Assessment, Management and Knowledge of Sport-Related Concussion: Systematic Review

Frequency of Self-Reported Concussion Amongst Professional and Semi-Professional Footballers in Ireland During the 2014 Season: a Cross-Sectional Study

BACKGROUND

This paper examines the occupational risk of concussion amongst professional and semi-professional footballers in Ireland during the 2014 League of Ireland season. As part of a broader nationally representative study examining occupational safety and health (OSH) awareness amongst professional footballers, this empirical quantitative study, utilising a convenience sample is the first and largest investigation of the frequency of, and attitudes towards, concussion and concussion reporting amongst Irish senior professional and semi-professional footballers.

METHODS

A census survey using an anonymous questionnaire was provided to available League of Ireland clubs between March and May 2015. Permission to access players was provided by the Professional Footballers Association of Ireland. This convenience sample was determined by club availability in relation to match fixtures. Participation by the footballers was voluntary. At the time, there were 250 professional and semi-professional players within the League available to participate.

RESULTS

A total of 149 footballers participated in the study. Sixty percent of the participants were employed on a semi-professional basis and the majority of all participants were aged between 18 and 30. 15.7% of the participants reported having received a concussion in the 2014 season with semi-professional players having a noticeably higher (though not significant) reporting rate. Analysis indicated that there was a significant association between playing position and concussion reporting with defenders having the greater odds of reporting a concussion than other playing positions. Professional and semi-professional footballers have a relatively equal risk of receiving a concussion.

CONCLUSION

This research is the first major investigation of the self-reported frequency of, and attitudes towards, concussion amongst Irish senior professional and semi-professional footballers. The results have important implications for coaches, clinicians, parents, players and national governing bodies. Further research is needed to ascertain whether professional footballers perceive concussion as an occupational risk, and whether they appreciate that accepting such risks can have long-term implications for health.

Do Neurocognitive SCAT3 Baseline Test Scores Differ Between Footballers (Soccer) Living With and Without Disability? A Cross-Sectional Study

OBJECTIVE

To determine if baseline Sport Concussion Assessment Tool, third Edition (SCAT3) scores differ between athletes with and without disability.

DESIGN

Cross-sectional comparison of preseason baseline SCAT3 scores for a range of England international footballers.

SETTING

Team doctors and physiotherapists supporting England football teams recorded players' SCAT 3 baseline tests from August 1, 2013 to July 31, 2014.

PARTICIPANTS

A convenience sample of 249 England footballers, of whom 185 were players without disability (male: 119; female: 66) and 64 were players with disability (male learning disability: 17; male cerebral palsy: 28; male blind: 10; female deaf: 9).

ASSESSMENT AND OUTCOME MEASURES

Between-group comparisons of median SCAT3 total and section scores were made using nonparametric Mann-Whitney-Wilcoxon ranked-sum test.

MAIN RESULTS

All footballers with disability scored higher symptom severity scores compared with male players without disability. Male footballers with learning disability demonstrated no significant difference in the total number of symptoms, but recorded significantly lower scores on immediate memory and delayed recall compared with male players without disability. Male blind footballers' scored significantly higher for total concentration and delayed recall, and male footballers with cerebral palsy scored significantly higher on balance testing and immediate memory, when compared with male players without disability. Female footballers with deafness scored significantly higher for total concentration and balance testing than female footballers without disability.

CONCLUSIONS

This study suggests that significant differences exist between SCAT3 baseline section scores for footballers with and without disability. Concussion consensus guidelines should recognize these differences and produce guidelines that are specific for the growing number of athletes living with disability.

Characterizing Verified Head Impacts in High School Girls' Lacrosse

BACKGROUND

Girls' high school lacrosse players have higher rates of head and facial injuries than boys. Research indicates that these injuries are caused by stick, player, and ball contacts. Yet, no studies have characterized head impacts in girls' high school lacrosse.

PURPOSE

To characterize girls' high school lacrosse game-related impacts by frequency, magnitude, mechanism, player position, and game situation.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

Thirty-five female participants (mean age, 16.2 ± 1.2 years; mean height, 1.66 ± 0.05 m; mean weight, 61.2 ± 6.4 kg) volunteered during 28 games in the 2014 and 2015 lacrosse seasons. Participants wore impact sensors affixed to the right mastoid process before each game. All game-related impacts recorded by the sensors were verified using game video. Data were summarized for all verified impacts in terms of frequency, peak linear acceleration (PLA), and peak rotational acceleration (PRA). Descriptive statistics and impact rates were calculated.

