Return to play after an initial or recurrent concussion in a prospective study of physician-observed junior ice hockey concussions: implications for return to play after a concussion

Symptom resolution following a repeat concussion within the same athlete

INTRODUCTION

Repeat sport-related concussion (SRC) is anecdotally associated with prolonged recovery. Few studies have examined repeat concussion within the same athlete. We sought to explore differences in symptom burden and recovery outcomes in an individual athlete's initial and repeat SRC.

METHODS

A retrospective within-subject cohort study of athletes aged 12-23 years diagnosed with two separate SRCs from 11/2017-10/2020 was conducted. Primary outcomes were initial symptom severity and time-to-symptom-resolution. Secondary outcomes included return-to-learn (RTL) and return-to-play (RTP) duration.

RESULTS

Of 868 athletes seen, 47 athletes presented with repeat concussions. Median time between concussions was 244 days (IQR 136-395). Comparing initial to repeat concussion, no differences were observed in time-to-clinic (4.3 ± 7.3vs.3.7 ± 4.6 days, p = 0.56) or initial PCSS (26.2 ± 25.3 vs. 30.5 ± 24.1, p = 0.32). While a difference was observed in time-to-symptom resolution between initial/repeat concussion (21.2 ± 16.3 vs. 41.7 ± 86.0 days, p = 0.30), this did not reach statistical significance. No significant differences were observed in time-to-RTL (17.8 ± 60.6 vs. 6.0 ± 8.3 days, p = 0.26) and RTP (33.2 ± 44.1 vs. 29.4 ± 39.1 days, p = 0.75). Repeat concussion was not associated with symptom resolution on univariate (HR 1.64, 95% CI 0.96-2.78, p = 0.07) and multivariable (HR 0.85, 95% CI 0.49-1.46, p = 0.55) Cox regression.

CONCLUSION

No significant differences in symptom duration and RTP/RTL were seen between initial/repeat concussion.

Consensus statement: An evidence-based review of exercise, rehabilitation, rest, and return to activity protocols for the treatment of concussion and mild traumatic brain injury

BACKGROUND

Early diagnosis and appropriate management of concussion/mild traumatic brain injury (mTBI) is critical for preventing poor outcomes and minimizing health care burden. Current clinical guidelines for concussion management focus mostly on diagnosis and return to cognitive and physical activity but provide limited guidance on the use of specific therapeutic interventions.

OBJECTIVE

To systematically review the available evidence on therapeutic interventions for concussion/mTBI and develop an evidence-based consensus statement on the use of these interventions in clinical practice.

LITERATURE SURVEY

A systematic literature search was performed first in 2018 and 2019, and again in 2022, to identify relevant original research on these interventions. A total of 6303 articles were retrieved through the systematic literature search and screened for inclusion. Eighty articles met inclusion criteria and were included in this review and consensus process.

METHODOLOGY

A multispecialty panel was convened to explore management of concussion/mTBI. Interventions evaluated included rest, exercise, rehabilitation, and return to activity (RTA) protocols. Studies were assessed for relevance and methodologic quality and were voted upon to develop an evidence-based consensus statement on the therapeutic appropriateness of these interventions for concussion/mTBI. A meta-analysis was not performed.

SYNTHESIS

There was sufficient evidence to recommend exercise as an appropriate therapy for adolescents with acute concussion/mTBI. In other age groups and for other therapeutic modalities, although some studies demonstrated benefits for some of the interventions, mixed results and study limitations prevented the panel from drawing firm conclusions on the efficacy of those interventions. The panel found evidence of detrimental effects from strict rest and high-intensity physical activity.

CONCLUSIONS

The panel recommended exercise as an appropriate therapy for acute concussion in adolescents. The evidence on other therapeutic interventions for concussion/mTBI remains limited to small randomized controlled trials and observational studies of moderate to low quality. The panel found no strong evidence to support or recommend against the other evaluated interventions but found most interventions to be safe when used judiciously and in consideration of individual patient needs. High-quality randomized studies with sufficient power are needed to evaluate the effects of rest, rehabilitation, and RTA protocols for the management of concussion/mTBI.

Epidemiological analysis of concussions in youth ice hockey players: A national emergency room database study

PURPOSE

To evaluate the epidemiology of concussions in youth ice hockey players.

METHODS

The National Electronic Injury Surveillance System (NEISS) database was used to gather data. Concussions occurring during ice hockey participation in youth patients (4-21 years old) from 2012 to 2021 was gathered. Concussion mechanisms were grouped into 7 categories: head-to-player, head-to-puck, head-to-ice, head-to-board/glass, head-to-stick, head-to-goal post, and unknown. Hospitalization rates were also tabulated. Linear regression models were used to assess changes in yearly concussion and hospitalization rates over the study period. Results from these models were reported using parameter estimates [with 95% confidence intervals (CI)] and the estimated Pearson correlation coefficient. Additionally, logistic regression was used to model the risk of hospitalization across the different cause categories.

RESULTS

A total of 819 ice hockey related concussions were analyzed between 2012 and 2021. The average age of our cohort was 13.4 years, with 89.3% (n = 731) of concussions occurring in males. The incidence of head-to-ice, head-to-board/glass, head-to-player, and head-to-puck concussion mechanisms decreased significantly over the study period (slope estimate = -2.1 concussions/year [CI: (-3.9, -0.2)], r = -0.675, p = 0.032), (slope estimate = -2.7 concussions/year [CI: (-4.3, -1.2)], r = -0.816, p = 0.004), (slope estimate = -2.2 concussions/year [CI: (-3.4, -1.0)], r = -0.832, p = 0.003), and (slope estimate = -0.4 concussions/year [CI: (-0.62, -0.09)], r = -0.768, p = 0.016), respectively. Majority of patients were discharged from the emergency department (ED) to their home, as only 20 people (2.4%) were hospitalized over our study period. The majority of concussions were due to head-to-ice (n = 285, 34.8%), followed by head-to-board/glass (n = 217, 26.5%) and head-to-player (n = 207, 25.3%). The most common cause for hospitalizations due to concussions was head-to-board/glass (n = 7, 35%), followed by head-to-player (n = 6, 30%) and head-to-ice (n = 5, 25%).

