Epidemiology of concussion in sport: a literature review

Traumatic Brain Injury and Alzheimer's Disease Biomarkers: A Systematic Review of Findings from Amyloid and Tau Positron Emission Tomography

Traumatic brain injury (TBI) has been discussed as a risk factor for Alzheimer's disease (AD) due to its association with AD risk and earlier cognitive symptom onset. However, the mechanisms behind this relationship are unclear. Some studies have suggested TBI may increase pathological protein deposition in an AD-like pattern; others have failed to find such associations. This review covers literature that uses positron emission tomography (PET) of β-amyloid (Aβ) and/or tau to examine individuals with a history of TBI who are at increased risk for AD due to age. A comprehensive literature search was conducted on January 9, 2023, and 26 resulting citations met inclusion criteria. Common methodological concerns included small samples, limited clinical detail about participants' TBI, recall bias due to reliance on self-reported TBI, and an inability to establish causation. For both Aβ and tau, results were widespread but inconsistent. The regions that showed the most compelling evidence for increased Aβ deposition were the cingulate gyrus and cuneus/precuneus. Evidence for elevated tau was strongest in the medial temporal lobe, entorhinal cortex, precuneus, and frontal, temporal, parietal, and occipital lobes. However, conflicting findings across most regions in both Aβ- and tau-PET studies indicate the critical need for future work in expanded samples and with greater clinical detail to offer a clearer picture of the relationship between TBI and protein deposition in older individuals at risk for AD.

Where is the research on sport-related concussion in Olympic athletes? A descriptive report and assessment of the impact of access to multidisciplinary care on recovery

OBJECTIVES

This cohort study reported descriptive statistics in athletes engaged in Summer and Winter Olympic sports who sustained a sport-related concussion (SRC) and assessed the impact of access to multidisciplinary care and injury modifiers on recovery.

METHODS

133 athletes formed two subgroups treated in a Canadian sport institute medical clinic: earlier (≤7 days) and late (≥8 days) access. Descriptive sample characteristics were reported and unrestricted return to sport (RTS) was evaluated based on access groups as well as injury modifiers. Correlations were assessed between time to RTS, history of concussions, the number of specialist consults and initial symptoms.

RESULTS

160 SRC (median age 19.1 years; female=86 (54%); male=74 (46%)) were observed with a median (IQR) RTS duration of 34.0 (21.0-63.0) days. Median days to care access was different in the early (1; nSRC=77) and late (20; nSRC=83) groups, resulting in median (IQR) RTS duration of 26.0 (17.0-38.5) and 45.0 (27.5-84.5) days, respectively (p<0.001). Initial symptoms displayed a meaningful correlation with prognosis in this study (p<0.05), and female athletes (52 days (95% CI 42 to 101)) had longer recovery trajectories than male athletes (39 days (95% CI 31 to 65)) in the late access group (p<0.05).

CONCLUSIONS

Olympic athletes in this cohort experienced an RTS time frame of about a month, partly due to limited access to multidisciplinary care and resources. Earlier access to care shortened the RTS delay. Greater initial symptoms and female sex in the late access group were meaningful modifiers of a longer RTS.

Traumatic brain injuries in paediatric patients: individual vs. team sports-related hospitalizations

Paediatric sport participation continues to increase in the United States, with a corresponding increase in sports-related concussions or traumatic brain injuries (TBIs). It is important to recognize which sports are at elevated risk and identify risk factors for hospital admission and length of stay (LOS). Paediatric patients (ages 5-18) from 2008 to 2014 were identified from the Healthcare Cost and Utilization Project (HCUP) National Inpatient Sample (NIS). Eight hundred and ninety-four patients included those who were hospitalized with a TBI resulting from participation in an individual (451 patients) or team (443 patients) sport. We evaluated the differences in LOS and total charges between individual and team sports and found that compared to team sports, TBI patients in individual sports had significantly longer hospital stays compared to team sports (1.75 days versus 1.34 days, p < 0.001) and costlier ($27,333 versus $19,069, p < 0.001) hospital stays. This may be due to reduced awareness and reduced compliance with return-to-play protocols in individual sports. Safety education information at a young age, increased awareness of TBIs, and additional medical support for individual sports as well as team sports may help mitigate these findings.

Enhancing Protocols for Concussion Management in Professional Soccer Events

AIM

Every year, there are an estimated 1.7 to 3.8 million sports-related traumatic brain injuries. A sports concussion results from an external force or a blow to the head or body, causing cranial encephalic trauma that can affect motor skills and brain function, producing varying symptoms related to an alteration in neurological functioning. Soccer poses a risk of concussions due to heading, where the player's head directly hits the ball to redirect or accelerate it. However, most concussions are caused by contact between players, such as head-to-head or head-to-elbow contact. This study analyzed the incidence of concussions or mild traumatic brain injuries in professional soccer during the "Copa America 2019" to understand the feasibility of soccer concussion protocols and propose evidence-based enhancements.

METHODS

The data were previously collected by our first two authors, O. Pangrazio and F. Forriol, during the 46th edition of the "Copa America 2019," where the South American Football Confederation implemented the Concussion Fast Recognition Protocol to detect traumatic brain injuries. The descriptive basic data will help to raise awareness and motivate further research in this field. We have analyzed and correlated it with global data to provide a comprehensive review and tangible evidence of the population size where soccer protocols are typically applied, thus calculating incidence rates to measure it mathematically.

RESULTS

Our study reveals that the incidence rate of concussions during the "Copa America 2019" was 5.3 per 1,000 athlete exposures, with a total of three concussions occurring among 567 players. Despite the effectiveness of current protocols in detecting concussions rapidly and accurately, the relatively low incidence rate at this level of professional competition poses a challenge to validating these protocols. These results indicate that while the protocols in place are efficient, the testing and validation of new tools and approaches would be more beneficial at different levels of play where the incidence rates of concussions are higher. In environments with a greater frequency of concussions, the robustness and reliability of these protocols can be more thoroughly evaluated, ensuring they provide optimal protection and care for athletes.

CONCLUSION

The incidence of concussions is low in professional soccer tournaments. Protocols are necessary to protect players and educate sports professionals. However, their validation is difficult given the low incidence of concussions at this level of competition. Our proposed protocol helps unify a basic approach in the field and an advanced approach in any emergency department, providing better detection of concussions and improved outcomes for players. This protocol should be validated in populations with higher incidence rates to demonstrate its effectiveness.

Contemporary diagnosis and management of mild TBI (concussions): What you need to know

ABSTRACT

Concussion is a common injury in children and adolescents and is a form of mild traumatic brain injury that surgeons will see in their acute care practice. With a rapidly changing evidence base for diagnosis and management, we will focus on the importance of timely identification and diagnosis, as well as the early initiation of active management of pediatric concussion immediately after injury through recovery. This approach involves the application of targeted therapies for specific deficits identified after concussion, addressing the individual pattern of symptoms experienced by patients following concussion. We will review what is known about the underlying pathophysiology that drives the clinical manifestations of concussion, the targeted clinical assessments that can both aid in the diagnosis of concussion, as well as drive the active rehabilitation of deficits seen after concussion. The standardized approach to the return to activities will also be described, including return to learning and sports.