RESULTS

Fifty-eight verified game-related impacts ≥20 g were recorded (median PLA, 33.8 g; median PRA, 6151.1 rad/s²) during 467 player-games. The impact rate for all game-related verified impacts was 0.12 per athlete-exposure (AE) (95% CI, 0.09-0.16), equivalent to 2.1 impacts per team game, indicating that each athlete suffered fewer than 2 head impacts per season ≥20 g. Of these impacts, 28 (48.3%) were confirmed to directly strike the head, corresponding with an impact rate of 0.05 per AE (95% CI, 0.00-0.10). Overall, midfielders (n = 28, 48.3%) sustained the most impacts, followed by defenders (n = 12, 20.7%), attackers (n = 11, 19.0%), and goalies (n = 7, 12.1%). Goalies demonstrated the highest median PLA and PRA (38.8 g and 8535.0 rad/s², respectively). The most common impact mechanisms were contact with a stick (n = 25, 43.1%) and a player (n = 17, 29.3%), followed by the ball (n = 7, 12.1%) and the ground (n = 7, 12.1%). One hundred percent of ball impacts occurred to goalies. Most impacts occurred to field players within the attack area of the field (n = 32, 55.2%) or the midfield (n = 18, 31.0%). Most (95%) impacts did not result in a penalty.

CONCLUSION

The incidence of verified head impacts in girls' high school lacrosse was quite low. Ball to head impacts were associated with the highest impact magnitudes. While stick and body contacts are illegal in girls' high school lacrosse, rarely did such impacts to the head result in a penalty. The verification of impact mechanisms using video review is critical to collect impact sensor data.

Baseline King-Devick scores for adults are not generalizable; however, age and education influence scores

OBJECTIVE

To establish normative values for the King-Devick (K-D) test to be used as a reference for determining impairment related to concussion when individual baseline scores are lacking.

METHOD

Baseline K-D scores were collected for 243 participants aged 18-86.

RESULTS

The mean age of subjects was 40.46; range 18-86 years. The mean time was 42.2 seconds; 26.19-75.96 seconds. There was a relationship (r = 0.376) between K-D score and age; scores increased (worsened) with age. There was also a relationship between score and education with scores decreasing as education increased (r = -0.194; p = 0.002). The K-D score was not influenced by sex or concussion history. A regression equation using education and age to predict K-D time explained 0.418 of the variance in K-D test time.

CONCLUSION

Although this research established a relationship between K-D score and age and education, the range in scores was too broad to establish normative values. In the absence of a baseline score, the use of a regression equation considering age and education level may provide some indication of expected score. However, the most reliable use of the test as a screen for impairment following concussion involves the use of a baseline test.

Comparison of knowledge, perception and attitudes of concussion in previously concussed versus non-concussed youth soccer players

OBJECTIVES

To examine if history of concussion is correlated with a difference in knowledge, attitude, and perception of concussive injuries in youth soccer players.

METHODS

A convenience sample of youth soccer athletes aged 14 to 18 years completed a survey assessing prior history of concussive injury, knowledge of concussive injury, self-reporting attitudes, and perception of the injury. The survey consists of 16 knowledge questions (eleven on a scale of 1-2, and five on a scale of 1-4) and 12 attitude questions (seven on a scale of 1-4, and five on a scale of 1-5). The primary outcomes are the total scores calculated by summing the standardized raw scores for all knowledge questions and attitude questions, respectively. Linear regression was used to estimate the mean difference in the primary outcomes between previously concussed and non-concussed athletes (calculated as previously concussed - non-concussed).

RESULTS

Surveys were obtained from 90 athletes, with 32 (36%) previously sustaining at least one concussion. Thirty-one out of these 32 concussions were diagnosed by a medical provider. On average, the mean total raw scores of all knowledge questions are 34.6 (82.2% of 42 possible points) and 33.7 (80.2% of 42 total points) for previously concussed and non-concussed athletes, respectively, and the mean total raw scores of all attitude questions are 38.7 (72.9% of 53 possible points) and 39.6 (74.7% of 53 possible points), respectively. Mean differences estimated from univariate linear regression in the standardized total scores of knowledge questions and attitude questions are 1.56(95% confidence interval: -1.52-4.65) and -1.23 (%95 confidence interval: -4.64-2.19), respectively. Adjusting for age and years of playing soccer gave similar results.

CONCLUSION

Although we did not find significant differences between previously concussed and non-concussed athletes in either the knowledge or the attitude questions as measured by their total scores, this study showed a high level of awareness of concussion in youth soccer players, while still highlighting a need for education. Limited distinctions were made among subgroups of players, suggesting directions of future research in investigating the role that outside factors may have on knowledge and perception of concussion.