CONCLUSION

The most common mechanism of youth ice hockey concussions was head-to-ice in our 10-year study period, while head-to-board/glass was the most common cause of hospitalizations. IRB: This project did not require review by the institutional review board.

Pallidal deep brain stimulation in primary Meige syndrome: clinical outcomes and psychiatric features

OBJECTIVES

To study the efficacy and safety of bilateral globus pallidus internus deep brain stimulation (GPi-DBS) in refractory Meige syndrome (MS) and evaluate the psychiatric disorders before and after surgery.

METHODS

Twenty-two patients with MS treated with bilateral GPi-DBS were retrospectively analysed before surgery and after continuous neurostimulation. Before surgery, patients were assessed by the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS), Self-Rating Depression Scale, Medical Outcomes Study 36-Item Short-Form General Health Survey (SF-36) and Pittsburgh Sleep Quality Index (PQSI), which corresponded to motor symptoms, depressive state, quality of life and sleep quality, respectively. The implantable pulse generator of each patient was activated at 1 month after surgery. At 1 month, 3 months, 6 months and 12 months after continuous neurostimulation, all patients were evaluated by the same scales above.

RESULTS

The BFMDRS movement scores decreased from 15.0±5.3 before surgery to 3.5±4.5 at 12 months after neurostimulation, with a mean improvement of 78% (p<0.001). The BFMDRS disability scores improved from 7.4±4.9 before surgery to 4.0±4.6 at 12 months after neurostimulation, with a mean improvement of 56% (p<0.001). The postoperative SF-36 scores had the remarkable improvement compared with baseline scores. Impaired sleep quality was found in 82% of patients and depression in 64% before surgery, which didn't neither obtained amelioration after continuous neurostimulation.

CONCLUSIONS

Bilateral pallidal neurostimulation is a beneficial therapeutic option for refractory MS, which could improve the motor symptoms except for depression and sleep quality.

Prevalence and Incidence of Microhemorrhages in Adolescent Football Players

BACKGROUND AND PURPOSE

SWI is an advanced imaging modality that is especially useful in cerebral microhemorrhage detection. Such microhemorrhages have been identified in adult contact sport athletes, and the sequelae of these focal bleeds are thought to contribute to neurodegeneration. The purpose of this study was to utilize SWI to determine whether the prevalence and incidence of microhemorrhages in adolescent football players are significantly greater than those of adolescent noncontact athletes.

MATERIALS AND METHODS

Preseason and postseason SWI was performed and evaluated on 78 adolescent football players. SWI was also performed on 27 adolescent athletes who reported no contact sport history. Two separate one-tailed Fisher exact tests were performed to determine whether the prevalence and incidence of microhemorrhages in adolescent football players are greater than those of noncontact athlete controls.

RESULTS

Microhemorrhages were observed in 12 football players. No microhemorrhages were observed in any controls. Adolescent football players demonstrated a significantly greater prevalence of microhemorrhages than adolescent noncontact controls (P = .02). Although 2 football players developed new microhemorrhages during the season, microhemorrhage incidence during 1 football season was not statistically greater in the football population than in noncontact control athletes (P = .55).

CONCLUSIONS

Adolescent football players have a greater prevalence of microhemorrhages compared with adolescent athletes who have never engaged in contact sports. While microhemorrhage incidence during 1 season is not significantly greater in adolescent football players compared to adolescent controls, there is a temporal association between playing football and the appearance of new microhemorrhages.

Neuronal Enriched Extracellular Vesicle Proteins as Biomarkers for Traumatic Brain Injury

Traumatic brain injury (TBI) is a major cause of injury-related death throughout the world and lacks effective treatment. Surviving TBI patients often develop neuropsychiatric symptoms, and the molecular mechanisms underlying the neuronal damage and recovery following TBI are not well understood. Extracellular vesicles (EVs) are membranous nanoparticles that are divided into exosomes (originating in the endosomal/multi-vesicular body [MVB] system) and microvesicles (larger EVs produced through budding of the plasma membrane). Both types of EVs are generated by all cells and are secreted into the extracellular environment, and participate in cell-to-cell communication and protein and RNA delivery. EVs enriched for neuronal origin can be harvested from peripheral blood samples and their contents quantitatively examined as a window to follow potential changes occurring in brain. Recent studies suggest that the levels of exosomal proteins and microRNAs (miRNAs) may represent novel biomarkers to support the clinical diagnosis and potential response to treatment for neurological disorders. In this review, we focus on the biogenesis of EVs, their molecular composition, and recent advances in research of their contents as potential diagnostic tools for TBI.

Biofluid biomarkers of traumatic brain injury

PRIMARY OBJECTIVE

The purpose of this paper is to review the clinical and research utility and applications of blood, cerebrospinal fluid (CSF), and cerebral microdialysis biomarkers in traumatic brain injury (TBI).

RESEARCH DESIGN

Not applicable.

METHODS AND PROCEDURES

A selective review was performed on these biofluid biomarkers in TBI.

MAIN OUTCOME AND RESULTS

Neurofilament heavy chain protein (NF-H), glial fibrillary acidic protein (GFAP), ubiquitin C-terminal hydrolase-L1 (UCHL1), neuron-specific enolase (NSE), myelin basic protein (MBP), tau, and s100β blood biomarkers are elevated during the acute phase of severe head trauma but have key limitations in their research and clinical applications to mild TBI (mTBI). CSF biomarkers currently provide the best reflection of the central nervous system (CNS) pathobiological processes in TBI. Both animal and human studies of TBI have demonstrated the importance of serial sampling of biofluids and suggest that CSF biomarkers may be better equipped to characterize both TBI severity and temporal profiles.

CONCLUSIONS

The identification of biofluid biomarkers could play a vital role in identifying, diagnosing, and treating the underlying individual pathobiological changes of TBI. CNS-derived exosomes analyzed by ultra-high sensitivity detection methods have the potential to identify blood biomarkers for the range of TBI severity and time course.

