Future Concussion Research Articles

Experience with Canada's First Policy on Concussion Education and Management in Schools.

In response to the rising incidence of concussions among children and adolescents, the province of Ontario recently introduced the Ontario Policy/Program Memorandum on Concussions (PPM No. 158) requiring school boards to develop a concussion protocol. As this is the first policy of its kind in Canada, the impact of the PPM is not yet known. An electronic survey was sent to all high school principals in the Toronto District School Board 1 year after announcement of the PPM. Questions covered extent of student, parent, and staff concussion education along with concussion management protocols. Of 109 high school principals contacted, 39 responded (36%). Almost all schools provided concussion education to students (92%), with most education delivered through physical education classes. Nearly all schools had return to play (92%) and return to learn (77%) protocols. Although 85% of schools educated staff on concussions, training was aimed at individuals involved in sports/physical education. Only 43.6% of schools delivered concussion education to parents, and many principals requested additional resources in this area. One year after announcement of the PPM, high schools in the Toronto District School Board implemented significant student concussion education programs and management protocols. Staff training and parent education required further development. A series of recommendations are provided to aid in future concussion policy development.

The Incidence Of Concussion And The Risk Of Subsequent Concussions In Professional Rugby League

BACKGROUND: Proper recognition and management of concussion within sport has become a hot topic as research suggests that the mismanagement of these injuries can lead to extended time out of play, and morbidity after a player retires. Computerised neuropsychological testing (CogSport) was introduced in Rugby League (RL) in 2004 to aid in return to play criteria and to help safeguard player’s welfare. AIMS: To identify the incidence and lifetime risk following a concussion over the years 2006-2012 within the Rugby Football League (RFL) and whether a full recovery from concussion lends to an increased risk of subsequent concussions. METHOD: Participant players were those who held a professional contract with the Rugby Football League UK between 2006-2012 representing 39 professional clubs at first and academy team level. It is mandatory within the professional game to provide an annual baseline test and following any diagnosed concussion, with full symptom resolution, a valid return to play test test. Concussion test data was provided by CogState Australia from tests performed over 7 seasons. RESULTS: Over the 7 year period there were 4762 players within the RFL (age range 16-34 years), suffering 470 concussion (2.65/1000 hours). The odds of sustaining 1 concussion was 7%, whereas the chances of receiving 2 or more was 1%. Incidentally, the probability of having 3 or more concussions was 0.2%. The time between concussions for any individual who suffered two or more concussions was on average 355 days. The average return to play time was 1.46 days following the first return to play test. The mean age of suffering a concussion was 22.6years. The study showed a moderate association between age and concussion risk, with each advancing year giving rise to an 8% increased risk of a concussion. CONCLUSIONS: This report is the first to follow RL players over a prolonged period and as such is the first to demonstrate the risk of subsequent concussions. In RL concussions managed correctly and fully resolved have not been shown to have detrimental effects on future concussions and in general there is a lack of evidence linking appropriately managed concussions in other sports to detrimental future effects. Ethics University of Nottingham

Mixed Martial Arts Fighter Susceptibility to In-Fight Concussion

PURPOSE: To investigate whether susceptibility to concussion with and without loss of consciousness (LOC) increases as multiple concussions are experienced among mixed martial arts (MMA) fighters. It was hypothesized that by using publicly available data, an analysis of in-fight concussion susceptibility would demonstrate that fighters became more susceptible to in-fight concussions after experiencing one or more in-fight concussions. Findings will provide information that may assist with development efforts to establish Warrior and athlete return-to-duty assessments, fitness-for-duty standards, and injury prevention countermeasures and requirements. METHODS: For this IRB-exempt project, researchers from the U.S. Army Aeromedical Research Laboratory (USAARL) reviewed fight records from 20 years of archived online data. Fights resulting in LOC, (knock out [KO]), or suspected concussion (technical KO [TKO]) were flagged, and technicians later reviewed video footage to determine if the KO or TKO was the result of a significant blow to the head. An analysis of variance (ANOVA) for concussion susceptibility was completed, and a within-groups test was conducted to determine if fighters were significantly more or less susceptible to concussion after receiving their first suspected in-fight concussion. RESULTS: Concussion susceptibility ratios were computed for 51 MMA fighters, all of whom had at least one suspected in-fight concussion and had fought in at least one MMA fight after receiving their first suspected concussion. Concussion susceptibility ratios were simply a ratio of the number of concussions to number of total fights, with separate ratios conducted for fights up to the first concussion (pre) and for fights after the first concussion (post). A one-way repeated-measures ANOVA on pre- and post-concussion susceptibility ratios demonstrated that fighters experienced a lower rate of concussions per fight following their first suspected in-fight concussion. CONCLUSIONS: The lower number of concussions may be explained by increased awareness and caution taken by fighters to avoid additional concussions, which does not exclude or address the possibility of a physiologically based predisposition to future concussion following an initial concussion event.