Pediatric providers' attitudes and practices regarding concussion diagnosis and management

Background Concussions, a form of mild traumatic brain injury, are a current "hot topic" in sports and medicine, with current research focusing on diagnosis, treatment, and the long-term effects of repeated concussions on development of chronic traumatic encephalopathy. Concussions represent 8.9% of all high school athletic injuries, and pediatricians see many of these patients in their practices, however evolving guidelines and recommendations have resulted in varying practices among providers. Objective To assess how local pediatricians in New York Chapter 2 of the American Academy of Pediatrics (AAP) diagnose and treat concussion patients, and to evaluate the need for continuing education in this area. Design and methods Survey Monkey™ was used to query providers regarding their diagnosis and treatment of concussion patients. A total of three emails containing a link to the 22 question multiple-choice survey were sent to AAP Chapter 2 members between January 2015 and June 2015. The survey was adapted and modified with permission from one previously used by "Zonfrillo MR, Master CL, Grady MF, Winston FK, Callahan JM, Arbogast KB. Pediatric providers' self-reported knowledge, practices, and attitudes about concussion. Pediatrics. 2012;130:1120-5". Results We received 115 responses from 1436 potential participants to whom the survey link was sent, resulting in an 8% response rate. We excluded subspecialists from our data analysis, resulting in data from 95 primary care pediatricians. Of the PCPs 98.7% reported seeing at least one child or adolescent with a concussion in the previous 12 months and 76.6% reported referring some or all of their concussion patients for ongoing management. The most common reason for referral was "I am not always comfortable with management" and the most common subspecialist referral was to a neurologist. Most providers reported that they did not use any guidelines for management (58.3%) and only 57.4% were familiar with the New York State Education Department concussion guidelines. Almost half reported inadequate training in performing neurocognitive assessments (48.6%). Most were comfortable educating families about the diagnosis of concussion (81.7%), as well as recommending the appropriate time to resume school (70.4%) and prescribing and monitoring a return to play protocol (62%). A total of 84.3% also responded, however, that they would be interested in a webinar for a continuing medical education(CME) credit focused on concussion diagnosis and management. Conclusions Most pediatric providers care for patients who have suffered a concussion, however many identify barriers to diagnosis and treatment, which results in patients being referred to subspecialists for further management. Many providers are also unfamiliar with, or do not use, published concussion guidelines and report varying practices in treatment of concussion patients due to evolving recommendations. This study demonstrates that there is a need for further education for pediatric providers who see patients with concussion.

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.

Clinical evaluation of concussion: the evolving role of oculomotor assessments

Sports-related concussion is a change in brain function following a direct or an indirect force to the head, identified in awake individuals and accounting for a considerable proportion of mild traumatic brain injury. Although the neurological signs and symptoms of concussion can be subtle and transient, there can be persistent sequelae, such as impaired attention and balance, that make affected patients particularly vulnerable to further injury. Currently, there is no accepted definition or diagnostic criteria for concussion, and there is no single assessment that is accepted as capable of identifying all patients with concussion. In this paper, the authors review the available screening tools for concussion, with particular emphasis on the role of visual function testing. In particular, they discuss the oculomotor assessment tools that are being investigated in the setting of concussion screening.

The Influence of Head Impact Threshold for Reporting Data in Contact and Collision Sports: Systematic Review and Original Data Analysis

BACKGROUND

Head impacts and resulting head accelerations cause concussive injuries. There is no standard for reporting head impact data in sports to enable comparison between studies.

OBJECTIVE

The aim was to outline methods for reporting head impact acceleration data in sport and the effect of the acceleration thresholds on the number of impacts reported.

METHODS

A systematic review of accelerometer systems utilised to report head impact data in sport was conducted. The effect of using different thresholds on a set of impact data from 38 amateur senior rugby players in New Zealand over a competition season was calculated.

RESULTS

Of the 52 studies identified, 42% reported impacts using a >10-g threshold, where g is the acceleration of gravity. Studies reported descriptive statistics as mean ± standard deviation, median, 25th to 75th interquartile range, and 95th percentile. Application of the varied impact thresholds to the New Zealand data set resulted in 20,687 impacts of >10 g, 11,459 (45% less) impacts of >15 g, and 4024 (81% less) impacts of >30 g.