Sub-concussive trauma, acute concussion, and history of multiple concussions: Effects on quiet stance postural control stability

Although balance control has been studied extensively following acute concussion, little is known regarding repetitive sub-concussive head impacts or chronic exposure to multiple concussive events. Quiet stance postural control was characterized in contact sport athletes at pre-season (n = 135) and post-season (n = 48) to evaluate the effects of subconcussive trauma to the head. To determine the impact of acute concussion on postural control, athletes diagnosed with a concussion during the season (n = 12) were tested at 72-h, 2-weeks, and 1-month post-injury. Because only 4 of the concussed athletes completed baseline testing, control athletes (n = 12) matched for sport, age, body mass index (BMI), and previous concussion history served as a comparison group. Finally, the effects of previous concussion history on quiet stance postural control were determined by comparing pre-season data in contact sport athletes with either zero (Hx⁰, n = 50) or three or more (Hx³⁺, n = 25) previous concussions. A force plate was used to compare changes in centre-of-pressure root-mean-square displacement (RMSdisp) and mean-velocity (COPvel) in the anterior/posterior (AP) and medial/lateral (ML) directions. One-minute trials were performed with feet hip-width apart, hands-on-hips, and A) eyes-open and B) eyes-closed. Biomechanical head-impact exposure (impacts over 10 g) was indexed over the season using mastoid-fixed impact sensors. In acutely injured athletes, repeated-measures ANOVA revealed a significant effect of time for RMSdisp AP with increased displacement at 2 weeks compared to 72 h (p = 0.008, 95% CI: -0.180, -0.310 cm). No other COP variables were affected by acute concussion. Moreover, there was no effect of concussion history or repeated sub-concussive impacts on any quiet stance metric. Additionally, head-impact exposure metrics were not correlated with COP metrics. Taken together, the data suggests alterations in COP sway during quiet stance persist in the acute 2-week period after injury. These findings were not present with either a history of multiple concussions or exposure to sub-concussive head impacts indicating acute concussion does not have appear to have long term effects for these measures.

Sex differences in white matter alterations following repetitive subconcussive head impacts in collegiate ice hockey players

Objective

Repetitive subconcussive head impacts (RSHI) may lead to structural, functional, and metabolic alterations of the brain. While differences between males and females have already been suggested following a concussion, whether there are sex differences following exposure to RSHI remains unknown. The aim of this study was to identify and to characterize sex differences following exposure to RSHI.

Methods

Twenty-five collegiate ice hockey players (14 males and 11 females, 20.6 ± 2.0 years), all part of the Hockey Concussion Education Project (HCEP), underwent diffusion-weighted magnetic resonance imaging (dMRI) before and after the Canadian Interuniversity Sports (CIS) ice hockey season 2011-2012 and did not experience a concussion during the season. Whole-brain tract-based spatial statistics (TBSS) were used to compare pre- and postseason imaging in both sexes for fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD). Pre- and postseason neurocognitive performance were assessed by the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT).

Results

Significant differences between the sexes were primarily located within the superior longitudinal fasciculus (SLF), the internal capsule (IC), and the corona radiata (CR) of the right hemisphere (RH). In significant voxel clusters (p < 0.05), decreases in FA (absolute difference pre- vs. postseason: 0.0268) and increases in MD (0.0002), AD (0.00008), and RD (0.00005) were observed in females whereas males showed no significant changes. There was no significant correlation between the change in diffusion scalar measures over the course of the season and neurocognitive performance as evidenced from postseason ImPACT scores.

Conclusions

The results of this study suggest sex differences in structural alterations following exposure to RSHI. Future studies need to investigate further the underlying mechanisms and association with exposure and clinical outcomes.

Factors Influencing the Underreporting of Concussion in Sports: A Qualitative Study of Minor Hockey Participants

OBJECTIVE

The present study is to identify factors contributing to underreporting of concussion in adolescent athletes.

DESIGN

Qualitative interviews.

SETTING

Participants were interviewed in an office environment.

PARTICIPANTS

Interviews were conducted with 31 minor hockey players, 10 parents, 6 coaches, 4 trainers, 2 managers, and one game official. Players were 13 to 15 year old. With selective sampling, an inductive approach of analyzing the interviews was undertaken and themes were identified and analyzed.

ASSESSMENT OF RISK FACTORS

Underreporting is a complex phenomenon. A number of risk factors related to hockey culture, players, reference others, and rules of play were assessed.

MAIN OUTCOME MEASURES

Reasons not reporting concussion is accepted in minor hockey.

RESULTS

Aspects of hockey culture such as an overemphasis on winning games and upheld misperceptions about the risks associated with concussion were identified as relevant to the underreporting of concussions. Various factors relevant to the underreporting of concussions include player's motivation to win, group membership dynamics such as a player's role as the team's "enforcer," coaches' own motivation to win to further their own opportunities in the sport, and parents' personal financial interest or alternative agenda in terms of time commitments and their child's future career prospects.

CONCLUSIONS

Our findings indicate that underreporting of concussion among those players interviewed appears to be prevalent and associated with misconceptions about injury risk, and a culture that both reinforces and encourages underreporting with tacit or overt complicity of parents and coaches. Our findings support the need to alter the culture of violence and tough play in hockey by education, rule changes, economic measures, and changes in governance of the sport. Interviewing more stakeholders and policy makers would shed light on such potential interventions.

Validity of the Immediate Post Concussion Assessment and Cognitive Testing (ImPACT)

BACKGROUND

The immediate post concussion assessment and cognitive testing (ImPACT) is the most widely used concussion assessment tool. Despite its popularity, it is unclear if validation studies for the ImPACT test covered all aspects of validity to support its widespread use in research and clinical practice.

OBJECTIVE

The purpose of this report is to review literature surrounding the validity and the utility of the ImPACT test.

DATA SOURCES AND APPRAISAL

A systematic review of relevant studies in PubMed, CINAHL, and PsycINFO was carried out. Studies were evaluated using the STROBE (strengthening the reporting of observational studies in epidemiology) or the STARD (standards for reporting of diagnostic accuracy) criteria.

RESULTS

The literature search yielded 5968 studies. Sixty-nine studies met the inclusion criteria and were included in the qualitative review. Although the convergent validity of ImPACT was supported, evidence of discriminant and predictive validity, diagnostic accuracy and responsiveness was inconclusive. The utility of the ImPACT test after acute symptom resolution was sparse. The review found many factors influenced the validity and utility of ImPACT scores.

