Summary and agreement statement of the First International Conference on Concussion in Sport, Vienna 2001. Recommendations for the improvement of safety and health of athletes who may suffer concussive injuries

Injury surveillance of head and neck injuries with a special focus on sport-related concussions: Eight seasons observational study in professional football in Qatar

OBJECTIVES

To describe the head and neck injuries with a focus on Sport-Related Concussion (SRC) in professional football in Qatar (PFQ) during eight consecutive seasons.

DESIGN

Prospective observational study.

METHODS

Seventeen PFQ teams were included over eight seasons (2013/14-2020/21) study. The injury data were collected by the respective clubs' medical staff using standardized (time-loss injuries) protocols.

RESULTS

Data were obtained from 119 teams' seasons resulting in a total of 87 head and neck injuries (1.8 % of the 4736 time-loss injuries). Head and neck injury rate was of 0.57 injury/squad-season (95%CI: 0.56-0.59), representing 0.12 injury/1000 h (95%CI: 0.09-0.14). Thirty-three concussions were recorded. The concussion rate was 0.25 injury/squad-season (95%CI: 0.23-0.26), representing 0.04 injury/1000 h (95%CI: 0.03-0.06). The concussion proportion of all head injuries was 31.7 % during the four initial seasons and 43.5 % during the following four seasons with a non-significant increase of 11.8 % (X2 = 1267, p = 0.26).

CONCLUSIONS

Injury rates in this cohort remain lower than comparable leagues elsewhere. Even though the incidence rate of SRC did not change significantly over the eight seasons, seasonal variations' trend may indicate that the medical staff are more aware of diagnosing head and neck injuries, including concussion.

Association of Alzheimer's disease polygenic risk score with concussion severity and recovery metrics

Identification of genetic alleles associated with both Alzheimer's disease (AD) and concussion severity/recovery could help explain the association between concussion and elevated dementia risk. However, there has been little investigation into whether AD risk genes associate with concussion severity/recovery, and the limited findings are mixed. We used AD polygenic risk scores (PRS) and APOE genotypes to investigate any such associations in the NCAA-DoD Grand Alliance CARE Consortium (CARE) dataset. We assessed six outcomes in 931 total participants. The outcomes were two concussion recovery measures (number of days to asymptomatic status, number of days to return to play (RTP)) and four concussion severity measures (scores on SAC and BESS, SCAT symptom severity, and total number of symptoms). We calculated PRS using a published score [1] and performed multiple linear regression (MLR) to assess the relationship of PRS with the outcomes. We also used t-tests and chi-square tests to examine outcomes by APOE genotype, and MLR to analyze outcomes in European and African genetic ancestry subgroups. Higher PRS was associated with longer injury to RTP in the normal RTP (<24 days) subgroup ( p = 0.024), and one standard deviation increase in PRS resulted in a 9.89 hour increase to the RTP interval. There were no other consistently significant effects, suggesting that high AD genetic risk is not strongly associated with more severe concussions or poor recovery in young adults. Future studies should attempt to replicate these findings in larger samples with longer follow-up using PRS calculated from diverse populations.

Medico-legal implications of dementia following concussion in rugby football

There is litigation in respect of dementia in ex-rugby football players. The allegation is that these ex-players have suffered a traumatic encephalopathy syndrome causing dementia and other neurological problems. The syndrome is alleged to have been caused by repeated concussion during play. It is alleged that governing bodies of rugby should have been aware, and players should have been warned, of this risk. The dilemma, for both claimants and defendants, is that there is no agreed definition of the syndrome nor are there any diagnostic tests that confirm or refute this diagnosis. This paper reviews the literature of traumatic encephalopathy syndrome and when governing bodies were aware of the possibility of rugby concussion causing dementia. The legal principles are discussed and a framework for determining the probability of an ex-rugby player having the syndrome is proposed.

A Multimodal Exertional Test for concussion: a pilot study in healthy athletes

Introduction

Exertional tests have become a promising tool to assist clinicians in the management of concussions, however require expensive equipment, extensive spaces, and specialized clinician expertise. As such, we developed a test with minimal resource requirements encompassing key elements of sport and physical activity. The purpose of this study was to pilot test the Multimodal Exertional Test (MET) protocol in a sample of healthy interuniversity athletes.

Methods

The MET comprises four stages, each featuring three distinct tasks. The test begins with engaging in squats, alternating reverse lunges, and hip hinges (Stage 1). The next stage progressively evolves into executing these tasks within specified time limits (Stage 2). Following this, the test advances to a stage that incorporates cognitive tasks (Stage 3), and the final stage demands greater levels of physical exertion, cognition, and multi-directional movements (Stage 4). Heart rate (HR) was obtained during each stage of the MET and participants' symptom severity scores were recorded following each task.

Results

Fourteen healthy interuniversity athletes (n = 8 female, n = 6 male) participated in the study. HR was obtained for 10 of the 14 athletes (females: n = 6, males: n = 4). Increases in average and maximum HR were identified between pre-MET and Stage 1, and between Stages 3 and 4. Consistent with the tasks in each stage, there were no increases in average and maximum HR observed between MET Stages 1 to 3. Female athletes exhibited higher average and maximum HRs compared to male athletes during all four stages. All 14 athletes reported minimal changes in symptom severity following each task.

Conclusion

Among healthy athletes, the MET elicits an increase in average and maximum HR throughout the protocol without symptom provocation. Female athletes exhibit higher HRs during all four stages in comparison to male athletes.

Sport-related concussion research agenda beyond medical science: culture, ethics, science, policy

The Concussion in Sport Group guidelines have successfully brought the attention of brain injuries to the global medical and sport research communities, and has significantly impacted brain injury-related practices and rules of international sport. Despite being the global repository of state-of-the-art science, diagnostic tools and guides to clinical practice, the ensuing consensus statements remain the object of ethical and sociocultural criticism. The purpose of this paper is to bring to bear a broad range of multidisciplinary challenges to the processes and products of sport-related concussion movement. We identify lacunae in scientific research and clinical guidance in relation to age, disability, gender and race. We also identify, through multidisciplinary and interdisciplinary analysis, a range of ethical problems resulting from conflicts of interest, processes of attributing expertise in sport-related concussion, unjustifiably narrow methodological control and insufficient athlete engagement in research and policy development. We argue that the sport and exercise medicine community need to augment the existing research and practice foci to understand these problems more holistically and, in turn, provide guidance and recommendations that help sport clinicians better care for brain-injured athletes.

What is the Injury Incidence and Profile in Professional Male Ice Hockey? A Systematic Review

BACKGROUND

Professional male ice hockey is characterized by a congested in-season match schedule and by different scenarios where the whole body is exposed to great internal and external forces. Consequently, injuries occur from head to toe. However, there is a lack of data synthesis regarding the injury incidence and profile in this population.

PURPOSE

The aim of this study was to conduct a systematic review to quantify the injury incidence rates in professional male ice hockey.

STUDY DESIGN

Systematic Review.

METHODS

The electronic databases PubMed, CINAHL, Web of Science, ProQuest-Sport medicine & Education Index, and Pro-Quest Dissertation and Thesis were searched utilizing terms related to ice hockey and injuries. Studies were included if they provided the incidence of injury in professional male hockey players and reported injuries in terms of time lost. The modified Newcastle Ottawa Scale for cohort studies and the Strengthening the Reporting of Observational Studies in Epidemiology - Sports Injury and Illness Surveillance Statement were used to assess the methodological quality of the studies.

RESULTS

Eleven studies were included in the review. Match injury incidence ranged from 38 to 88.6 injuries/1000 hours of exposure, whereas training injury incidence varied from 0.4 to 2.6 injuries/1000 hours of exposure. Injuries of traumatic origin accounted for 76% to 96.6% of all injuries, with contusions and lacerations being the most common. Severe injuries accounted for 7.8% - 20% of all injuries. The lower extremities were the most susceptible to injury, comprising 27% to 53.7% of all reported injuries.