DISCUSSION

Linear and angular raw data were most frequently reported. Metrics combining raw data may be more useful; however, validity of the metrics has not been adequately addressed for sport. Differing data collection methods and descriptive statistics for reporting head impacts in sports limit inter-study comparisons. Consensus on data analysis methods for sports impact assessment is needed, including thresholds. Based on the available data, the 10-g threshold is the most commonly reported impact threshold and should be reported as the median with 25th and 75th interquartile ranges as the data are non-normally distributed. Validation studies are required to determine the best threshold and metrics for impact acceleration data collection in sport.

CONCLUSION

Until in-field validation studies are completed, it is recommended that head impact data should be reported as median and interquartile ranges using the 10-g impact threshold.

Multiple Past Concussions in High School Football Players: Are There Differences in Cognitive Functioning and Symptom Reporting?

BACKGROUND

There is increasing concern about the possible long-term effects of multiple concussions, particularly on the developing adolescent brain. Whether the effect of multiple concussions is detectable in high school football players has not been well studied, although the public health implications are great in this population.

PURPOSE

To determine if there are measureable differences in cognitive functioning or symptom reporting in high school football players with a history of multiple concussions.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Participants included 5232 male adolescent football players (mean [±SD] age, 15.5 ± 1.2 years) who completed baseline testing between 2009 and 2014. On the basis of injury history, athletes were grouped into 0 (n = 4183), 1 (n = 733), 2 (n = 216), 3 (n = 67), or ≥4 (n = 33) prior concussions. Cognitive functioning was measured by the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) battery, and symptom ratings were obtained from the Post-Concussion Symptom Scale.

RESULTS

There were no statistically significant differences between groups (based on the number of reported concussions) regarding cognitive functioning. Athletes with ≥3 prior concussions reported more symptoms than did athletes with 0 or 1 prior injury. In multivariate analyses, concussion history was independently related to symptom reporting but less so than developmental problems (eg, attention or learning problems) or other health problems (eg, past treatment for psychiatric problems, headaches, or migraines).

CONCLUSION

In the largest study to date, high school football players with multiple past concussions performed the same on cognitive testing as those with no prior concussions. Concussion history was one of several factors that were independently related to symptom reporting.

A Normative Dataset of the Balance Error Scoring System in Children Aged Between 5 and 14

OBJECTIVE

Pediatric head injuries occur commonly and are being reported in increasing numbers. Balance testing is a key component in the evaluation of suspected concussion, and the balance error scoring system (BESS) is likely the most well-known and widely used measure. To date, normative BESS scores for adults have been reported but not for children.

DESIGN

Normative data for BESS scores and modified BESS scores were created in a cohort of healthy children. Potential variables were analyzed as predictors of BESS performance.

SETTING

Local elementary and junior high schools.

PARTICIPANTS

A total of 373 healthy children between the ages of 5 and 14.

INTERVENTIONS

The BESS was performed on all children.

ASSESSMENT OF RISK FACTORS

Gender, body mass index percentile, previous concussions, athletic participation, age, and the parental opinion of child's balance ability were examined as factors associated with the BESS score.

MAIN OUTCOME MEASURES

BESS scores.

RESULTS

Normative data are reported, stratified by age groups of 5 to 7 years, 8 to 10 years, and 11 to 14 years of age, for both BESS and modified BESS. Median BESS scores are 23 for children aged 5 to 7, 18 for children aged 8 to 10, and 16 for children aged 11 to 14. Median modified BESS scores are 8 for children age 5 to 7, 5 for children age 8 to 10, and 4 for children age 11 to 14. Increasing age and positive parental opinion regarding their child's balance ability were independently correlated with decreasing BESS scores (P < 0.01).

CONCLUSIONS

The normative data on BESS scores for healthy children reported here provide age-stratified reference values for suspected balance alterations.

SCAT2 and SCAT3 scores at baseline and after sports-related mild brain injury/concussion: qualitative synthesis with weighted means

Objective

Identify all Sport Concussion Assessment Tool (SCAT2/3) studies, compare baseline and postconcussion results.

Design

Systematic review (qualitative synthesis, weighted means).

Data sources

18 databases, 9 grey literature resources searched for SCAT2/3 data; 9150 articles identified, titles/abstracts assessed/data-entry independently by two reviewers.

Eligibility criteria for selecting studies

Any studies reporting partial/complete SCAT2/3 data.

