Does age play a role in recovery from sports-related concussion? A comparison of high school and collegiate athletes

Aggression, Violence and Injury in Minor League Ice Hockey: Avenues for Prevention of Injury

Background

In North America, more than 800,000 youth are registered in organized ice hockey leagues. Despite the many benefits of involvement, young players are at significant risk for injury. Body-checking and aggressive play are associated with high frequency of game-related injury including concussion. We conducted a qualitative study to understand why youth ice hockey players engage in aggressive, injury-prone behaviours on the ice.

Methods

Semi-structured interviews were conducted with 61 minor ice hockey participants, including male and female players, parents, coaches, trainers, managers and a game official. Players were aged 13–15 playing on competitive body checking teams or on non-body checking teams. Interviews were manually transcribed, coded and analyzed for themes relating to aggressive play in minor ice hockey.

Results

Parents, coaches, teammates and the media exert a large influence on player behavior. Aggressive behavior is often reinforced by the player’s social environment and justified by players to demonstrate loyalty to teammates and especially injured teammates by seeking revenge particularly in competitive, body-checking leagues. Among female and male players in non-body checking organizations, aggressive play is not reinforced by the social environment. These findings are discussed within the framework of social identity theory and social learning theory, in order to understand players’ need to seek revenge and how the social environment reinforces aggressive behaviors.

Conclusion

This study provides a better understanding of the players’ motivations and environmental influences around aggressive and violent play which may be conducive to injury. The findings can be used to help design interventions aimed at reducing aggression and related injuries sustained during ice hockey and sports with similar cultures and rules.

Gender Differences in Concussion Reporting Among High School Athletes

Background:

An athlete’s lack of concussion knowledge could lead to significant underreporting and injury mismanagement. To provide more effective management strategies of concussions in adolescent athletes, further examination of reporting behaviors is of critical importance.

Hypothesis:

The hypotheses for this study were as follows: (1) Girls are more likely to report concussion, (2) girls are more likely to report future concussions after an educational intervention, and (3) a difference in rationale for not reporting concussion will be found between sexes.

Study Design:

Cross-sectional, cohort design.

Level of Evidence:

Level 3.

Methods:

Survey answers were collected on 454 high school athletes (212 girls, 242 boys; mean age, 15.7 ± 1.15 years). Individual team meetings lasting approximately 30 minutes were held to collect data and provide an educational lecture. Participants were randomly provided an iClicker to submit a response to questions asked.

Results:

Girls were more likely to report a concussion (χ² = 8.32, df = 3, N = 454, P = 0.040) and more likely to report future concussions after educational intervention (χ² = 8.54, df = 2, N = 454, P = 0.014). There were no differences between sexes regarding rationale for not reporting a concussion (χ² = 6.42, df = 4, N = 454, P = 0.170).

Conclusion:

There is concern these athletes still fail to understand the severity and potential sequelae of concussion injury. Both sexes cited that concussion is not a serious enough injury to warrant reporting to a medical professional.

Clinical Relevance:

High school athletes recover more slowly from concussions compared with college athletes; therefore, educating this population and promoting the importance of being knowledgeable regarding concussion recognition may increase reporting prevalence.

Academic Dysfunction After a Concussion Among US High School and College Students

OBJECTIVES

To determine whether concussed students experience greater academic dysfunction than students who sustain other injuries.

METHODS

We conducted a prospective cohort study from September 2013 through January 2015 involving high school and college students who visited 3 emergency departments in the Rochester, New York, area. Using telephone surveys, we compared self-reported academic dysfunction between 70 students with concussions and a comparison group of 108 students with extremity injuries at 1 week and 1 month after injury.

RESULTS

At 1 week after injury, academic dysfunction scores were approximately 16 points higher (b = 16.20; 95% confidence interval = 6.39, 26.00) on a 174-point scale in the concussed group than in the extremity injury group. Although there were no differences overall at 1-month after injury, female students in the concussion group and those with a history of 2 or more prior concussions were more likely to report academic dysfunction.

CONCLUSIONS

Our results showed academic dysfunction among concussed students, especially female students and those with multiple prior concussions, 1 week after their injury. Such effects appeared to largely resolve after 1 month. Our findings support the need for academic adjustments for concussed students.

Repetitive Traumatic Brain Injury in Patients From Kashan, Iran

Background

Traumatic brain injury (TBI) is a worldwide problem, especially in countries with high incidence of road traffic accidents such as Iran. Patients with a single occurrence of TBI have been shown to be at increased risk to sustain future TBI.

Objectives

The aim of this study was to present the incidence and characteristics of repeated TBI (RTBI) in Iranian patients.

Patients and Methods

During one year, all admitted TBI patients with prior TBI history were enrolled into the study. In each patient, data such as age, gender, past medical history, injury cause, anatomic site of injury, TBI severity, clinical findings and CT scan findings were collected.

Results

RTBI comprised 2.5% of TBI cases (41 of 1629). The incidence of RTBI per 100,000 individuals per years was 9.7. The main cause of RTBI was road traffic accident (68.3%); 9.7 % of cases had preexisting seizure/epilepsy disorder; 36.6% of patients with RTBI had pervious ICU admission due to severe TBI. Ten patients had Glasgow coma scale (GCS) ≤ 13 (24.4%). Seizure was seen in seven patients (17.1%). Thirty-nine percent of patients with RTBI had associated injuries. Eleven patients had abnormal CT scan findings (26.9%).

Conclusions

Considering the high incidence of trauma in developing countries, RTBI may also be more common compared with that of developed countries. This mandates a newer approach to preventive strategies, particularly in those with a previous experience of head injury.

Retirement and Activity Restrictions Following Concussion

Sport-related concussion is prevalent at all levels of play. Increased attention from sports media and scientific and medical communities has prompted players and physicians to explore the long-term effects of concussion and ask the questions of when and how players should begin to mitigate their concussion risk. The authors evaluate their risks from the perspective of epidemiology, symptomatology, neuropsychological performance, and biomechanics. The authors propose that there is not a set number of concussions that necessitates retirement in athletes and, aside from a few absolute contraindications to return to collision sport, return to play should be an individualized process.