CONCLUSION

Professional male ice hockey players are exposed to a substantial risk of injury during competitions, with lower extremities being the most commonly affected body part. The majority of injuries are traumatic and severe injuries account for a notable portion of overall injury cases.

Microstructural Organization of Distributed White Matter Associated With Fine Motor Control in US Service Members With Mild Traumatic Brain Injury

Mild traumatic brain injury (mTBI) is the most common form of brain injury. While most individuals recover from mTBI, roughly 20% experience persistent symptoms, potentially including reduced fine motor control. We investigate relationships between regional white matter organization and subcortical volumes associated with performance on the Grooved Pegboard (GPB) test in a large cohort of military Service Members and Veterans (SM&Vs) with and without a history of mTBI(s). Participants were enrolled in the Long-term Impact of Military-relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium. SM&Vs with a history of mTBI(s) (n = 847) and without mTBI (n = 190) underwent magnetic resonance imaging and the GPB test. We first examined between-group differences in GPB completion time. We then investigated associations between GPB performance and regional structural imaging measures (tractwise diffusivity, subcortical volumes, and cortical thickness) in SM&Vs with a history of mTBI(s). Lastly, we explored whether mTBI history moderated associations between imaging measures and GPB performance. SM&Vs with mTBI(s) performed worse than those without mTBI(s) on the non-dominant hand GPB test at a trend level (p < 0.1). Higher fractional anisotropy (FA) of tracts including the posterior corona radiata, superior longitudinal fasciculus, and uncinate fasciculus were associated with better GPB performance in the dominant hand in SM&Vs with mTBI(s). These findings support that the organization of several white matter bundles are associated with fine motor performance in SM&Vs. We did not observe that mTBI history moderated associations between regional FA and GPB test completion time, suggesting that chronic mTBI may not significantly influence fine motor control.

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

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

Early intervention treatment in the first 2 weeks following concussion in adults: A systematic review of randomised controlled trials

OBJECTIVE

International guidelines support a repertoire of therapeutic interventions that may assist recovery following concussion. We aimed to systematically review the efficacy of early pharmacological and non-pharmacological interventions initiated within two weeks of injury on symptoms and functional recovery of adults with concussion.

METHODS

We conducted a Systematic Review (SR) of Randomised Controlled Trials (RCTs) without meta-analysis utilising the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search was performed of four databases. Study inclusion criteria were adult participants diagnosed with concussion and commencing active intervention within 14 days of injury.

RESULTS AND CONCLUSIONS

Of 7531 studies identified, 11 were included in the final review. Six studies were rated as high-risk of bias, three with some concerns and two as low-risk of bias. We found no evidence to support specific pharmacotherapeutic management to hasten the natural recovery time-course. Two studies reported significant improvement in selected concussion symptoms following manual therapy (at 48-72 hours post-treatment) or telephone counselling interventions (at 6 months post-injury). No high quality RCTs demonstrate superior effects of early therapeutic interventions on concussion recovery in the first 2 weeks. We advocate future research to examine impacts of health-clinician contact points aligned with symptom-specific interventions.

Does Frequency of Baseline Testing Influence Concussion Diagnostic Decision Making Among College Athletes

OBJECTIVE

Concussion is a growing public health concern given the large number of youth and collegiate athletes participating in collision sports. Sport-related concussions can have an adverse impact on student-athletes' health and academic performance. Athletic programs within academic organizations are motivated to employ the most effective and efficient diagnostic and recovery procedures to minimize the duration and impact of these symptoms on student-athletes' functioning. The present study sought to further our understanding regarding the value and frequency of conducting baseline assessments when evaluating sport-related concussions.

METHOD

A total of 41 athletes (24 men, 17 women) between the ages of 18 and 22 were evaluated following suspected concussive injury between 2015 and 2018. Post-injury test results were compared to baselines that had been collected either 1 or 2 years prior, and to normative data, to determine consistency in diagnostic outcomes.

RESULTS

Baseline test/retest reliability using Pearson's bivariate correlations revealed modest correlations on measures of verbal and visual memory (0.437-0.569) and very strong correlations on measures of reaction time and visual-motor speed (0.811-0.821). Meanwhile, minimal if any differences in clinical decision-making regarding the diagnostic outcome was observed when comparing post-injury test results to different baselines and to normative data.

CONCLUSIONS

Findings indicate that yearly baseline testing may not improve diagnostic accuracy, and in many cases, normative data may be adequate for decision-making. Additional research should evaluate the potential benefit of baseline testing in return-to-play decision-making among broader athletic populations.

Amsterdam 2022 process: A summary of the methodology for the Amsterdam International Consensus on Concussion in Sport

The purpose of this paper is to summarise the consensus methodology that was used to inform the International Consensus Statement on Concussion in Sport (Amsterdam 2022). Building on a Delphi process to inform the questions and outcomes from the 5th International Conference on Concussion in Sport, the Scientific Committee identified key questions, the answers to which would help encapsulate the current science in sport-related concussion and help guide clinical practice. Over 3½ years, delayed by 2 years due to the pandemic, author groups conducted systematic reviews on each selected topic. The 6th International Conference on Concussion in Sport was held in Amsterdam (27-30 October 2022) and consisted of 2 days of systematic review presentations, panel discussions, question and answer engagement with the 600 attendees, and abstract presentations. This was followed by a closed third day of consensus deliberations by an expert panel of 29 with observers in attendance. The fourth day, also closed, was dedicated to a workshop to discuss and refine the sports concussion tools (Concussion Recognition Tool 6 (CRT6), Sport Concussion Assessment Tool 6 (SCAT6), Child SCAT6, Sport Concussion Office Assessment Tool 6 (SCOAT6) and Child SCOAT6). We include a summary of recommendations for methodological improvements for future research that grew out of the systematic reviews.

Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport-Amsterdam, October 2022

For over two decades, the Concussion in Sport Group has held meetings and developed five international statements on concussion in sport. This 6th statement summarises the processes and outcomes of the 6th International Conference on Concussion in Sport held in Amsterdam on 27-30 October 2022 and should be read in conjunction with the (1) methodology paper that outlines the consensus process in detail and (2) 10 systematic reviews that informed the conference outcomes. Over 3½ years, author groups conducted systematic reviews of predetermined priority topics relevant to concussion in sport. The format of the conference, expert panel meetings and workshops to revise or develop new clinical assessment tools, as described in the methodology paper, evolved from previous consensus meetings with several new components. Apart from this consensus statement, the conference process yielded revised tools including the Concussion Recognition Tool-6 (CRT6) and Sport Concussion Assessment Tool-6 (SCAT6, Child SCAT6), as well as a new tool, the Sport Concussion Office Assessment Tool-6 (SCOAT6, Child SCOAT6). This consensus process also integrated new features including a focus on the para athlete, the athlete's perspective, concussion-specific medical ethics and matters related to both athlete retirement and the potential long-term effects of SRC, including neurodegenerative disease. This statement summarises evidence-informed principles of concussion prevention, assessment and management, and emphasises those areas requiring more research.

'If in Doubt, Sit Them Out': How Long to Return to Elite Cycling Competition following a Sports-Related Concussion (SRC)?

INTRODUCTION

A concussion or sports-related concussion (SRC) is a traumatic brain injury induced by biomechanical forces. After a SRC diagnosis is made, a concussed individual must undergo a period away from competition while they return to their baseline level of functioning. The Union Cycliste Internationale (UCI) currently recommend a minimum of 6 days restriction from competitive cycling following a SRC but there is a growing feeling amongst those involved in brain injury research that this period is too short. Therefore, how much time should cyclists be removed from competitive sporting action following a SRC?

AIMS

To review the time out of competition following the diagnosis of a SRC for elite cyclists within British Cycling (BC).