Concussion-Related Disruptions to Hub Connectivity in the Default Mode Network Are Related to Symptoms and Cognition

Concussions present with a myriad of symptomatic and cognitive concerns; however, the relationship between these functional disruptions and the underlying changes in the brain are not yet well understood. Hubs, or brain regions that are connected to many different functional networks, may be specifically disrupted after concussion. Given the implications in concussion research, we quantified hub disruption within the default mode network (DMN) and between the DMN and other brain networks. We collected resting-state functional magnetic resonance imaging data from collegiate student-athletes (n = 44) at three time points: baseline (before beginning their athletic season), acute post-injury (approximately 48h after a diagnosed concussion), and recovery (after starting return-to-play progression, but before returning to contact). We used self-reported symptoms and computerized cognitive assessments collected across similar time points to link these functional connectivity changes to clinical outcomes. Concussion resulted in increased connectivity between regions within the DMN compared with baseline and recovery, and this post-injury connectivity was more positively related to symptoms and more negatively related to visual memory performance compared with baseline and recovery. Further, concussion led to decreased connectivity between DMN hubs and visual network non-hubs relative to baseline and recovery, and this post-injury connectivity was more negatively related to somatic symptoms and more positively related to visual memory performance compared with baseline and recovery. Relationships between functional connectivity, symptoms, and cognition were not significantly different at baseline versus recovery. These results highlight a unique relationship between self-reported symptoms, visual memory performance, and acute functional connectivity changes involving DMN hubs after concussion in athletes. This may provide evidence for a disrupted balance of within- and between-network communication highlighting possible network inefficiencies after concussion. These results aid in our understanding of the pathophysiological disruptions after concussion and inform our understanding of the associations between disruptions in brain connectivity and specific clinical presentations acutely post-injury.

Prevalence, diagnosis and management of musculoskeletal disorders in elite athletes: A mini-review

Musculoskeletal injuries in elite sports are ones of the most impact issue because their remarkable impact on performance caused by drastic absence of training and competition and a progressive deterioration in physical health, emotional and social athletes' dimensions. Also, the prevalence of epidemiologic research found an incidence of musculoskeletal disorders vary within sports and in elite athletes which is even higher as a consequence of higher demand physical performance. This way, the loss of physical performance due to an sport injury impacts not only the individual economic sphere of the professional but also that ofsports entities, reaching, according to some studies, a loss estimated in the range of 74.7 million pounds. Thus, the purpose of this article is to review and to provide an overview of the most common musculoskeletal injuries in elite sports precipitating factors, clinical presentation, evidence-based diagnostic evaluation, and treatment recommendations with a view to preventing medical conditions or musculoskeletal injuries that may alter performance and general health in the elite athletes.

Decreased Concussion Incidence Following the Implementation of the Targeting Rules: An Updated Epidemiology of National Football League Concussions From 2017 to 2022

The incidence of concussions in football, and the ensuing media attention, has garnered scientific investigation, prompted technological advances in protective gear, and altered the rules of the game, including the National Football League's (NFL) "Targeting" rule, which began in 2018, but the impact of these changes is unclear. This study aims to describe the epidemiology of concussions that occurred in five NFL seasons from the 2017-2018 season through the 2021-2022 season and characterize positional differences in rate and games missed. There was a significant decrease (p = 0.02) in total concussions between the 2017-2018 season (102 concussions) and the remaining four seasons (average of 73.80 concussions per year), accounting for a 38% decrease. Offensive and defensive units had decreased concussion rates and average games missed per concussion. Defensive backs (10.46 per 1,000 athlete exposures (AEs)) and tight ends (10.69 per 1,000 AEs) had the highest concussion rates, and the defensive line had the highest average games missed per concussion at 3.97. The introduction of the "Targeting" rule and other rule changes in the NFL in 2018 correlated with a decrease in total concussions per year, total games missed due to concussion, and average games missed per concussion. Offense and defense experienced similar reductions in concussion incidence and severity. Overall, the updated epidemiology of NFL concussions suggests that the incidence of concussions has decreased; however, players continue to experience concussions that require them to miss multiple games.

Traumatic brain injury and Alzheimer's Disease biomarkers: A systematic review of findings from amyloid and tau positron emission tomography (PET)

Traumatic brain injury (TBI) has been discussed as a risk factor for Alzheimer's disease (AD) due to its association with dementia risk and earlier cognitive symptom onset. However, the mechanisms behind this relationship are unclear. Some studies have suggested TBI may increase pathological protein deposition in an AD-like pattern; others have failed to find such associations. This review covers literature that uses positron emission tomography (PET) of amyloid-β and/or tau to examine subjects with history of TBI who are at risk for AD due to advanced age. A comprehensive literature search was conducted on January 9, 2023, and 24 resulting citations met inclusion criteria. Common methodological concerns included small samples, limited clinical detail about subjects' TBI, recall bias due to reliance on self-reported TBI, and an inability to establish causation. For both amyloid and tau, results were widespread but inconsistent. The regions which showed the most compelling evidence for increased amyloid deposition were the cingulate gyrus, cuneus/precuneus, and parietal lobe. Evidence for increased tau was strongest in the medial temporal lobe, entorhinal cortex, precuneus, and frontal, temporal, parietal, and occipital lobes. However, conflicting findings across most regions of interest in both amyloid- and tau-PET studies indicate the critical need for future work in expanded samples and with greater clinical detail to offer a clearer picture of the relationship between TBI and protein deposition in older subjects at risk for AD.

Psychometric Properties of Computerized Cognitive Tools and Standard Neuropsychological Tests Used to Assess Sport Concussion: A Systematic Review

Athletic programs are more frequently turning to computerized cognitive tools in order to increase efficiencies in concussion assessment. However, assessment using a traditional neuropsychological test battery may provide a more comprehensive and individualized evaluation. Our goal was to inform sport clinicians of the best practices for concussion assessment through a systematic literature review describing the psychometric properties of standard neuropsychological tests and computerized tools. We conducted our search in relevant databases including Ovid Medline, Web of Science, PsycINFO, and Scopus. Journal articles were included if they evaluated psychometric properties (e.g., reliability, sensitivity) of a cognitive assessment within pure athlete samples (up to 30 days post-injury). Searches yielded 4,758 unique results. Ultimately, 103 articles met inclusion criteria, all of which focused on adolescent or young adult participants. Test-retest reliability estimates ranged from .14 to .93 for computerized tools and .02 to .95 for standard neuropsychological tests, with strongest correlations on processing speed tasks for both modalities, although processing speed tasks were most susceptible to practice effects. Reliability was improved with a 2-factor model (processing speed and memory) and by aggregating multiple baseline exams, yet remained below acceptable limits for some studies. Sensitivity to decreased cognitive performance within 72 h of injury ranged from 45%-93% for computerized tools and 18%-80% for standard neuropsychological test batteries. The method for classifying cognitive decline (normative comparison, reliable change indices, regression-based methods) affected sensitivity estimates. Combining computerized tools and standard neuropsychological tests with the strongest psychometric performance provides the greatest value in clinical assessment. To this end, future studies should evaluate the efficacy of hybrid test batteries comprised of top-performing measures from both modalities.

Preliminary Development of a Brainwave Model for K1 Kickboxers Using Quantitative Electroencephalography (QEEG) with Open Eyes