Patterns of Recovery Following Sport-Related Concussion in Children and Adolescents

Time to symptom resolution, return to school, and return to play after a sport-related concussion in children and adolescents (8-17 years of age) was examined using a retrospective cohort design. A total of 198 patients aged 8 to 17 years were included, with a mean age of 13.5 years (SD = 2.2). Patients aged 8 to 12 years were symptom-free in a median of 12.0 (range 1-60) days whereas 13- to 17-year olds were symptom-free in a median of 14.0 (range 1-300) days (P = .04). Patients aged 8 to 12 years returned to learn in a median of 4.0 (range 0-30) days compared with 2.5 (range 0-55.0) days in 13- to 17-year-olds (P = .86). Patients aged 8 to 12 years returned to play in a median of 14.0 (range 4-75) days compared with a median of 19.5 (range 5-75) days in 13- to 17-year-olds (P = .06). These results indicate that children and adolescents generally take 2 to 4 weeks to recover from a sport-related concussion.

Predictors of delayed recovery following pediatric sports-related concussion: a case-control study

OBJECT Pediatric sports-related concussions are a growing public health concern. The factors that determine injury severity and time to recovery following these concussions are poorly understood. Previous studies suggest that initial symptom severity and diagnosis of attention deficit hyperactivity disorder (ADHD) are predictors of prolonged recovery (> 28 days) after pediatric sports-related concussions. Further analysis of baseline patient characteristics may allow for a more accurate prediction of which patients are at risk for delayed recovery after a sports-related concussion. METHODS The authors performed a single-center retrospective case-control study involving patients cared for at the multidisciplinary Concussion Clinic at Children's of Alabama between August 2011 and January 2013. Patient demographic data, medical history, sport concussion assessment tool 2 (SCAT2) and symptom severity scores, injury characteristics, and patient balance assessments were analyzed for each outcome group. The control group consisted of patients whose symptoms resolved within 28 days. The case group included patients whose symptoms persisted for more than 28 days. The presence or absence of the SCAT2 assessment had a modifying effect on the risk for delayed recovery; therefore, stratum-specific analyses were conducted for patients with recorded SCAT2 scores and for patients without SCAT2 scores. Unadjusted ORs and adjusted ORs (aORs) for an association of delayed recovery outcome with specific risk factors were calculated with logistic regression analysis. RESULTS A total of 294 patients met the inclusion criteria of the study. The case and control groups did not statistically significantly differ in age (p = 0.7). For the patients who had received SCAT2 assessments, a previous history of concussion (aOR 3.67, 95% CI 1.51-8.95), presenting SCAT2 score < 80 (aOR 5.58, 95% CI 2.61-11.93), and female sex (aOR 3.48, 95% CI 1.43-8.49) were all associated with a higher risk for postconcussive symptoms lasting more than 28 days. For patients without SCAT2 scores, female sex and reporting a history of ADHD significantly increased the odds of prolonged recovery (aOR 4.41, 95% CI 1.93-10.07 and aOR 3.87, 95% CI 1.13-13.24, respectively). Concussions resulting from playing a nonhelmet sport were also associated with a higher risk for prolonged symptoms in patients with and without SCAT2 scores (OR 2.59, 95% CI 1.28-5.26 and OR 2.17, 95% CI 0.99-7.73, respectively). Amnesia, balance abnormalities, and a history of migraines were not associated with symptoms lasting longer than 28 days. CONCLUSIONS This case-control study suggests candidate risk factors for predicting prolonged recovery following sports-related concussion. Large prospective cohort studies of youth athletes examined and treated with standardized protocols will be needed to definitively establish these associations and confirm which children are at highest risk for delayed recovery.

Physical Activity Level and Symptom Duration Are Not Associated After Concussion

BACKGROUND

Physical rest after a concussion has been described as a key component in the management of the injury. Evidence supporting this recommendation, however, is limited.

PURPOSE

To examine the association between physical activity and symptom duration in a cohort of patients after a concussion.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

This study included 364 patients who were diagnosed with a concussion, were seen by a physician within 3 weeks of injury, and completed a questionnaire at the initial clinic visit. The questionnaire assessed the postconcussion symptom scale (PCSS) score, previous number of concussions, presence of the loss of consciousness or amnesia at the time of injury, and prior treatment for headaches. During each follow-up clinic visit, physical activity level was self-reported. A Cox proportional hazard model was constructed to determine the association between symptom duration, initial clinic visit responses, and self-reported physical activity level after the injury.

RESULTS

Study participants ranged in age from 8 to 27 years (mean age, 15.0 years) and had sustained a mean of 0.8 prior concussions; 222 patients (61%) were male. On initial examination, the mean PCSS score was 34.7. The mean symptom duration was 48.9 days after the injury. Among the variables included in the model, initial PCSS score and female sex were independently associated with symptom duration, while physical activity level after the injury was not. For participants aged between 13 and 18 years, however, higher levels of physical activity after the injury were associated with a shorter symptom duration.

CONCLUSION

Results from this study indicate that physical activity after the injury may not be universally detrimental to the recovery of concussion symptoms.

Physical Maturity and Concussion Symptom Duration among Adolescent Ice Hockey Players

OBJECTIVE

To investigate the association between physical maturity and risk of prolonged concussion symptoms in adolescent ice hockey players.

STUDY DESIGN

Prospective cohort study of 145 patients ages 13-18 years with concussion referred to 3 hospital-affiliated sports medicine clinics between September 1, 2012 and March 31, 2015. Concussion evaluations included Post Concussive Symptom Score, neurologic examination, and postinjury computerized neurocognitive testing. Pubertal development at initial visit was assessed by the Pubertal Developmental Scale. Duration of concussion symptoms (days) was the main outcome. Statistical comparisons were conducted using Student t test, Wilcoxon rank sum, and logistic regression.

RESULTS

Mean symptom duration was 44.5 ± 48.7 days. Nearly one-half (48.3%) of all players enrolled had prolonged concussion symptoms (≥ 28 days); most (86.9%) had symptom resolution by 90 days. Among males, less physically mature adolescents took longer to recover than more physically mature players (54.5 days vs 33.4 days; P = .004). "Early" Pubertal Category Score was the strongest predictor of prolonged symptoms (OR = 4.29, 95% CI 1.24-14.85; P = .021) among males. Among females, heavier weight increased the odds of experiencing prolonged symptoms (OR 1.07, 95% CI 1.00-1.14; P = .039).

CONCLUSIONS

Among adolescent ice hockey players, early-pubertal stage is independently associated with longer recovery from concussion in males, and heavier weight is associated with longer concussion recovery in females. Until further studies determine valid physical maturity indicators, peripubertal collision sport athletes should compete in leagues grouped by relative age and be discouraged from "playing up" on varsity teams.