CONCLUSION

Clinicians must consider the benefit of ImPACT testing for their patients on a case-by-case scenario and must take the psychometric properties of the test into account when interpreting results.

Rest and Return to Activity After Sport-Related Concussion: A Systematic Review of the Literature

OBJECTIVE

To systematically review the literature regarding rest and return to activity after sport-related concussion.

DATA SOURCES

The search was conducted in the Cochrane Central Register of Controlled Trials, CINAHL, SPORTDiscus, Educational Resources Information Center, Ovid MEDLINE, and PubMed using terms related to concussion, mild traumatic brain injury, physical and cognitive rest, and return to activity.

STUDY SELECTION

Studies were included if they were published in English; were original research; and evaluated the use of, compliance with, or effectiveness of physical or cognitive rest or provided empirical evidence supporting the graded return-to-activity progression.

DATA EXTRACTION

The study design, patient or participant sample, interventions used, outcome measures, main results, and conclusions were extracted, as appropriate, from each article.

DATA SYNTHESIS

Articles were categorized into groups based on their ability to address one of the primary clinical questions of interest: use of rest, rest effectiveness, compliance with recommendations, or outcome after graded return-to-activity progression. A qualitative synthesis of the results was provided, along with summary tables.

CONCLUSIONS

Our main findings suggest that rest is underused by health care providers, recommendations for rest are broad and not specific to individual patients, an initial period of moderate physical and cognitive rest (eg, limited physical activity and light mental activity) may improve outcomes during the acute postinjury phase, significant variability in the use of assessment tools and compliance with recommended return-to-activity guidelines exists, and additional research is needed to empirically evaluate the effectiveness of graded return-to-activity progressions. Furthermore, there is a significant need to translate knowledge of best practices in concussion management to primary care providers.

What are the critical elements of sideline screening that can be used to establish the diagnosis of concussion? A systematic review

BACKGROUND

Sideline detection is the first and most significant step in recognising a potential concussion and removing an athlete from harm. This systematic review aims to evaluate the critical elements aiding sideline recognition of potential concussions including screening tools, technologies and integrated assessment protocols.

DATA SOURCES

Bibliographic databases, grey literature repositories and relevant websites were searched from 1 January 2000 to 30 September 2016. A total of 3562 articles were identified.

STUDY SELECTION

Original research studies evaluating a sideline tool, technology or protocol for sports-related concussion were eligible, of which 27 studies were included.

DATA EXTRACTION

A standardised form was used to record information. The QUADAS-2 and Newcastle-Ottawa tools were used to rate risk of bias. Strength of evidence was assessed using the Grades of Recommendation, Assessment, Development and Evaluation Working Group system.

DATA SYNTHESIS

Studies assessing symptoms, the King-Devick test and multimodal assessments reported high sensitivity and specificity. Evaluations of balance and cognitive tests described lower sensitivity but higher specificity. However, these studies were at high risk of bias and the overall strength of evidence examining sideline screening tools was very low. A strong body of evidence demonstrated that head impact sensors did not provide useful sideline concussion information. Low-strength evidence suggested a multimodal, multitime-based concussion evaluation process incorporating video review was important in the recognition of significant head impact events and delayed onset concussion.

CONCLUSION

In the absence of definitive evidence confirming the diagnostic accuracy of sideline screening tests, consensus-derived multimodal assessment tools, such as the Sports Concussion Assessment Tool, are recommended. Sideline video review may improve recognition and removal from play of athletes who have sustained significant head impact events. Current evidence does not support the use of impact sensor systems for real-time concussion identification.

Depression as a Modifying Factor in Sport-Related Concussion: A Critical Review of the Literature

Since its third iteration in 2008, the international Concussion in Sport Group (CISG) has delineated several 'modifying factors' that have the potential to influence the management of sport-related concussions (SRC). One of these factors is co- and pre-morbidities, which includes migraines, mental health disorders, attention-deficit hyperactive disorder (ADHD), learning disability, and sleep disorders. Mental health disorders, and in particular, depression, have received some attention in the management of SRC and in this review we summarize the empirical evidence for its inclusion as a modifying factor. This review is divided into three main bodies of findings: (1) the incidence and prevalence of depression and depressive symptoms in non-concussed and concussed athletes, with comparison made to the general population; (2) managing the post-concussion athlete and accounting for premorbid depressive symptoms; and (3) depression as a long-term effect of repetitive head trauma. Overall, it has been reported that certain subpopulations of athletes have similar or even higher rates of depressive symptoms when compared to the general population. The challenge of accounting for these baseline-depressive symptoms while managing the post-concussive athlete is stressed. And lastly, the prevalence of depression and its relationship to concussion in later-life is discussed.

Pediatric sports-related traumatic brain injury in United States trauma centers

OBJECTIVE

Traumatic brain injury (TBI) in children is a significant public health concern estimated to result in over 500,000 emergency department (ED) visits and more than 60,000 hospitalizations in the United States annually. Sports activities are one important mechanism leading to pediatric TBI. In this study, the authors characterize the demographics of sports-related TBI in the pediatric population and identify predictors of prolonged hospitalization and of increased morbidity and mortality rates.

METHODS

Utilizing the National Sample Program of the National Trauma Data Bank (NTDB), the authors retrospectively analyzed sports-related TBI data from children (age 0–17 years) across 5 sports categories: fall or interpersonal contact (FIC), roller sports, skiing/snowboarding, equestrian sports, and aquatic sports. Multivariable regression analysis was used to identify predictors of prolonged length of stay (LOS) in the hospital or intensive care unit (ICU), medical complications, inpatient mortality rates, and hospital discharge disposition. Statistical significance was assessed at α < 0.05, and the Bonferroni correction (set at significance threshold p = 0.01) for multiple comparisons was applied in each outcome analysis.