K1 kickboxing fighting is characterised by high injury rates due to the low restrictions of fighting rules. In recent years, much attention has been paid to research on changes in brain function among athletes, including those in combat sports. One of the tools that are likely to help diagnose and assess brain function is quantitative electroencephalography (QEEG). Therefore, the aim of the present study was an attempt to develop a brainwave model using quantitative electroencephalography in competitive K1 kickboxers. A total of thirty-six male individuals were purposefully selected and then comparatively divided into two groups. The first group consisted of specialised K1 kickboxing athletes exhibiting a high level of sports performance (experimental group, n = 18, mean age: 29.83 ± 3.43), while the second group comprised healthy individuals not training competitively (control group, n = 18, mean age: 26.72 ± 1.77). Body composition assessment was performed in all participants before the main measurement process. Measurements were taken for kickboxers during the de-training period, after the sports competition phase. Quantitative electroencephalography of Delta, Theta, Alpha, sensimotor rhytm (SMR), Beta1 and Beta2 waves was performed using electrodes placed on nine measurement points (frontal: FzF3F4, central: CzC3C4, and parietal: PzP3P4) with open eyes. In the course of the analyses, it was found that the level of brain activity among the study population significantly differentiated the K1 formula competitors compared with the reference standards and the control group in selected measurement areas. For kickboxers, all results of the Delta amplitude activity in the area of the frontal lobe were significantly above the normative values for this wave. The highest value was recorded for the average value of the F3 electrode (left frontal lobe), exceeding the norm by 95.65%, for F4 by 74.45% and Fz by 50.6%, respectively. In addition, the Alpha wave standard value for the F4 electrode was exceeded by 14.6%. Normative values were found for the remaining wave amplitudes. Statistically significant differentiation of results, with a strong effect (d = 1.52-8.41), was shown for the activity of Delta waves of the frontal area and the central part of the parietal area (Fz,F3,F4,Cz-p < 0.001), Theta for the frontal area as well as the central and left parietal lobes (Fz,F3,F4-p < 0.001, Cz-p = 0.001, C3-p = 0.018; d = 1.05-3.18), Alpha for the frontal, parietal and occipital areas (for: Fz,F3-p < 0.001, F4-p = 0.036, Cz-p < 0.001, C3-p = 0.001, C4-p = 0.025, Pz-p = 0.010, P3-p < 0.001, P4-p = 0.038; d = 0.90-1.66), SMR for the central parietal and left occipital lobes (Cz-p = 0.043; d = 0.69, P3-p < 0.001; d = 1.62), Beta for the frontal area, occipital and central lobes and left parietal segment (Fz,F3-p < 0.001, F4-p = 0.008, Cz, C3, Pz, P3,P4-p < 0.001; d = 1.27-2.85) and Beta 2 for all measurement areas (Fz, F3, F4, Cz, C3, C4, Pz, P3, P4-p < 0.001; d = 1.90-3.35) among the study groups. Significantly higher results were shown in the kickboxer group compared to the control. In addition to problems with concentration or over-stimulation of neural structures, high Delta waves, with elevated Alpha, Theta and Beta 2 waves, can cause disorders in the limbic system and problems in the cerebral cortex.

Characteristics of binocular vision and oculomotor function among sports-concussed athletes

Purpose

To compare the binocular vision and oculomotor function between sports-concussed athletes and aged-matched controls.

Methods

Thirty mild concussed athletes were recruited and compared with aged-matched controls. All the participants underwent a comprehensive ocular assessment followed by an oculomotor assessment which included tests for accommodation, vergence, eye movements, and reading parameters.

Results

Three categories of oculomotor-based deficits were found: convergence insufficiency (40%), accommodative insufficiency (25%), and oculomotor-based reading dysfunctions (20%). A statistically significant reduction in the mean ± SD of the following parameters was noted in concussed athletes v/s controls:- binocular accommodative amplitude: 7.13 ± 1.59 v/s 15.35 ± 2.95 (P < 0.001), convergence amplitude: 14.23 ± 5.00 v/s 5.65 ± 0.90 (P < 0.001), positive fusional vergence for distance: 21.17 ± 8.97 v/s 31.32 ± 6.23 (P < 0.001), vergence facility: 6.47 ± 1.47 v/s 11.84 ± 1.00 (P < 0.001), accommodative facility: 7.10 ± 4.57 v/s 11.67 ± 1.83 (P < 0.001), reading speed: 66.97 ± 17.82 v/s 144.13 ± 24.45 (P = 0.03) and Developmental Eye Movement ratio: 1.40 ± 0.19 v/s 1.17 ± 0.06 (P < 0.001).

Conclusion

Concussions caused by sports have a considerable impact on binocular vision and oculomotor parameters. These findings have substantial therapeutic implications in terms of establishing a periodic screening program for athletes so that essential therapy can be provided for a better outcome.

Regional variances depict a unique glial-specific inflammatory response following closed-head injury

Mild traumatic brain injuries (mTBI) constitute a significant health concern with clinical symptoms ranging from headaches to cognitive deficits. Despite the myriad of symptoms commonly reported following this injury, there is still a lack of knowledge on the various pathophysiological changes that occur. Preclinical studies are at the forefront of discovery delineating the changes that occur within this heterogeneous injury, with the emergence of translational models such as closed-head impact models allowing for further exploration of this injury mechanism. In the current study, male rats were subjected to a closed-head controlled cortical impact (cCCI), producing a concussion (mTBI). The pathological effects of this injury were then evaluated using immunoflourescence seven days following. The results exhibited a unique glial-specific inflammatory response, with both the ipsilateral and contralateral sides of the cortex and hippocampus showing pathological changes following impact. Overall these findings are consistent with glial changes reported following concussions and may contribute to subsequent symptoms.

Sports-related concussion: assessing the comprehension, collaboration, and contribution of chiropractors

Over the last 2 decades, sports-related concussion (SRC) awareness and management have evolved from an emphasis on complete cognitive and physical rest to evidence-based protocols and interventions. Chiropractors are primary care providers with exposure to athletes and teams in collision sports and, in addition, manage patients with concussion-like symptoms including neck pain, dizziness, and headache. With SRC frequently occurring in the absence of a medical practitioner, the role of allied health practitioners like chiropractors should be emphasised when it comes to the recognition, assessment, and management of SRC. This commentary discusses the potential contribution of chiropractors in SRC and the specific role their expertise in the cervical spine may play in symptom evaluation and management. A PubMed and Google scholar review of the chiropractic SRC literature suggests that the chiropractic profession appears under-represented in concussion research in athletic populations compared to other medical and allied health fields. This includes an absence of chiropractic clinicians with a focus on SRC participating in the Concussion in Sport Group (CISG) and the International Consensus Conferences on Concussion. Furthermore, with evolving evidence suggesting the importance of cervicogenic manifestations in SRC, there is an opportunity for chiropractors to participate in SRC diagnosis and management more fully and contribute scientifically to an area of specialised knowledge and training. With a dearth of chiropractic orientated SRC science, clinical SRC expertise, and clinical chiropractic representation in the CISG; it is incumbent on chiropractic clinicians and scientists to take up this opportunity through meaningful contribution and involvement in the SRC field.

The Incidence, Cost, and Burden of Concussion in Women's Rugby League and Rugby Union: A Systematic Review and Pooled Analysis

BACKGROUND

The extent of concussion injury in the rugby codes for women is unclear.

OBJECTIVE

Our aim was to review all published studies reporting concussion injuries from match and training participation in rugby codes and report the pooled data estimates for rugby league and union concussion injury epidemiology.

METHODS

We conducted a systematic literature analysis of concussion in rugby league and rugby union for published studies from January 1990 to July 2021. Data from 16 studies meeting the inclusion criteria were extracted for women's concussion injuries and were subsequently pooled. Costs from Accident Compensation Corporation (ACC) data were attributed to the results to provide cost estimates.

RESULTS

The pooled analysis match injury incidence of women's concussion was higher for rugby league (10.3 per 1000 match hours) than rugby 15 s (2.8 per 1000 match hours) or rugby 7 s (8.9 per 1000 match hours). There was a fourfold difference in the pooled incidence of concussion in women's rugby league (risk ratio [RR] 4.53, 95% confidence interval [CI] 1.8-11.3]; p = 0.0001) when compared with rugby 15 s. There was also a ninefold higher risk of a concussion during match participation compared with training participation for women's rugby 15 s (RR 9.3, 95% CI 1.29-66.78; p = 0.0070). The total estimated costs for the concussions reported were NZ$1,235,101. For rugby 7 s, the pooled concussive injury burden was 33.2 days.

CONCLUSIONS

Our pooled analysis clarified the extent of concussion injury and the possible associated costs at several levels of the game for women's rugby codes. The pooled mean days lost because of concussions was 33 days. As this was considerably longer than the 7- to 10-day expected timeframe outlined in the Concussion in Sport Consensus statement, these guidelines need to be updated to include sex-specific differences.