A Review of Sport-Related Head Injuries.

We review current topics in sport-related head injuries including acute subdural hematoma (ASDH), traumatic cerebrovascular disease, cerebral concussion, and chronic traumatic encephalopathy (CTE). Sports-related ASDH is a leading cause of death and severe morbidity in popular contact sports like American football and Japanese judo. Rotational acceleration can cause either cerebral concussion or ASDH due to rupture of a parasagittal bridging vein. Although rare, approximately 80% of patients with cerebral infarction due to sport participation are diagnosed with ischemia or infarction due to arterial dissection. Computed tomography angiography, magnetic resonance angiography, and ultrasound are useful for diagnosing arterial dissection; ultrasound is particularly useful for detecting dissection of the common and internal carotid arteries. Repeated sports head injuries increase the risks of future concussion, cerebral swelling, ASDH, and CTE. To avoid fatal consequences of CTE, it is essential to understand the criteria for safe post-concussion sports participation. Once diagnosed with a concussion, an athlete should not be allowed to return to play on the same day and should not resume sports before the concussion symptoms have completely resolved. Information about the risks and management of head injuries in different sports should be widely disseminated in educational institutions and by sport organization public relations campaigns.

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

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

Current Topics in Sports-related Head Injuries: A Review

We review the current topic in sports-related head injuries including acute subdural hematoma (ASDH), concussion, and chronic traumatic encephalopathy (CTE). Sports-related ASDH is a leading cause of death and severe morbidity in popular contact sports like American football in the USA and judo in Japan. It is thought that rotational acceleration is most likely to produce not only cerebral concussion but also ASDH due to the rupture of a parasagittal bridging vein, depending on the severity of the rotational acceleration injury. Repeated sports head injuries increase the risk for future concussion, cerebral swelling, ASDH or CTE. To avoid fatal consequences or CTE resulting from repeated concussions, an understanding of the criteria for a safe post-concussion return to play (RTP) is essential. Once diagnosed with a concussion, the athlete must not be allowed to RTP the same day and should not resume play before the concussion symptoms have completely resolved. If brain damage has been confirmed or a subdural hematoma is present, the athlete should not be allowed to participate in any contact sports. As much remains unknown regarding the pathogenesis and pathophysiology of sports-related concussion, ASDH, and CTE, basic and clinical studies are necessary to elucidate the crucial issues in sports-related head injuries.

The Prevalence of Undiagnosed Concussions in Athletes

Previous studies suggest athletes underreport concussions. We sought to determine whether athletes in our clinics have sustained previous concussions that went undiagnosed. Multicentered cross sectional study. Two sport concussion clinics. Patients diagnosed with sport-related concussions or concussions with injury mechanisms and forces similar to those observed in sports were included. The proportion of patients who answered "yes" to the following question were defined as having a previously undiagnosed concussion: "Have you ever sustained a blow to the head which was NOT diagnosed as a concussion but was followed by one or more of the signs and symptoms listed in the Post Concussion Symptom Scale?" Of the 486 patients included in the final analysis, 148 (30.5%) patients reported a previously undiagnosed concussion. Athletes reporting previously undiagnosed concussions had a higher mean Post Concussion Symptom Scale (PCSS) score (33 vs 25; P < 0.004) and were more likely to have lost consciousness (31% vs 22%; P = 0.038) with their current injury than athletes without previously undiagnosed concussions. Nearly one-third of athletes have sustained previously undiagnosed concussions, defined as a blow to the head followed by the signs and symptoms included in the PCSS. Furthermore, these previously undiagnosed concussions are associated with higher PCSS scores and higher loss of consciousness rates when future concussions occur. Many athletes have sustained previous blows to the head that result in the signs and symptoms of concussion but have not been diagnosed with a concussion. These injuries are associated with increased rates of loss of consciousness and higher symptom scale scores with future concussions.

Concussion Symptoms and Neurocognitive Performance of High School and College Athletes Who Incur Multiple Concussions

Background: Multiple concussions have been associated with prolonged symptoms, recovery time, and risk for future concussions. However, very few studies have examined the effect of multiple concussions on neurocognitive performance and the recently revised symptom clusters using a large database. Purpose: To examine concussed athletes with a history of 0, 1, 2, or ≥3 concussions on neurocognitive performance and the recently revised symptom clusters. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: The independent variables were concussion group (0, 1, 2, and ≥3 concussions) and time (baseline, 3 days, and 8 days). The dependent variables were neurocognitive test scores as measured by the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) neurocognitive test battery (verbal and visual memory, processing speed, and reaction time) and 4 concussion symptom clusters (migraine-cognitive-fatigue, affective, somatic, and sleep). All concussed athletes (n = 596) were administered the ImPACT test at a mean 2.67 ± 1.98 and 7.95 ± 4.46 days after injury. A series of 4 (concussion group) × 3 (time) repeated-measures analyses of covariance (age = covariate) were performed on ImPACT composite scores and symptom clusters. Results: Concussed athletes with ≥3 concussions were still impaired 8 days after a concussion compared with baseline scores on verbal memory (P < .001), reaction time (P < .001), and migraine-cognitive-fatigue symptoms (P < .001). There were no significant findings on the remaining dependent variables. Conclusion: Concussed athletes with a history of ≥3 concussions take longer to recover than athletes with 1 or no previous concussion. Future research should concentrate on validating the new symptom clusters on multiple concussed athletes, examining longer recovery times (ie, >8 days) among athletes with multiple concussions.