RESULTS

From 2003 to 2012, in total 3046 pediatric sports-related TBIs were recorded in the NTDB, and these injuries represented 11,614 incidents nationally after sample weighting. Fall or interpersonal contact events were the greatest contributors to sports-related TBI (47.4%). Mild TBI represented 87.1% of the injuries overall. Mean (± SEM) LOSs in the hospital and ICU were 2.68 ± 0.07 days and 2.73 ± 0.12 days, respectively. The overall mortality rate was 0.8%, and the prevalence of medical complications was 2.1% across all patients. Severities of head and extracranial injuries were significant predictors of prolonged hospital and ICU LOSs, medical complications, failure to discharge to home, and death. Hypotension on admission to the ED was a significant predictor of failure to discharge to home (OR 0.05, 95% CI 0.03–0.07, p < 0.001). Traumatic brain injury incurred during roller sports was independently associated with prolonged hospital LOS compared with FIC events (mean increase 0.54 ± 0.15 days, p < 0.001).

CONCLUSIONS

In pediatric sports-related TBI, the severities of head and extracranial traumas are important predictors of patients developing acute medical complications, prolonged hospital and ICU LOSs, in-hospital mortality rates, and failure to discharge to home. Acute hypotension after a TBI event decreases the probability of successful discharge to home. Increasing TBI awareness and use of head-protective gear, particularly in high-velocity sports in older age groups, is necessary to prevent pediatric sports-related TBI or to improve outcomes after a TBI.

Social norms theory and concussion education

Secondary prevention of harm from sport-related concussion is contingent on immediate removal from play post-injury. To-date, educational efforts to reduce the prevalent risk behavior of continued play while symptomatic have been largely ineffective. Social norms theory may hold promise as a foundation for more effective concussion education aimed at increasing concussion reporting. The primary objective of this study was to assess whether perceived team concussion reporting norms would be less supportive of an individual's safe concussion symptom reporting behavior than objective team norms. Participants were 328 male and female US collegiate athletes. Written surveys were completed in person during the spring of 2014. Among both male and female athletes, team concussion reporting norms were significantly misperceived, with athletes tending to think that they themselves have safer attitudes about concussion reporting than their teammates. Perceived norms were associated with symptom reporting intention, independent of the team's objective reporting norm. A social norms approach to concussion education, in which misperceived group norms are corrected and shifted in the direction of safety, is an important avenue for program development and evaluation research aimed at the secondary prevention of harm from concussion. Implications for the design of this type of educational programming are discussed.

Hockey STAR: A Methodology for Assessing the Biomechanical Performance of Hockey Helmets

Optimizing the protective capabilities of helmets is one of several methods of reducing brain injury risk in sports. This paper presents the experimental and analytical development of a hockey helmet evaluation methodology. The Summation of Tests for the Analysis of Risk (STAR) formula combines head impact exposure with brain injury probability over the broad range of 227 head impacts that a hockey player is likely to experience during one season. These impact exposure data are mapped to laboratory testing parameters using a series of 12 impact conditions comprised of three energy levels and four head impact locations, which include centric and non-centric directions of force. Injury risk is determined using a multivariate injury risk function that incorporates both linear and rotational head acceleration measurements. All testing parameters are presented along with exemplar helmet test data. The Hockey STAR methodology provides a scientific framework for manufacturers to optimize hockey helmet design for injury risk reduction, as well as providing consumers with a meaningful metric to assess the relative performance of hockey helmets.

Developmental and gender influences on executive function following concussion in youth hockey players

BACKGROUND

Concussion is the most common athletic injury in youth who are simultaneously undergoing rapid developmental changes in the brain, specifically the development of executive functions (EF). The developing brain is more vulnerable to concussive injury with a protracted and different trajectory of recovery than that of adults. Thus, there is a critical need to enhance understanding of how concussion affects EF in youth.

OBJECTIVE

To investigate the effects of age, gender and concussion history (i.e. concussion incidence, recency, severity) on EF in youth hockey players.

METHODS

This 3-year cross-sectional and longitudinal multiple cohort study examined data from 211 hockey players of 8-15 years of age. Mixed-effects modelling was used to examine the influence of age, gender and concussion on EF in youth athletes.

FINDINGS

Baseline analyses revealed significant age and gender effects on measures of EF. Multiple effects of concussion history on measures of cognitive flexibility (F = 2.48, p = 0.03) and psychomotor speed (F = 2.59, p = 0.04) were found.

IMPLICATIONS

This study highlights the impact of age, gender and concussion on EF in youth. These findings provide foundational knowledge to better manage cognitive sequelae following sports-related concussion.

Engaging Teammates in the Promotion of Concussion Help Seeking

Concussion underreporting contributes to the substantial public health burden of concussions from sport. Teammates may be able to play an important role in encouraging injury identification and help seeking. This study assessed whether there was an association between beliefs about the consequences of continued play with a concussion and intentions to engage as a proactive bystander in facilitating or encouraging teammate help seeking for a possible concussion. Participants were 328 (male and female) members of 19 U.S. collegiate contact or collision sports teams. Athletes who believed that there were negative health or performance consequences of continued play with a concussion were significantly more likely than their peers to intend to encourage teammate help seeking, but not more likely to alert a coach or medical personnel. Additionally, athletes who believed that their teammates were more supportive of concussion safety were more likely to intend to engage as proactive bystanders in encouraging teammate help seeking. Exploring how to encourage bystander promotion of concussion safety is an important direction for future programming and evaluation research and may provide an opportunity to improve the effectiveness of concussion education.

