Aaron M. Yengo-Kahn

Epidemiology of Sports-Related Concussion in NCAA Athletes From 2009-2010 to 2013-2014 Incidence, Recurrence, and Mechanisms

Background: The epidemiology of sports-related concussion (SRC) among student-athletes has been extensively researched. However, recent data at the collegiate level are limited. Purpose: To describe the epidemiology of SRC in 25 National Collegiate Athletic Association (NCAA) sports. Study Design: Descriptive epidemiology study. Methods: SRC data from the NCAA Injury Surveillance Program during the 2009-2010 to 2013-2014 academic years were analyzed. Concussion injury rates, rate ratios (RRs), and injury proportion ratios were reported with 95% CIs. National estimates were also calculated to examine linear trends across time. Results: During the study period, 1670 SRCs were reported, representing a national estimate of 10,560 SRCs reported annually. Among the 25 sports, the overall concussion rate was 4.47 per 10,000 athlete-exposures (AEs) (95% CI, 4.25-4.68). Overall, more SRCs occurred in competitions (53.2%). The competition rate (12.81 per 10,000 AEs) was larger than the practice rate (2.57 per 10,000 AEs) (competition vs practice, RR = 4.99; 95% CI, 4.53-5.49). Of all SRCs, 9.0% were recurrent. Most SRCs occurred from player contact (68.0%). The largest concussion rates were in men’s wrestling (10.92 per 10,000 AEs; 95% CI, 8.62-13.23), men’s ice hockey (7.91 per 10,000 AEs; 95% CI, 6.87-8.95), women’s ice hockey (7.50 per 10,000 AEs; 95% CI, 5.91-9.10), and men’s football (6.71 per 10,000 AEs; 95% CI, 6.17-7.24). However, men’s football had the largest annual estimate of reported SRCs (n = 3417), followed by women’s soccer (n = 1113) and women’s basketball (n = 998). Among all SRCs, a linear trend did not exist in national estimates across time (P = .17). However, increases were found within specific sports, such as men’s football, women’s ice hockey, and men’s lacrosse. Conclusion: The estimated number of nationally reported SRCs has increased within specific sports. However, it is unknown whether these increases are attributable to increased reporting or frequency of concussions. Many sports report more SRCs in practice than in competition, although competition rates are higher. Men’s wrestling and men’s and women’s ice hockey have the highest reported concussion rates. Men’s football had the highest annual national estimate of reported SRCs, although the annual participation count was also the highest. Future research should continue to longitudinally examine SRC incidence while considering differences by sex, division, and level of competition.

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.

Predictors of postconcussion syndrome in collegiate student-athletes

OBJECTIVE Sport-related concussion (SRC) has emerged as a public health problem, especially among student-athletes. Whereas most concussions resolve by 2 weeks, a minority of patients experience postconcussion syndrome (PCS), in which symptoms persist for months. The objective of this study was to elucidate factors predictive of PCS among a sample of National Collegiate Athletic Association (NCAA) student-athletes in the academic years 2009-2010 to 2014-2015. METHODS The SRC data originated from the NCAA Injury Surveillance Program (ISP) in the 2009-2010 to 2014-2015 academic seasons. The NCAA ISP is a prospective database made up of a convenience sample of schools across all divisions. All SRCs are reported by certified athletic trainers. The PCS group consisted of concussed student-athletes with concussion-related symptoms that lasted ≥ 4 weeks. The non-PCS group consisted of concussed student-athletes with symptom resolution in ≤ 2 weeks. Those with symptoms that resolved in the intermediate area of 2-4 weeks were excluded. Odds ratios (ORs) were estimated using logistic regression. RESULTS During the 2009-2010 to 2014-2015 seasons, 1507 NCAA student-athletes sustained an SRC, 112 (7.4%) of whom developed PCS (i.e., concussion-related symptoms that lasted ≥ 4 weeks). Mens ice hockey contributed the largest proportion of concussions to the PCS group (28.6%), whereas mens football contributed the largest proportion of concussions in the non-PCS group (38.6%). In multivariate analysis, recurrent concussion was associated with increased odds of PCS (OR 2.08, 95% CI 1.28-3.36). Concussion symptoms that were also associated with increased odds of PCS included retrograde amnesia (OR 2.75, 95% CI 1.34-5.64), difficulty concentrating (OR 2.35, 95% CI 1.23-4.50), sensitivity to light (OR 1.97, 95% CI 1.09-3.57), and insomnia (OR 2.19, 95% CI 1.30-3.68). Contact level, sex, and loss of consciousness were not associated with PCS. CONCLUSIONS Postconcussion syndrome represents one of the most impactful sequelae of SRC. In this study of exclusively collegiate student-athletes, the authors found that recurrent concussions and various concussion-related symptoms were associated with PCS. The identification of initial risk factors for the development of PCS may assist sports medicine clinicians in providing timely interventions and treatments to prevent morbidity and shorten recovery time after SRC.