METHODS

All medical records for elite cyclists within BC were audited for diagnoses of "concussion" or "sports-related concussions" from January 2017 until September 2022. The days out of competition following the concussion until ready to compete again (that is, returned to full training) was then calculated. All diagnoses and management of SRC were undertaken by the medical team at BC and in-keeping with current international guidelines.

RESULTS

Between January 2017 and September 2022, there were 88 concussions diagnosed, 54 being males and 8 in para-athletes. The median duration for time out of competition for all concussions was 16 days. There was no statistical difference between males (median 15.5 days) and females (median 17.5 days) for time out of competition (p-value 0.25). The median duration out of competition following a concussion for able-bodied athletes was 16 (80 athletes) compared to 51 days (8 athletes) in para-cyclists, which was not statistically different (p-value 0.39).

CONCLUSIONS

This is the first study to report SRC concussion recovery times in elite cycling, including para-athletes. Between January 2017 and September 2022, there were 88 concussions diagnosed at BC and the median duration for time out of competition for all concussions was 16 days. There was no statistically significant difference in recovery times between male and females and para- and able-bodied athletes. This data should be used to help establish minimum withdrawal times post-SRC for elite cycling participation and we call on the UCI to review this data when establishing SRC protocols for cycling, with further research required in para-cyclists.

Achieving Consensus Through a Modified Delphi Technique to Create the Post-concussion Collegiate Return-to-Learn Protocol

BACKGROUND

Sport-related concussions (SRCs) affect millions of adolescents and young adults annually in the USA; however, current SRC consensus statements provide limited guidance on academic support for students within higher education.

OBJECTIVE

To generate consensus on appropriate academic recommendations for clinicians, students, and academic stakeholders to support university students during their recovery.

METHODS

Panelists participated in three stages of a modified Delphi procedure: the first stage included a series of open-ended questions after reviewing a literature review on post-SRC return-to-learn (RTL) in higher education; the second stage asked panelists to anonymously rate the recommendations developed through the first Delphi stage using a 9-point scale; and the final stage offered panelists the opportunity to change their responses and/or provide feedback based on the group's overall ratings.

RESULTS

Twenty-two panelists including clinicians, concussion researchers, and academic stakeholders (54.5% female) from 15 institutions and/or healthcare systems participated in a modified Delphi procedure. A total of 42 statements were developed after round one. Following the next two rounds, 27 statements achieved consensus amongst the panel resulting in the four-stage Post-Concussion Collegiate RTL Protocol.

CONCLUSION

There are several unique challenges when assisting university students back to the classroom after SRC. Explicit guidelines on when to seek additional medical care (e.g., if they are experiencing worsening or persistent symptoms) and how to approach their instructor(s) regarding academic support may help the student self-advocate. Findings from the present study address barriers and provide a framework for universities to facilitate a multidisciplinary approach amongst medical and academic stakeholders.

Blood biomarkers of secondary outcomes following concussion: A systematic review

Introduction

Blood biomarkers have been identified as an alternative tool for predicting secondary outcomes following concussion. This systematic review aimed to summarize the literature on blood biomarkers of secondary outcomes following concussion in both pediatric and adult cohorts.

Methods

A literature search of Embase, Medline and PubMed was conducted. Two reviewers independently assessed retrieved studies to determine inclusion in systematic review synthesis.

Results

A total of 1771 unique studies were retrieved, 58 of which were included in the final synthesis. S100B, GFAP and tau were identified as being associated with secondary outcomes following concussion. Seventeen percent of studies were performed in a solely pediatric setting.

Conclusions

Validation of biomarkers associated with secondary outcomes following concussion have been largely limited by heterogeneous study cohorts and definitions of concussion and mTBI, presenting a hurdle for translation of these markers into clinical practice. Additionally, there was an underrepresentation of studies which investigated pediatric cohorts. Adult markers are not appropriate for children, therefore pediatric specific markers of secondary outcomes following concussion present the biggest gap in this field.

Multi-domain assessment of sports-related and military concussion recovery: A scoping review

OBJECTIVE

This review explores the literature on multi-domain assessments used in concussion recovery, to inform evidence-based and ecologically valid return-to-play. It asks: What simultaneous, dynamic multi-domain paradigms are used to assess recovery of youth and adults following concussion?

METHODS

Five databases were searched (CINAHL, EMBASE, MEDLINE, PsycInfo, SPORTDiscus) until September 30, 2021. Records were limited to those published in peer-reviewed journals, in English, between 2002 and 2021. Included studies were required to describe the assessment of concussion recovery using dynamic paradigms (i.e., requiring sport-like coordination) spanning multiple domains (i.e., physical, cognitive, socio-emotional functioning) simultaneously.

RESULTS

7098 unique articles were identified. 64 were included for analysis, describing 36 unique assessments of 1938 concussed participants. These assessments were deconstructed into their constituent tasks: 13 physical, 17 cognitive, and one socio-emotional. Combinations of these "building blocks" formed the multi-domain assessments. Forty-six studies implemented level walking with a concurrent cognitive task. The most frequently implemented cognitive tasks were 'Q&A' paradigms requiring participants to answer questions aloud during a physical task.

CONCLUSIONS

A preference emerged for dual-task assessments, specifically combinations of level walking and Q&A tasks. Future research should balance ecological validity and clinical feasibility in multi-domain assessments, and work to validate these assessments for practice.

Symptom Provocation Following Post-concussion Computerized Neurocognitive Testing and Its Relationship to Other Clinical Measures of Concussion

OBJECTIVE

The objective of this study was to document the prevalence of post-computerized neurocognitive test (post-CNT) increases in symptoms in athletes with sport-related concussion, and to examine the effect of post-CNT symptom increases on concussion neurocognitive and vestibular/ocular motor clinical outcomes.

METHODS

This was a retrospective analysis of medical records from a concussion specialty clinic. Two hundred and three athletes (M = 16.48 ± 1.97 years; 44% [90/203] female) completed a clinical visit for concussion within 30 days of injury (M = 7.73 ± 5.54 days). Computerized neurocognitive testing (the Immediate Post-concussion Assessment and Cognitive Testing: ImPACT), the Post-Concussion Symptom Scale (PCSS), and the Vestibular Ocular Motor Screening (VOMS) were the main outcome measures for the current study.

RESULTS

Sixty-nine percent (141/203) of the sample did not report significant increases in PCSS scores following post-concussion CNT and were classified into a No Provocation (NO PROV) group. Thirty-one percent (62/203) of participants did report a significant increase in symptoms following post-concussion CNT and were classified into a Provocation (PROV) group. Neurocognitive performance was similar between groups. However, the PROV group reported significantly higher scores on the VOMS symptom items than the NO PROV group.

CONCLUSIONS

The majority of adolescent athletes can complete a post-concussion CNT without experiencing significant increases in concussion symptoms. Individuals that report symptom increases from completing a post-concussion CNT are more likely to exhibit increased vestibular/ocular motor symptoms. These findings underscore the relationship between the clinical findings from both CNT and vestibular/ocular motor measures following concussion.

Survey on Sports-Related Concussions among Japanese University Students

In recent years, head injuries in sports have garnered attention, and in particular, international discussions have been held on the prevention of and response to sports-related concussions (SRCs). The purpose of this study is to investigate past SRCs experienced by university students in Japan, clarify the state and mechanism of such injuries in each sport, and consider the creation of an environment for future SRC prevention and responses. A questionnaire survey on past SRC experience was conducted among 1731 students who belonged to Fukuoka University in Japan and took "sports medicine" classes in 2020. Responses from 1140 students (collection rate: 65.9%) were obtained. According to this survey, it was revealed that 39 students (3.7%) had experienced SRC. The male-female ratio of those who had experienced SRC was 31 males (79.5%) and 8 females (20.5%). Two males had experienced SRC twice. In this study, SRCs were recognized in a variety of sports, not just in a few contact sports. It is necessary to further disseminate education on head injury prevention and SRCs among both athletes and coaches, because SRCs have been frequently recognized in various sports.

