Sports-related concussions - media, science and policy

Comparing peer relationship ratings among adolescents with sport and non-sport related concussions

OBJECTIVE

To evaluate if peer relationship ratings differ among adolescents who sustain a sport-related concussion compared to those who sustain a non-sport-related concussion.

STUDY DESIGN

We conducted a cross-sectional investigation of 123 adolescents who sustained a concussion within 21 days before their initial post-injury evaluation (mean = 9.2 ± 3.9 days post-concussion). Participants reported whether their injury occurred during organized sport participation (sport-related concussion group) or not (non-sport-related concussion group). Participants completed the PROMIS Global Pediatric 25 assessment, as well as the Post-Concussion Symptom Inventory (PCSI) to rate concussion symptom severity and a background/demographic intake form during the evaluation. We compared PROMIS peer relationship ratings between groups using independent t-tests and evaluated the association between peer relationship ratings and sport-related concussion using multiple linear regression after adjusting for covariates including PROMIS anxiety rating, age, sex, concussion and musculoskeletal injury history, loss of consciousness at time of concussion, physical activity participation prior to study evaluation, and concussion symptom severity.

RESULTS

Most (N = 96, 78%) participants reported sustaining a concussion during sports. The group who sustained sport-related concussion reported significantly better post-concussion peer relationship ratings compared to the group who sustained a non-sport-related concussion (52.7 ± 7.7 vs. 47.7 ± 10.4; p = 0.009, Cohen's d = 0.60). After covariate adjustment, those who sustained a sport-related concussion had a significantly greater post-concussion peer relationship rating than those who sustained a non-sport-related concussion (β = 4.19, 95% CI = 0.39, 8.00; p = 0.03). Higher peer relationship ratings were also associated with lower anxiety ratings following concussion (β= -0.21, 95% CI= -0.38, -0.04; p = 0.03).

CONCLUSION

Adolescents who sustained a concussion during sports reported significantly greater post-concussion peer relationship ratings than those in non-sport settings. Better peer relationship ratings were associated with less anxiety in the post-injury period. These findings suggest the potential effects of contextual factors (e.g. peer support) to facilitate improved outcomes following adolescent concussion.

Video-Based Analysis of Suspected Concussions in Slap Fighting: Incidence and Characteristics

OBJECTIVE

Despite the high frequency of head impacts in slap fighting, little is known about suspected concussions in this sport. This study examined the frequency and characteristics of observable signs of suspected concussions in slap fighting among male athletes.

SETTING

Video-based analysis.

PARTICIPANTS

Athletes who participated in official male power slap matches from January 1, 2023 to June 31, 2024.

DESIGN

Video footage of all official male power slap matches during the study period was retrospectively analyzed by 3 sports medicine specialists experienced in sports injuries.

MAIN MEASURES

The frequency, total number, and types of observable signs of suspected concussion, and whether the fight continued after signs of suspected concussion were observed.

RESULTS

A total of 115 fights (97.5%) during the study period were available for video review. Of these, 40 (38.4%) resulted in knockouts and 21 (18.3%) in technical knockouts. Observable signs of suspected concussion were observed in 79.1% of fights, averaging 1.41 concussion signs per fight, and 0.31 per slap. Forty-eight (52.7%) of the fights with signs of suspected concussion continued following observed concussion signs.

CONCLUSION

The frequency, early identification, and management of suspected concussions in slap fighting should be prioritized, with further studies combining clinical assessments strongly recommended.

Is contact sport participation associated with chronic traumatic encephalopathy or neurodegenerative decline? A systematic review and meta-analysis

INTRODUCTION

We sought to evaluate a potential association between contact vs. non-contact sport participation and long-term neurologic outcomes and chronic traumatic encephalopathy (CTE).

EVIDENCE ACQUISITION

PubMed/Embase/PsycINFO/CINAHL databases were queried for studies between 1950-2020 with contact and non-contact sports, longitudinal assessment >10 years, and long-term neurologic outcomes in four-domains: I) clinical diagnosis; II) CTE neuropathology; III) neurocognition; and IV) neuroimaging.

EVIDENCE SYNTHESIS

Of 2561 studies, 37 met inclusion criteria, and 19 contained homogenous outcomes usable in the meta-analysis. Domain I: Across six studies, no significant relationship was seen between contact sport participation and antemortem diagnosis of neurodegenerative disease or death related to such a diagnosis (RR1.88, P=0.054, 95%CI0.99, 3.49); however, marginal significance (P<0.10) was obtained. Domain II: Across three autopsy studies, no significant relationship was seen between contact sport participation and CTE neuropathology (RR42.39, P=0.086, 95%CI0.59, 3057.46); however, marginal significance (P<0.10) was obtained. Domain III: Across five cognitive studies, no significant relationship was seen between contact sport participation and cognitive function on the Trail Making Test (TMT) scores A/B (A:d=0.17, P=0.275,95% CI-0.13, 0.47; B:d=0.13, P=0.310, 95%CI-0.12, 0.38). Domain IV: In 10 brain imaging-based studies, 32% comparisons showed significant differences between those with a history of contact sport vs. those without.

CONCLUSIONS

No statistically significant increased risk of neurodegenerative diagnosis, CTE neuropathology, or neurocognitive changes was found to be associated with contact sport participation, yet marginal significance was obtained in two domains. A minority of imaging comparisons showed differences of uncertain clinical significance. These results highlight the need for longitudinal investigations using standardized contact sport participation and neurodegenerative criteria.

Machine embroidery of light-emitting textiles with multicolor electroluminescent threads

Advances in electroluminescent threads, suitable for weaving or knitting, have opened doors for the development of light-emitting textiles, driving growth in the market for flexible and wearable displays. Although direct embroidery of these textiles with custom designs and patterns could offer substantial benefits, the rigorous demands of machine embroidery challenge the integrity of these threads. Here, we present embroiderable multicolor electroluminescent threads-in blue, green, and yellow-that are compatible with standard embroidery machines. These threads can be used to stitch decorative designs onto various consumer fabrics without compromising their wear resistance or light-emitting capabilities. Demonstrations include illuminating specific messages or designs on consumer products and delivering emergency alerts on helmet liners for physical hazards. Our research delivers a comprehensive toolkit for integrating light-emitting textiles into trendy, customized crafts tailored to the unique requirements of diverse flexible and wearable displays.