Results

21 studies with data (partial/complete data 16 SCAT2 (4087 athletes); 5 SCAT3 (891). Newcastle-Ottawa risk-of-bias scale: studies with maximum possible score of 4, 85% scored 3 or 4; studies with maximum possible score of 6, 75% scored 5 or 6. SCAT2 high schoolers: weighted mean score for symptoms 18.46 (22=no symptoms), Balance Error Scoring System (BESS) 26.14, Standardised Assessment of Concussion (SAC) 26.00 and SCAT2 total 88.63. Collegiate/adults weighted means: symptoms 20.09, BESS 25.54, SAC 27.51 and total SCAT2 91.20. Between-study and within-study variability similar to those of the high schoolers. Limited variability between genders. Only 2 studies report baseline and postconcussion scores and 9 partial scores, but data are too limited to provide weighted average scores.

Conclusions

Group mean baseline SCAT scores for high school and collegiate athletes are similar, with minimal gender differences; baseline symptoms show more variability than other components. There are minimal data for elementary students and professionals, no data for adult non-collegiate athletes. Two studies provide preconcussion and postconcussion scores. No data on minimal significant clinical differences to guide players/coaches in withdrawing from a game in progress and deciding when recovery is complete and play can be resumed. The SCAT needs supplementing with clinical and neuropsychological return-to-play assessments.

Ondansetron for pediatric concussion; a pilot study for a randomized controlled trial

Objectives

Assess the feasibility of a study evaluating one dose of oral ondansetron to decrease post-concussion symptoms at one week and one month following concussion in children aged 8 to 17 years old.

Method

This was a pilot study for a randomized, triple-blind controlled trial of one dose of either ondansetron or placebo performed in a tertiary care pediatric emergency department. Participants were children aged 8 to 17 years who sustained a concussion in the previous 24 hours and visited a single emergency department. The outcome of interest was an increase from pre-concussion baseline of at least 3 symptoms from the Post-Concussion Symptom Inventory, measured at one week and at one month following concussion. The primary outcome was to determine the proportion of children who completed the assessment at one week following the intervention. Secondary outcome was the proportion of children who completed the assessment at one month following the intervention. All children, care givers, and those assessing the outcomes were blinded to the group assignment.

Results

Of the 218 children presenting with a concussion during the study period, we screened 108 and found 36/108 (33%) eligible to participate and 16/108 (14.8%) agreed to participate. All enrolled patients were compliant with the intervention and follow-up.

Conclusion

In our study population, approximately one-third of the screened concussion patients were eligible to participate and approximately one half of those eligible agreed to participate. Our study found that most enrolled patients preferred electronic follow-up; the noncompliance rate was minimal.

Content, Delivery, and Effectiveness of Concussion Education for US College Coaches

OBJECTIVE

The primary objective of this study was to examine the proportion of US college coaches who receive annual concussion education from their institution and to describe the content and delivery modalities of this education. This study also tested the hypothesis that coaches receiving concussion education from their institution will have greater knowledge about concussions independent of other individual and institutional characteristics.

DESIGN

Cross-sectional online survey.

SETTING

US college sport.

PARTICIPANTS

College coaches in National Collegiate Athletic Association Division I, II, and III (n = 1818).

INDEPENDENT VARIABLES

Self-reported receipt of education from institution, sex, sport coached, division of competition.

MAIN OUTCOME MEASURES

Concussion identification and management knowledge.

RESULTS

Two-thirds of coaches reported receiving informational materials about concussion from their institution. The content of the education most frequently referred to symptoms of a concussion and information about proper management of a concussion. Coaches who received educational materials from their institution were better able to identify symptoms and had more conservative responses to concussion management scenarios. Male coaches of male contact or collision teams less frequently endorsed safe or correct response as compared with female coaches of noncontact or collision teams.

CONCLUSIONS

Not all US college coaches receive concussion education from their institution. Male Division I coaches of male contact/collision sport are a population for whom targeted educational outreach may be particularly valuable.

CLINICAL RELEVANCE

Education for coaches, delivered by clinicians at many institutions, is an important component of ensuring that coaches are prepared to be informed partners in supporting concussion safety.

Long-Term Anesthetic-Dependent Hypoactivity after Repetitive Mild Traumatic Brain Injuries in Adolescent Mice