Return to Full Participation Following Concussion in the National Football League, 2015 Through 2020

OBJECTIVE

Quantify days missed, games missed, injury burden, and time to return to full participation (RTFP) among National Football League (NFL) players who sustained a concussion.

DESIGN

Retrospective cohort study.

SETTING

2015 through 2020 NFL seasons.

PARTICIPANTS

National Football League players diagnosed with a concussion from 2015 to 2020.

INTERVENTIONS

National Football League-mandated graduated RTFP protocol.

MAIN OUTCOME MEASURES

Days missed, games missed, burden, and time to RTFP, overall and by position.

RESULTS

An annual average of 3639 player-days of participation and 255 games were missed across NFL because of concussion. Concussed players missed a median of 9 days (mean = 15.0), a relatively stable metric over 6 years, with slight variation by position. Offensive linemen, tight ends, running backs, and linebackers missed the most days per concussion; defensive secondary, offensive linemen, and wide receivers sustained the highest injury burden. Postconcussion, 59% of players missed one or more scheduled games. Among players concussed in a Sunday game, 38% played in a Sunday game one week later.

CONCLUSIONS

The 9-day median time missed post-concussion may be related to emphasis on graduated phase-based concussion management. No concussed player returned to competition on the day of injury, and less than 40% participated in games the following week. Further work is needed to better understand characteristics of concussions that take longer to return and movement through stages of return.

Association of Concussion History and Prolonged Recovery in Youth

OBJECTIVE

To determine the number of prior concussions associated with increased incidence of persistent postconcussive symptoms (PPCS) in a cohort of acutely concussed pediatric patients.

DESIGN

Prospective observational cohort study.

SETTING

Three university-affiliated concussion clinics.

PARTICIPANTS

Two hundred seventy participants (14.9 ± 1.9 years, 62% male, 54% with prior concussion) were assessed within 14 days of concussion and followed to clinical recovery. Participants with a second head injury before clinical recovery were excluded.

MEASURES AND MAIN OUTCOME

Concussion history, current injury characteristics, recovery time, and risk for prolonged recovery from current concussion.

RESULTS

There was no statistically significant change in PPCS risk for participants with 0, 1 or 2 prior concussions; however, participants with 3 or more prior concussions had a significantly greater risk of PPCS. Twelve participants sustained a subsequent concussion after clinical recovery from their first injury and were treated as a separate cohort. Our secondary analysis found that these participants took longer to recover and had a greater incidence of PPCS during recovery from their latest concussion.

CONCLUSION

Pediatric patients with a history of 3 or more concussions are at greater risk of PPCS than those with fewer than 3 prior concussions.

An assessment of current concussion identification and diagnosis methods in sports settings: a systematic review

BACKGROUND

Concussion in sport is an ongoing global concern. The head injury assessment (HIA) by the field of play is acknowledged as the first step in recognising and identifying concussion. While previous systematic literature reviews have evaluated the sensitivity of side-line screening tools and assessment protocols, no systematic review has evaluated the research designs and assessments used in a field setting. This systematic review investigated existing screening and diagnostic tools used in research as part of the HIA protocol to identify concussion that are currently used in professional, semi-professional and amateur (club) sports settings.

METHODS

A systematic searching of relevant databases was undertaken for peer-reviewed literature between 2015 and 2020.

RESULTS

Twenty-six studies met the inclusion criteria. Studies were of moderate to good quality, reporting a variety of designs. The majority of studies were undertaken in professional/elite environments with medical doctors and allied health practitioners (e.g., physical therapists) involved in 88% of concussion assessments. While gender was reported in 24 of the 26 studies, the majority of participants were male (77%). There was also a variety of concussion assessments (n = 20) with the sports concussion assessment tool (SCAT) used in less than half of the included studies.

CONCLUSION

The majority of studies investigating concussion HIAs are focused on professional/elite sport. With concussion an issue at all levels of sport, future research should be directed at non-elite sport. Further, for research purposes, the SCAT assessment should also be used more widely to allow for consistency across studies.

Reframing postconcussional syndrome as an interface disorder of neurology, psychiatry and psychology

Persistent symptoms following a minor head injury can cause significant morbidity, yet the underlying mechanisms for this are poorly understood. The shortcomings of the current terminology that refer to non-specific symptom clusters is discussed. This update considers the need for a multi-dimensional approach for the heterogenous mechanisms driving persistent symptoms after mild traumatic brain injury. Relevant pathophysiology is discussed to make the case for mild traumatic brain injury to be conceptualized as an interface disorder spanning neurology, psychiatry and psychology. The relevance of pre-injury factors, psychological co-morbidities and their interaction with the injury to produce persistent symptoms are reviewed. The interplay with psychiatric diagnoses, functional and somatic symptom disorder presentations and the influence of the medicolegal process is considered. The judicious use and interpretation of investigations given the above complexity is discussed, with suggestions of how the explanation of the diagnostic formulation to the patient can be tailored, including insight into the above processes, to aid recovery. Moving beyond the one-dimensional concept of 'postconcussional syndrome' and reframing the cause of persistent symptoms following mild traumatic brain injury in a bio-psycho-socio-ecological model will hopefully improve understanding of the underlying contributory mechanistic interactions and facilitate treatment.

Hidden Truth in Cerebral Concussion—Traumatic Axonal Injury: A Narrative Mini-Review

This study reviewed traumatic axonal injury (TAI) in patients with concussion. Concussion refers to transient changes in the neurological function of the brain resulting from head trauma that should not involve any organic brain injury. On the other hand, TAI has been reported in autopsy studies of the human brain and histopathological studies of animal brains following concussion before the development of diffusion tensor imaging (DTI). The diagnosis of TAI in live patients with concussion is limited because of the low resolution of conventional brain magnetic resonance imaging. Since the first study by Arfanakis et al. in 2002, several hundred studies have reported TAI in patients with concussion using DTI. Furthermore, dozens of studies have demonstrated TAI using diffusion tensor tractography for various neural tracts in individual patients with concussion. Hence, DTI provides valuable data for the diagnosis of TAI in patients with concussion. Nevertheless, the confirmation of TAI in live patients with concussion can be limited because a histopathological study via a brain biopsy is required to confirm TAI. Accordingly, further studies for a diagnostic approach to TAI using DTI without a histopathological test in individual patients with concussion will be necessary in the clinical field.

A Scoping Review: Mapping the Evidence for Undergraduate Concussion Education and Proposing the Content for Medical Student Concussion Teaching

INTRODUCTION

Concussion is a common yet complex condition, with each new case requiring assessment by a medical doctor. Recent research has shown that doctors working in the UK have significant knowledge deficits regarding concussion diagnosis and management.

AIM

The aim of this scoping review was to map out the evidence about how undergraduate medical students are being educated about concussion.

METHOD

This scoping review involved seven research papers identified by searching five online databases in October 2020. Search terms relevant to concussion included: brain injuries, post-concussion syndrome, brain concussion and concussion, combined with search criteria for undergraduate education: medical students, undergraduate medical education, or curriculum.

RESULTS

All seven papers were published in North America, with five papers recruiting medical students from single institutions (n = 590) and two papers surveying universities. Canadian medical schools have shown an upward trend in the quantity of teaching about concussion-specific teaching: from 0.57 to 2.65 h between 2012 and 2018. Lectures were the commonest mode of delivery of teaching, followed by problem-based learning and clinical rotations. The studies reach a common conclusion that medical students are not being adequately prepared for diagnosing and managing concussion, with insufficient undergraduate teaching, particularly exposure during clinical rotations, cited as the cause.

CONCLUSIONS

Concussion: education of medical students is inadequate in North America. Medical schools should help address this by providing lectures and clinical presentations on concussion to learn from, particularly via problem-based learning. There is a paucity of evidence about concussion education in other geographical areas.