Neurophysiological Markers to Guide Return to Sport After Sport-Related Concussion

SUMMARY

Sport-related concussion (SRC) has been defined as a subset of mild traumatic brain injury (mTBI), without structural abnormalities, reflecting a functional disturbance. Over the past decade, SRC has gained increasing awareness and attention, which coincides with an increase in incidence rates. Because this injury has been considered one of the most challenging encounters for clinicians, there is a need for objective biomarkers to aid in diagnosis (i.e., presence/severity) and management (i.e., return to sport) of SRC/mTBI.The primary aim of this article was to present state-of-the-art neurophysiologic methods (e.g., electroencephalography, magnetoencephalography, transcranial magnetic stimulation, and autonomic nervous system) that are appropriate to investigate the complex pathophysiological process of a concussion. A secondary aim was to explore the potential for evidence-based markers to be used in clinical practice for SRC management. The article concludes with a discussion of future directions for SRC research with specific focus on clinical neurophysiology.

Epidemiological analysis of pediatric baseball and softball concussions in United States emergency departments

PURPOSE

To evaluate the epidemiology of concussions in pediatric baseball and softball players. We hypothesized that head-to-ball injuries would be the most common cause of concussions.

METHODS

The National Electronic Injury Surveillance System (NEISS) database was used to gather data. Concussions occurring during baseball and softball participation in pediatric patients (4-17 years old) from 2012 to 2021 was gathered. Concussion mechanisms were grouped into 5 categories: head-to-player, head-to-ball, head-to-surface (ground, walls, railings), head-to-bat, and unknown. Linear regression models were used to assess changes in yearly concussion rates over the study period. Results from these models were reported using parameter estimates and the estimated Pearson correlation coefficient.

RESULTS

A weighted total of 54,978 baseball and softball related concussion injuries were analyzed. The average weighted age of our cohort at the time of injury was 13.1 years, with 54.1% (n = 29,761) of concussions occurring in males. The national estimated incidence of concussion injuries decreased non-significantly over the study period (slope estimate = -311 concussions/year, r = -0.625, p-value = 0.054). The majority of weighted national estimate concussions were due to head-to-ball injuries (n = 34,650; 63.0%), followed by head-to-player (n = 8501; 15.5%), head-to-surface (n = 5347; 9.7%), and head-to-bat (n = 5089; 9.3%). On sub-analysis, individuals were grouped into 3 age brackets: 4-8, 9-13, and 14-17 years. The most common mechanism of concussions in children of all ages was head-to-ball. The incidence of head-to-player and head-to-surface injuries increased throughout each age group, while head-to-bat decreased.

CONCLUSION

The incidence of concussions in pediatric baseball and softball athletes has been decreasing non-significantly over our 10-year study period. The most common mechanism of concussions in our study was head-to-ball injuries.

Epidemiological analysis of concussions in youth ice hockey players: A national emergency room database study

PURPOSE

To evaluate the epidemiology of concussions in youth ice hockey players.

METHODS

The National Electronic Injury Surveillance System (NEISS) database was used to gather data. Concussions occurring during ice hockey participation in youth patients (4-21 years old) from 2012 to 2021 was gathered. Concussion mechanisms were grouped into 7 categories: head-to-player, head-to-puck, head-to-ice, head-to-board/glass, head-to-stick, head-to-goal post, and unknown. Hospitalization rates were also tabulated. Linear regression models were used to assess changes in yearly concussion and hospitalization rates over the study period. Results from these models were reported using parameter estimates [with 95% confidence intervals (CI)] and the estimated Pearson correlation coefficient. Additionally, logistic regression was used to model the risk of hospitalization across the different cause categories.

RESULTS

A total of 819 ice hockey related concussions were analyzed between 2012 and 2021. The average age of our cohort was 13.4 years, with 89.3% (n = 731) of concussions occurring in males. The incidence of head-to-ice, head-to-board/glass, head-to-player, and head-to-puck concussion mechanisms decreased significantly over the study period (slope estimate = -2.1 concussions/year [CI: (-3.9, -0.2)], r = -0.675, p = 0.032), (slope estimate = -2.7 concussions/year [CI: (-4.3, -1.2)], r = -0.816, p = 0.004), (slope estimate = -2.2 concussions/year [CI: (-3.4, -1.0)], r = -0.832, p = 0.003), and (slope estimate = -0.4 concussions/year [CI: (-0.62, -0.09)], r = -0.768, p = 0.016), respectively. Majority of patients were discharged from the emergency department (ED) to their home, as only 20 people (2.4%) were hospitalized over our study period. The majority of concussions were due to head-to-ice (n = 285, 34.8%), followed by head-to-board/glass (n = 217, 26.5%) and head-to-player (n = 207, 25.3%). The most common cause for hospitalizations due to concussions was head-to-board/glass (n = 7, 35%), followed by head-to-player (n = 6, 30%) and head-to-ice (n = 5, 25%).

CONCLUSION

The most common mechanism of youth ice hockey concussions was head-to-ice in our 10-year study period, while head-to-board/glass was the most common cause of hospitalizations. IRB: This project did not require review by the institutional review board.

Fluid biomarkers and risk of neurodegenerative disease in retired athletes with multiple concussions: results from the International Concussion and Head Injury Research Foundation Brain health in Retired athletes Study of Ageing and Impact-Related Neurodegenerative Disease (ICHIRF-BRAIN study)

Objectives

To investigate the association and utility of blood plasma markers of neurodegeneration in a population of retired athletes self-reporting multiple concussions throughout a sporting career. It is hypothesised that this type of athletic history would cause an increased prevalence of neurodegenerative disease, as detected by biomarkers for neurodegenerative disease processes.