Are There Subconcussive Neuropsychological Effects in Youth Sports? An Exploratory Study of High- and Low-Contact Sports

This exploratory study was designed to examine the neuropsychological effects of sports-related head trauma-specifically, repetitive subconcussive impacts or head blows that do not result in a diagnosable concussion. The researchers compared the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) neurocognitive test scores of 2 groups of nonconcussed youth athletes (n = 282), grouped according to the frequency of concussions in their respective sports, with the assumption that more subconcussive impacts occur in sports in which there are more reported concussions. The results indicated that high-contact-sport (football) athletes had significantly poorer performance in processing speed and reaction time compared with athletes in low-contact sports (wrestling, soccer, baseball, judo, and basketball). This study into the effects of repetitive subconcussive head trauma tentatively raises concern that participation in high-contact sports, even without evidence of a diagnosable concussion, could result in lowered neuropsychological functioning among high school athletes. Limitations of this exploratory research effort are discussed.

Age Differences in Recovery After Sport-Related Concussion: A Comparison of High School and Collegiate Athletes

CONTEXT

Younger age has been hypothesized to be a risk factor for prolonged recovery after sport-related concussion, yet few studies have directly evaluated age differences in acute recovery.

OBJECTIVE

To compare clinical recovery patterns for high school and collegiate athletes.

DESIGN

Prospective cohort study.

SETTING

Large, multicenter prospective sample collected from 1999-2003 in a sports medicine setting.

SUBJECTS

Concussed athletes (n = 621; 545 males and 76 females) and uninjured controls (n = 150) participating in high school and collegiate contact and collision sports (79% in football, 15.7% in soccer, and the remainder in lacrosse or ice hockey).

MAIN OUTCOME MEASURE(S)

Participants underwent evaluation of symptoms (Graded Symptom Checklist), cognition (Standardized Assessment of Concussion, paper-and-pencil neuropsychological tests), and postural stability (Balance Error Scoring System). Athletes were evaluated preinjury and followed serially at several time points after concussive injury: immediately, 3 hours postinjury, and at days 1, 2, 3, 5, 7, and 45 or 90 (with neuropsychological measures administered at baseline and 3 postinjury time points).

RESULTS

Comparisons of concussed high school and collegiate athletes with uninjured controls suggested that high school athletes took 1 to 2 days longer to recover on a cognitive (Standardized Assessment of Concussion) measure. Comparisons with the control group on other measures (symptoms, balance) as well as direct comparisons between concussed high school and collegiate samples revealed no differences in the recovery courses between the high school and collegiate groups on any measure. Group-level recovery occurred at or before 7 days postinjury on all assessment metrics.

CONCLUSIONS

The findings suggest no clinically significant age differences exist in recovery after sport-related concussion, and therefore, separate injury-management protocols are not needed for high school and collegiate athletes.

Vision Diagnoses Are Common After Concussion in Adolescents

OBJECTIVE

To determine the prevalence of vision diagnoses after concussion in adolescents.

METHODS

Cross-sectional study from July 1, 2013 to February 28, 2014, of patients aged 11 to 17 years with concussion evaluated in a comprehensive concussion program.

RESULTS

A total of 100 adolescents were examined, with a mean age of 14.5 years. Overall, 69% had one or more of the following vision diagnoses: accommodative disorders (51%), convergence insufficiency (49%), and saccadic dysfunction (29%). In all, 46% of patients had more than one vision diagnosis.

CONCLUSIONS

A high prevalence of vision diagnoses (accommodative, binocular convergence, and saccadic eye movement disorders) was found in this sample of adolescents with concussion, with some manifesting more than one vision diagnosis. These data indicate that a comprehensive visual examination may be helpful in the evaluation of a subset of adolescents with concussion. Academic accommodations for students with concussion returning to the classroom setting should account for these vision diagnoses.

Sex-Based Differences as a Predictor of Recovery Trajectories in Young Athletes After a Sports-Related Concussion

BACKGROUND

To date, few studies have delineated clear sex-based differences in symptom resolution after a sports-related concussion (SRC), and equivocal results have been identified in sex-based differences on baseline assessments.

PURPOSE

To assess whether female athletes displayed prolonged recovery and more symptoms at baseline and after an SRC compared with male athletes.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The current study assessed 135 male and 41 female athletes (10-18 years old) who participated in high-impact sports in metropolitan Atlanta middle and high schools. All athletes completed a baseline assessment and at least 1 postconcussion assessment from the Immediate Post-Concussion Assessment and Cognitive Testing battery. Longitudinal hierarchical linear modeling was employed to examine individual-level variables and their associations with adolescents' rates of recovery in concussive symptoms after controlling for age and number of prior concussions.

RESULTS

Aggregate symptoms were rated as higher in female athletes compared with male athletes at baseline (mean ± SD: females, 13.49 ± 11.20; males, 4.88 ± 8.74; F(1,175) = 10.59, P < .001) and immediately after a concussion (females: 16.75 ± 18.08; males: 10.58 ± 14.21; F(1,175) = 3.99, P = .05). There were no group differences in the slope of recovery between male and female athletes, indicating generally similar trajectories of change for both groups. Post hoc analyses revealed higher baseline levels of migraine and neuropsychological symptoms in female athletes.

CONCLUSION

Although female athletes in the current study reported increased symptoms, identical recovery patterns were observed in both sexes, suggesting that sex-based differences in concussion recovery are better explained by increased symptom frequency among female athletes when compared with their male counterparts.

Postconcussion syndrome: demographics and predictors in 221 patients

OBJECTIVE The objective of this study was to determine the demographics and predictors of postconcussion syndrome (PCS) in a large series of patients using a novel definition of PCS. METHODS The authors conducted a retrospective cohort study of 284 consecutive concussed patients, 221 of whom had PCS on the basis of at least 3 symptoms persisting at least 1 month. This definition of PCS was uniformly employed and is unique in accepting an expanded list of symptoms, in shortening the postconcussion interval to 1 month from 3 months, and in excluding those with focal injuries such as hemorrhages and contusions. RESULTS The 221 cases showed considerable heterogeneity in clinical features of PCS. They averaged 3.3 concussions, with a range of 0 to 12 or more concussions, and 62.4% occurred during sports and recreation. The median duration of PCS was 7 months at the time of examination, with 11.8% lasting more than 2 years, and 23.1% with PCS had only 1 concussion. The average patient age was 27 years (range 10-74 years). The average number of persistent symptoms was 8.1; 26.2% had a previous psychiatric condition, attention-deficit disorder/attention-deficit hyperactivity disorder, a learning disability, or previous migraine headaches. The prevalence of arachnoid cysts and Chiari malformation in PCS exceeded the general population. Additionally, involvement in litigation, presence of extracranial injuries, amnesia and/or loss of consciousness, and female sex were predictive of reporting a high number of symptoms. A prior history of psychiatric conditions or migraines, cause of injury, number of previous concussions, and age did not significantly predict symptom number. Only the number of symptoms reported predicted the duration of PCS. To predict the number of symptoms for those who fulfilled PCS criteria according to the International Classification of Diseases, 10th Revision (ICD-10), and the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV), the number of previous concussions was significant. CONCLUSIONS PCS is commonly associated with multiple concussions, but 23.1% in the present series occurred after only 1 concussion. Most patients with PCS had multiple symptoms persisting for months or years. The median duration of PCS was 7 months, with a range up to 26 years. In only 11.3%, the PCS had ended at the time of consultation. Not all predictors commonly cited in the literature align with the findings in this study. This is likely due to differences in the definitions of PCS used in research. These results suggest that the use of ICD-10 and DSM-IV to diagnose PCS may be biased toward those who are vulnerable to concussions or with more severe forms of PCS. It is thus important to redefine PCS based on evidence-based medicine.