Physical Activity Following Sport-Related Concussion in Adolescents: A Systematic Review

OBJECTIVE

To evaluate the evidence related to how physical activity (PA) affects recovery following a sport-related concussion (SRC) in adolescents.

DESIGN

Systematic review Data Source: PUBMED, MEDLINE, and SPORTDiscus Eligibility criteria for selecting study:(1) original research article (e.g., randomized controlled trials (RCT), quasi-experimental designs, cohort, case-control studies), (2) 66% or greater of the sample has to have a SRC diagnosed by a clinician, (4) human research, (5) evaluate the effect of a SRC on PA in adolescents only (<18 years). Participants were seen within 1-2 weeks post-SRC for acute studies and 4 weeks post-SRC for studies focused on prolonged recoveries.

RESULTS

Twenty-two studies met the inclusion criteria (i.e., 8 regarding PA (PA-daily aerobic activity including light-moderate intensities), 8 evaluating active rehabilitation/exercise programs (20 minutes of daily aerobic exercise below symptom threshold), 6 examining a single bout of exertion). The methodological quality of the literature was assessed using the Downs and Black risk of bias (ROB) checklist. The ROB scores ranged from 7-24, with only two RCTs included. Studies demonstrated single bouts of exertion testing were safe and feasible. Daily PA or active rehabilitation/exercise programs led to a reduction in symptoms present and a decrease in number of days to medical clearance.

CONCLUSION

Following a brief period of rest (24-48 hours), individuals can gradually and safely return to PA below their physical symptom exacerbation thresholds. Further research is warranted to delineate how to optimize the timing, intensity, duration, and modality of PA impacts symptom resolution and physiological recovery following SRC.

Incidence of Injury for Professional Soccer Players in the United States: A 6-Year Prospective Study of Major League Soccer

Background:

Despite an abundance of injury research focusing on European professional soccer athletes, there are limited injury data on professional soccer players in the United States.

Purpose:

To describe the epidemiology of injury across multiple years in Major League Soccer (MLS) players.

Study Design:

Descriptive epidemiology study.

Methods:

A web-based health management platform was used to prospectively collect injury data from all MLS teams between 2014 and 2019. An injury was defined as an incident that required medical attention and was recorded into the health management platform anytime over the course of the 2014-2019 seasons. Injuries and exposure data were recorded in training and match settings to calculate injury incidence.

Results:

A total of 9713 injuries were recorded between 2014 and 2019. A mean 1.1 injuries per year per player were identified, with midfielders sustaining the largest number of injuries. The most common injuries were hamstring strains (12.3%), ankle sprains (8.5%), and adductor strains (7.6%). The mean time missed per injury was 15.8 days, with 44.2% of injuries resulting in no days missed. Overall injury incidence was 8.7 per 1000 hours of exposure, declining over the course of the investigation, with a 4.1-times greater mean incidence during matches (14.0/1000 h) than training (3.4/1000 h).

Conclusion:

Between 2014 and 2019, the most commonly reported injuries in MLS players were hamstring strains, ankle sprains, and adductor strains. Injury incidence during matches was 4.1 times greater when compared with training, while overall injury incidence was found to decline during the course of the study period.

Changes in circulating microRNAs following head impacts in soccer

AIM

To explore the short-term effects of accidental head impacts and repetitive headers on circulating microRNAs, accounting for the effects of high-intensity exercise alone.

METHODS

Blood samples were collected from professional soccer players at rest. Repeat samples were drawn 1 h and 12 h after three conditions: (1) accidental head impacts in a match, (2) repetitive headers during training, and (3) high-intensity exercise. 89 samples were screened to detect microRNAs expressed after each exposure. Identified microRNAs were then validated in 98 samples to determine consistently deregulated microRNAs. Deregulated microRNAs were further explored using bioinformatics to identify target genes and characterize their involvement in biological pathways.

RESULTS

Accidental head impacts led to deregulation of eight microRNAs that were unaffected by high-intensity exercise; target genes were linked to 12 specific signaling pathways, primarily regulating chromatin organization, Hedgehog and Wnt signaling. Repetitive headers led to deregulation of six microRNAs that were unaffected by high-intensity exercise; target genes were linked to one specific signaling pathway (TGF-β). High-intensity exercise led to deregulation of seven microRNAs; target genes were linked to 31 specific signaling pathways.

CONCLUSION

We identified microRNAs specific to accidental head impacts and repetitive headers in soccer, potentially being useful as brain injury biomarkers.

Acute Physical and Mental Activity Influence on Concussion Recovery

INTRODUCTION

Physical activity (PA) and mental activity (MA) postconcussion has received renewed attention to improve concussion management; however, most protocols start after several days and do not assess the acute window. Therefore, the purpose of this study was to assess PA and MA in the first 48 h postconcussion on the time to symptom-free status and return to play.

METHODS

We recruited 78 NCAA Division I athletes (male, 51.3%; age, 19.6 ± 1.4 yr; height, 173.7 ± 11.5 cm; weight, 80.1 ± 23.2 kg) who were diagnosed with a sports-related concussion. Participants completed a 0-5 PA and MA scale daily until fully cleared for return to participation (mean, 15.1 ± 6.9 d). A quadratic model regression assessed PA and MA over the first 2 d (acute) postconcussion on to time to symptom-free status and return to play.

RESULTS

The overall model was significant for both time to symptom free (r2 = 0.27, P = 0.004) and return to play (r2 = 0.23, P = 0.019). Reported PA was the only significant predictor for time to symptom-free (P = 0.002) and return-to-participation (P = 0.006) day. Reported MA was not associated either outcome.

CONCLUSIONS

The primary finding of this study was that mild to moderate PA acutely postconcussion was associated with reduced time to symptom free and return to participation as opposed to either lower or higher levels of PA. Conversely, acute MA was not associated with recovery outcomes. These results further elucidate the role of postconcussion PA.

Age-Group Differences and Annual Variation in Return-To-Play Practices After Sport-Related Concussion

OBJECTIVE

To examine return-to-play (RTP) practice differences between high school and collegiate athletes, as well as the stability (ie, year-by-year) in these practices over a 5-year period. We hypothesized that similar protocols for treatment will be comparable across competition levels and that these practices will vary year-to-year.

DESIGN

Prospective cohort study.

SETTING

Nine high schools and 4 National Collegiate Athletic Association Division III colleges in Southeastern Wisconsin.

PARTICIPANTS AND INDEPENDENT VARIABLES

Two-hundred seventy-three (N = 273) athletes with sport-related concussions (SRCs). Independent predictors included competition level (high school, n = 88 vs collegiate, n = 185) and year-of-injury.

OUTCOME MEASURES

Athletes were evaluated prospectively for differences in symptom duration, symptom free waiting period (SFWP), and time to RTP, as well as longitudinal changes in management.

RESULTS

High school and collegiate athletes experienced comparable median symptom duration (high school, 6.0 days, interquartile range (IQR) = 3.5-11.0; college, 6.0 days, IQR = 4.0-9.0, P = 0.95), SFWP (high school, 5.0 days, IQR = 3.0-8.0; college, 5.0 days, IQR = 3.0-7.0, P = 0.12), and total time to RTP (high school, 10.5 days, IQR = 7.0-16.0; college, 11.0 days, IQR = 8.0-14.0 days, P = 0.94). A Cox regression analysis revealed a nonsignificant trend toward longer SFWPs in high school athletes (P = 0.055; hazard ratio = 1.347, confidence interval = 0.99-1.83). Among football players, SFWPs in 2017 (Median = 3.5 days, IQR = 1.5-5.0 days) were significantly longer than those in 2014 (Median = 5.0 days, IQR = 4.0-8.5 days, P = 0.029) after correction for multiple comparisons.

CONCLUSION

Similar postinjury and RTP management practices were observed at the high school and collegiate levels after SRCs. Symptom duration and time from injury to unrestricted RTP were comparable, although high school athletes may have longer SFWPs.