Methods

One hundred and fifty-nine participants were recruited (90 males, 69 females, mean age 61.3±9.13 years), including 121 participants who had retired from playing professional or semiprofessional sports and self-reported ≥1 concussion during their careers (range 1–74; mean concussions=10.7). The control group included 38 age-matched and sex-matched controls, with no history of concussion. We measured neurofilament light (NfL) and tau (neurodegeneration markers), glial fibrillar acidic protein (GFAP) (astrocytic activation marker) and 40 and 42 amino acid-long amyloid beta (Aβ40 and Aβ42) (Alzheimer-associated amyloid pathology markers) concentrations using ultrasensitive single molecule array technology.

Results

We found retired athletes reporting one or more concussions throughout an athletic career showed no significant changes in NfL, tau, GFAP and Aβ40 and Aβ42 concentrations in comparison to a control group. No correlations were found between biomarkers and number of concussions (mean=10.7). A moderate correlation was found between NfL concentration and age.

Conclusion

No difference in blood concentrations of neurodegeneration markers NfL, tau, GFAP and Aβ40 and Aβ42 was found in retired athletes with a history of concussion compared with controls. An increased prevalence of neurodegenerative diseases is not detected by biomarkers in a population self-reporting multiple concussions.

Trial registration number

ISRCTN 11312093

Postconcussion discharge advice does not improve concussion knowledge in a community sample

OBJECTIVE

Poor concussion knowledge in the community has been linked to reduced injury identification. This study investigated if concussion knowledge could be improved by providing standard postinjury advice (written brochure).

METHODS

This study was a prospective, controlled study, with random allocation of 199 Australian adults to receive either a concussion information (CI, n=101), or non-CI (n=98). All participants completed the Rosenbaum Concussion Knowledge and Attitudes Survey on three occasions: pre-education and posteducation, and 1 week later.

RESULTS

A 2 (condition) × 3 (occasion) mixed analysis of variance with concussion knowledge as the dependent variable did not find a statistically significant interaction (p>0.05). This result was unchanged: (1) with the covariate addition of background education and; (2) in a subgroup analysis (individuals with initially 'low' self-rated knowledge). Some key misconceptions about concussion were identified.

CONCLUSION

The community knowledge of concussion was not significantly improved by the concussion advice. Since injury recognition relies ton an extent on community knowledge, the identified misconceptions should be addressed. This could occur via public health messaging. In clinical settings and for future research, the next steps should also include regular updating of concussion information to keep pace with advances in the field.

Child participation in collision sports and football: what influences parental decisions?

OBJECTIVE

Sport participation promotes health benefits for children. Current media and scientific coverage of sport-related head injury may influence a parent's decision on sports participation. Physicians must understand what influences these decisions to effectively counsel patients and families. This study sought to better understand and quantify the parental decisions to allow/disallow collision sports, including football participation.

METHODS

A 31-question survey related to child/parent demographics, sports history, and influences to allow/disallow sport participation was available to parents in the United States through a national volunteer registry, between November 2016 and September 2019. Pearson's chi-squared and Wilcoxon's signed-rank test were used to analyze categorical and continuous variables, respectively. Multivariate logistic regression was performed to identify the most powerful factors associated with the decision.

RESULTS

Of the 884 responses, 430 (49%) parents would disallow collision sport participation and 334 (38%) would disallow football. Parents who would allow collision sports more commonly cited child desire, while those parents who would disallow cited safety concern as the greatest influence to generally disallow a sport. Those who would disallow reported doctors (35.1% vs 25.3%; P = 0.002), media (12.8% vs 7.3%; P = 0.006) and other parents (11.2% vs 7.3%; P = 0.045) as influences. A child's age (OR 1.039, 95%CI 1.007-1.073; P = 0.018) was independently associated with their parent responding that they would allow collision sports. Parent educational status showed that those with higher than a bachelor's degree would be less likely to allow football participation (OR 0.635, 95%CI 0.443-0.910; P = 0.013).

CONCLUSIONS

Parents incorporate many sources of information into the decision to allow or disallow their child to participate in collision sports. A child's desire to play a sport and child safety are driving factors for parents faced with the decision of whether to allow participation in collision sports. Physician input is more frequently influential to parents than the media, underscoring the responsibility of physicians to engage families on the risks, benefits, and resources available for sport participation.

Concussion in Women's Flat-Track Roller Derby

Concussions are common among flat-track roller derby players, a unique and under-studied sport, but little has been done to assess how common they are or what players can do to manage injury risk. The purpose of this study is to provide an epidemiological investigation of concussion incidence and experience in a large international sampling of roller derby players. Six hundred sixty-five roller derby players from 25 countries responded to a comprehensive online survey about injury and sport participation. Participants also responded to a battery of psychometric assessment tools targeting risk-factors for poor injury recovery (negative bias, social support, mental toughness) and players' thoughts and feelings in response to injury. Per 1,000 athletes, 790.98 concussions were reported. Current players reported an average of 2.2 concussions, while former players reported 3.1 concussions. However, groups were matched when these figures were corrected for differences in years of play (approximately one concussion every 2 years). Other frequent injuries included fractures in extremities and upper limbs, torn knee ligaments, and sprained ankles. We found no evidence that players' position, full-contact scrimmages, or flooring impacted number of concussions. However, neurological history and uncorrected vision were more influential predictors of an individual's number of concussions during roller derby than years of participation or age, though all four contributed significantly. These findings should assist athletes in making informed decisions about participation in roller derby, though more work is needed to understand the nature of risk.

Pathogenic cis p-tau levels in CSF reflects severity of traumatic brain injury

Traumatic brain injury (TBI) is the main cause of death and disability among young people. Following TBI, immune system activation and cytokine release induce kinase activity and hyperphosphorylation of tau protein, a structural molecule in axonal microtubules. The cis configuration of phosphorylated tau at Th231 is extremely neurotoxic and is having a prion nature, spreads to brain areas as well as CSF.We examined the cerebrospinal fluid (CSF) cis p-tau levels in 32 TBI patients and 5 non-TBI controls to find out the correlation with TBI severity.   CSF samples were drained 5-7 days after TBI and subjected for ELISA analysis with anti cis p-tau and β-amyloid antibodies.We had no patients with mild TBI, two patients with moderate (6.2%), 23 patients with severe (71.9%), and 7 patients with critical TBI (21.9%). While mean CSF β-amyloid in TBI and control groups did not show a statistically significant difference, the mean CSF cis p-tau level was significantly higher in the TBI group than the control samples. Also, intergroup analysis demonstrated that CSF cis p-tau levels were statistically different according to the head injury severity.Although CSF cis p-tau increased in the TBI patients, β-amyloid did not show a significant difference between patients and controls. Also, we observed an obvious negative correlation between CSF cis p-tau levels and GCS scores. Therefore, future researches on suppression of cis P-tau production or removing previously produced cis P-tau could be a suitable approach in treating TBI in order to prevent tauopathies and future neurodegeneration.