Evaluation of the anatomical and functional consequences of repetitive mild cervical contusion using a model of spinal concussion

Spinal cord concussion is characterized by a transient loss of motor and sensory function that generally resolves without permanent deficits. Spinal cord concussions usually occur during vehicular accidents, falls, and sport activity, but unlike brain concussions, have received much less attention despite the potential for repeated injury leading to permanent neurological sequelae. Consequently, there is no consensus regarding decisions related to return to play following an episode of spinal concussion, nor an understanding of the short- and long-term consequences of repeated injury. Importantly, there are no models of spinal concussion to study the anatomical and functional sequelae of single or repeated injury. We have developed a new model of spinal cord concussion focusing on the anatomical and behavioral outcomes of single and repeated injury. Rats received a very mild (50 kdyn, IH impactor) spinal contusion at C5 and were separated into two groups three weeks after the initial injury--C1, which received a second, sham surgery, and C2, which received a second contusion at the same site. To track motor function and recovery, animals received weekly behavioral tests--BBB, CatWalk™, cylinder, and Von Frey. Analysis of locomotor activity by BBB demonstrated that rats rapidly recovered, regaining near-normal function by one week after the first and second injury, which was confirmed using the more detailed CatWalk™ analysis. The cylinder test showed that a single contusion did not induce significant deficits of the affected limb, but that repeated injury resulted in significant alteration in paw preference, with animals favoring the unaffected limb. Intriguingly, Von Frey analysis demonstrated an increased sensitivity in the contralateral hindlimb in the C2 group vs. the C1 group. Anatomical analyses revealed that while the lesion volume of both groups was minimal, the area of spared white matter in the C2 group was significantly reduced 1 and 2mm rostral to the lesion epicenter. Reactive astrocytes were present in both groups, with the majority found at the lesion epicenter in the C1 group, whereas the C2 group demonstrated increased reactive astrocytes extending 1mm caudal to the lesion epicenter. Macrophages accumulated within the injured, dorsal and ipsilateral spinal cord, with significant increases at 2 and 3mm rostral to the epicenter in the C2 group. Our model is designed to represent the clinical presentation of spinal cord concussion, and highlight the susceptibility and functional sequelae of repeated injury. Future experiments will examine the temporal and spatial windows of vulnerability for repeated injuries.

Concussion under-reporting and pressure from coaches, teammates, fans, and parents

Concussions from sport present a substantial public health burden given the number of youth, adolescent and emerging adult athletes that participate in contact or collision sports. Athletes who fail to report symptoms of a suspected concussion and continue play are at risk of worsened symptomatology and potentially catastrophic neurologic consequences if another impact is sustained during this vulnerable period. Understanding why athletes do or do not report their symptoms is critical for developing efficacious strategies for risk reduction. Psychosocial theories and frameworks that explicitly incorporate context, as a source of expectations about the outcomes of reporting and as a source of behavioral reinforcement, are useful in framing this problem. The present study quantifies the pressure that athletes experience to continue playing after a head impact--from coaches, teammates, parents, and fans--and assesses how this pressure, both independently and as a system, is related to future concussion reporting intention. Participants in the study were 328 male and female athletes from 19 teams competing in one of seven sports (soccer, lacrosse, basketball, softball, baseball, volleyball, field hockey) at four colleges in the northeast region of the United States. Results found that more than one-quarter of the sample had experienced pressure from at least one source to continue playing after a head impact during the previous year. Results of a latent profile mixture model indicated that athletes who experienced pressure from all four of the measured sources were significantly more likely to intend to continue playing in the future than were athletes who had not experienced pressure from all sources, or only pressure from coaches and teammates. These findings underscore the importance of designing interventions that address the system in which athletes make decisions about concussion reporting, including athletes' parents, rather than focusing solely on modifying the individual's reporting cognitions.

Hockey STAR: A Methodology for Assessing the Biomechanical Performance of Hockey Helmets

Optimizing the protective capabilities of helmets is one of several methods of reducing brain injury risk in sports. This paper presents the experimental and analytical development of a hockey helmet evaluation methodology. The Summation of Tests for the Analysis of Risk (STAR) formula combines head impact exposure with brain injury probability over the broad range of 227 head impacts that a hockey player is likely to experience during one season. These impact exposure data are mapped to laboratory testing parameters using a series of 12 impact conditions comprised of three energy levels and four head impact locations, which include centric and non-centric directions of force. Injury risk is determined using a multivariate injury risk function that incorporates both linear and rotational head acceleration measurements. All testing parameters are presented along with exemplar helmet test data. The Hockey STAR methodology provides a scientific framework for manufacturers to optimize hockey helmet design for injury risk reduction, as well as providing consumers with a meaningful metric to assess the relative performance of hockey helmets.

Development of a conservative protocol to return children and youth to activity following concussive injury

BACKGROUND

Consensus-based guidelines exist for adult athletes returning to play after concussion, but there are no protocols developed specifically for children. The goal of this knowledge translation research was to develop evidence-based materials to inform physicians about pediatric concussion.

METHODS

A pediatric concussion protocol was developed based on the National Institute for Health and Care Excellence procedures.

RESULTS

This return to activity protocol was developed to guide management when children/youth sustain a concussion. The protocol incorporated 3 main themes: (a) a protocol must include return to all activity, including sport and school; (b) existing consensus-based adult protocols are not appropriate for children; and (c) a more conservative protocol is needed. After pilot testing, the developed protocol is being used across Ontario.

CONCLUSION

Implementation of these new pediatric recommendations is an important addition to prevention of subsequent concussions during vulnerable recovery periods, with potential to facilitate recovery by preventing prolonged symptomatology, and secondary sequelae.

Return-to-play guidelines in concussion: revisiting the literature

Return-to-play (RTP) guidelines in concussion management and treatment continue to challenge clinicians, despite recent updates to the protocols and the ongoing media attention. The current guidelines address individualized treatment planning but are difficult to apply to athletes who experience prolonged symptoms, are younger, or have sustained multiple concussions. Recent literature findings have contributed to an improved understanding and applicability of the guidelines while emphasizing a multidisciplinary paradigm in formulating an individualized RTP decision. Successful implementation of the RTP guidelines will ensure that athletes are protected from further injury and return to their baseline functional status.

A prospective study of physician-observed concussion during a varsity university hockey season: white matter integrity in ice hockey players. Part 3 of 4

OBJECT

The aim of this study was to investigate the effect of repetitive head impacts on white matter integrity that were sustained during 1 Canadian Interuniversity Sports (CIS) ice hockey season, using advanced diffusion tensor imaging (DTI).

METHODS

Twenty-five male ice hockey players between 20 and 26 years of age (mean age 22.24 ± 1.59 years) participated in this study. Participants underwent pre- and postseason 3-T MRI, including DTI. Group analyses were performed using paired-group tract-based spatial statistics to test for differences between preseason and postseason changes.