Reach and knowledge change among coaches and other participants of the online course: "concussion in sports: what you need to know"

OBJECTIVES

To describe the reach of the Heads Up "Concussion in Sports: What You Need to Know," online course and to assess knowledge change.

SETTING

Online.

PARTICIPANTS

Individuals who have taken the free online course since its inception in May 2010 to July 2013.

DESIGN

Descriptive, uncontrolled, before and after study design.

MAIN MEASURES

Reach is measured by the number of unique participants and the number of times the course was completed by state and sport coached and the rate of participation per 100,000 population by state. Knowledge change is measured by the distribution and mean of pre- and posttest scores by sex, primary role (e.g., coach, student, and parent), and sport coached.

RESULTS

Between May 2010 and July 2013, the online concussion course was completed 819,223 times, reaching 666,026 unique participants, including residents from all US states and the District of Columbia. The distribution of overall scores improved from pre- to posttests, with 21% answering all questions correctly on the pretest and 60% answering all questions correctly on the posttest.

CONCLUSION

Online training can be effective in reaching large audiences and improving knowledge about emerging health and safety issues such as concussion awareness.

Prohibiting Headgear for Safety in Amateur Boxing? Opinion of the Canadian Boxing Community: an Online Poll

Background

In 2013, the Amateur International Boxing Association (AIBA) introduced a rule banning headgear for male-senior open class boxers during competition. The AIBA has defended the rule change as motivated by safety and supported by internal unpublished studies. As a result, in 2018, the AIBA plans to universally prohibit headgear in competition: for all competitors (male and female), all ages and all levels. Within Canada, this ruling has generated controversy in the boxing community, yet there has been no overall measure of opinion.

Methods

To address this, we instituted a voluntary, anonymous, online open-access poll to allow members of the boxing community to express their stance on headgear use in competition.

Results

In total, 636 responses were received. A total of 71.5 % of Canadian respondents believed headgear should be mandatory at all levels. Only 5.8 % agreed that headgear should be prohibited, as planned for 2018. Estimating results on a representative breakdown of boxing membership in Canada, a similar pattern emerged, whereby 68.2 % concurred with mandatory headgear while only 4.95 % supported its prohibition. Parents of boxers were almost unanimously against banning headgear, stating they would change sports as a result. Similarly, only 1.7 % of women believed headgear should be prohibited.

Conclusions

The consensus of the Canadian boxing community largely opposes the rule changes that the AIBA has implemented. The results highlight risks posed to the long-term viability of the sport, if significant grassroots safety concerns are disregarded.

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

BACKGROUND

Concussion diagnosis and management is made through the clinical exam using assessment tools that include self-report symptomatology, postural control, and cognitive evaluations. The specific timing of concussion resolution varies between individuals. However, despite a lack of research in concussion recovery, it is widely accepted that the majority of young adults will recover in 7-10 days, with youth athletes taking longer.

OBJECTIVES

The purpose of this review is to directly compare the recovery duration among high school and collegiate athletes on symptom reports and cognitive assessments following concussion.

DATA SOURCES

Data were collected from a literature search comprising high school or college athletes only. This included studies (n = 6) that reported symptom or cognitive performance recovery to the exact day.

RESULTS

High school athletes self-reported symptom recovery at 15 days compared with 6 days in collegiate athletes. Both college and high school athletes showed cognitive recovery at similar rates of 5 and 7 days.

LIMITATIONS

This review only included articles that were directly related to concussed high school or college athletes. Additionally, athletes in the high school and college setting typically receive a battery of neurocognitive tests that may not be as sensitive or as comprehensive as a full neuropsychological exam.

CONCLUSION

The review finds that neurocognitive recovery rates are similar among high school and college athletes, while symptom reporting shows longer recovery time points in high school than in college.

IMPLICATIONS OF KEY FINDINGS

An individualized and stepwise concussion management plan is important for proper concussion recovery regardless of age.

An evaluation of Gaelic Athletic Association (GAA) athletes' self-reported practice of playing while concussed, knowledge about and attitudes towards sports-related concussion

BACKGROUND/AIM

Sports-related concussions are now recognized as a major public health concern. However, despite the association of concussion with short- and long-term health consequences, many young athletes still lack basic knowledge about concussion and seem to believe that concussions may be "toughed out" and do not require medical attention. This study assessed self-reported practice of playing in training or a match while concussed among Gaelic Athletic Association (GAA) athletes in Ireland aged 13-25 years old (M=19.19, SD=3.54). This study also assessed knowledge about and attitudes towards sports-related concussion in GAA players in Ireland.

METHODS

Using a self-report questionnaire, data were captured electronically on GAA athletes aged 13-25 years old (n=80) regarding knowledge about the detection, assessment and management of sports-related concussion, as well as participant's attitudes towards concussion and self-reported practice of playing in training or a match while concussed. Data were collected from June to August 2013.

RESULTS

This study revealed that approximately one in four athletes reported having played while concussed in practice or during a match. Males were significantly more likely to play while concussed than females (40.9% and 17.2%, respectively). Results from this study indicated participants lack a complete understanding of concussion, as common misconceptions about concussion prevailed. Analyses revealed that participants generally have safe attitudes towards concussion and concussion management.

CONCLUSION

Generating awareness of the potential short- and long-term health consequences of concussion, coupled with the promotion of safer attitudes towards this injury, could minimize the number of players who return-to-play pre-maturely and promote a more safety-conscious sports culture in Ireland.

The sensitivity and specificity of clinical measures of sport concussion: three tests are better than one

CONTEXT

A battery of clinical measures of neurocognition, balance and symptoms has been recommended for the management of sport concussion (SC) but is based on variable evidence.