Subjective Concerns Regarding the Effects of Sport-Related Concussion on Long-Term Brain Health among Former NFL Players: An NFL-LONG Study

BACKGROUND

Potential links between a history of sport-related concussions and later-life neurobiological and psychological brain health have been studied in former collision-sport athletes. However, empirical studies of how former athletes perceive the future of their brain health as a result of these injuries are missing.

OBJECTIVES

We aimed to (1) identify the extent to which former National Football League players currently have concerns about their long-term psychological and cognitive functioning as a result of concussions sustained while playing football; (2) examine whether current concerns are different than concerns they had while playing football; (3) examine the relationship between current brain health concerns and self-reported concussion history (SR-CHx); and (4) explore other important factors associated with these concerns.

METHODS

In this cross-sectional study, former National Football League players with a SR-CHx of one or more concussions (n = 1514; aged mean [standard deviation] = 52.3 [15.7] years) completed a general health questionnaire. Participants reported their lifetime concussion history, as well as both their current concerns and concerns while playing football (i.e., retrospective concerns) regarding the long-term effects of concussions on their memory, thinking skills, and risk of developing chronic traumatic encephalopathy. Current and retrospective concerns were self-reported on a five-point Likert scale. Four concussion history categories were created based on SR-CHx: 1-2 (n = 309); 3-5 (n = 413); 6-9 (n = 356); and 10 + (n = 436) lifetime concussions. Proportions of participants reporting each level of current and retrospective concerns were examined to identify whether concerns presently exist in these former players, and whether their current concerns are different than retrospective concerns. Next, we explored associations between current concerns and SR-CHx.

RESULTS

More than one-third of participants reported being currently "extremely concerned" about memory problems (36.9%), thinking skills (37.8%), and developing chronic traumatic encephalopathy (39.5%). In contrast, when asked about concerns while playing, most reported being "not at all concerned" regarding memory = 61.2%, thinking skills = 56.1%, and developing chronic traumatic encephalopathy = 71.2%. Of those who retrospectively endorsed being "not at all" or "slightly" concerned regarding memory (n = 1159/1514), thinking skills (n = 1080/1514), and developing chronic traumatic encephalopathy (n = 1219/1514), approximately half reported being currently "moderately" or "extremely" concerned about those same issues (n = 586/1159; n = 534/1080; n = 619/1219, respectively). Current concerns regarding memory (χ²₁₆ = 316.61; p < 0.001; V = 0.264), thinking skills (χ²₁₆ = 333.17; p < 0.001; V = 0.271), and developing chronic traumatic encephalopathy (χ²₁₆ = 280.85; p < 0.001; V = 0.249) were significantly related to SR-CHx, with more concussions being associated with greater current concerns.

CONCLUSIONS

Former National Football League players reported significant concerns regarding the potential effects of their prior concussions on long-term brain health, and these concerns are more prevalent now than when they were playing football. Cognitive and mental health concerns are readily identifiable targets for clinical intervention. Clinicians working with former players may wish to explore the extent to which individual players experience these concerns, the nature and depth of these concerns, and the impact of these concerns on the player's functioning and well-being.

Characteristics of potential concussive events in elite male gaelic football players: A descriptive video-analysis

Gaelic football (GF) is a high-impact sport and Sport-Related Concussion (SRC) is an issue within the game. Our aim was to evaluate the characteristics of Potential Concussive Events (PCEs) that occur in the Gaelic Athletic Association National Football League and extrapolate this data to reduce the incidence and severity of SRC. PCEs may or may not lead to a clinical diagnosis of SRC, but represent high-risk events and therefore may be a useful indicator. A video-analysis approach was undertaken to identify PCEs throughout two seasons of play using broadcast footage, and characteristics of each PCE were measured based on previously validated methods. A total of 242 PCEs were identified over 111 matches (2.18 per match, 58.14 per 1000 hours of exposure). PCEs were frequently not anticipated by the player (40.5%, n = 98). The most common impact locations were the mandibular region (33.1%, n = 80) and the temporal region (21.1%, n = 51), and the most frequently observed mechanism was hand/fist to head (27.3%, n = 66). A second-hit was observed in 34 PCEs (14.0%). The findings provide initial guidance for the development of player protection strategies to reduce the incidence and severity of SRC in Gaelic Football.

Racial Disparities in Diagnosis of Concussion and Minor Head Trauma and Mechanism of Injury in Pediatric Patients Visiting the Emergency Department

OBJECTIVE

To determine if racial/ethnic differences exist in the diagnosis and mechanism of injury among children and adolescents visiting the emergency department (ED) for concussion and minor head trauma (MHT).

STUDY DESIGN

A retrospective, cross-sectional study of patient (age ≤19 years) visits to the ED for concussion between 2010-2015, using the National Hospital Ambulatory Medical Care Survey, was completed. The primary study exposure was race/ethnicity. Outcome measures included ED visits that resulted in a concussion/MHT diagnosis and mechanism of injury. Mechanism categories included sport, motor vehicle collision, fall, assault, and other mechanism. A multivariable logistic regression and multinomial logistic regression were conducted to assess relationships between race/ethnicity and outcomes. Findings were weighted to reflect population estimates.

RESULTS

In total, 1263 child/adolescent visits for concussion/MHT were identified, representing an estimated 6.6 million child/adolescent visits nationwide. Compared with non-Hispanic White pediatric patients, non-Hispanic Black patients were least likely to have an ED visit for a concussion/MHT (P < .001; OR, 0.66; 95% CI, 0.52-0.83) The odds of non-Hispanic Black children/adolescents (OR, 3.80; 95% CI, 1.68-8.55) and children/adolescents of other race/ethnicity (OR, 4.93; 95% CI, 1.09-22.23) sustaining a concussion/MHT resulting from assault vs sport was higher.