A Cross-Cultural Examination of Parental Knowledge of Concussion in Three Countries

The aim of the present study was to examine and compare knowledge regarding concussion among parents of youth soccer players, ages 5-17, from the United States, Israel, and Sicily. Results revealed parents from the United States were more knowledgeable than Israeli and Sicilian parents and were more likely to have a previous history of concussion in their children, themselves, and their social contacts. The success of concussion education, programming, and legislation in the US may account for the greater knowledge of US parents and is reason to advocate for similar resources for youth athletes internationally.

Improving Discharge Instructions Following a Concussion Diagnosis in the Pediatric Emergency Department: A Pre-post Intervention Study

Introduction

Many children are discharged from the pediatric emergency department (PED) with incomplete or inappropriate instructions following a concussion. Our objective was to evaluate the effectiveness of a simple intervention in improving discharge instruction disbursement and completeness following PED diagnosis of concussion.

Methods

A pre/post intervention study of 935 patients (375 preintervention and 560 postintervention) ages 5-19, diagnosed with a concussion and discharged from the PED between July 2016 and November 2019, was performed at a single United States pediatric tertiary-care center. Dedicated provider education sessions were held, and a consensus guideline-based set of discharge instructions were implemented in the electronic health record. Primary outcomes included the presence of return-to-play (RTP) instructions, return-to-learn (RTL) instructions, follow-up recommendations, and "complete" discharge (ie, all 3 components present). Statistical process control charts were generated and tested for special cause variation.

Results

More patients received instructions for RTP (87% versus 59%) and RTL (60% versus 3%), and a complete discharge was more frequent (45% versus 2%), following the conclusion of the intervention. Only the improvement in RTP instructions was completely sustained into the following academic year, whereas RTL and complete discharge rates declined to 27% and 20%, respectively.

Conclusions

A simple, low-cost intervention such as peer-to-peer education and consensus guideline-based discharge instruction templates can significantly improve discharge readiness after pediatric concussion. Further work is needed to maintain progress and continue improvements, at our large academic trauma center.

Practical Management: Prescribing Subsymptom Threshold Aerobic Exercise for Sport-Related Concussion in the Outpatient Setting

ABSTRACT

Exercise intolerance is an objective biomarker of the physiological dysfunction after sport-related concussion (SRC). Several trials have established the safety and clinical efficacy of subsymptom threshold aerobic exercise prescribed within 1 week of injury as treatment for SRC. Clinicians, however, may not be comfortable prescribing aerobic exercise after SRC. This article presents 3 methods of exercise prescription for patients with SRC. The first requires a graded exertion test plus a home-based exercise program requiring a heart rate (HR) monitor. The second requires a graded exertion test but no HR monitor for home-based exercise. The third requires solely an HR monitor to safely progress through the home-based exercise prescription. Patients are encouraged to keep a symptom and exercise diary and return for re-evaluation every 1 to 2 weeks. Delayed recovery should prompt the clinician to evaluate for other potential symptom generators (eg, cervical, vestibular, oculomotor, mood, or migraine disorders).

Trends in match concussion incidence and return-to-play time in male professional Rugby Union: A 16-season prospective cohort study

AIM

To describe trends in the incidence of match concussions and time to return-to-play in professional rugby union.

METHODS

Match concussion incidence (injuries per 1000 player-match-hours) and time to return-to-play (mean and median days absence) were recorded in 3006 male professional rugby union players over 16 seasons (2002/03 - 2018/19).

RESULTS

From 2002/03 to 2009/10, incidence of concussions was stable at 4.3/1000 player-match-hours. From 2009/10 to 2018/19, there was an increase in concussion incidence, with the highest incidence in 2016/17 at 20.9/1000 player-match-hours (95% CI: 17.9-24.3). Annual prevalence of concussion also increased, suggesting more players were concussed rather than the same players sustaining more concussions. Before the introduction of standardized graduated return-to-play (GRTP) guidelines in 2011, 27% of players returned to play in <6 days. After the introduction of the GRTP, this decreased to 7%, with no players returning in <6 days after 2014/15. Between 2002/03 and 2018/19, incidence of all other injuries remained stable.

CONCLUSIONS

From 2009/10 onwards, the incidence of diagnosed concussions increased. Since the introduction of the GRTP, there has been a dramatic reduction in the number of players returning in <6 days.

Sports Related Concussion Impacts Speech Rate and Muscle Physiology

OBJECTIVE

Establish objective and subjective speech rate and muscle function differences between athletes with and without sports related concussion (SRC) histories and provide potential motor speech evaluation in SRC.

METHODS

Over 1,110 speech samples were obtained from 30, 19-22 year-old athletes who had sustained an SRC within the past 2 years and 30 pair-wise matched control athletes with no history of SRC. Speech rate was measured via average time per syllable, average unvoiced time per syllable, and expert perceptual judgment. Speech muscle function was measured via surface electromyography over the obicularis oris, masseter, and segmental triangle. Group differences were assessed using MANOVA, bootstrapping and predictive ROC analyses.

RESULTS

Athletes with SRC had slower speech rates during DDK tasks than controls as evidenced by longer average time per syllable longer average unvoiced time per syllable and expert judgment of slowed rate. Rate measures were predictive of concussion history. Further, athletes with SRC required more speech muscle activation than controls to complete DDK tasks.

CONCLUSION

Clear evidence of slowed speech and increased muscle activation during the completion of DDK tasks in athletes with SRC histories relative to controls. Future work should examine speech rate in acute concussion.

Management of sport-related concussion in emergency departments in England: a multi-center study

OBJECTIVE

To establish the current knowledge of sport-related concussion (SRC) management of clinicians in emergency departments in the North West of England.

METHODS

A cross-sectional, multi-center study design was used and included emergency department clinicians (EDCs) across 15 centers in the North West of England. A 22-question survey was issued with questions focused on the 5th International Conference on Concussion Consensus Statement. Absolute and percentages were presented, and comparisons in knowledge of guidelines and confidence between EDCs were made using the Kruskal-Wallis test.

RESULTS

Of an estimated 300 EDCs, 111 (37%) responded. Thirty (27%) were aware of the guidelines, whilst 63 (57%) had heard of a graduated return-to-sport protocol. Physical rest was advised by 106 (95%) respondents, with 68 (61%) advising cognitive rest and 47 (42%) providing written advice. There was no difference (p > .05) in awareness of SRC guidelines or confidence between clinician grade, with most receiving no SRC training.

CONCLUSIONS

There is a lack of knowledge amongst EDCs in the North West of England in managing and providing discharge advice to patients with SRC. This is likely due to the limited awareness of guidelines and training, and therefore further education delivery on SRC management guidelines is required.

More Physical Activity after Concussion Is Associated with Faster Return to Play among Adolescents

Concussion management has evolved to de-emphasize rest in favor of early introduction of post-injury physical activity. However, the optimal quantity, frequency and intensity of physical activity are unclear. Our objective was to examine the association between objective physical activity metrics and clinical recovery after concussion. We prospectively enrolled a cohort of 32 youth athletes with concussion, evaluated within 14 days of injury and after return-to-play (RTP) clearance. For two weeks after enrollment, we quantified steps/day and exercise frequency, duration, and intensity via wrist-worn actigraphy. We grouped participants by RTP clearance timing (<28 days vs. ≥28 days). Seventeen (53%) participants required ≥28 days post-concussion for RTP clearance. Groups were similar in age (14.9 ± 1.9 vs. 15.4 ± 1.5 years; p = 0.38), proportion of females (47% vs. 40%; p = 0.69), and concussion history (59% vs. 47%; p = 0.49). During the study period, the RTP ≥ 28 days group took fewer steps/day (8158 ± 651 vs. 11,147 ± 4013; p = 0.02), exercised fewer days/week (2.9 ± 2.4 vs. 5.0 ± 1.9 days/week; p = 0.01), and exercised fewer total minutes/week (117 ± 122 vs. 261 ± 219 min/week; p = 0.03). Furthermore, we observed ≥10,251 average steps/day, ≥4 exercise sessions/week, and exercising ≥134 total minutes/week were optimal cutpoints to distinguish between groups. These findings support the benefit of physical activity during concussion recovery.