Towards defining biomarkers to evaluate concussions using virtual reality and a moving platform (BioVRSea)

Current diagnosis of concussion relies on self-reported symptoms and medical records rather than objective biomarkers. This work uses a novel measurement setup called BioVRSea to quantify concussion status. The paradigm is based on brain and muscle signals (EEG, EMG), heart rate and center of pressure (CoP) measurements during a postural control task triggered by a moving platform and a virtual reality environment. Measurements were performed on 54 professional athletes who self-reported their history of concussion or non-concussion. Both groups completed a concussion symptom scale (SCAT5) before the measurement. We analyzed biosignals and CoP parameters before and after the platform movements, to compare the net response of individual postural control. The results showed that BioVRSea discriminated between the concussion and non-concussion groups. Particularly, EEG power spectral density in delta and theta bands showed significant changes in the concussion group and right soleus median frequency from the EMG signal differentiated concussed individuals with balance problems from the other groups. Anterior-posterior CoP frequency-based parameters discriminated concussed individuals with balance problems. Finally, we used machine learning to classify concussion and non-concussion, demonstrating that combining SCAT5 and BioVRSea parameters gives an accuracy up to 95.5%. This study is a step towards quantitative assessment of concussion.

How a Gel Can Protect an Egg: A Flexible Hydrogel with Embedded Starch Particles Shields Fragile Objects Against Impact

Hydrogels are networks of polymer chains that are swollen in water. In recent years, several routes have been devised to make hydrogels that are flexible and bendable. This work investigates whether such flexible gels can be wrapped around brittle or fragile objects (such as an egg or a fruit) and protect the objects against impact. We study gels made by either physical cross-linking (e.g., gelatin) or chemical cross-linking (e.g., acrylamide) and the same gels with various particulate additives. None of the bare gels are protective, and nanoparticles like iron oxide or silica do not help. However, the addition of starch granules to the above gels greatly enhances their protective abilities. When a load strikes a gelatin gel containing 20% starch, the peak impact force is reduced by 25% when compared to a bare gel without the starch. Correspondingly, the coefficient of restitution (COR) is also lowered by the presence of starch (i.e., a ball bounces less on a starch-bearing gel). We correlate the impact-absorbing effects of starch granules to their ability to shear-thicken water. When starch granules are gelatinized by heat, they no longer give rise to shear-thickening, and in turn, their protective ability in a gel is also eliminated. Our research can guide the rational design of protective coatings or armor for fragile objects, which could be applied in the sports, defense, and consumer sectors.

Safeguarding Athletes Against Head Injuries Through Advances in Technology: A Scoping Review of the Uses of Machine Learning in the Management of Sports-Related Concussion

Sports injury prevention is an important part of the athlete welfare and safeguarding research field. In sports injury prevention, sport-related concussion (SRC) has proved to be one of the most difficult and complex injuries to manage in terms of prevention, diagnosis, classification, treatment and rehabilitation. SRC can cause long-term health issues and is a commonly reported injury in both adult and youth athletes around the world. Despite increased knowledge of the prevalence of SRC, very few tools are available for diagnosing SRC in athletic settings. Recent technological innovations have resulted in different machine learning and deep learning methodologies being tested to improve the management of this complex sports injury. The purpose of this article is to summarize and map the existing research literature on the use of machine learning in the management of SRC, ascertain where there are gaps in the existing research and identify recommendations for future research. This is explored through a scoping review. A systematic search in the three electronic databases SPORTDiscus, PubMed and Scopus identified an initial 522 studies, of which 24 were included in the final review, the majority of which focused on machine learning for the prediction and prevention of SRC (N = 10), or machine learning for the diagnosis and classification of SRC (N = 11). Only 3 studies explored machine learning approaches for the treatment and rehabilitation of SRC. A main finding is that current research highlights promising practical uses (e.g., more accurate and rapid injury assessment or return-to-sport participation criteria) of machine learning in the management of SRC. The review also revealed a narrow research focus in the existing literature. As current research is primarily conducted on male adolescents or adults from team sports in North America there is an urgent need to include wider demographics in more diverse samples and sports contexts in the machine learning algorithms. If research datasets continue to be based on narrow samples of athletes, the development of any new diagnostic and predictive tools for SRC emerging from this research will be at risk. Today, these risks appear to mainly affect the health and safety of female athletes.

Saffron extract and crocin exert anti-inflammatory and anti-oxidative effects in a repetitive mild traumatic brain injury mouse model

Saffron Crocus sativus L. (C. sativus) is a flower from the iridaceous family. Crocin, saffron’s major constituent, and saffron have anti-oxidative and anti-inflammatory activities. In this work, the neuroprotective effects of saffron and crocin are being investigated in a repetitive mild traumatic brain injury (rmTBI) mouse model. A weight drop model setup was employed to induce mild brain injury in male albino BABL/c mice weighing 30–40 g. Saffron (50 mg/kg) and crocin (30 mg/kg) were administrated intraperitoneally 30 min before mTBI induction. Behavioral tests were conducted to assess behavioral deficits including the modified neurological severity score (NSS), Morris water maze (MWM), pole climb test, rotarod test, and adhesive test. The levels of TNF alpha (TNF-α), interferon-gamma (IFN-γ), myeloperoxidase activity (MPO), malonaldehyde (MDA), and reduced glutathione (GSH) were measured. Histological analysis of different brain parts was performed. Both saffron and crocin demonstrated marked improved neurological, cognitive, motor, and sensorimotor functions. Besides, both compounds significantly reduced the oxidative stress and inflammatory processes. No abnormal histological features were observed in any of the injured groups. Saffron extract and crocin provide a neuroprotective effect in a mouse model of rmTBI by decreasing oxidative stress, inflammatory responses, and behavioral deficits.

Genetic Factors That Could Affect Concussion Risk in Elite Rugby

Elite rugby league and union have some of the highest reported rates of concussion (mild traumatic brain injury) in professional sport due in part to their full-contact high-velocity collision-based nature. Currently, concussions are the most commonly reported match injury during the tackle for both the ball carrier and the tackler (8-28 concussions per 1000 player match hours) and reports exist of reduced cognitive function and long-term health consequences that can end a playing career and produce continued ill health. Concussion is a complex phenotype, influenced by environmental factors and an individual's genetic predisposition. This article reviews concussion incidence within elite rugby and addresses the biomechanics and pathophysiology of concussion and how genetic predisposition may influence incidence, severity and outcome. Associations have been reported between a variety of genetic variants and traumatic brain injury. However, little effort has been devoted to the study of genetic associations with concussion within elite rugby players. Due to a growing understanding of the molecular characteristics underpinning the pathophysiology of concussion, investigating genetic variation within elite rugby is a viable and worthy proposition. Therefore, we propose from this review that several genetic variants within or near candidate genes of interest, namely APOE, MAPT, IL6R, COMT, SLC6A4, 5-HTTLPR, DRD2, DRD4, ANKK1, BDNF and GRIN2A, warrant further study within elite rugby and other sports involving high-velocity collisions.

Concussion Management for the Orthopaedic Surgeon

Orthopaedic surgeons functioning as team physicians are in a unique position to recognize subtle changes in an athlete's behavior and may be the first responders to concussions at sporting events. The rate of sports-related concussions has increased over the past few decades, necessitating that orthopaedic team physicians gain a greater understanding of the diagnosis and management of this condition. During the sideline evaluation, life-threatening injuries must be ruled out before concussion evaluation may take place. In most cases, patients experience a resolution of symptoms within a week; however, a smaller subset of patients experience persistent symptoms. Physicians covering sporting events must remain current regarding recommendations for treating sports-related concussions and must document their management plan to minimize potential harm to an athlete.

Patterns of head impact exposure in men's and women's collegiate club water polo

OBJECTIVES

Recent reports have demonstrated a risk of concussion and subconcussive head impacts in collegiate varsity and international elite water polo. We sought to characterize patterns of head impact exposure at the collegiate club level of water polo.

DESIGN

Prospective cohort study.

METHODS

Head impact sensors (SIM-G, Triax Technologies) were worn by men's (n=16) and women's (n=15) collegiate club water polo players during 11 games. Peak linear acceleration (PLA) and peak rotational acceleration (PRA) of head impacts were recorded by the sensors. Two streams of competition video were used to verify and describe the nature of head impacts.