OBJECTIVE

To examine the sensitivity and specificity of a battery of tests to assess SC in college athletes.

DESIGN

Cross-sectional.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Division 1 athletes diagnosed with a SC (n=40) who were 20.2±1.60 years of age and 180.5±11.12 cm tall and healthy athletes (n=40) who were 19.0±0.93 years of age and 179.1±11.39 cm tall were enrolled.

INTERVENTIONS

Participants were administered Immediate Postconcussion Assessment and Cognitive Test (ImPACT), the Sensory Organization Test (SOT) and the Revised Head Injury Scale (HIS-r) prior to and up to 24 h following injury between the 2004 and 2014 sport seasons. Sensitivity and specificity were calculated using predictive discriminant analyses (PDA) and clinical interpretation guidelines.

MAIN OUTCOME MEASURES

Outcome measures included baseline and postinjury ImPACT, SOT and HIS-r composite scores.

RESULTS

Using PDA, each clinical measure's sensitivity ranged from 55.0% to 77.5% and specificity ranged from 52.5% to 100%. The test battery possessed a sensitivity and specificity of 80.0% and 100%, respectively. Using clinical interpretation guidelines, sensitivity ranged from 55% to 97.5% individually, and 100% when combined.

CONCLUSIONS

Our results support a multidimensional approach to assess SC in college athletes which correctly identified 80-100% of concussed participants as injured. When each test was evaluated separately, up to 47.5% of our sample was misclassified. Caution is warranted when using singular measures to manage SC.

Epidemiology of Sports-Related Concussions in National Collegiate Athletic Association Athletes From 2009-2010 to 2013-2014: Symptom Prevalence, Symptom Resolution Time, and Return-to-Play Time

BACKGROUND

Limited data exist among collegiate student-athletes on the epidemiology of sports-related concussion (SRC) outcomes, such as symptoms, symptom resolution time, and return-to-play time.

PURPOSE

This study used the National Collegiate Athletic Association (NCAA) Injury Surveillance Program (ISP) to describe the epidemiology of SRC outcomes in 25 collegiate sports.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

SRC data from the NCAA ISP during the 2009-2010 to 2013-2014 academic years were analyzed regarding symptoms, time to resolution of symptoms, and time to return to play. Findings were also stratified by sex in sex-comparable sports (ie, ice hockey, soccer, basketball, lacrosse, baseball/softball) and whether SRCs were reported as recurrent.

RESULTS

Of the 1670 concussions reported during the 2009-2010 to 2013-2014 academic years, an average (±SD) of 5.29 ± 2.94 concussion symptoms were reported, with the most common being headache (92.2%) and dizziness (68.9%). Most concussions had symptoms resolve within 1 week (60.1%); however, 6.2% had a symptom resolution time of over 4 weeks. Additionally, 8.9% of concussions required over 4 weeks before return to play. The proportion of SRCs that required at least 1 week before return to play increased from 42.7% in 2009-2010 to 70.2% in 2013-2014 (linear trend, P < .001). Within sex-comparable sports analyses, the average number of symptoms and symptom resolution time did not differ by sex. However, a larger proportion of concussions in male athletes included amnesia and disorientation; a larger proportion of concussions in female athletes included headache, excess drowsiness, and nausea/vomiting. A total of 151 SRCs (9.0%) were reported as recurrent. The average number of symptoms reported with recurrent SRCs (5.99 ± 3.43) was greater than that of nonrecurrent SRCs (5.22 ± 2.88; P = .01). A greater proportion of recurrent SRCs also resulted in a long symptom resolution time (14.6% vs 5.4%, respectively; P < .001) and long return-to-play time (21.2% vs 7.7%, respectively; P < .001) compared with nonrecurrent SRCs.

CONCLUSION

Trends in return-to-play time may indicate changing concussion management practices in which team medical staff members withhold players from participation longer to ensure symptom resolution. Concussion symptoms may differ by sex and recurrence. Future research should continue to examine the trends and discrepancies in symptom resolution time and return-to-play time.

Initial symptom burden predicts duration of symptoms after concussion

OBJECTIVES

To determine which variables predict prolonged (>28 days) duration of symptoms after a concussion.

DESIGN

We conducted a prospective cohort study of adult (>18yo) patients cared for in a specialty concussion clinic.

METHODS

Symptoms were assessed using the Post-Concussion Symptom Scale (PCSS) developed at the 3rd International Conference on Concussion in Sports. Possible predictors including age, sex, loss of consciousness, amnesia, history of prior concussion, prior treatment for headaches, history of migraines, and family history of concussions, were measured by self-report. We recorded a PCSS score at each clinical visit and defined time to symptom resolution as the number of days between the date of injury and date of last symptoms.

RESULTS

Of 64 adult patients included in the study, 53.3% were male; 20.3% reported experiencing a loss of consciousness at the time of injury while 23.4% reported amnesia. Patients ranged in age from 18 to 27 years (mean 21±2 years). Most concussions (92.2%) occurred during sports. The mean initial PCSS score for those suffering symptoms for longer than 28 days was significantly higher than those who symptoms resolved within 28 days (42.5 vs. 19.2, p<0.01). Of all potential predictor variables, only the initial PCSS score was independently associated with the odds of symptoms lasting longer than 28 days (aOR 1.037; 95% CI 1.011, 1.063).

CONCLUSIONS

Among adult patients with concussions, those with a higher symptom burden after injury have an increased odds of suffering from prolonged symptoms. Other potential predictor variables are not associated with the risk of prolonged recovery.

Repetitive Mild Traumatic Brain Injury in the Developing Brain: Effects on Long-Term Functional Outcome and Neuropathology

Although accumulating evidence suggests that repetitive mild TBI (rmTBI) may cause long-term cognitive dysfunction in adults, whether rmTBI causes similar deficits in the immature brain is unknown. Here we used an experimental model of rmTBI in the immature brain to answer this question. Post-natal day (PND) 18 rats were subjected to either one, two, or three mild TBIs (mTBI) or an equivalent number of sham insults 24 h apart. After one or two mTBIs or sham insults, histology was evaluated at 7 days. After three mTBIs or sham insults, motor (d1-5), cognitive (d11-92), and histological (d21-92) outcome was evaluated. At 7 days, silver degeneration staining revealed axonal argyrophilia in the external capsule and corpus callosum after a single mTBI, with a second impact increasing axonal injury. Iba-1 immunohistochemistry showed amoeboid shaped microglia within the amygdalae bilaterally after mTBI. After three mTBI, there were no differences in beam balance, Morris water maze, and elevated plus maze performance versus sham. The rmTBI rats, however, showed impairment in novel object recognition and fear conditioning. Axonal silver staining was observed only in the external capsule on d21. Iba-1 staining did not reveal activated microglia on d21 or d92. In conclusion, mTBI results in traumatic axonal injury and microglial activation in the immature brain with repeated impact exacerbating axonal injury. The rmTBI in the immature brain leads to long-term associative learning deficit in adulthood. Defining the mechanisms damage from rmTBI in the developing brain could be vital for identification of therapies for children.