CONCLUSIONS

Amid the emerging focus on sport-related concussion, these ethnic/racial differences in ED diagnosis of concussion/MHT demonstrate sociodemographic differences that warrant further attention. Assault may be a more common mechanism of concussion among children/adolescents of a racial minority.

Symptom Burden, School Function, and Physical Activity One Year Following Pediatric Concussion

OBJECTIVES

To characterize symptom burden, school function, and physical activity in youth 1 year following acute concussion and those with subsequent repeat concussion.

STUDY DESIGN

Secondary analysis of Predicting Persistent Postconcussive Problems in Pediatrics prospective, multicenter cohort study conducted in 9 Canadian emergency departments. Participants were children between ages 5 and 18 years who presented consecutively ≤48 hours of concussion and agreed to participate in a post hoc electronic survey 1 year after injury. Outcomes were assessed using a standardized 25-question symptom scale derived from the Post-Concussion Symptom Inventory-Parent; school function and physical activity outcomes were queried. The primary outcome was total symptom score 1 year following concussion, defined as the number of symptoms experienced more than before injury.

RESULTS

Of 3052 youth enrolled in the Predicting Persistent Postconcussive Problems in Pediatrics study, 432 (median [IQR] age, 11.5 [9,14] years; 266 [62%] male) completed the 1-year survey; 34 respondents reported a repeat concussion. Following acute concussion, youth were more likely to be symptom-free than following repeat concussion (75% vs 50%; difference = 25% [95% CI 8-41]; P = .002) and to have recovered fully (90% vs 74%; difference = 17% [95% CI 5-34]; P = .002) after 1 year. Although physical symptoms were less 1 year after initial emergency department presentation for both groups (P < .001), youth with a repeat concussion reported greater headache persistence (26% vs 13%; difference = 13% [95% CI 1,31]; P = .024). Both groups returned to their normal school routine (100% vs 95%; difference = 5% [95% CI -5 to 8; P = .618). Youth without repeat concussion more frequently returned to normal physical activities (98% vs 85%; difference = 13% [95% CI 4-28]; P < .0001) and sport (95% vs 82%; difference = 13% [95% CI 3-29]; P = .009).

CONCLUSIONS

Most youth are symptom-free and fully recovered 1 year following concussion. Some children with repeat concussion have worse outcomes and have delays in returning to normal school routines and sport.

Chronic traumatic encephalopathy-a blueprint for the bridge between neurological and psychiatric disorders

Chronic traumatic encephalopathy (CTE) is a perplexing condition characterized by a broad and diverse range of neuropathology and psychopathology. While there are no agreed upon or validated clinical criteria for CTE, case series of CTE have described a wide range of neuropsychiatric symptoms that have been attributed to repetitive traumatic brain injuries (rTBI). However, the direct links between the psychopathology of psychiatric and neurological conditions from rTBI to CTE remains poorly understood. Prior studies suggest that repetitive cerebral injuries are associated with damage to neural circuitry involved in emotional and memory processes, but these studies do not offer longitudinal assessments that prove causation. More recent studies on novel targets, such as transmission of misfolded proteins, as well as newly advanced non-invasive imaging techniques may offer more direct evidence of the pathogenesis of CTE by tracing the progression of pathology and display of related behavioral impairments. Understanding this interface in the context of rTBI can play an important role in future approaches to the definition, assessment, prevention, and treatment of CTE and mental illnesses.

Considerations for Athlete Retirement After Sport-Related Concussion

The recommendation to retire from sport after concussion has evolved with the understanding of concussion. Age, sport, position, level of play, relevant medical and concussion history, severity and duration of symptoms, neuroimaging and neuropsychological testing should all be considered. Susceptibility to injury, persistence of symptoms, psychological distress, and personal values and support may also play a role. Pediatric athletes may require a more conservative approach, given ongoing growth and development. For professional and/or elite athletes, financial or career implications may be considerations. When possible, retirement should be a shared decision among the athlete, the family, and the health care team.

Examination of Racial Disparities in Adolescents Seen in the Emergency Department for Head, Neck, or Brain Injury

BACKGROUND

Given the frequency, severity, and attention of traumatic brain injury in children, benchmarking disparities and injury characteristics for adolescent patients is pivotal in understanding and enhancing both clinical care and outcomes.

OBJECTIVES

The purpose of this study was to investigate racial disparities on mechanism of injury, clinical outcomes, and social-health factors among adolescents treated in the emergency department (ED) for a head, neck, or brain injury.

METHODS

This study is the result of a retrospective chart review of head-, neck-, and brain-injured adolescent patients (n = 2857) treated at three community hospital EDs and one stand-alone ED. Outcome measures included patient demographics (gender, race/ethnicity, age), Glasgow Coma Scale score, hospital length of stay, intensive care unit length of stay, mechanism of injury, primary diagnosis, secondary diagnosis of a concussion, ventilation days, discharge disposition, and primary insurance.

RESULTS

There were racial differences in primary diagnosis, mechanism of injury, and insurance status. Results indicated that a higher proportion of white patients were diagnosed with a concussion compared with black patients (p < 0.001). Moreover, a higher proportion of white patients were seen in the ED for head, neck, or brain injury as a result of a sports or motor vehicle incident, whereas a leading mechanism among black patients was assault (p = 0.01). More white patients had private insurance, whereas more black patients had Medicaid (p < 0.001).

CONCLUSION

The disparities in mechanisms for which black and white adolescent patients are seeking care at the ED for head, neck, or brain injury help to identify social-health risks of sustaining a head, neck, or brain injury. These racial disparities between black and white adolescents seen at the ED for head, neck, or brain injury suggest the need for further research to better understand the national representation of these disparities.