RESULTS

Men's players sustained 52 verified head impacts of magnitude 39.7±16.3g PLA and 5.2±3.2 krad/s2 PRA, and women's players sustained 43 verified head impacts of magnitude 33.7±12.6g PLA and 4.0±2.8krad/s2 PRA. Impacts sustained by men had greater PLA than those sustained by women (p=.045). Athletes were impacted most frequently at the offensive center position, to the back of the head, and by an opponent's torso or limb.

CONCLUSIONS

Our cohort of male and female athletes sustained relatively infrequent head impacts during water polo competitions played at the collegiate club level. The amount of head impact exposure in our cohort was dependent on player position, with offensive centers prone to sustaining the most impacts. Head impact sensors are subject to large amounts of false positives and should be used in conjunction with video recordings to verify the validity of impact data.

Preliminary Validation of an Abbreviated Acute Concussion Symptom Checklist Using Item Response Theory

BACKGROUND

Symptom assessment is a critical component of concussion diagnosis and management, with item selection primarily driven by clinical judgment or expert consensus. We recently demonstrated that concussion symptoms assessed by the Sport Concussion Assessment Tool (SCAT) are essentially unidimensional, implying that overall symptom severity may be accurately estimated with relatively few questions. Briefer, evidence-based forms for symptom assessment would provide clinicians flexibility.

PURPOSE

To develop and validate an abbreviated assessment of general concussion symptom severity using item response theory analyses.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

Broad clinical assessments (SCAT3, Immediate Post-concussion and Cognitive Testing, Balance Error Scoring System, and Brief Symptom Inventory-18 Global Severity Index) were completed by 265 injured athletes and 235 matched teammate controls at 24 to 48 hours and 8, 15, and 45 days after concussion. Symptom checklist short forms (3-14 items from the original 22) were selected using item response theory item information curves. Internal consistency reliability (Cronbach alpha), correlation with criterion measures assessed concurrently (ie, acute neurocognitive performance, balance, and emotional symptoms), predictive validity (correlations with symptom duration), and differences between concussed and control groups (Cohen d) were examined across forms. Sensitivity and false-positive rates of the forms were estimated and compared using reliable change indices derived from controls.

RESULTS

Across the 3- to 22-item forms, internal consistency was excellent (Cronbach alphas, 0.90-0.94). Clinical correlations were significant (P≤ .017) and to similar degrees for all short forms. Group difference confidence intervals overlapped across forms at 24- to 48-hour (Cohen d, 1.27-1.51) and 8-day follow-up (Cohen d, 0.31-0.44). Sensitivity remained similar across short forms, with a low false-positive rate in controls.

CONCLUSION

Our findings suggest that even an ultrashort (3-item) inventory provides sufficiently reliable and valid estimates of overall concussion symptom severity 24 to 48 hours after injury. Future revisions of the SCAT could eliminate inefficient items, although replication in larger samples and extension to other postinjury time points are warranted.

Sex-Related Differences in the Effects of Sports-Related Concussion: A Review

Sports-related concussion is a serious health challenge, and females are at higher risk of sustaining a sports-related concussion compared to males. Although there are many studies that investigate outcomes following concussion, females remain an understudied population, despite representing a large proportion of the organized sports community. In this review, we provide a summary of studies that investigate sex-related differences in outcome following sports-related concussion. Moreover, we provide an introduction to the methods used to study sex-related differences after sports-related concussion, including common clinical and cognitive measures, neuroimaging techniques, as well as biomarkers. A literature search inclusive of articles published to March 2020 was performed using PubMed. The studies were reviewed and discussed with regard to the methods used. Findings from these studies remain mixed with regard to the effect of sex on clinical symptoms, concussion-related alterations in brain structure and function, and recovery trajectories. Nonetheless, there is initial evidence to suggest that sex-related differences following concussion are important to consider in efforts to develop objective biomarkers for the diagnosis and prognosis of concussion. Additional studies on this topic are, however, clearly needed to improve our understanding of sex-related differences following concussion, as well as to understand their neurobiological underpinnings. Such studies will help pave the way toward more personalized clinical management and treatment of sports-related concussion.

Concussion knowledge, attitudes and behaviour in equestrian athletes

OBJECTIVE

To determine knowledge, attitudes and behaviour towards concussion in adult equestrian athletes.

DESIGN

Nationwide, cross-sectional, questionnaire.

METHODS

Participants were recruited via advertisements circulated through social media, community presentations and equestrian organisations. Participants were sent a web link to an online questionnaire previously designed for high school athletes and modified to ensure relevance to equestrian activities. The percentage of correct responses per item and a total knowledge score were calculated. Differences in concussion knowledge by age, sex, level of experience and previous history of concussion were explored using t-tests, 95% confidence intervals (CI) and effect sizes.

RESULTS

The questionnaire was completed by 1486 participants (Mean age=39.1±15.4). Knowledge of what concussion was, how to recognise it and key symptoms (except poor sleep) was high (>80%). In contrast, awareness of guidelines was moderate (56%) and inability of helmets to prevent concussion was low (12%). Significantly higher levels of knowledge of concussion were identified in females compared with males (t=-6.55 p<0.001, 95%CI=-3.26 to -1.75). The majority (87%) of participants reported that a helmet should be replaced after a fall, yet 46% reported re-using a helmet following a hit to the head.

CONCLUSIONS

Knowledge of and attitudes towards concussion were positive. However, there were knowledge gaps and discrepancies between some attitudes and behaviour on some aspects of concussion. Targeted campaigns to promote awareness of concussion and improve recognition and onward management are needed. Education related to equestrian activities such as helmet use and injury mechanisms is needed to change behaviour and minimise the risk of injury.

Awareness and Perceived Value of Eye Tracking Technology for Concussion Assessment among Sports Medicine Clinicians: A Multinational Study

Objective: The awareness of concussion as a serious and frequently occurring sports injury and its management has evolved significantly. One viable objective diagnostic tool is eye tracking technology. The authors hypothesized that while clinicians may be aware that assessing eye movements in concussed athletes can be beneficial, it is possible that, due to the novelty of the eye tracking technology and limited exposure, only a few actually use it in their practice. The study aimed to assess the awareness of eye movement deficits associated with concussion amongst sports medicine clinicians and to determine the utilization and perceptions of the eye tracking technology for concussion diagnosis.Methods: An online 18-question survey was distributed internationally from January until December 2017 and completed by 171 sports medicine clinicians (sport physicians, therapists, general practitioners, neuropsychologists) from 32 countries.Results: Respondents indicated that subjectivity of assessments remained a major limitation of established diagnostic tools. Eye tracking technology, despite its potential to attenuate this limitation, was only used by 12% of respondents. To diagnose concussion, 77% did not use any eye movement assessment tools other than own clinical assessment. With the exception of abnormal pupil light reflex, which was checked by 68%, eye movement deficits were inspected by less than half of the respondents (46.3 ± 12%).Conclusion: Even among sports medicine clinicians who regularly attend to patients with concussions, there is insufficient awareness that concussion can lead to abnormal eye tracking behavior. Lack of exposure to the sensitive eye tracking equipment may be a limiting factor for using eye movement metrics for concussion diagnostics. Facilitating the awareness of objective methods, like eye tracking technology, may help assure the appropriate continuum of identification and treatment for concussed athletes. Increasing educational opportunities and practical experience of clinicians regarding concussive symptoms and potential innovative technology is strongly advocated.

Concussion History and Career Status Influence Performance on Baseline Assessments in Elite Football Players

OBJECTIVE

To determine if concussion history and career status is associated with neurocognitive performance in elite football players.

METHODS

The study design was a cross-sectional single assessment. Fifty-seven elite football players (age 29.39 ± 7.49 years) categorized as draft prospects, active professional players, and retired professional players were assessed on the Sport Concussion Assessment Tool - third edition (SCAT-3), in an outpatient therapy setting.