RESULTS

Tract-based spatial statistics revealed an increase in trace, radial diffusivity (RD), and axial diffusivity (AD) over the course of 1 season. Compared with preseason data, postseason images showed higher trace, AD, and RD values in the right precentral region, the right corona radiata, and the anterior and posterior limb of the internal capsule. These regions involve parts of the corticospinal tract, the corpus callosum, and the superior longitudinal fasciculus. No significant differences were observed between preseason and postseason for fractional anisotropy.

CONCLUSIONS

Diffusion tensor imaging revealed changes in white matter diffusivity in male ice hockey players over the course of 1 season. The origin of these findings needs to be elucidated.

A prospective study of physician-observed concussion during a varsity university ice hockey season: incidence and neuropsychological changes. Part 2 of 4

OBJECT

The primary objective of this study was to measure the incidence of concussion according to a relative number of athlete exposures among 25 male and 20 female varsity ice hockey players. The secondary objective was to present neuropsychological test results between preseason and postseason play and at 72 hours, 2 weeks, and 2 months after concussion.

METHODS

Every player underwent baseline assessments using the Sport Concussion Assessment Tool-2 (SCAT2), Immediate Post-Concussion Assessment and Cognitive Test (ImPACT), and MRI. Each regular season and postseason game was observed by 2 independent observers (a physician and a nonphysician observer). Players with a diagnosed concussion were removed from the game, examined in the team physician's office using the SCAT2 and ImPACT, and sent to undergo MRI.

RESULTS

Eleven concussions occurred during the 55 physician-observed games (20%). The incidence of concussion, expressed as number of concussions per 1000 athlete exposures, was 10.70 for men and women combined in regular season play, 11.76 for men and women combined across both the regular season and playoff season, 7.50 for men and 14.93 for women in regular season play, and 8.47 for men across both the regular season and playoff season. One male player experienced repeat concussions. No concussions were reported during practice sessions, and 1 concussion was observed and diagnosed in an exhibition game. Neuropsychological testing suggested no statistically significant preseason/postseason differences between athletes who sustained a physician-diagnosed concussion and athletes who did not sustain a physician-diagnosed concussion on either the ImPACT or SCAT2. The athletes who sustained a physician-diagnosed concussion demonstrated few reliable changes postinjury.

CONCLUSIONS

Although the incidence of game-related concussions per 1000 athlete exposures in this study was half the highest rate reported in the authors' previous research, it was 3 times higher than the incidence reported by other authors within the literature concerning men's collegiate ice hockey and 5 times higher than the highest rate previously reported for woman's collegiate ice hockey. Interestingly, the present results suggest a substantively higher incidence of concussion among women (14.93) than men (7.50). The reproducible and significantly higher incidence of concussion among both men and woman ice hockey players, when compared with nonphysician-observed games, suggests a significant underestimation of sports concussion in the scientific literature.

Considerations for return-to-play and retirement decisions after concussion

Return-to-play and retirement decisions after concussion are often difficult and complex. The complexity of these decisions may be influenced by many factors, including the number, proximity, and severity of previous concussions; gender; age; sport played; exposure to head impacts; and predisposing or pre-existing conditions. These circumstances and conditions can confound the decisions concerning return to play and retirement. Clinicians should carefully weigh how these circumstances and conditions influence quality of life and how they interact with the effects of concussion. Furthermore, clinicians should consider past and potential exposures to both subconcussive and concussive impacts during the athlete's lifetime when deliberating a return to play or retirement. The purpose of this overview is to highlight and discuss these issues as they factor into the return-to-play and retirement decisions after a concussive injury in an effort to provide clinicians with evidence-based information that can be used in the decision-making process.

Time-to-subsequent head injury from sports and recreation activities

OBJECTIVE

To provide population-based risk estimates for sustaining subsequent head injuries (HIs), which occur in sports and recreation (SR).

DESIGN

Population-based, retrospective, cross-sectional study.

SETTING

Retrospective review of data from 2 tertiary care and 3 community care emergency departments (EDs) in Edmonton, Alberta, Canada.

PATIENTS

Individuals younger than 36 years presenting to an ED with an SR-related injury between April 1, 1997, and March 31, 2008. There were 9246 subsequent ED records identified for 8958 patients in the main analysis.

MAIN OUTCOME MEASURES

Clinically diagnosed HI occurring in SR activities after an index presentation, and the number of days between ED presentations for diagnosed SR-HIs.

RESULTS

Individuals with 1 and 2 previous SR-related HIs were 2.62 [95% confidence interval (CI), 2.23-3.07] and 5.94 times, respectively, more likely (95% CI, 3.43-10.29) to sustain a subsequent HI than those without a previous HI. The median time-to first HI was 758 days from an initial injury and decreased to 613 days and 303 days for those at risk of second and third SR-related HIs (P < 0.0001). Individuals aged 7 to 13 years were 4.29 times more likely (95% CI, 2.65-6.92) to sustain an HI when presenting with a subsequent SR injury, compared with those aged 30 to 35 years.

CONCLUSIONS

The odds of sustaining a subsequent HI substantially increase with each successive HI. Time between SR-related HIs shortens as the number of HIs increases. Initial HI may be a key marker to institute high-risk injury prevention measures directed at young persons who present to EDs.

Proceedings from the Ice Hockey Summit on concussion: a call to action

OBJECTIVE

The objective of this proceeding is to integrate the concussion in sport literature and sport science research on safety in ice hockey to develop an action plan to reduce the risk, incidence, severity, and consequences of concussion in ice hockey.

METHODS

A rationale paper outlining a collaborative action plan to address concussions in hockey was posted for review 2 months before the Ice Hockey Summit: Action on Concussion. Focused presentations devoted specifically to concussion in ice hockey were presented during the Summit, and breakout sessions were used to develop strategies to reduce concussion in the sport. This proceedings and a detailed scientific review (a matrix of solutions) were written to disseminate the evidence-based information and resulting concussion reduction strategies. The manuscripts were reviewed by the authors, advisers, and contributors to ensure that the opinions and recommendations reflect the current level of knowledge on concussion in hockey.