Two Sports, Two Systems, One Goal: A Comparative Study of Concussion Policies and Practices of the Australian Football League and Hockey Canada

Concussion in sport is today regarded as both a public health issue and high profile injury concern in many contact and collision sports. This paper undertakes a comparative review of the current policies and practices of two high profile national sporting organisations of such sports-the Australian Football League (AFL) and Hockey Canada (HC)-in governing the issue as a regulatory concern. By examining the policies and practices of the AFL and HC, this study aims to identify common themes, divergent practices, and nuanced sport-specific approaches to develop understandings on the regulation and governance of this high profile sports injury. The paper aims to contribute to understanding concussion as a regulatory concern, while at the same time recognising the heterogeneity of sport and reinforcing nuanced understandings that align to specific social and cultural settings. We make recommendations based on regulatory and cultural legitimacy. The paper concludes that these NSOs are institutional actors with historical and cultural roots who assert regulatory legitimacy by steering and influencing behaviour and directing the regulatory agenda to manage and mitigate the harm associated with concussion.

Effectiveness of the Auditory Temporal Ordering and Resolution Tests to Detect Central Auditory Processing Disorder in Adults With Evidence of Brain Pathology: A Systematic Review and Meta-Analysis

Background: Auditory temporal processing tests are key clinical measures in order to diagnose central auditory processing disorder (CAPD). Although these tests have been used for decades, there is no up-to-date evidence to determine the effectiveness of detecting the abnormalities in central auditory processing in adults while the available national CAPD guidelines predominantly address CAPD in the pediatric population.

Purpose: To determine the efficacy of the auditory temporal ordering tests [duration pattern test (DPT) and frequency pattern test (FPT)], and a temporal resolution test [gaps-in-noise (GIN) test] for detecting the central auditory processing abnormalities in adults with documented brain pathology.

Research Design: Systematic reviews and meta-analyses.

Study samples: Four databases, including PubMed, Web of Science, Embase, and Scopus, were systematically searched. The publications in the English language that recruited adults (above 16 years old) with pathologic brain conditions and described the diagnostic tests for auditory temporal processing were selected for review.

Data Collections and Analysis: All data were systematically evaluated, extracted, categorized, and summarized in tables. The meta-analysis was done in order to determine the effectiveness of the DPT, FPT, and GIN tests.

Results: The results showed significantly poorer performance of DPT and FPT, compared between participants with confirmed brain disease and normal controls, at the mean differences of percent correct −21.93 (95% CI, −26.58 to −17.29) and −31.37 (95% CI, −40.55 to −22.19), respectively. Subjects with brain pathology also performed poorer in GIN test at the mean difference of 3.19 milliseconds (95% CI, 2.51 to 3.87).

Conclusion: The results from the meta-analysis provide evidence that DPT, FPT, and GIN clinical measures are effective in the diagnosis of CAPD in adults with neurological disorders. Poor performance on these tests is significantly related to the confirmed brain pathology. However, different units in results presentation and variety of testing strategies are limitations for this meta-analysis. The standard pattern of result reporting and international protocols test strategies should be developed in order to conduct better meta-analyses with a larger collection of suitable studies and less heterogeneity.

Multimodal Assessment of Sport-Related Concussion

OBJECTIVE

The purpose of this study was to determine which assessments best identify athletes with sport-related concussion (SRC) from healthy controls in the acute/early subacute phase (within 10 days of SRC) of injury.

DESIGN

Prospective, cohort study.

SETTING

Specialty concussion clinic.

PARTICIPANTS

Sixty-four athletes with SRC (52% male) and 59 matched (age and sex), healthy controls (56% male) aged 12 to 20 years (Mean [M] = 15.07, Standard Deviation [SD] = 2.23).

ASSESSMENT

Participants completed symptom, cognitive, vestibular/oculomotor, near point of convergence (NPC), and balance assessments.

MAIN OUTCOME MEASURES

Univariate analyses were conducted to compare athletes with SRC to healthy controls across all assessments. Assessments that significantly differed between the SRC group and healthy controls were used as predictors in an enter method logistic regression (LR) model and subsequent forward stepwise LR.

RESULTS

Results of LR analyses indicated that symptom inventory and symptom provocation on vestibular/oculomotor assessments significantly predicted athletes with SRC versus controls. The forward stepwise LR accurately classified 84.6% of the overall sample (78.3% of athletes with SRC and 91.2% of controls were accurately predicted) and accounted for 60.5% of the variance in predicting athletes with SRC versus controls. Total symptom inventory score (P = 0.003) and vestibular/oculomotor symptom provocation (P < 0.01) were the most sensitive and specific measures in a comprehensive, multimodal assessment for distinguishing athletes with SRC from healthy controls within 10 days of injury.

CONCLUSIONS

Elements within a multimodal evaluation that are the most robust at discriminating athletes with SRC from healthy controls in the acute/early subacute phase of injury include symptom report and provocation of symptoms on vestibular/oculomotor assessment. These assessments should be considered in conjunction with other objective assessments (ie, NPC measurement and cognitive testing) as part of a comprehensive evaluation of SRC.

Evidence based management of sports related concussion

Sports related concussion (SRC) is a common condition evaluated by healthcare professionals. In an article entitled "Return to Play After Concussion: Clinical Guidelines for Young Athletes" published in the December 2019 issue of the Journal of the American Osteopathic Association, guidelines for the management of SRC were presented to assist healthcare professionals in the management of patients with SRC. However, much of the information presented in that article is contradicted by current expert recommendations and evidence based practice guidelines. The management of SRC has evolved to a nuanced, domain driven diagnosis requiring a multidisciplinary treatment team and a customized management plan for each patient to ensure competent treatment of patients with SRC. As such, this Commentary summarizes current recommendations for diagnosis and management of SRC.

The care of the concussed pediatric patient prior to presentation to primary care pediatrician versus concussion specialists: Implications for management

Objective

Absent adequate randomized control trials to inform appropriate treatment for concussion in pediatric patients, guidelines have been developed based on expert opinion and observational data that may not apply to all groups. This study examines differences in the previous clinical care between concussed patients who present in pediatric practice and specialty clinics. Differences found might influence treatment recommendations for each setting.

Study design

Prospective data collected from a pediatric practice in 2011 to 2013 were compared to chart review data from two specialty clinics between 2015 and 2017. In all three groups patients 11–19 years of age with an ICD9 billing code for concussion were included if they met the 4th International Consensus definition of concussion. Patients were excluded if hospitalized or had abnormal CNS imaging.

Results

The time between injury and presentation was substantially longer in specialty clinic patients versus those seen in the primary pediatric care office. (median 10 vs. 2 days-p < 0.001) Primary care patients presenting had higher rates of immediate rest after injury, 61.4% vs 27.9% (p < 0.001). More specialty clinic patients had been seen in the emergency departments prior to presentation (47.5% vs. 18.8% p < 0.001) regardless of rest status at presentation to the office.

Conclusion

Several differences in previous clinical care between the groups were found. These included the time of presentation from injury, rates of cognitive rest both immediate and non-immediate, and emergency department visits. These differences may have implications for management recommendations. Accordingly, the appropriate treatment for patients seen by the primary pediatric care physicians may be different from those referred to specialty care. Given these findings randomized controlled trails should be conducted independently in both groups of patients.