Impact of preseason concussion education on knowledge, attitudes, and behaviors of high school athletes

BACKGROUND

The benefit of preseason concussion education on athletes' knowledge, attitudes, and behaviors is unclear. The purpose of the study was to determine the influence of preseason concussion education on knowledge and self-reported attitudes and reporting behaviors. We hypothesized that preseason education would lead to better knowledge and self-reported attitudes and better reporting of concussion symptoms during the season.

METHODS

This study involved a prospective cohort comparing the benefits of a preseason lectured-based concussion education session at one high school with a control school. Participants included males and females age 13 years to 18 years from two community high schools who were participating in higher concussion risk, fall or winter sports (football, soccer, wrestling, and basketball). The education school and control school included 234 and 262 participants, respectively. Outcomes were a preseason and postseason survey assessing knowledge and self-reported attitudes about concussions and an end-of-season questionnaire assessing concussion reporting behaviors during the season.

RESULTS

Total scores on the combined (p < 0.0001), knowledge-based (p = 0.016), and behavioral-based (p < 0.0001) questions demonstrated statistically significant improvement in the education group. Scores peaked immediately after education but dissipated at the end of the season. There was a lower proportion in the education school (72%) compared with the control school (88%) that reported continued play despite having concussion symptoms during the season (p = 0.025). A similar proportion of athletes diagnosed with concussion during the season in the education (27%) and control schools (23%) reported returning to play before symptoms resolved (p = 0.81).

CONCLUSION

These findings suggest that a didactic-based preseason concussion education likely has minimal benefits. Other factors besides knowledge are likely influencing student-athlete concussion reporting behavior. Future research focused on changing the culture of concussion reporting is needed.

LEVEL OF EVIDENCE

Therapeutic study, level III.

Found in translation: Understanding the biology and behavior of experimental traumatic brain injury

The aim of this review is to discuss in greater detail the topics covered in the recent symposium entitled "Traumatic brain injury: laboratory and clinical perspectives," presented at the 2014 International Behavioral Neuroscience Society annual meeting. Herein, we review contemporary laboratory models of traumatic brain injury (TBI) including common assays for sensorimotor and cognitive behavior. New modalities to evaluate social behavior after injury to the developing brain, as well as the attentional set-shifting test (AST) as a measure of executive function in TBI, will be highlighted. Environmental enrichment (EE) will be discussed as a preclinical model of neurorehabilitation, and finally, an evidence-based approach to sports-related concussion will be considered. The review consists predominantly of published data, but some discussion of ongoing or future directions is provided.

Cognitive and physical symptoms of concussive injury in children: a detailed longitudinal recovery study

BACKGROUND

Recovery from concussion sustained in childhood and adolescence is poorly understood. We explored patterns of recovery for neurocognition and postconcussive symptoms following concussion in children and adolescents.

METHODS

Using a prospective, longitudinal design, we collected baseline data on 728 children and adolescents aged 10-17 years. 10 participants sustained a concussive injury (n=10) in the 12 months following baseline testing and they were reviewed at day 5, 10 and 30 postconcussion. Assessments included the CogSport for Kids computerised test battery to evaluate neurocognitive function and self-report, and parent measures of postconcussive symptoms. At day 30, parents also completed measures rating their child's quality of life and executive functions.

RESULTS

Children and adolescents displayed a gradual reduction in postconcussive symptoms over the 30 days following injury. At day 5, 87% of participants were reporting physical and cognitive symptoms, with a generalised reduction in all symptoms by day 10 (40% of participants). On the computerised measure, reaction time was slower after concussion, but returned to baseline levels by day 30. At day 30, 10% of participants demonstrated ongoing postconcussive symptoms. Number of previous concussions was related to speed of symptom resolution.

CONCLUSIONS

At 5 days postconcussion, the majority of children and adolescents experienced debilitating postconcussive symptoms. However, by 30 days postinjury, 90% demonstrated recovery to normal for both neurocognition and postconcussive symptoms.

Can Computerized Neuropsychological Testing in the Emergency Department Predict Recovery for Young Athletes With Concussions?

OBJECTIVE

The objective of this study was to determine if computerized neurocognitive testing (Immediate Post-Concussion Assessment and Cognitive Testing [ImPACT]) in the emergency department (ED) can be used as a prognostic tool to detect young athletes at risk of having protracted concussive symptoms.

METHODS

This was a prospective cohort study of athletes aged 11 to 18 years who presented to an ED less than 24 hours after sustaining a sports-related concussion. ImPACT was administered in the ED, and performance was categorized as "poor" if the athlete had 3 (of 4) or greater low domain scores. Participants completed the Post-Concussion Symptom Scale (PCSS) in the ED and by phone at 1 and 2 weeks after injury. Athletes were symptomatic if their PCSS score was more than 6 in males and more than 8 in females.

RESULTS

One hundred nine patients were enrolled; 60% and 36% remained symptomatic at 1 and 2 weeks after injury, respectively. "Poor" ImPACT performance was not particularly useful in predicting athletes with protracted symptoms (at 1 week: positive predictive value, 70.8%; negative predictive value, 43.5%; at 2 weeks: positive predictive value, 47.8%; negative predictive value, 68.9%). In bivariate analysis, a higher ED PCSS score was associated with protracted symptoms (at 1 week: odds ratio, 1.1 [confidence interval, 1.0-1.1]; at 2 weeks: odds ratio, 1.0 [confidence interval, 1.0-1.1]).

CONCLUSIONS

Computerized neurocognitive testing in the ED has limited usefulness in predicting protracted symptoms. Total acute symptom burden may be a useful prognostic tool in the ED evaluation of concussed young athletes, yet further research is necessary.

Chronic traumatic encephalopathy: contributions from the Boston University Center for the Study of Traumatic Encephalopathy

OBJECTIVE

Chronic Traumatic Encephalopathy (CTE) is a neurodegenerative disease associated with repetitive brain trauma (RBT). Initially described in boxers, CTE has now been found in other contact sport athletes with a history of RBT. In recent years, there has been tremendous media attention regarding CTE, primarily because of the deaths of high profile American football players who were found to have CTE upon neuropathological examination. However, the study of CTE remains in its infancy. This review focuses on research from the Centre for the Study of Traumatic Encephalopathy (CSTE) at Boston University.