RESULTS

Six components of a potential solution were articulated in the Rationale paper and became the topics for breakout groups that followed the professional, scientific lectures. Topics that formed the core of the action plan were metrics and databases; recognizing, managing, and returning to play; hockey equipment and ice arenas; prevention and education; rules and regulations; and expedient communication of the outcomes. The attendees in breakout sessions identified action items for each section. The most highly ranked action items were brought to a vote in the open assembly by using an Audience Response System. The strategic planning process was conducted to assess the following: Where are we at? Where must we get to? What strategies are necessary to make progress on the prioritized action items?

CONCLUSIONS

Three prioritized action items for each component of the solution and the percentage of the votes received are listed in the body of this proceeding.

Proceedings from the Ice Hockey Summit on concussion: a call to action

The objective of this proceedings is to integrate the concussion in sport literature and sport science research on safety in ice hockey to develop an action plan to reduce the risk, incidence, severity, and consequences of concussion in ice hockey. A rationale paper outlining a collaborative action plan to address concussions in hockey was posted for review two months prior to the Ice Hockey Summit: Action on Concussion. Focused presentations devoted specifically to concussion in ice hockey were presented during the Summit and breakout sessions were used to develop strategies to reduce concussion in the sport. This proceedings and a detailed scientific review (a matrix of solutions) were written to disseminate the evidence-based information and resulting concussion reduction strategies. The manuscripts were reviewed by the authors, advisors and contributors to ensure that the opinions and recommendations reflect the current level of knowledge on concussion in hockey. Six components of a potential solution were articulated in the Rationale paper and became the topics for breakout groups that followed the professional, scientific lectures. Topics that formed the core of the action plan were: metrics and databases; recognizing, managing and return to play; hockey equipment and ice arenas; prevention and education; rules and regulations; and expedient communication of the outcomes. The attendees in breakout sessions identified action items for each section. The most highly ranked action items were brought to a vote in the open assembly, using an Audience Response System (ARS). The strategic planning process was conducted to assess: Where are we at?; Where must we get to?; and What strategies are necessary to make progress on the prioritized action items? Three prioritized action items for each component of the solution and the percentage of the votes received are listed in the body of this proceedings.

Trauma and impaired consciousness

This article discusses brain trauma and impaired consciousness. It reviews the various states of impaired consciousness related to trauma, with an historical and current literature viewpoint. The causes and pathophysiology of impaired consciousness in concussion, diffuse axonal injury, and focal brain lesions are discussed and management options evaluated.

Return-to-play guidelines in concussion: a closer look at the literature

Traumatic brain injuries that occur during sports have gained significant attention in the literature. Despite improved education and research on proper identification, risk management, and treatment, standardized methods for returning an athlete to play after a concussion are lacking in universal applicability. Current return-to-play guidelines are considered appropriate for the majority of athletes who recover within a few weeks. However, applicability of such guidelines becomes difficult when treating those athletes who experience prolonged symptoms or do not have the resources available to adequately manage complex presentations of concussions. Understanding the guidelines with consideration to special populations will assist the treating physician in providing an appropriate and individualized evaluation and treatment plan to safely return an athlete with a concussion back to play without compromising his or her health.

Proceedings from the Ice Hockey Summit on Concussion: a call to action

OBJECTIVE

: The objective of this proceeding was to integrate the concussion in sport literature and sport science research on safety in ice hockey to develop an action plan to reduce the risk, incidence, severity, and consequences of concussion in ice hockey.

DESIGN

: A rationale paper outlining a collaborative action plan to address concussions in hockey was posted for review 2 mos before the "Ice Hockey Summit: Action on Concussion." Focused presentations devoted specifically to concussion in ice hockey were presented during the summit, and breakout sessions were used to develop strategies to reduce concussion in the sport. The proceedings and a detailed scientific review (a matrix of solutions) were written to disseminate the evidence-based information and resulting concussion reduction strategies. The manuscripts were reviewed by the authors, advisors, and contributors to ensure that the opinions and recommendations reflect the current level of knowledge on concussion in hockey.

RESULTS

: Six components of a potential solution were articulated in the "Rationale" paper and became the topics for breakout groups that followed the professional scientific lectures. Topics that formed the core of the action plan were metrics and databases; recognizing, managing, and return to play; hockey equipment and ice arenas; prevention and education; rules and regulations; and expedient communication of the outcomes. The attendees in the breakout sessions identified the action items for each section. The most highly ranked action items were brought to a vote in the open assembly, using an Audience Response System. The strategic planning process was conducted to assess the following: "Where are we at?" "Where must we get to?" "What strategies are necessary to make progress on the prioritized action items?"

CONCLUSIONS

: Three prioritized action items for each component of the solution and the percentage of the votes received are listed in the body of this proceeding.

Proceedings from the ice hockey summit on concussion: a call to action

OBJECTIVE

The objective of this proceeding is to integrate the concussion in sport literature and sport science research on safety in ice hockey to develop an action plan to reduce the risk, incidence,severity, and consequences of concussion in ice hockey. methods: A rationale paper outlining a collaborative action plan to address concussions in hockey was posted for review two months prior to the Ice Hockey Summit: Action on Concussion. Focused presentations devoted specifically to concussion in ice hockey were presented during the Summit and break out sessions were used to develop strategies to reduce concussion in the sport. This proceedings and a detailed scientific review (a matrix of solutions) were written to disseminate the evidence based information and resulting concussion reduction strategies. The manuscripts were reviewed by the authors, advisors and contributors to ensure that the opinions and recommendations reflect the current level of knowledge on concussion in hockey.

RESULTS

Six components of a potential solution were articulated in the Rationale paper and became the topics for breakout groups that followed the professional, scientific lectures. Topics that formed the core of the action plan were: metrics and databases; recognizing,managing, and return to play; hockey equipment and ice arenas;prevention and education; rules and regulations; and expedient communication of the outcomes. The attendees in breakout sessions identified action items for each section. The most highly ranked action items were brought to a vote in the open assembly, using an Audience Response System (ARS). The strategic planning process was conducted to assess: Where are we at?; Where must we get to?; and What strategies are necessary to make progress on the prioritized action items?

CONCLUSIONS

Three prioritized action items for each component of the solution and the percentage of the votes received are listed in the body of this proceeding.