Sports concussion research, chronic traumatic encephalopathy and the media: repairing the disconnect

Todd Ewen was a National Hockey League (NHL) ‘tough guy’ who accumulated over 1900 penalty minutes in 518 games across 12 NHL seasons. He recently committed suicide after bouts of depression at the age of 49. Before an autopsy had been performed, the media pre-emptively wrote about how his depression and suicide were most likely the result of a career in the NHL, repetitive head trauma and the inevitable onset of chronic traumatic encephalopathy (CTE).1 Ewen himself was convinced he had developed CTE, as his wife recalled him being terrified by the thought of a future living with a neurodegenerative disease.2 Ewens brain was examined by neuropathologists at the University of Toronto—they found no evidence of CTE. So we ask, how did a professional athlete who had treatable depression, come to believe that he had an untreatable condition and committed suicide?3 The publics perception of sport-related concussion (SRC) and CTE is likely not based on the totality of empirical data, but rather …

Concussions in the National Football League: a current concepts review

Background: Significant attention has been directed toward the immediate and long-term effects of sport-related concussions on athletes participating in contact sports, particularly football. The highest level of football, the National Football League (NFL), has received significant attention and criticism regarding player management and safety after mild traumatic brain injury (mTBI). Several review articles have reported data related to concussion in the NFL, but a succinct review and synthesis of data regarding NFL concussions is currently lacking. Purpose: To (1) review systematically the published data regarding concussion in the NFL and assess limitations of the studies, (2) elucidate areas where further research is needed, and (3) identify methods to improve future investigations of concussion in the NFL. Study Design: Systematic review of literature. Methods: English-language titles and abstracts published between 1900 and September 2014 were searched systematically across electronic databases, and a review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Peer-reviewed journal articles were included if they contained NFL concussion data with or without additional associated long-term effects. Reviews, editorials, letters to the editor, and comments were not included. Results: Of the 344 records screened for review, 88 articles were assessed for eligibility. There were 31 studies that met the inclusion criteria and formed the basis of the evidence synthesis. Included in the current review were 8 case-control studies (Oxford Centre for Evidence-Based Medicine evidence level 3b), 6 descriptive epidemiological studies (level 4), 6 cross-sectional studies (level 4), 6 cohort studies (level 2b), and 5 case series (level 4). Conclusion: The study of concussions in the NFL has been limited by lack of recent empirical data, reliance on self-reported concussion history, and ascertainment bias of brains donated for autopsy studies. The scientific community as well as the public should be cautious in interpreting the current literature surrounding concussion.

Are psychotropic medications associated with differences in baseline neurocognitive assessment scores for young athletes? A pilot study