RESULTS

Common symptoms were the following: fatigue (45.6%), trouble falling asleep (35.1%), difficulty remembering (33.3%) and irritability (22.8%); 36.8% reported no symptoms. The low concussion (0-1) group reported fewer symptoms (U = 608.50, p < .001), less symptom severity (U = 598.00, p = -.001), and produced greater scores on the Standardized Assessment of Concussion (SAC) total scores compared to the multiple concussion (2+) group (U = 253.00, p = .024), but no differences were observed on modified Balance Error Scoring System (m-BESS) scores (U = 501.50, p = .066) on the Mann-Whitney U test. The Kruskal-Wallis test and post-hoc analysis indicated retired players were significantly different from draft prospects and current professional players for total symptom scores (p < .001), total symptom severity (p < .001), SAC total scores (p = .030), and m-BESS (p < .001).

CONCLUSIONS

Concussion history and career status appear associated with total symptoms, symptom severity, performance on the SAC, and the m-BESS in elite football players. With this in mind, future research is recommended to determine longitudinal impact for elite football players.

Development of an Eco-Friendly Head Impact Protection Device

Nowadays, the number of people practising contact sports has increased. In many of them, using head protective equipment is not mandatory, even if the use of headbands could increase the level of safety regarding several types of traumatic brain injuries. Many commercial solutions are currently available, based on plastic-based foams providing a decent level of protection and comfort to the user. This work introduces the use of agglomerated cork as an eco-friendly alternative to synthetic foams but at least keeping safety levels. Cork is a natural cellular material that has been showing excellent crashworthiness properties. In this study, cork agglomerate density is carefully chosen to be incorporated into a protective headband. Results are compared against three other commercial headbands. For each one, the risk of brain injury was analysed for different injury thresholds and impact energies. The results clearly demonstrate that the cork-based apparel may provide comparable, and in some cases, better performances, outlasting the commercial ones.

An Examination of 4 Questions Assessing Self-reported Concussions Among High School Students Participating in Team Sports

OBJECTIVE

Current prevalence estimates of youth sports-related concussions are inconsistent because of variation in methodology and potentially unreported concussions.

METHODS

In 2013, Connecticut, Ohio, and Utah each added different questions that assessed self-reported concussions to the Youth Risk Behavior Survey. Two questions referenced recognition of a concussion by the student, 1 referenced identification by a doctor, and 1 referenced suspicion by a coach. Chi-square analyses were used to identify whether there was an association between demographic characteristics and the concussion questions among high school students who played on at least 1 sports team.

RESULTS

The percentage of students who reported concussions ranged from 17.6% to 20.1%.

CONCLUSIONS

These estimates are higher than rates of concussions diagnosed in emergency departments or reported by athletic trainers but were similar across the 4 questions. The field would benefit from a better understanding of the impact of question wording and format on estimates of concussion prevalence.

Spreading Depolarizations Occur in Mild Traumatic Brain Injuries and Are Associated with Postinjury Behavior

Millions of people suffer mild traumatic brain injuries (mTBIs) every year, and there is growing evidence that repeated injuries can result in long-term pathology. The acute symptoms of these injuries may or may not include the loss of consciousness but do include disorientation, confusion, and/or the inability to concentrate. Most of these acute symptoms spontaneously resolve within a few hours or days. However, the underlying physiological and cellular mechanisms remain unclear. Spreading depolarizations (SDs) are known to occur in rodents and humans following moderate and severe TBIs, and SDs have long been hypothesized to occur in more mild injuries. Using a closed skull impact model, we investigated the presence of SDs immediately following a mTBI. Animals remained motionless for multiple minutes following an impact and once recovered had fewer episodes of movement. We recorded the defining electrophysiological properties of SDs, including the large extracellular field potential shifts and suppression of high-frequency cortical activity. Impact-induced SDs were also associated with a propagating wave of reduced cerebral blood flow (CBF). In the wake of the SD, there was a prolonged period of reduced CBF that recovered in approximately 90 min. Similar to SDs in more severe injuries, the impact-induced SDs could be blocked with ketamine. Interestingly, impacts at a slower velocity did not produce the prolonged immobility and did not initiate SDs. Our data suggest that SDs play a significant role in mTBIs and SDs may contribute to the acute symptoms of mTBIs.

Helmet Use and Risk-Taking Behavior Among Skiers and Snowboarders

OBJECTIVE

To characterize factors associated with helmet use and risk-taking behavior among recreational skiers and snowboarders.

DESIGN

Observational study.

SETTING

Large, western United States mountain resort.

PARTICIPANTS

1285 male and female recreational skiers and snowboarders were interviewed during a single winter ski season.

INDEPENDENT VARIABLES

Helmet use, demographic, and sport-related characteristics.

MAIN OUTCOME MEASURES

Brief sensation seeking scale (BSSS) as a measure of risk-taking behavior and self-reported risk compensation.

RESULTS

Of the respondents (N = 1285), 17.5%, 12.5%, and 70.0% reported that they never, sometimes, and always wore a helmet, respectively. Multiple linear regression analysis showed that individuals reporting sometimes wearing a helmet had significantly higher BSSS scores than those reporting never wearing a helmet (P = 0.031) or always wearing it (P = 0.018). Male gender, younger age, snowboarding, higher perceived sport ability, more days per year skiing or snowboarding, and more time spent in the terrain park were significantly associated with higher BSSS scores (P < 0.05). Logistic regression analysis focusing on subgroups of respondents who reported either sometimes or always wearing a helmet indicated that the odds of taking more risks when wearing a helmet for inconsistent helmet users was 75% higher than the odds for those who reported always wearing a helmet (P = 0.06).

CONCLUSIONS

Inconsistent helmet users have characteristics of risk-taking behavior and risk compensation. Male gender, younger age, snowboarding, higher perceived sport ability, and more time spent on the mountain and in the terrain park are also important determinants of risk-taking behavior.

A review of impact testing methods for headgear in sports: Considerations for improved prevention of head injury through research and standards

Standards for sports headgear were introduced as far back as the 1960s and many have remained substantially unchanged to present day. Since this time, headgear has virtually eliminated catastrophic head injuries such as skull fractures and changed the landscape of head injuries in sports. Mild traumatic brain injury (mTBI) is now a prevalent concern and the effectiveness of headgear in mitigating mTBI is inconclusive for most sports. Given that most current headgear standards are confined to attenuating linear head mechanics and recent brain injury studies have underscored the importance of angular mechanics in the genesis of mTBI, new or expanded standards are needed to foster headgear development and assess headgear performance that addresses all types of sport-related head and brain injuries. The aim of this review is to provide a basis for developing new sports headgear impact tests for standards by summarizing and critiquing: 1) impact testing procedures currently codified in published headgear standards for sports and 2) new or proposed headgear impact test procedures in published literature and/or relevant conferences. Research areas identified as needing further knowledge to support standards test development include defining sports-specific head impact conditions, establishing injury and age appropriate headgear assessment criteria, and the development of headgear specific head and neck surrogates for at-risk populations.

Sport related concussion - Potential for biomarkers to improve acute management

Sport-related concussion is a common form of mild traumatic brain injury that is now recognised as a serious health issue. Growing evidence suggests concussion may result in long-term and severe neurological disabilities. Recent research into the diagnosis and management of concussion may provide new approaches to concussion management that limit the potential long-term adverse effects of concussion. This paper summarises the problem of sport-related concussion and reviews key factors (sex, age, genetics) that may modify concussion outcomes. Current sport-related concussion tools are described. Analysis of emerging methods of acute concussion diagnosis using objective fluid and neuroimaging biomarkers is provided. These new concussion biomarkers have the potential to change management of sport-related concussion.

Biofluid biomarkers of traumatic brain injury

PRIMARY OBJECTIVE

The purpose of this paper is to review the clinical and research utility and applications of blood, cerebrospinal fluid (CSF), and cerebral microdialysis biomarkers in traumatic brain injury (TBI).

