and 30 days post-injury. Fatty acid composition of food, plasma, and brain tissues was determined. In rats exposed to mTBI, NF-L levels were significantly elevated at 48 h post-injury (P < 0.005), and decreased to levels seen in uninjured rats by 14 days post-injury. T-tau, GFAP, and UCH-L1 plasma levels did not change at 48 h or 14 days post-injury. However, at 30 days post-injury, T-tau, GFAP and UCH-L1 all significantly increased in rats exposed to mTBI and fed CON diets (P < 0.005), but not in rats fed AIDM diets. Behavioral tests conducted post-injury showed that exercise counteracted cognitive deficits associated with mTBI. The AIDM diets significantly increased docosahexaenoic acid levels in plasma and brain tissue (P < 0.05), and in serum levels of vitamin D (P < 0.05). The temporal response of the four injury biomarkers examined is consistent with studies by others demonstrating acute and chronic neural tissue damage following exposure to TBI. The anti-inflammatory diet significantly altered the temporal profiles of plasma T-tau, GFAP, and UCH-L1 following mTBI. Voluntary exercise protected against mTBI-induced cognitive deficits, but had no impact on plasma levels of neurotrauma biomarkers. Thus, the prophylactic effect of exercise, when combined with an anti-inflammatory diet, may facilitate recovery in patients with mTBI.

Effects of CranioSacral therapy upon symptoms of post-acute concussion and Post-Concussion Syndrome: A pilot study

OBJECTIVE

The purpose of this study was to investigate the utilization of CranioSacral Therapy (CST) in patients with Post-Concussion Syndrome (PCS) and capture patient-reported perceptions of clinical outcomes of lived treatment experiences.

DESIGN

Two-part, longitudinal study conducted through a chart review of target group, followed by a Patient-reported Treatment Outcome Survey (PTOS).

PARTICIPANTS

A convenience sample of 212 patients with a historical incidence of head trauma not requiring hospitalization was obtained through medical records department dating back ten years. Inclusion criteria for further chart review (n = 67) was determined by identifying patients with a confirmed concussion directly correlated with presenting symptoms and for which CST was specifically sought as a treatment option. Demographics and patient-determined treatment duration data were analyzed by comparison groups extensively suggested in existing literature: Recovery time since injury as either Post-acute concussion (<6 months) or Post-Concussion Syndrome (PCS) (≥6 months); Athletes (A) or Non-athletes (NA); and traditional gender. Final PTOS group criteria was determined by eliminating confounding issues reporting (n = 47): (A, n = 24 and NA, n = 23).

RESULTS

Quantitative data was analyzed via Numerical Analysis, and qualitative data was analyzed via Inductive Content Analysis. Symptoms reported in all charts as well as in the PTOS were consistent with identified PCS subtypes. Utilization of CST revealed that most patients determined the treatment effect upon concussion symptoms within 1-3 sessions. Nearly twice as many sessions were attended in the PCS than post-acute groups. Referral sources, studied for a perspective on local concussion after-care discharge planning, ranged from professional to personal recommendation or self-discovery. A majority of patients met goals of reducing post-acute or PCS as reasons cited by self-determined change-in-status or discharge from service. Patients were asked to indicate on the PTOS which pre- and post-treatment symptoms were helped or not helped by this particular intervention.

CONCLUSIONS

Patient-reported changes of PCS symptoms is critical when evaluating treatment options. CST is an experiential treatment that addresses subjective levels of dysfunction, thus it is the patient deciding the value of an intervention. A sizable portion of patients in all groups reported a positive effect upon their symptoms by CST. Patients indicated personal meaning to CST through their utilization of multiple sessions. A high percentage indicated the likelihood of referring others with PCS for CST. Of the 212 patient charts first studied, the 145 not meeting inclusion criteria suggest some chronic conditions may present as long-term effects of older head injuries. CST is a low-risk, conservative treatment option for PCS sub-types worthy of further clinical study.