Abstract Objectives. Baseline and post-concussive neurocognitive testing is useful in managing concussed athletes. The Concussion in Sport Group has postulated that the use of psychotropic medications is a modifying factor in the management of sport-related concussion. About 7% of US adolescents are prescribed psychotropics in a given year. Our aim was to investigate whether psychotropic medication use or psychiatric illness is associated with differences in baseline neurocognitive test scores. Methods. From 2007 to 2012, over 7000 athletes underwent pre-participation baseline neurocognitive testing using the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) battery. Following application of inclusion and exclusion criteria, athletes’ self-reported medication lists were reviewed and: 1) classified as psychotropic or not and 2) subclassified. Group subclassification yielded: 1) use of any psychotropic medication, 2) psychostimulant use, 3) antidepressant use and 4) self-reported history of depression and/or anxiety without psychotropic use. Each group was matched, by sex, age, body mass index, education level and concussion history with athletes who were not reportedly prescribed psychotropic medications or did not report a depression/anxiety history, respectively. Each group’s baseline ImPACT scores were compared to matched controls. Results. The use of prescribed psychotropic medications without regard to subclass had no effect on baseline ImPACT composite scores among athletes ages 13–25. However, athletes reportedly prescribed psychostimulants displayed significantly lower visual motor speed scores (32.8 vs 37.1, p = 0.030) and slower reaction times (0.65 vs 0.60, p = 0.044) than non-users. In contrast, antidepressant users displayed significantly faster reaction times (0.58 vs 0.61, p = 0.029). Those reporting a history of depression/anxiety, not treated with psychotropics, displayed significantly lower visual memory (70.4 vs 75.2, p = 0.010) and higher symptom scores (8.83 vs 4.72, p = 0.005). Conclusions. This pilot study suggests that self-reported psychotropic medications are associated with differences in baseline ImPACT test scores, which appear dependent on medication subclass. Our preliminary results support the inclusion of psychotropic medications, specifically psychostimulants and antidepressants, as well as history of depression/anxiety as potential concussion modifiers.

Comparison of baseline and post-concussion ImPACT test scores in young athletes with stimulant-treated and untreated ADHD

ABSTRACT Objectives: Baseline and post-concussion neurocognitive testing is useful in managing concussed athletes. Attention deficit hyperactivity disorder (ADHD) and stimulant medications are recognized as potential modifiers of performance on neurocognitive testing by the Concussion in Sport Group. Our goal was to assess whether individuals with ADHD perform differently on post-concussion testing and if this difference is related to the use of stimulants. Methods: Retrospective case-control study in which 4373 athletes underwent baseline and post-concussion testing using the ImPACT battery. 277 athletes self-reported a history of ADHD, of which, 206 reported no stimulant treatment and 69 reported stimulant treatment. Each group was matched with participants reporting no history of ADHD or stimulant use on several biopsychosocial characteristics. Non-parametric tests were used to assess ImPACT composite score differences between groups. Results: Participants with ADHD had worse verbal memory, visual memory, visual motor speed, and reaction time scores than matched controls at baseline and post-concussion, all with p ≤ .001 and |r|≥ 0.100. Athletes without stimulant treatment had lower verbal memory, visual memory, visual motor speed, and reaction time scores than controls at baseline (p ≤ 0.01, |r|≥ 0.100 [except verbal memory, r = −0.088]) and post-concussion (p = 0.000, |r|> 0.100). Athletes with stimulant treatment had lower verbal memory (Baseline: p = 0.047, r = −0.108; Post-concussion: p = 0.023, r = −0.124) and visual memory scores (Baseline: p = 0.013, r = −0.134; Post-concussion: p = 0.003, r = −0.162) but equivalent visual motor speed and reaction time scores versus controls at baseline and post-concussion. Conclusions: ADHD-specific baseline and post-concussion neuropsychological profiles, as well as stimulant medication status, may need to be considered when interpreting ImPACT test results. Further investigation into the effects of ADHD and stimulant use on recovery from sport-related concussion (SRC) is warranted.

Socioeconomic status and outcomes after sport-related concussion: a preliminary investigation