Increase in Seizure Susceptibility After Repetitive Concussion Results from Oxidative Stress, Parvalbumin-Positive Interneuron Dysfunction and Biphasic Increases in Glutamate/GABA Ratio

Chronic symptoms indicating excess cortical excitability follow mild traumatic brain injury, particularly repetitive mild traumatic brain injury (rmTBI). Yet mechanisms underlying post-traumatic excitation/inhibition (E/I) ratio abnormalities may differ between the early and late post-traumatic phases. We therefore measured seizure threshold and cortical gamma-aminobutyric acid (GABA) and glutamate (Glu) concentrations, 1 and 6 weeks after rmTBI in mice. We also analyzed the structure of parvalbumin-positive interneurons (PVIs), their perineuronal nets (PNNs), and their electroencephalography (EEG) signature (gamma frequency band power). For mechanistic insight, we measured cortical oxidative stress, reflected in the reduced/oxidized glutathione (GSH/GSSG) ratio. We found that seizure susceptibility increased both early and late after rmTBI. However, whereas increased Glu dominated the E/I 1 week after rmTBI, Glu concentration normalized and the E/I was instead characterized by depressed GABA, reduced per-PVI parvalbumin expression, and reduced gamma EEG power at the 6-week post-rmTBI time point. Oxidative stress was increased early after rmTBI, where transient PNN degradation was noted, and progressed throughout the monitoring period. We conclude that GSH depletion, perhaps triggered by early Glu-mediated excitotoxicity, leads to late post-rmTBI loss of PVI-dependent cortical inhibitory tone. We thus propose dampening of Glu signaling, maintenance of redox state, and preservation of PVI inhibitory capacity as therapeutic targets for post-rmTBI treatment.

Premortem Chronic Traumatic Encephalopathy Diagnoses in Professional Football

OBJECTIVE

American-style football (ASF) has gained attention because of possible links between repetitive head injury and neurodegenerative diseases. Although postmortem pathologic changes consistent with chronic traumatic encephalopathy (CTE) have been reported in ASF players, there are currently no established premortem diagnostic criteria for CTE. Nevertheless, presented with symptoms of cognitive impairment, clinicians treating former players may be inclined to suggest CTE without a thorough exploration of comorbid factors that demonstrate similar clinical phenotypes to putative CTE.

METHODS

A survey of 3,913 former ASF players aged 24 to 89 was conducted for those who responded by March 2019.

RESULTS

Despite being a postmortem diagnosis, 108 players (2.8%) self-reported clinician-diagnosed CTE. The percentage of players under age 60 years reporting a CTE diagnosis was 2.3% versus 3.7% in participants age 60 or older. Comorbidities in participants self-reporting CTE were significantly more common, including sleep apnea, hypercholesterolemia, obesity, indicators of past or current depression, hypertension, prescription pain medication use, heart conditions, and low testosterone when compared to non-CTE respondents. Patterns of reporting for obesity, hypertension, heart conditions, or hypercholesterolemia differed between older and younger participants. Cognitive impairment symptoms were significantly higher in participants self-reporting CTE.

INTERPRETATION

Some former professional football players have been clinically diagnosed with CTE, a postmortem condition. Comorbidities that can affect cognition were associated with CTE diagnoses in both older and younger players. Although underlying neuropathology cannot be ruled out, treatable conditions should be explored in former athletes demonstrating CTE-linked clinical phenotypes or symptoms as a means of improving cognitive health in these patients. ANN NEUROL 2020 ANN NEUROL 2020;88:106-112.

An investigation of plasma interleukin-6 in sport-related concussion

BACKGROUND

Increasing evidence suggests inflammation is an important component of concussion pathophysiology. However, its etiology, restitution, and potential clinical repercussions remain unknown. The purpose of the current study was to compare the blood concentrations of interleukin (IL) -6, a prominent inflammatory cytokine, between healthy athletes and athletes with a sport-related concussion (SRC), while addressing the potential confounds of sex, recent physical activity, and the interacting effect of concussion history.

METHOD

A prospective, observational cohort study was conducted on athletes at a single academic institute participating across 13 interuniversity sports. Follow-up of 96 athletes who agreed to provide a blood sample was completed: 41 athletes with a physician diagnosed SRC, and 55 healthy athletes. Ella™, the high sensitivity immunoassay system by ProteinSimple was used to measure peripheral plasma concentrations of IL-6 within the first week (median = 4 days, range = 2-7) following injury. A resampled ordinary least squares regression was used to evaluate the relationship between IL-6 concentrations and concussion status, while partial least squares regression was used to evaluate the relationship between IL-6 and both symptom burden and time to clinical recovery.

RESULTS

Regression analysis identified a negative relationship between plasma IL-6 concentrations and the interaction between an acute SRC and a history of concussion (β = -0.29, p = 0.029). IL-6 did not differ between healthy athletes and those with an acute SRC independent of concussion history, and was not correlated with either recovery time or symptom burden in athletes with SRC.

CONCLUSION

Perturbations to circulating IL-6 concentrations, a key inflammatory cytokine, may be more pronounced following SRC in athletes who have a history of concussion. These results add to a growing body of evidence supporting the involvement of inflammation at all phases of recovery following SRC, and potentially support a concomitant effect of prior concussion on acute SRC pathophysiology.

Video Analysis of Concussion Exposures in a National Collegiate Athletic Association Division I Football Team

Background:

Research into improving player safety of sport-related concussion (SRC) in American football has been an ongoing endeavor. In an attempt to better understand the incidence of SRCs in American football, research has focused on the characteristics of SRC during gameplay. Determining SRC specifics and assessing them quantitatively can help identify high-risk scenarios and predict exposure risk.

Purpose:

To identify and assess the incidence of SRCs in a National Collegiate Athletic Association football team by comparing field location, player positions, collision partners, and player cues.

Study Design:

Descriptive epidemiology study.

Methods:

We used physician sideline reports of diagnosed concussions from a Division I football team from September 2010 to December 2018. Game videos were analyzed to identify the field location where the SRC occurred, collision partner, and player behavior postconcussion. The incidence of in-game SRCs by position was also assessed. We used the “words of estimative probability” model to categorize each concussion as certain, almost certain, probable, or even on the basis of our confidence in identifying them using game film.