RESEARCH DESIGN

Not applicable.

METHODS AND PROCEDURES

A selective review was performed on these biofluid biomarkers in TBI.

MAIN OUTCOME AND RESULTS

Neurofilament heavy chain protein (NF-H), glial fibrillary acidic protein (GFAP), ubiquitin C-terminal hydrolase-L1 (UCHL1), neuron-specific enolase (NSE), myelin basic protein (MBP), tau, and s100β blood biomarkers are elevated during the acute phase of severe head trauma but have key limitations in their research and clinical applications to mild TBI (mTBI). CSF biomarkers currently provide the best reflection of the central nervous system (CNS) pathobiological processes in TBI. Both animal and human studies of TBI have demonstrated the importance of serial sampling of biofluids and suggest that CSF biomarkers may be better equipped to characterize both TBI severity and temporal profiles.

CONCLUSIONS

The identification of biofluid biomarkers could play a vital role in identifying, diagnosing, and treating the underlying individual pathobiological changes of TBI. CNS-derived exosomes analyzed by ultra-high sensitivity detection methods have the potential to identify blood biomarkers for the range of TBI severity and time course.

Consequences of Traumatic Brain Injury in Professional American Football Players: A Systematic Review of the Literature

OBJECTIVE

The purpose of this study was to systematically review the literature for the consequences Traumatic brain injury (TBI) has on cognitive, psychological, physical, and sports-related functioning in professional American Football players.

DATA SOURCES

We performed a systematic search in 2 databases, PubMed and SPORTDiscus, to obtain literature from January 1990 to January 2015. To be eligible for inclusion, a study had to examine the relationship between TBI and the consequences for several aspects of functioning in professional American football players older than 18 years. Methodological quality was assessed using a 5-item checklist which assessed selection bias, information bias, and correct reporting of the population and exposure characteristics.

MAIN RESULTS

The search yielded 21 studies that met our inclusion criteria. An evidence synthesis was performed on the extracted data and resulted in 5 levels of evidence. The evidence synthesis revealed that there is strong evidence that concussions are associated with late-life depression and short-term physical dysfunctions. Evidence for the relationship between concussion and impaired sports-related function, prolonged reaction time, memory impairment, and visual-motor speed was inconclusive. Moderate evidence was found for the association between TBI and mild cognitive impairment (MCI), and limited evidence was found for the association between TBI and executive dysfunction.

CONCLUSIONS

There is strong evidence that a history of concussion in American football players is associated with depression later in life and short-term physical dysfunctions. Also cognitive dysfunctions such as MCI are seen in older players with a history of TBI. These results provide input for actions to prevent TBI and their consequences in (retired) American football players.

Developing the Standard of Care for Post-Concussion Treatment: Neuroimaging-Guided Rehabilitation of Neurovascular Coupling

Background

Emerging research proposes the imbalance between microvascular supply and metabolic demand as a contributing factor in the pathophysiology of mild traumatic brain injury. Prolonged effects on the dysregulation of neurovascular coupling may explain persistent symptomatic models such as Post-Concussion Syndrome.

Objective

Increased knowledge of what we refer to as neurovascular uncoupling provides a template for establishing a new concussion treatment standard in the assessment and therapeutic guidance of concussion.

Methods

The degree and localization of neurovascular uncoupling were statistically contextualized against a normative-based atlas in 270 concussed patients. Functional NeuroCognitive Imaging^TM was used to establish pre-treatment benchmarks and guide neurotherapy. Conventional and functional neurocognitive imaging-directed measures were used to evaluate post-rehabilitative outcomes.

Results

Functional neurocognitive imaging was successful in identifying regions of Neurovascular uncoupling unique to each patient's brain and concussion profile. Longitudinal objective outcome measures demonstrated timely and lasting improvement of neurovascular coupling functioning in a significant majority of patients.

Conclusion

We present practice-based evidence supporting the clinical administration of functional neurocognitive imaging with particular efficacy in the neurorehabilitation of concussion. We advocate the reliability of functional neurocognitive imaging in assessing severity and localization of neurovascular uncoupling, and promote its use in the therapeutic guidance and neurorehabilitation of mild traumatic brain injury. We further support the continual exploration of other potential pathophysiological alterations resulting from concussion.

Sport concussion assessment tool-Third edition normative reference values for professional Rugby Union players

OBJECTIVES

To establish normative reference data for the SCAT3 in professional Rugby Union players.

DESIGN

A cross sectional study in professional Rugby Union players competing in national and international professional competitions between 2015 and 2016.

METHODS

The SCAT3 was administered pre-season or prior to tournaments. Data was collected electronically using a custom tablet application. SCAT3 subcomponents distributions were described and normative ranges determined using percentile cut-offs for average, unusually low/high, and extremely low/high scores. The association between player characteristics and performance in SCAT3 subcomponents was also investigated in exploratory analyses.

RESULTS

A total of 3611 professional Rugby Union players were included. The most common baseline symptom was fatigue (14%). The symptom score median (md) was 0 (interquartile range (IQR)=0-1). Symptom severity md was 0 (IQR=0-1). The md of the SAC score was 28 (IQR=26-29). The md of the MBESS was 2 (IQR=0-4). The Tandem gait md was 11.1s (IQR=10.0-12.7s). Upper limb coordination was normal in 98.4%. Younger age and lower educational level were associated with worse performance on delayed recall and reverse month sub-components of the SCAT3 (p<0.0001). No statistically significant differences in SCAT3 subcomponents were evident across gender.

CONCLUSIONS

Representative normative reference values for the SCAT3 among professional Rugby Union players are provided. Baseline performance on concentration and delayed recall tests may be lower in younger athletes or in those with lower educational level.

Sports-related Concussion in Children and Adolescents

Concussions are becoming increasingly important to manage properly as sports participation continues to rise. Repeated injuries occurring before the brain has had a chance to recover from an initial insult are particularly dangerous and must be prevented. Although much national media attention has been devoted to concussions in professional sports, it is important to appreciate that athletes in any age group, children and adolescents in particular, are at risk of sports-related concussion. It is crucial to remove an athlete from play any time concussion is suspected. Once removed from play, recovery then begins with a period of cognitive and physical rest, followed by a gradual return to cognitive and athletic activities as symptoms resolve. Children and adolescents pose a unique challenge to the clinician managing their recovery, as the physical and cognitive rest periods required often involve time away from school and sports, which can be academically detrimental and socially isolating. Recently developed sideline assessment tools have greatly aided the urgent sideline assessment of an athlete suspected of having a concussion. In this article, a brief review of current guidelines is presented in tandem with the authors' preferred treatment of concussion.

White matter changes in patients with mild traumatic brain injury: MRI perspective

This review focuses on white matter (WM) changes in mild traumatic brain injury (mTBI) as assessed by multimodal MRI. All the peer reviewed publications on WM changes in mTBI from January 2011 through September 2016 are included in this review. This review is organized as follows: introduction to mTBI, the basics of multimodal MRI techniques that are potentially useful for probing the WM integrity, summary and critical evaluation of the published literature on the application of multimodal MRI techniques to assess the changes of WM in mTBI, and correlation of MRI measures with behavioral deficits. The MRI–pathology correlation studies based on preclinical models of mTBI are also reviewed. Finally, the author's perspective of future research directions is described.

Asymptomatic Chiari Type I malformation: should patients be advised against participation in contact sports?

BACKGROUND

Chiari type I malformation (CM-I) is characterised by caudal displacement of the cerebellar tonsils through the foramen magnum, crowding the craniocervical junction. It is being increasingly diagnosed in asymptomatic patients due to the widespread availability of MRI, and there are case reports of these patients suffering sudden death or neurological injury following head or neck trauma, raising the issue of whether they should be prohibited from contact sport participation, given the likelihood of frequent trauma. General neurosurgical opinion is that patients who are symptomatic and those with an associated spinal cord syrinx should be offered foramen magnum decompression, however asymptomatic patients without syringomyelia are not offered this in the majority of cases.