Exercise for Sport-Related Concussion and Persistent Postconcussive Symptoms

CONTEXT

Emerging research supports the use of mild to moderate aerobic exercise for treating sport-related concussion (SRC) and persistent postconcussive symptoms (PPCS), yet the current standard of care remains to be strict rest. The purpose of this review is to summarize the existing literature on physical activity and prescribed exercise for SRC and PPCS.

EVIDENCE ACQUISITION

PubMed and Embase were searched in April of 2019 for studies assessing rest or prescribed exercise for SRC and PPCS. No specific search syntax was used.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

A majority of studies show that spontaneous physical activity is safe after SRC and that subsymptom threshold aerobic exercise safely speeds up recovery after SRC and reduces symptoms in those with PPCS. Exercise tolerance can safely be assessed using graded exertion test protocols within days of injury, and the degree of early exercise tolerance has diagnostic and prognostic value.

CONCLUSION

Subsymptom threshold aerobic exercise is safe and effective for the treatment of SRC as well as in athletes with PPCS. Further research is warranted to establish the most effective method and dose of aerobic exercise for the active treatment of SRC and whether early exercise treatment can prevent PPCS in athletes.

STRENGTH OF RECOMMENDATION TAXONOMY

2.

De-implementing Prolonged Rest Advice for Concussion in Primary Care Settings: A Pilot Stepped Wedge Cluster Randomized Trial

OBJECTIVE

To evaluate the feasibility and preliminary efficacy of a de-implementation intervention to support return-to-activity guideline use after concussion.

SETTING

Community.

PARTICIPANTS

Family physicians in community practice (n = 21 at 5 clinics).

DESIGN

Pilot stepped wedge cluster randomized trial with qualitative interviews. Training on new guidelines for return to activity after concussion was provided in education outreach visits.

MAIN MEASURES

The primary feasibility outcomes were recruitment, retention, and postencounter form completion (physicians prospectively recorded what they did for each new patient with concussion). Efficacy indicators included a knowledge test and guideline compliance based on postencounter form data. Qualitative interviews covered Theoretical Domains Framework elements.

RESULTS

Recruitment, retention, and postencounter form completion rates all fell below feasibility benchmarks. Family physicians demonstrated increased knowledge about the return-to-activity guideline (M = 8.8 true-false items correct out of 10 after vs 6.3 before) and improved guideline adherence (86% after vs 25% before) after the training. Qualitative interviews revealed important barriers (eg, beliefs about contraindications) and facilitators (eg, patient handouts) to behavior change.

CONCLUSIONS

Education outreach visits might facilitate de-implementation of prolonged rest advice after concussion, but methodological changes will be necessary to improve the feasibility of a larger trial. The qualitative findings highlight opportunities for refining the intervention.

Examination of Reaction Time Deficits Following Concussion: A Systematic Review and Meta-analysis

BACKGROUND

Reaction time (RT) deficits are reported following concussion, but it is unknown when these deficits normalize to pre-injury status. It is also unclear how factors such as RT measurement technique and participant characteristics influence post-concussion RT.

OBJECTIVE

The purpose of this systematic review and meta-analysis was to (1) characterize acute post-concussion (0-3 days) RT impairments, (2) examine RT recovery over time, and (3) explore moderating factors related to acute RT impairment following concussion.

METHODS

Database searches (PubMed, CINAHL, EBSCOhost) were conducted according to PRISMA guidelines for articles published in English from January 2002 to March 2019. Studies compared baseline-to-post-injury RT within individuals (within-subject) and/or RT in concussed individuals to non-concussed controls (between-subject). Sixty studies met inclusion criteria, reporting on a total of 9688 participants with 214 discrete RT effects (Hedges' d; between-subject: N = 29, k = 129; within-subject: N = 42, k = 85). Of the 214 effects, 93 occurred in the acute (0-3 days) post-injury timeframe (k = 47 between-subject). Numerous demographic [sex, age, concussion history, population type (athlete, military, and general population), athlete level (high school, college), and sport], and method-based (RT test and measure type, computerized neurocognitive testing platform, concussion definition, and time post-injury) moderators were examined for mean effect influence. Mixed-effects multi-level modeling with restricted-maximum-likelihood estimation was used to account for nested effects and high heterogeneity for the pooled effect size (D+).

RESULTS

Significant medium-magnitude RT deficits were observed acutely for between- (D+ = - 0.7279, 95% CI - 0.9919, - 0.4639, I² = 88.66, p < 0.0001) and within-subject (D+ = - 0.7472, 95% CI - 0.9089, - 0.5855, I² = 89.21, p < 0.0001) effect models. RT deficits were present at the sub-acute and intermediate-term timeframes for between-subject effects (sub-acute: D+ = - 0.5655, 95% CI - 0.6958, - 0.4352, p < 0.0001; intermediate-term: D+ = - 0.3219, 95% CI - 0.5988, - 0.0450, p = 0.0245). No significant RT mean effect was observed for the between-subject model at the long-term timeframe, indicating RT recovery among concussed participants relative to controls (D+ = 0.3505, 95% CI - 0.4787, 1.1797, p = 0.3639). Sex was a significant moderator for between-subject effects, with every 1% male sample size increase demonstrating - 0.0171 (95% CI - 0.0312, - 0.0029, p = 0.0193) larger RT deficits. Within-subject effect models resulted in RT measure type (simple: [D+ = - 0.9826] vs. mixed: [D+ = - 0.6557], p = 0.0438) and computerized neurocognitive testing platforms (ANAM: [D+ = - 0.3735] vs. HeadMinder CRI: [D+ = - 1.4799] vs. ImPACT: [D+ = - 0.6749], p = 0.0004) having significantly different RT-deficit magnitudes. No other moderators produced significantly different RT-deficit magnitudes (between-subject: [p ≥ 0.0763], within-subject: [p ≥ 0.1723]).

CONCLUSIONS

Robust RT deficits were observed acutely following concussion. Minimal magnitude differences were noted when comparing between- and within-subject effects, suggesting that pre-injury baselines may not add clinical value in determining post-injury RT impairment. RT deficits persisted up till the intermediate-term (21-59 days post-injury) timeframe and indicate lingering deficits exist. Mean effect size differences were observed between RT measure types and computerized neurocognitive testing platforms; however, all categories displayed negative effects consistent with impaired RT following concussion. Clinical interpretation suggests that measuring RT post-concussion is more important than considering the RT method employed so long as reliable and valid tools are used. PROSPERO Registration #CRD42019119323.

Concussion Guidelines in National and International Professional and Elite Sports

The Berlin statement on sport-related concussion was published in 2017 using evidence-based recommendations. We aimed to examine (1) the implementation of, distribution and education based on the Berlin recommendations, and the development of sport-specific protocols/guidelines among professional and elite sports, (2) the implementation of guidelines at the community level, (3) translation of guidelines into different languages, and (4) research activities. Senior medical advisers and chief medical officers from Australian Football League, All Japan Judo Federation, British Horseracing Authority, Cricket Australia, Fédération Equestre Internationale, Football Association, Gaelic Athletic Association, International Boxing Association, Irish Horseracing Regulatory Board, Major League Baseball, National Football League, National Hockey League, National Rugby League, and World Rugby completed a questionnaire. The results demonstrated that all 14 sporting organizations have published concussion protocols/guidelines based on the Berlin recommendations, including Recognize, Removal from play, Re-evaluation, Rest, Recovery, and Return to play. There is variable inclusion of Prolonged symptoms. Prevention and Risk reduction and Long-term effects are addressed in the guidelines, rules and regulations, and/or sport-specific research. There is variability in education programs, monitoring compliance with guidelines, and publication in other languages. All sporting bodies are actively involved in concussion research. We conclude that the Berlin recommendations have been included in concussion protocols/guidelines by all the sporting bodies, with consistency in the essential components of the recommendations, whilst also allowing for sport- and regional-specific variations. Education at the elite, community, and junior levels remains an ongoing challenge, and future iterations of guidelines may consider multiple language versions, and community- and junior-level guidelines.