Results:

This study examined 44 SRCs that occurred over 9 seasons. The SRC incidence was significantly higher in the middle defense (5-20 yards from the line of scrimmage) compared with all other field locations (relative risk, 2.46; 95% CI, 1.14-5.29; P < .05). In-game collision partners were most commonly defensive backs. The most common player cue was a hand to helmet/face mask. The positions with the highest SRC incidence by athlete-exposure, game position, and position play belonged to the defensive backs, wide receivers, and running backs.

Conclusion:

The middle defense had a significantly higher incidence of SRCs than all other field locations. We pose a new method to categorize concussions during video analysis by using words of estimative probability. Knowledge of SRC gameplay characteristics can potentially guide the medical staff and medical observer to better identify them.

The Changing Landscape of Sport Concussion

It was not too long ago that many people referred to concussion as a “hidden injury” and a “complex injury for which we still had much to learn.” We still have a lot to learn about these injuries, but because of the advancement of concussion research we are better informed today than we were just a decade ago. Much of this work began in the early to mid-1990s with studies aimed at equipping clinicians with better concussion-assessment tools. We needed to remove the guesswork, so more systematic and objective concussion-assessment batteries (sideline and clinic) that included symptom checklists, cognitive tests, and balance assessments were developed and validated. As a result, it became easier to detect and/or rule out concussions and to track recovery for several days postinjury. From 2009 through 2014, all 50 states and the District of Columbia passed concussion legislation requiring concussion education for high school and youth athletes, among other things. This was a critical period in which more emphasis was placed on concussion prevention, ultimately leading to increased reporting of these injuries and a reduction in the number of unreported and undiagnosed concussions. More recently, the corpus of science has evolved to identify potential blood and neuroimaging biomarkers to complement the traditional-clinical assessment tools, and newer studies are focused on treatment after concussion—challenging the notions that “rest is best” and that the effects of concussion are permanent and immutable. The research is ongoing, and several large multisite studies will yield important findings to help guide clinical decision making in the next few years.

Preventing injuries must be a priority to prevent disease in the twenty-first century

Injuries continue to be the leading cause of morbidity and mortality for children, adolescents, and young adults aged 1-24 years in industrialized countries in the twenty-first century. In this age group, injuries cause more fatalities than all other causes combined in the United States (U.S.). Importantly, many of these injuries are preventable. Annually in the U.S. there are >9 million emergency department visits for injuries and >16,000 deaths in children and adolescents aged 0-19 years. Among injury mechanisms, motor vehicle crashes, firearm suicide, and firearm homicide remain the leading mechanisms of injury-related death. More recently, poisoning has become a rapidly rising cause of both intentional and unintentional death in teenagers and young adults aged 15-24 years. For young children aged 1-5 years, water submersion injuries are the leading cause of death. Sports and home-related injuries are important mechanisms of nonfatal injuries. Preventing injuries, which potentially cause lifelong morbidity, as well as preventing injury deaths, must be a priority. A multi-pronged approach using legislation, advancing safety technology, improving the built environment, anticipatory guidance by clinical providers, and education of caregivers will be necessary to decrease and prevent injuries in the twenty-first century.

Wearable sensors for monitoring the internal and external workload of the athlete

The convergence of semiconductor technology, physiology, and predictive health analytics from wearable devices has advanced its clinical and translational utility for sports. The detection and subsequent application of metrics pertinent to and indicative of the physical performance, physiological status, biochemical composition, and mental alertness of the athlete has been shown to reduce the risk of injuries and improve performance and has enabled the development of athlete-centered protocols and treatment plans by team physicians and trainers. Our discussions in this review include commercially available devices, as well as those described in scientific literature to provide an understanding of wearable sensors for sports medicine. The primary objective of this paper is to provide a comprehensive review of the applications of wearable technology for assessing the biomechanical and physiological parameters of the athlete. A secondary objective of this paper is to identify collaborative research opportunities among academic research groups, sports medicine health clinics, and sports team performance programs to further the utility of this technology to assist in the return-to-play for athletes across various sporting domains. A companion paper discusses the use of wearables to monitor the biochemical profile and mental acuity of the athlete.

Racial and Ethnic Differences in Emergency Department Utilization and Diagnosis for Sports-Related Head Injuries

Background: Prior studies have shown racial differences in concussion awareness and outcome.

Objective: To assess if racial or ethnic differences exist in Emergency Department (ED) utilization and diagnosis for children with sports-related head injuries.

Methods: We performed a retrospective, cross-sectional analysis of ED visits from 2008 to 2017 using National Electronic Injury Surveillance System (NEISS) data. Population-weighted ED visits for children age 7–18 years with a sport-related injury were included. We compared the probability of an ED visit being for an injury to the head or diagnosed as a concussion between children of different races/ethnicities. Analyses were adjusted for age, gender, sport, year, and location where the injury occurred.

Results: We identified 11,529,994 population-weighted ED visits for pediatric sports-related injuries, of which 1,497,717 (13.0%) were injuries to the head and 619,714 (5.4%) received a diagnosis of concussion. Black children were significantly less likely than non-Hispanic white children to have their ED visit be for an injury to the head [Odds Ratio (OR) 0.72, 95%CI 0.65–0.79] or concussion (OR 0.58, 95%CI 0.50–0.68). Black children presenting to the ED with an injury to their head were less likely than non-Hispanic white children to be diagnosed with a concussion (OR = 0.71, 95%CI 0.59–0.85).

Conclusions: Racial differences exist in both ED utilization for pediatric sports-related head injuries and in the diagnosis of concussion. Further work is needed to understand these differences to ensure all brain injured athletes receive optimal care, regardless of race.