When Treating Sport Concussion, Check the Boxes, But Also Go the Extra Mile

Pick up a newspaper or watch the evening news or ‘‘Sports Center,’’ and you’re bound to read or hear something about sport concussion. The media are obsessed with this topic, particularly with the negative news that makes headlines and ultimately sells newspapers. Even so, there is good news to report, and progress is being made. Although the neuroscience community has learned much about concussion in the last 2 decades, admittedly, we have much more to investigate and to understand. The tests for detecting concussion and tracking recovery are becoming more sensitive, especially when used in combination with other tools to create a multimodal approach to concussion assessment. Despite all that has been accomplished, caring for athletes at risk for sustaining cerebral concussion has always been a challenging task and never more so than in today’s litigious society. Concussion is different from other athletic injuries in that we still rely heavily on an athlete’s subjective reporting of symptoms for decision making, and we lack the neuroimaging protocols that might allow us to see the damage and understand its severity. The cause-andeffect relationships, or lack of same, between repetitive head trauma and neurodegenerative diseases such as Alzheimer and chronic traumatic encephalopathy (CTE) are the subject of significant debate. Several published case reports have described s protein deposits in the brains of deceased contact-sport athletes, but most of the neuroscience community does not believe that controlled experimental research has yet identified a causal relationship linking repetitive head trauma in sports and CTE. Our responsibility is to safely care for our athletes, which includes educating them about what is known and unknown about the long-term effects of repetitive head trauma. Unfortunately, the large amount of misinformation on this topic sometimes results in hysteria rather than rational thinking. Sports medicine clinicians can sometimes be overly focused on avoiding negligence, leading them to simply ‘‘check the boxes.’’ This goes against our training and best practices. Concussions are like snowflakes: no 2 are alike, and no cookbook or calendar can specify exactly how they should be treated. Therefore, we need to go the extra mile. In many cases, it’s a matter of counseling our athletes about the shortand long-term risks of not reporting symptoms, returning to play while still experiencing symptoms, and not modifying risky behaviors that can predispose them to future concussions. No checkbox system can be applied to every concussion, and because concussions are diverse and unique injuries that affect each athlete differently, we must learn how to treat them individually. Likewise, concussed athletes are unique, and we must work to understand what makes them different. As athletic trainers, we sometimes forget the important role we play as counselor to our athletes. Getting to know each athlete’s mindset and reaction to injuries allows us to build trust and forge honest lines of communications, thus enabling us to develop an appropriate and individualized plan for managing concussion, which is just as vital as knowing how to interpret the results of a cognitive or balance test. Within a 6-month period, 4 major consensus or evidencebased documents focused on concussion management will have been released, 1 of which is published in this issue of JAT (originally published in the British Journal of Sports Medicine, March 2013): ‘‘Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport, Zurich, November 2012.’’ This, along with other manuscripts published or soon to be published by the American Medical Society for Sports Medicine, the American Academy of Neurology, and the National Athletic Trainers’ Association should all be mandatory reading for sports medicine clinicians because they will define the standard of care for athletic trainers and team physicians for at least the next 4 to 5 years. These documents are very well prepared and will make significant contributions to the sports medicine community. Although the documents share many themes, and many of the recommendations across the documents are consistent, they can leave the impression that checking the boxes is all we need to do to reassure ourselves that we have done our job when treating a concussed athlete. In summary, I leave you a checklist:

Do the Physical Characteristics of a Virtual Reality Device Contraindicate Its Use for Balance Assessment?

Virtual reality environments may allow researchers to investigate functional balance performance without risks associated with testing in the real world. To investigate the effects of the mass of a head-mounted display (HMD) on balance performance. Counterbalanced pretest-posttest. Virtual reality laboratory. 20 healthy college students. Balance Error Scoring System (BESS) with a tracker-only headband and again with tracker plus HMD was performed. BESS error scores, elliptical sway area, and center of pressure travel distance were recorded. No effect of the HMD mass on balance performance was observed. A significant stance by surface interaction was present but was negated when the HMD conditions were included in the model. The mass of a HMD has not been proven to adversely affect balance performance. These data suggest the HMD mass is not a contraindication to the use of immersive virtual environments in future concussion research involving balance.