METHODS

The authors performed a full review of the published literature, including all case reports, case series, studies and literature reviews regarding CM-I and either contact sports or trauma, excluding patients that had undergone surgical intervention and those becoming symptomatic in circumstances other than head or neck trauma.

RESULTS

21 case reports of CM-I patients deteriorating following trauma were identified, including four cases of sudden death following head or neck injury. However, studies of large samples of CM-I patients are yet to capture an incident of sudden death or acute neurological deterioration, suggesting that the risk is very low. CM-I patients may have an increased risk of concussion and post-concussion syndrome compared to the background population however.

CONCLUSION

Overall, the authors feel that there should be no restriction of sports participation for CM-I patients, but a discussion to make them and their families aware of the possible increased risks is important.

Concussion in Sports: What Do Orthopaedic Surgeons Need to Know?

A concussion is a relatively common sports-related injury that affects athletes of all ages. Although orthopaedic surgeons are not expected to replace sports medicine physicians and neurologists with regard to the management of concussions, orthopaedic surgeons, particularly those who are fellowship-trained in sports medicine, must have a current knowledge base of what a concussion is, how a concussion is diagnosed, and how a concussion should be managed. Orthopaedic surgeons should understand the pathophysiology, assessment, and management of concussion so that they have a basic comprehension of this injury, which is at the forefront of the academic literature and North American media. This understanding will prepare orthopaedic surgeons to work in concert with and assist sports medicine physicians, athletic trainers, and physical therapists in providing comprehensive care for athletes with a concussion.

Chronic Traumatic Encephalopathy in Athletes Involved with High-impact Sports

BACKGROUND AND PURPOSE

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease occurring most commonly in athletes and is caused by repeated concussive or subconcussive blows to the head. The main purpose of this review is to evaluate the published literature on chronic traumatic encephalopathy (CTE) in athletes participating in high-impact sports. In particular, we highlight the significance of concussive and subconcussive impacts in multiple sports, elucidate the differences between clinical/pathological features of CTE and related neurodegenerative diseases, and provide an explanation for the variation in clinical presentation between athletes of different sports.

METHODS

A review targeting relevant publications to CTE was performed. The PubMed/MEDLINE index was searched for keywords such as "chronic traumatic encephalopathy," "repetitive traumatic brain injury," "mild traumatic brain injury," and "concussion" from year 1924 through March 1, 2016.

RESULTS

A consensus panel's recent identification of a pathognomonic pathology in CTE, characterized by an irregular distribution of phosphorylated tau deposits, is an important step in developing consensus diagnostic criteria and clinicopathological studies. After review of major clinical studies, evidence suggests that there are clear differences in neuropathological features, clinical progression, and manifestation of symptoms between CTE and other neurodegenerative diseases. The literature suggests boxers tend to have more severe symptoms than other athletes due to more frequent rotational and shearing impacts. Data regarding genetic predispositions of CTE have been inconsistent in part due to low subject populations. Positron emission tomography imaging involving tau-binding ligands has recently proven effective in differentiating CTE from control groups and other neurodegenerative diseases.

CONCLUSIONS

Further longitudinal studies should be conducted to correlate the number of suffered concussive/subconcussive forces to the likelihood of developing chronic traumatic brain injury symptoms. Research striving for a reliable antemortem CTE diagnosis would be immensely beneficial, leading to more accurate estimates of prevalence, allowing clinicians to assess future risk of athletes' continued participation in sports, and enabling clinicians to make appropriate preventive recommendations.

One-Year Concussion Prevalence in Marion County, Florida High School Athletes

OBJECTIVE

The purpose of this study was to evaluate data on concussion prevalence in 1 geographic location and to identify which sports have a higher prevalence of concussion in the Marion County, Florida, school district.

METHODS

High school athletic trainers in Marion County, Florida, are required to compile statistics related to number of participants and concussions sustained in the county school district during each season. They provided the data for the 2011-2012 school year to independent analysts with the permission of the athletic director. The study evaluated 3689 student-athletes (2102 male, 1587 female), and 34 concussions (24 male, 10 female) were reported. Concussions were self-reported by the athletes and diagnosed by trainers on field or by follow-up after physician referral. Consent was included in consent to participate in interscholastic athletics, and all athletes enrolling in a sport during the 2011-2012 academic year were included regardless of participation level. Number of participants and concussions sustained was calculated per 100 participants for each sport and in total for 1 year.

RESULTS

The percentages of concussions per sport were as follows: basketball, 1.83%; cheerleading, 0.40%; football, 2.83%; soccer, 1.84%; track and field, 0.44%; and wrestling, 0.70%. Ten additional sports were included in the study but had no reported concussions. Total prevalence for the district was 0.922% (1.14% male, 0.63% female) during a 1-year period.

CONCLUSION

The concussion prevalence in this district during the 2011-2012 school year was just under 1%. The sport reporting the highest prevalence was football, followed by soccer. Females reported a higher rate of concussions than males in sports played by both male and female participants. This highlights the need to minimize risk for concussion, especially in noncollision contact sports, and in female athletes.

Twitter Strategies for Web-Based Surveying: Descriptive Analysis From the International Concussion Study

Background

Social media provides researchers with an efficient means to reach and engage with a large and diverse audience. Twitter allows for the virtual social interaction among a network of users that enables researchers to recruit and administer surveys using snowball sampling. Although using Twitter to administer surveys for research is not new, strategies to improve response rates are yet to be reported.

Objective

To compare the potential and actual reach of 2 Twitter accounts that administered a Web-based concussion survey to rugby players and trainers using 2 distinct Twitter-targeting strategies. Furthermore, the study sought to determine the likelihood of receiving a retweet based on the time of the day and day of the week of posting.

Methods

A survey based on previous concussion research was exported to a Web-based survey website Survey Monkey. The survey comprised 2 questionnaires, one for players, and one for those involved in the game (eg, coaches and athletic trainers). The Web-based survey was administered using 2 existing Twitter accounts, with each account executing a distinct targeting strategy. A list of potential Twitter accounts to target was drawn up, together with a list of predesigned tweets. The list of accounts to target was divided into ‘High-Profile’ and ‘Low-Profile’, based on each accounts’ position to attract publicity with a high social interaction potential. The potential reach (number of followers of the targeted account), and actual reach (number of retweets received by each post) between the 2 strategies were compared. The number of retweets received by each account was further analyzed to understand when the most likely time of day, and day of the week, a retweet would be received.

Results

The number of retweets received by a Twitter account decreased by 72% when using the ‘high-profile strategy’ compared with the ‘low-profile strategy’ (incidence rate ratio (IRR); 0.28, 95% confidence interval (CI) 0.21-0.37, P<.001). When taking into account strategy and day of the week, the IRR for the number of retweets received during the hours of 12 AM to 5:59 AM (IRR 2.98, 95% CI 1.88-4.71, P>.001) and 6 PM to 11:59 PM (IRR 1.48, 95% CI 1.05-2.09, P>.05) were significantly increased relative to 6 AM to 11:59 AM. However, posting tweets during the hours of 12 PM to 5:59 PM, decreased the IRR for retweets by 40% (IRR 0.60, 95% CI 0.46-0.79, P<.001) compared with 6 AM to 11:59 AM. Posting on a Monday (IRR 3.57, 95% CI 2.50-5.09, P<.001) or Wednesday (IRR 1.50, 95% CI 1.11-1.11, P<.01) significantly increased the IRR compared with posting on a Thursday.

Conclusions

Surveys are a useful tool to measure the knowledge, attitudes, and behaviors of a given population. Strategies to improve Twitter engagement include targeting low-profile accounts, posting tweets in the morning (12 AM-11:59 AM) or late evenings (6 PM-11:59 PM), and posting on Mondays and Wednesdays.