Recent evidence supports the hypothesis that repetitive mild traumatic brain injuries (rmTBIs) culminate in neurological impairments and chronic neurodegeneration, which have wide-ranging implications for patient management and return-to-play decisions for athletes. Adolescents show a high prevalence of sports-related head injuries and may be particularly vulnerable to rmTBIs due to ongoing brain maturation. However, it remains unclear whether rmTBIs, below the threshold for acute neuronal injury or symptomology, influence long-term outcomes. To address this issue, we first defined a very mild injury in adolescent mice (postnatal day 35) as evidenced by an increase in Iba-1- labeled microglia in white matter in the acutely injured brain, in the absence of indices of cell death, axonal injury, and vasogenic edema. Using this level of injury severity and Avertin (2,2,2-tribromoethanol) as the anesthetic, we compared mice subjected to either a single mTBI or 2 rmTBIs, each separated by 48 h. Neurobehavioral assessments were conducted at 1 week and at 1 and 3 months postimpact. Mice subjected to rmTBIs showed transient anxiety and persistent and pronounced hypoactivity compared to sham control mice, alongside normal sensorimotor, cognitive, social, and emotional function. As isoflurane is more commonly used than Avertin in animal models of TBI, we next examined long-term outcomes after rmTBIs in mice that were anesthetized with this agent. However, there was no evidence of abnormal behaviors even with the addition of a third rmTBI. To determine whether isoflurane may be neuroprotective, we compared the acute pathology after a single mTBI in mice anesthetized with either Avertin or isoflurane. Pathological findings were more pronounced in the group exposed to Avertin compared to the isoflurane group. These collective findings reveal distinct behavioral phenotypes (transient anxiety and prolonged hypoactivity) that emerge in response to rmTBIs. Our findings further suggest that selected anesthetics may confer early neuroprotection after rmTBIs, and as such mask long-term abnormal phenotypes that may otherwise emerge as a consequence of acute pathogenesis.

The Sport Concussion Assessment Tool: a systematic review

OBJECTIVE

Over the last 2 decades, sport-related concussion (SRC) has garnered significant attention. Even with increased awareness and athlete education, sideline recognition and real-time diagnosis remain crucial. The need for an objective and standardized assessment of concussion led to the eventual development of the Sport Concussion Assessment Tool (SCAT) during the Second International Conference on Concussion in Sport in 2004, which is now in its third iteration (SCAT3). In an effort to update our understanding of the most well-known sideline concussion assessment, the authors conducted a systematic review of the SCAT and the evidence supporting its use to date.

METHODS

English-language titles and abstracts published between 1995 and October 2015 were searched systematically across 4 electronic databases and a review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines adapted for the review of a heterogeneous collection of study designs. Peer-reviewed journal articles were included if they reported quantitative data on any iteration of the SCAT, Standardized Assessment of Concussion (SAC), or modified Balance Error Scoring System (mBESS) data at baseline or following concussion in an exclusively athlete population with any portion older than 13 years of age. Studies that included nonathletes, only children less than 13 years old, exclusively BESS data, exclusively symptom scale data, or a non–SCAT-related assessment were excluded.

RESULTS

The database search process yielded 549 abstracts, and 105 full-text articles were reviewed with 36 meeting criteria for inclusion. Nineteen studies were associated with the SAC, 1 was associated with the mBESS exclusively, and 16 studies were associated with a full iteration of the SCAT. The majority of these studies (56%) were prospective cohort studies. Male football players were the most common athletes studied. An analysis of the studies focused on baseline differences associated with age, sex, concussion history, and the ability to detect an SRC.

CONCLUSIONS

Looking toward the upcoming Concussion in Sport Group meeting in fall 2016, one may expect further revision to the SCAT3. However, based on this systematic review, the authors propose further, in-depth study of an already comprehensive concussion test, with acute, diagnostic, as well as long-term use.

Using video analysis for concussion surveillance in Australian football

OBJECTIVES

The objectives of the study were to assess the relationship between various player and game factors and risk of concussion; and to assess the reliability of video analysis for mechanistic assessment of concussion in Australian football.

DESIGN

Prospective cohort study.

METHODS

All impacts and collisions resulting in concussion were identified during the 2011 Australian Football League season. An extensive list of factors for assessment was created based upon previous analysis of concussion in Australian Football League and expert opinions. The authors independently reviewed the video clips and correlation for each factor was examined.

RESULTS

A total of 82 concussions were reported in 194 games (rate: 8.7 concussions per 1000 match hours; 95% confidence interval: 6.9-10.5). Player demographics and game variables such as venue, timing of the game (day, night or twilight), quarter, travel status (home or interstate) or score margin did not demonstrate a significant relationship with risk of concussion; although a higher percentage of concussions occurred in the first 5min of game time of the quarter (36.6%), when compared to the last 5min (20.7%). Variables with good inter-rater agreement included position on the ground, circumstances of the injury and cause of the impact. The remainder of the variables assessed had fair-poor inter-rater agreement. Common problems included insufficient or poor quality video and interpretation issues related to the definitions used.

CONCLUSIONS

Clear definitions and good quality video from multiple camera angles are required to improve the utility of video analysis for concussion surveillance in Australian football.