OBJECTIVE A significant proportion of patients experience long-term symptoms after sport-related concussion (SRC), and several factors have been associated with this protracted recovery. Limited data exist on the role of socioeconomic status (SES) on SRC outcomes. The objective in this study was to conduct a preliminary investigation to determine the effect of SES on outcomes after SRC in student-athletes treated at a regional sports concussion center. METHODS A retrospective cohort study of 282 middle school, high school, and collegiate student-athletes was conducted. An attempt was made to contact all patients seen at a comprehensive SRC center between January 2012 and May 2015 for in-depth interviews. Subsequent demographic data were collected. The SES was defined as follows: cost of living percentile, median income percentile, percentage of college graduates, percentage of homeowners, county type, and insurance status. Outcomes after SRC were defined as follows: days of symptom duration, days of missed school, and days of missed practice. Statistically controlled covariates included sex, race, age, body mass index, concussion history, neuropsychiatric history, and type of sport. RESULTS A total of 282 student-athletes consented and were studied. The median age was 15.8 years (range 11.6-22.2 years) and 61.4% of student-athletes were male. A previous concussion was incurred by 34.0% of student-athletes. Football was the most common sport (32.3%), followed by soccer (16.3%), and basketball (15.6%). The median symptom duration was 21 days (range 1-365 days); the median missed school days was 2 (range 0-90 days); and median for days of missed practice was 10 (range 0-150 days). After multivariate Cox regression analysis, no relationship between any of the 6 SES variables and symptom duration or missed practice was seen. However, individuals with private insurance had more missed days of school than those with public insurance (hazard ratio 0.46, 95% CI 0.26-0.83, p = 0.009). CONCLUSIONS In a preliminary study of middle school, high school, and collegiate student-athletes, SES had no impact on the outcomes of symptom duration and missed practice. However, for individuals with private insurance, the return to school was slower than for those with public insurance. This pilot study reveals the complex relationship between SES and SRC recovery, which demands further study with more accurate and validated assessments of SES.

Performance following a first professional concussion among National Basketball Association players

ABSTRACT Objectives: Basketball is a physical game played on a hardwood floor among high-jumping athletes at risk for injury. It is currently unknown how sport-related concussion (SRC) affects player performance after injury among professional basketball players. The objective of this study was to explore the impact of SRC on basketball performance among National Basketball Association (NBA) players. Methods: A retrospective, archival cohort study was performed that compared NBA player performance following concussion to pre-concussive performance. A comprehensive NBA injury database, compiled from publically available sources, was queried for NBA players who suffered concussion from 2005–06 to 2014–15 (10 seasons). Intra-and inter-player analyses were performed against a matched control group of players who missed playing time for personal reasons. Results: Following application of inclusion/exclusion criteria and a matching process, 51 concussed players and 51 control players were included in analysis. There were no statistically significant decrements in baseline to post-concussion performance metrics in intra-player or player vs. controls after 5 return games. Conclusions: Our findings suggest that at the NBA level, an athlete’s performance in the initial 5 games following injury does not suffer from the after-effects of concussive injury. These results may be useful in counseling professional athletes following a concussion.

Sport-Related Structural Brain Injury: 3 Cases of Subdural Hemorrhage in American High School Football

BACKGROUND The risk of sport-related concussion (SRC) has emerged as a major public health concern. In rare instances, sport-related head injuries can be even more severe, such as subdural hemorrhage, epidural hemorrhage, or malignant cerebral edema. Unlike SRCs, sport-related structural brain injury (SRSBI) is rare, may require neurosurgical intervention, and can lead to permanent neurologic deficit or death. Data characterizing SRSBI are limited, and many have recognized the need to better understand these catastrophic brain injuries. The goal of the current series is to describe, in detail, the presentation, management, and outcomes of examples of these rare injuries. CASE DESCRIPTION During the fall of 2015, three high school football players presented with acute subdural hemorrhages following in-game collisions and were treated at our institution within a span of 2 months. For the 2 athletes who required surgical intervention, a previous SRC was sustained within 4 weeks before the catastrophic event. One year after injury, 2 players have returned to school, though with persistent deficits. One patient remains nonverbal and wheelchair bound. None of the athletes has returned to sports. CONCLUSIONS Acute subdural hemorrhage resultant from an in-game football collision is rare. The temporal proximity of the reported SRSBIs to recent SRCs emphasizes the importance of return-to-play protocols and raises questions regarding the possibility of second impact syndrome. Although epidemiologic conclusions cannot be drawn from this small sample, these cases provide a unique opportunity to demonstrate the presentation, management, and long-term outcomes of SRSBI in American high school football.