METHODS

This study reviews the formation of the CSTE, major CSTE publications and current ongoing research projects at the CSTE.

RESULTS

The neuropathology of CTE has been well-described. Current research focuses on: methods of diagnosing the disease during life (including the development of biomarkers), examination of CTE risk factors (including genetic susceptibility and head impact exposure variables); description of the clinical presentation of CTE; development of research diagnostic criteria for Traumatic Encephalopathy Syndrome; and assessment of mechanism and pathogenesis.

CONCLUSIONS

Current research at the BU CSTE is aimed at increasing understanding of the long-term consequences of repetitive head impacts and attempting to begin to answer several of the unanswered questions regarding CTE.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

FINDINGS

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

IMPLICATIONS

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

Test-retest reliability of KINARM robot sensorimotor and cognitive assessment: in pediatric ice hockey players

BACKGROUND

Better diagnostic and prognostic tools are needed to address issues related to early diagnosis and management of concussion across the continuum of aging but particularly in children and adolescents. The purpose of the current study was to evaluate the reliability of robotic technology (KINARM robot) assessments of reaching, position sense, bimanual motor function, visuospatial skills, attention and decision making in youth ice hockey players (ages 10-14).

METHODS

Thirty-four male children attended two testing days, one week apart. On day one, each subject completed five tasks on the robot with two examiners (alternating examiner sequence); the 2(nd) examiner followed the same procedure as the 1(st) immediately afterwards. One consistent examiner tested subjects one week later. This is a test-retest reliability study. The robotic tasks characterize sensorimotor and/or cognitive performance; 63 parameters from 5 tasks are reported. Session 1 was the 1(st) time the subject performed the 5 tasks, session 2 the 2(nd) time on day 1, and session 3 one week following.

RESULTS

Intra-class correlation coefficients ranged from 0.06 to 0.91 and 0.09 to 0.90 for session 1 to 2 and 2 to 3, respectively. Bland-Altman plots showed agreement in a majority of the parameters and a learning effect in 25 % and 24 % of parameters in session 1 vs 2 and 1 vs 3, respectively but none for session 2 vs 3. Of those that showed a learning effect, only 8 % of parameters in session 1 vs 2 and 10 % in session 1 vs 3 had a clinical relevance measure ≥ 0.8.

CONCLUSIONS

The relative homogeneity of the sample and the effect of learning seen in some of the task parameters appears to have negatively impacted the intra-class correlation coefficients from session 1 to 2, with less impact for 2 to 3. The Bland-Altman analysis supports good absolute reliability in healthy male children with no neurological impairment ranging in age from 10 to 14. The clinically relevant learning effect seen, in a small number of parameters could be addressed by creating a learning effect adjustment factor and/or implementing a practice session, which would eliminate the learning effect.

Trends in Ambulatory Care for Children with Concussion and Minor Head Injury from Eastern Massachusetts between 2007 and 2013

OBJECTIVE

To characterize trends in health care utilization and costs for children diagnosed with concussion or minor head injury within a large pediatric primary-care association.

STUDY DESIGN

We conducted a retrospective cohort analysis from 2007 through 2013 examining all outpatient medical claims related to concussion and minor head injury from 4 commercial insurance companies for children 6-21 years of age who were patients within a large pediatric independent practice association located throughout eastern Massachusetts.

RESULTS

Health care visits for concussion and minor head injury increased more than 4-fold during the study period, with primary-care and specialty clinics experiencing the greatest increases in the rate of visits while emergency department visits increased comparatively less. These increases were accounted for by both the proportion of children diagnosed with concussion or minor head injury (1.3% of all children in 2007 vs 3.3% in 2013) and the number of encounters per diagnosed patient (1.0 encounters per patient in 2007 vs 1.7 in 2013). Although the overall population costs devoted to care for concussion or minor head injury increased 34%, the cost per individual diagnosed child decreased 31%.

CONCLUSIONS

Over the past 7 years, health care encounters for children diagnosed with concussion or minor head injury increased substantially in eastern Massachusetts. Care for these injuries increasingly shifted from the emergency department to primary-care and specialty providers.

The Diagnosis and Management of Concussion in Children and Adolescents

BACKGROUND

Concussion is a complex brain injury that results in more than 100,000 emergency department visits for school-aged children each year in the United States. All 50 US states have passed concussion legislation designed to promote safety in youth sports. Most of these laws require medical clearance by a licensed health care provider before returning to sport, which may have contributed to an increase in pediatric subspecialty referrals, particularly referrals to the child neurologist.

METHODS

We reviewed the literature on pediatric concussion.

RESULTS

This review summarizes the current knowledge and recommendations for concussion diagnosis and management in children and adolescents, athletes and nonathletes. It highlights concussion epidemiology, pathophysiology, advances in neuroimaging, and potential health risks including second impact syndrome and chronic traumatic encephalopathy. It also underscores clinical areas where evidence is lacking.

CONCLUSIONS

The diagnosis and management of concussion requires specific considerations in children. Further concussion research must be done to minimize injury risk and to optimize medical care for this common problem.

Young age as a modifying factor in sports concussion management: what is the evidence?

In 2008, the Concussion in Sport Group (CISG) published its third consensus statement and introduced 10 'modifying' factors that were presumed clinically to influence the investigation and management of concussions in sports. Young age was listed as one of the modifying factors. In some cases, these modifiers were thought to be predictive of prolonged or persistent symptoms. These same modifying factors were retained in the fourth iteration of the CISG consensus statement (2013), although mention was made of possible limitations of their efficacy. The CISG statements provided several empirical references regarding young age as a modifying factor. We reviewed the published sports concussion literature with the purpose of determining empirical studies that support or refute the inclusion of young age as a modifier of concussive injury in sports. We performed a systematic review of the PubMed database utilizing the keywords concussion, sports, mild traumatic brain injury, youth, adolescents, and children. English language studies were extracted by the authors and summarized for review. Multiple empirical studies were found indicating that younger athletes may take longer to recover from a sports-related concussion (SRC) than their older peers. However, studies did not indicate that younger athletes were at more risk for prolonged recovery (>4 wk). Empirical evidence supports the inclusion of young age as a modifying factor in sports concussion. However, the difference in recovery time seems relatively small (a few days) and young age does not predict prolonged recovery (>4 wk). The findings support the inclusion of young age as a specific modifier in the treatment of SRC and have implications for the clinical management of this common injury.