Risk of suicide after a concussion

BACKGROUND

Head injuries have been associated with subsequent suicide among military personnel, but outcomes after a concussion in the community are uncertain. We assessed the long-term risk of suicide after concussions occurring on weekends or weekdays in the community.

METHODS

We performed a longitudinal cohort analysis of adults with diagnosis of a concussion in Ontario, Canada, from Apr. 1, 1992, to Mar. 31, 2012 (a 20-yr period), excluding severe cases that resulted in hospital admission. The primary outcome was the long-term risk of suicide after a weekend or weekday concussion.

RESULTS

We identified 235,110 patients with a concussion. Their mean age was 41 years, 52% were men, and most (86%) lived in an urban location. A total of 667 subsequent suicides occurred over a median follow-up of 9.3 years, equivalent to 31 deaths per 100,000 patients annually or 3 times the population norm. Weekend concussions were associated with a one-third further increased risk of suicide compared with weekday concussions (relative risk 1.36, 95% confidence interval 1.14-1.64). The increased risk applied regardless of patients' demographic characteristics, was independent of past psychiatric conditions, became accentuated with time and exceeded the risk among military personnel. Half of these patients had visited a physician in the last week of life.

INTERPRETATION

Adults with a diagnosis of concussion had an increased long-term risk of suicide, particularly after concussions on weekends. Greater attention to the long-term care of patients after a concussion in the community might save lives because deaths from suicide can be prevented.

Factors Associated With Concussion-like Symptom Reporting in High School Athletes

IMPORTANCE

Every state in the United States has passed legislation for sport-related concussion, making this health issue important for physicians and other health care professionals. Safely returning athletes to sport after concussion relies on accurately determining when their symptoms resolve.

OBJECTIVE

To evaluate baseline concussion-like symptom reporting in uninjured adolescent student athletes.

DESIGN, SETTING, AND PARTICIPANTS

In this cross-sectional, observational study, we studied 31 958 high school athletes from Maine with no concussion in the past 6 months who completed a preseason baseline testing program between 2009 and 2013.

RESULTS

Symptom reporting was more common in girls than boys. Most students with preexisting conditions reported one or more symptoms (60%-82% of boys and 73%-97% of girls). Nineteen percent of boys and 28% of girls reported having a symptom burden resembling an International Classification of Diseases, 10th Revision (ICD-10) diagnosis of postconcussional syndrome (PCS). Students with preexisting conditions were even more likely to endorse a symptom burden that resembled PCS (21%-47% for boys and 33%-72% for girls). Prior treatment of a psychiatric condition was the strongest independent predictor for symptom reporting in boys, followed by a history of migraines. For girls, the strongest independent predictors were prior treatment of a psychiatric condition or substance abuse and attention-deficit/hyperactivity disorder. The weakest independent predictor of symptoms for both sexes was history of prior concussions.

CONCLUSIONS AND RELEVANCE

In the absence of a recent concussion, symptom reporting is related to sex and preexisting conditions. Consideration of sex and preexisting health conditions can help prevent misinterpretation of symptoms in student athletes who sustain a concussion.

Cerebral Blood Flow Alterations in Acute Sport-Related Concussion

Sport-related concussion (SRC) is a major health problem, affecting millions of athletes each year. While the clinical effects of SRC (e.g., symptoms and functional impairments) typically resolve within several days, increasing evidence suggests persistent neurophysiological abnormalities beyond the point of clinical recovery after injury. This study aimed to evaluate cerebral blood flow (CBF) changes in acute SRC, as measured using advanced arterial spin labeling (ASL) magnetic resonance imaging (MRI). We compared CBF maps assessed in 18 concussed football players (age, 17.8 ± 1.5 years) obtained within 24 h and at 8 days after injury with a control group of 19 matched non-concussed football players. While the control group did not show any changes in CBF between the two time-points, concussed athletes demonstrated a significant decrease in CBF at 8 days relative to within 24 h. Scores on the clinical symptom (Sport Concussion Assessment Tool 3, SCAT3) and cognitive measures (Standardized Assessment of Concussion [SAC]) demonstrated significant impairment (vs. pre-season baseline levels) at 24 h (SCAT, p < 0.0001; SAC, p < 0.01) but returned to baseline levels at 8 days. Two additional computerized neurocognitive tests, the Automated Neuropsychological Assessment Metrics and Immediate Post-Concussion and Cognitive Testing, showed a similar pattern of changes. These data support the hypothesis that physiological changes persist beyond the point of clinical recovery after SRC. Our results also indicate that advanced ASL MRI methods might be useful for detecting and tracking the longitudinal course of underlying neurophysiological recovery from concussion.