Prolonged concussion effects: Constellations of cognitive deficits detected up to year after injury

Concussions are associated with an array of physical, emotional, cognitive, and sleep symptoms at multiple timescales. Cognitive recovery occurs relatively quickly – five-to-seven days on average. Yet, recent evidence suggests that some neurophysiological changes can be identified one year after a concussion. To that end, we examine more nuanced patterns in cognitive tests to determine whether cognitive abilities could identify a concussion within one-year post injury. A radial-basis (non-linear boundary) support vector machine classifier was trained to use cognitive performance measures to distinguish participants with no prior concussion from participants with prior concussion in the past year. After incorporating only 10 cognitive measures, or all 5 composite measures from the neurocognitive assessment (Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT)), over 90% accuracy was achieved in identifying both participants without prior concussions and participants with concussions in the past year, particularly when relying on non-linear patterns. Notably, classification accuracy stayed relatively constant between participants who had a concussion early or late in the one-year window. Thus, with substantial accuracy, a prior concussion can be identified using a non-linear combination of cognitive measures. Cognitive effects from concussion linger one-year post-injury, indicating the importance of continuing to follow concussion patients for many months after recovery and to take special note of constellations of cognitive abilities.

In it to win it: Competitiveness, concussion knowledge and nondisclosure in athletes

OBJECTIVES

Despite having a general understanding of concussions, many athletes choose not to report symptoms of a sports-related concussion (SRC) which leads to a larger burden on our healthcare system due to longer recoveries, more Emergency Department visits, and future medical appointments. Thus, there is a need to identify factors, such as competitiveness, that may help to better explain the nondisclosure of concussion symptoms. The current study aimed to investigate the role of athletes' concussion knowledge and competitiveness on concussion nondisclosure.

METHODS

Participants included 161 Canadian athletes (ages 14-32; 71% male) participating in collision sports (American football, rugby, hockey), soccer or rowing. Concussion knowledge, reporting and competitiveness were measured using the Rosenbaum Concussion Attitude and Knowledge Survey and Sports Orientation Questionnaire (SOQ). Two logistic regression models were performed to explain both history and future intention of playing despite experiencing concussion symptoms.

RESULTS

Age, sex, and concussion knowledge were not significant for the regression models. The SOQ scores (measuring competitiveness) were significant for both regression models, such that higher competitiveness was associated with increased likelihood for past nondisclosure (b =.03, p =.03, OR = 1.03 (97.5% CI: 1.003,1.06)) and future nondisclosure intention (b =.05, p =.00, OR = 1.05 (97.5% CI: 1.03,1.08)). Regarding concussion knowledge, soccer players had significantly higher knowledge than those in collision sports and rugby, F(2, 158) = 140.5, p =.00; female athletes had significantly higher knowledge than males, t(66) = -4.26, p =.00; age was negatively associated with concussion knowledge (r = -0.35, p < .01).

CONCLUSION

The results suggest that healthcare providers should be aware that athletes tend to have adequate concussion knowledge, but this knowledge does not explain past nondisclosure or future nondisclosure intention. Based on these findings, healthcare providers should focus on being able to identify highly competitive athletes who are most at risk of nondisclosure instead of exclusively aiming to increase concussion knowledge in athletes.

Persistent Visual and Vestibular Impairments for Postural Control Following Concussion: A Cross-Sectional Study in University Students

OBJECTIVE

To examine how concussion may impair sensory processing for control of upright stance.

METHODS

Participants were recruited from a single university into 3 groups: 13 participants (8 women, 21 ± 3 years) between 2 weeks and 6 months post-injury who initiated a return-to-play progression (under physician management) by the time of testing (recent concussion group), 12 participants (7 women, 21 ± 1 years) with a history of concussion (concussion history group, > 1 year post-injury), and 26 participants (8 women, 22 ± 3 years) with no concussion history (control group). We assessed sensory reweighting by simultaneously perturbing participants' visual, vestibular, and proprioceptive systems and computed center of mass gain relative to each modality. The visual stimulus was a sinusoidal translation of the visual scene at 0.2 Hz, the vestibular stimulus was ± 1 mA binaural monopolar galvanic vestibular stimulation (GVS) at 0.36 Hz, the proprioceptive stimulus was Achilles' tendon vibration at 0.28 Hz.

RESULTS

The recent concussion (95% confidence interval 0.078-0.115, p = 0.001) and the concussion history (95% confidence interval 0.056-0.094, p = 0.038) groups had higher gains to the vestibular stimulus than the control group (95% confidence interval 0.040-0.066). The recent concussion (95% confidence interval 0.795-1.159, p = 0.002) and the concussion history (95% confidence interval 0.633-1.012, p = 0.018) groups had higher gains to the visual stimulus than the control group (95% confidence interval 0.494-0.752). There were no group differences in gains to the proprioceptive stimulus or in sensory reweighting.

CONCLUSION

Following concussion, participants responded more strongly to visual and vestibular stimuli during upright stance, suggesting they may have abnormal dependence on visual and vestibular feedback. These findings may indicate an area for targeted rehabilitation interventions.