Relationship of Attention Deficit Hyperactivity Disorder and Postconcussion Recovery in Youth Athletes

OBJECTIVE

To investigate whether attention deficit hyperactivity disorder (ADHD) influences postconcussion recovery, as measured by computerized neurocognitive testing.

DESIGN

This is a retrospective case control study.

SETTING

Computer laboratories across 10 high schools in the greater Atlanta, Georgia area.

PARTICIPANTS

Immediate postconcussion assessment and cognitive testing (ImPACT) scores of 70 athletes with a self-reported diagnosis of ADHD and who sustained a sport-related concussion were compared with a randomly selected age-matched control group. Immediate postconcussion assessment and cognitive testing scores over a 5-year interval were reviewed for inclusion.

MAIN OUTCOME MEASURES

Postconcussion recovery was defined as a return to equivalent baseline neurocognitive score on the ImPACT battery, and a concussion symptom score of ≤7.

RESULTS

Athletes with ADHD had on average a longer time to recovery when compared with the control group (16.5 days compared with 13.5 days), although not statistically significant. The number of previous concussions did not have any effect on the rate of recovery in the ADHD or the control group. In addition, baseline neurocognitive testing did not statistically differ between the 2 groups, except in verbal memory.

CONCLUSIONS

Although not statistically significant, youth athletes with ADHD took on average 3 days longer to return to baseline neurocognitive testing compared with a control group without ADHD.

CLINICAL RELEVANCE

Youth athletes with ADHD may have a marginally prolonged recovery as indexed by neurocognitive testing and should be considered when prognosticating time to recovery in this subset of student athletes.

A Balanced Protocol for Return to School for Children and Youth Following Concussive Injury

BACKGROUND

Few protocols exist for returning children/youth to school after concussion. Childhood concussion can significantly affect school performance, which is vital to social development, academic learning, and preparation for future roles. The goal of this knowledge translation research was to develop evidence based materials to inform physicians about pediatric concussion.

METHODS

The Return to School (RTS) concussion protocol was developed following the National Institute for Health and Care Excellence procedures.

RESULTS

Based on a scoping review, and stakeholder opinions, an RTS protocol was developed for children/youth. This unique protocol focuses on school adaptation in 4 main areas: (a) timetable/attendance, (b) curriculum, (c) environmental modifications, and (d) activity modifications.

CONCLUSION

A balance of cognitive rest and timely return to school need to be considered for returning any student to school after a concussion. Implementation of these new recommendations may be an important tool in prevention of prolonged absence from school and academic failure while supporting brain recovery.

Repetitive head trauma, chronic traumatic encephalopathy and tau: Challenges in translating from mice to men

Chronic traumatic encephalopathy (CTE) is a neurological and psychiatric condition marked by preferential perivascular foci of neurofibrillary and glial tangles (composed of hyperphosphorylated-tau proteins) in the depths of the sulci. Recent retrospective case series published over the last decade on athletes and military personnel have added considerably to our clinical and histopathological knowledge of CTE. This has marked a vital turning point in the traumatic brain injury (TBI) field, raising public awareness of the potential long-term effects of mild and moderate repetitive TBI, which has been recognized as one of the major risk factors associated with CTE. Although these human studies have been informative, their retrospective design carries certain inherent limitations that should be cautiously interpreted. In particular, the current overriding issue in the CTE literature remains confusing in regard to appropriate definitions of terminology, variability in individual pathologies and the potential case selection bias in autopsy based studies. There are currently no epidemiological or prospective studies on CTE. Controlled preclinical studies in animals therefore provide an alternative means for specifically interrogating aspects of CTE pathogenesis. In this article, we review the current literature and discuss difficulties and challenges of developing in-vivo TBI experimental paradigms to explore the link between repetitive head trauma and tau-dependent changes. We provide our current opinion list of recommended features to consider for successfully modeling CTE in animals to better understand the pathobiology and develop therapeutics and diagnostics, and critical factors, which might influence outcome. We finally discuss the possible directions of future experimental research in the repetitive TBI/CTE field.

Characterization of acute stress reaction following an IED blast-related mild traumatic brain injury

PRIMARY OBJECTIVE

To characterize an acute stress reaction (ASR) following an improvised explosive device (IED) blast-related mild traumatic brain injury (mTBI).

RESEARCH DESIGN

Participants were male, US military personnel treated in Afghanistan within 4 days following an IED-related mTBI event (n = 239).

METHODS AND PROCEDURES

Demographics, diagnosis of ASR, injury history and self-reported mTBIs, blast exposures and psychological health histories were recorded.

MAIN OUTCOMES AND RESULTS

In total, 12.5% of patients met ASR criteria. Patients with ASR were significantly younger and junior in rank (p < 0.05). Patients with ASR were more likely to experience the IED-blast while dismounted, report a loss of consciousness (LOC) and higher pain levels (p < 0.05). Adjusting for age and rank, multivariate logistic regression showed an association between mTBI history and ASR (AOR = 1.405; 95% CI = 1.105-1.786, p < 0.01). Adjusting for mechanism of injury (dismounted vs. mounted), LOC and pain, multivariate logistic regression showed an association between mTBI history and ASR (AOR = 1.453; 95% CI = 1.132-1.864, p < 0.01). Prior blast exposure and past psychological health issues were not associated with ASR.

CONCLUSIONS

A history of multiple mTBIs is associated with increased risk of ASR. Future research is warranted.

The neuropathology of chronic traumatic encephalopathy

Repetitive brain trauma is associated with a progressive neurological deterioration, now termed as chronic traumatic encephalopathy (CTE). Most instances of CTE occur in association with the play of sports, but CTE has also been reported in association with blast injuries and other neurotrauma. Symptoms of CTE include behavioral and mood changes, memory loss, cognitive impairment and dementia. Like many other neurodegenerative diseases, CTE is diagnosed with certainty only by neuropathological examination of brain tissue. CTE is a tauopathy characterized by the deposition of hyperphosphorylated tau (p-tau) protein as neurofibrillary tangles, astrocytic tangles and neurites in striking clusters around small blood vessels of the cortex, typically at the sulcal depths. Severely affected cases show p-tau pathology throughout the brain. Abnormalities in phosphorylated 43 kDa TAR DNA-binding protein are found in most cases of CTE; beta-amyloid is identified in 43%, associated with age. Given the importance of sports participation and physical exercise to physical and psychological health as well as disease resilience, it is critical to identify the genetic risk factors for CTE as well as to understand how other variables, such as stress, age at exposure, gender, substance abuse and other exposures, contribute to the development of CTE.