Use of the King-Devick test for sideline concussion screening in junior rugby league

AIM

To determine whether the King-Devick (K-D) test used as a sideline test in junior rugby league players over 12 matches in a domestic competition season could identify witnessed and incidentally identified episodes of concussion.

METHODS

A prospective observational cohort study of a club level junior rugby league team (n=19) during the 2014 New Zealand competition season involved every player completing two pre-competition season baseline trials of the K-D test. Players removed from match participation, or who reported any signs or symptoms of concussion were assessed on the sideline with the K-D test and referred for further medical assessment. Players with a pre- to post-match K-D test difference >3s were referred for physician evaluation.

RESULTS

The baseline test-retest reliability of the K-D test was high (rs=0.86; p<0.0001). Seven concussions were medically identified in six players who recorded pre- to post-match K-D test times greater than 3s (mean change of 7.4s). Post-season testing of players demonstrated improvement of K-D time scores consistent with learning effects of using the K-D test (67.7s vs. 62.2s).

DISCUSSION

Although no witnessed concussions occurred during rugby play, six players recorded pre- to post-match changes with a mean delay of 4s resulting in seven concussions being subsequently confirmed post-match by health practitioners. All players were medically managed for a return to sports participation.

CONCLUSION

The K-D test was quickly and easily administered making it a practical sideline tool as part of the continuum of concussion assessment tools for junior rugby league players.

Repetitive concussions in adolescent athletes - translating clinical and experimental research into perspectives on rehabilitation strategies

Sports-related concussions are particularly common during adolescence, a time when even mild brain injuries may disrupt ongoing brain maturation and result in long-term complications. A recent focus on the consequences of repetitive concussions among professional athletes has prompted the development of several new experimental models in rodents, as well as the revision of guidelines for best management of sports concussions. Here, we consider the utility of rodent models to understand the functional consequences and pathobiology of concussions in the developing brain, identifying the unique behavioral and pathological signatures of concussive brain injuries. The impact of repetitive concussions on behavioral consequences and injury progression is also addressed. In particular, we focus on the epidemiological, clinical, and experimental evidence underlying current recommendations for physical and cognitive rest after concussion, and highlight key areas in which further research is needed. Lastly, we consider how best to promote recovery after injury, recognizing that optimally timed, activity-based rehabilitative strategies may hold promise for the adolescent athlete who has sustained single or repetitive concussions. The purpose of this review is to inform the clinical research community as it strives to develop and optimize evidence-based guidelines for the concussed adolescent, in terms of both acute and long-term management.

High School Athletes' Perceptions of Concussion

BACKGROUND

The perception high school athletes have regarding concussions may influence their injury-reporting behavior, and if their perceptions are based on incorrect or incomplete information, they may be at risk for subsequent head injuries.

PURPOSE

To determine whether the recent influx of concussion information has had a positive impact on high school athletes' knowledge of concussions, to determine their perceptions regarding the severity of a concussion injury, and to determine whether receiving correct information will potentially alter their future reporting behavior.

STUDY DESIGN

Cross-sectional study; Level of evidence, 4.

METHODS

A total of 454 high school athletes (212 females, 242 males; mean age, 15.7 ± 1.15 years) from 6 different schools participated in an anonymous survey. The researchers met with teams individually at their high schools to collect data and provide an educational intervention regarding sports-related concussions. The survey questions assessed the athletes' personal injury histories and perceptions and knowledge of the severity of concussion injuries.

RESULTS

There was a difference in the number of athletes who reported having their "bell rung" (n = 297) versus the number of athletes reporting at least 1 concussion (n = 172) (t (453) = -11.60, P = .000, d = -0.54). There was also a difference in the number of athletes who reported a history of at least 1 concussion at the beginning of the study session (n = 172) versus the number of athletes who reported at least 1 concussion at the end of the session (n = 292) (t (453) = -12.018, P = .000, d = 0.732). Fifty percent of athletes also stated that the importance of a game/event should dictate when they return to play.

CONCLUSION

High school athletes continue to fail to realize when they have sustained a concussion. Additionally, athletes lack understanding regarding the severity and seriousness of a concussion. A better effort at formalized education must be made if the culture of sports is to change.

CLINICAL RELEVANCE

Allied health care professionals need to continue to put forth a great effort in educating all student athletes on what a concussion is and the dangers of a concussion injury. Preseason meetings should be used as an opportunity to provide formalized education to all student athletes.