Traumatic Brain Injury-related voiding dysfunction in mice is caused by damage to rostral pathways, altering inputs to the reflex pathways

Brain degeneration, including that caused by traumatic brain injury (TBI) often leads to severe bladder dysfunction, including incontinence and lower urinary tract symptoms; with the causes remaining unknown. Male C57BL/6J mice underwent repetitive moderate brain injury (rmdTBI) or sham injury, then mice received either cis P-tau monoclonal antibody (cis mAb), which prevents brain degeneration in TBI mice, or control (IgG). Void spot assays revealed age-dependent incontinence in IgG controls 8 months after injury, while cis mAb treated or sham mice showed no dysfunction. No obvious bladder pathology occurred in any group. Urodynamic cystometry in conscious mice revealed overactive bladder, reduced maximal voiding pressures and incontinence in IgG control, but not sham or cis mAb treated mice. Hyperphosphorylated tau deposition and neural tangle-like pathology occurred in cortical and hippocampal regions only of IgG control mice accompanied with post-traumatic neuroinflammation and was not seen in midbrain and hindbrain regions associated with bladder filling and voiding reflex arcs. In this model of brain degeneration bladder dysfunction results from rostral, and not hindbrain damage, indicating that rostral brain inputs are required for normal bladder functioning. Detailed analysis of the functioning of neural circuits controlling bladder function in TBI should lead to insights into how brain degeneration leads to bladder dysfunction, as well as novel strategies to treat these disorders.

Medical assessment of potential concussion in elite football: video analysis of the 2016 UEFA European championship

OBJECTIVE

The objective is to determine if suspected concussions in elite football are medically assessed according to the International Conferences on Concussion in Sport consensus statement recommendations.

SETTING

Men's Union of European Football Association (UEFA) Football Championship.

PARTICIPANTS

All professional football players in the UEFA 2016 Championship Tournament.

DESIGN

Observational study.

OUTCOME MEASURES

Potential concussive events (PCEs) were defined as direct head collision incidents resulting in the athlete being unable to immediately resume play following impact. PCEs identified and description of PCE assessment and outcome were accomplished through direct standardised observation of video footage by trained observers in 51 games played in the Men's UEFA European Championship (10 June-10 July 2016).

RESULTS

Sixty-nine total PCEs (1.35 per match) were identified in 51 games played during the 2016 Men's UEFA European Championship. Forty-eight PCEs (69.6%) resulted in two observable signs of concussion, 13 (18.8%) resulted in three signs and 1 (1.4%) resulted in four signs in the injured athletes. Nineteen (27.5%) PCEs were medically assessed by sideline healthcare personnel while 50 (72.5%) were not. Of the 50 PCEs that were not medically assessed, 44 (88%) PCEs resulted in two or more signs of concussion among injured athletes. Of the 19 medically assessed PCEs, 8 resulted in 3 signs of concussion, and 1 resulted in 4 signs; all assessments concluded in the same-game return for the injured athletes.

CONCLUSIONS

PCEs were frequent events in the 2016 UEFA Euro championship, but were rarely assessed concordant with the International Conferences on Concussion in Sport consensus statement recommendations. There is an imperative need to improve the assessment and management of players suspected of concussion in elite football.

Concussions in Sports

Although concussions are common, they are complex, variable, and not entirely understood in terms of pathophysiology and treatment. The incidence of concussion is expected to continue to rise with the increased participation of youth in sports and improved awareness. The role of orthopedic surgeons in concussion management is murky. However, the existing literature does provide a foundation from which orthopedic surgeons who are exposed to concussed patients can function. [Orthopedics. 2019; 42(1):12-21.].

A review of the effects of physical activity and sports concussion on brain function and anatomy

Physical activity has been associated with widespread anatomical and functional brain changes that occur following acute exercise or, in the case of athletes, throughout life. High levels of physical activity through the practice of sports also lead to better general health and increased cognitive function. Athletes are at risk, however, of suffering a concussion, the effects of which have been extensively described for brain function and anatomy. The level to which these effects are modulated by increased levels of fitness is not known. Here, we review literature describing the effects of physical activity and sports concussions on white matter, grey matter, neurochemistry and cortical excitability. We suggest that the effects of sports concussion can be coufounded by the effects of exercise. Indeed, available data show that the brain of athletes is different from that of healthy individuals with a non-active lifestyle. As a result, sports concussions take place in a context where structural/functional plasticity has occurred prior to the concussive event. The sports concussion literature does not permit, at present, to separate the effects of intense and repeated physical activity, and the abrupt removal from such activities, from those of concussion on brain structure and function.

Traumatic brain injury reduction in athletes by neck strengthening (TRAIN)

Reporting of sports-related concussions (SRCs) has risen dramatically over the last decade, increasing awareness of the need for treatment and prevention of SRCs. To date most prevention studies have focused on equipment and rule changes to sports in order to reduce the risk of injury. However, increased neck strength has been shown to be a predictor of concussion rate. In the TRAIN study, student-athletes will follow a simple neck strengthening program over the course of three years in order to better understand the relationship between neck strength and SRCs. Neck strength of all subjects will be measured at baseline and biannually over the course of the study using a novel protocol. Concussion severity and duration in any subject who incurs an SRC will be evaluated using the Sports Concussion Assessment Tool 5th edition, a questionnaire based tool utilizing several tests that are commonly affected by concussion, and an automated eye tracking algorithm. Neck strength, and improvement of neck strength, will be compared between concussed and non-concussed athletes to determine if neck strength can indeed reduce risk of concussion. Neck strength will also be analyzed taking into account concussion severity and duration to find if a strengthening program can provide a protective factor to athletes. The study population will consist of student-athletes, ages 12-23, from local high schools and colleges. These athletes are involved in a range of both contact and non-contact sports.

Rates of concussions and minor head injuries in Quebec, 2003 and 2016, in children under 18 years old, and comparisons with Ontario's rates of mild traumatic brain injuries

OBJECTIVES

Increases of mild traumatic brain injuries in children have been reported in the USA and Ontario over the past decade. The main objective of this study is to calculate the pediatric rates of mild traumatic brain injury in Quebec, and our second objective is to compare them with those in Ontario.

METHODS

Analysts from the Régie de l'Assurance Maladie du Québec (RAMQ, Quebec Health Insurance Board) compiled tables, by age and sex, of all medical services for mild traumatic brain injuries (concussions and minor head injuries) between 2003 and 2016. Quebec's population rates were calculated and yearly graphs were plotted by age and sex.

RESULTS

In Quebec, there were statistically significant increases in rates of mild traumatic brain injury (concussion and minor head injury) in older children: a 2.0-fold increase for those aged 13-17 years, and 1.4-fold increase for those aged 9-12 years. When only considering concussions, girls (13-17 years) had more concussions than boys in 2015 and 2016. The increase in the rates of concussion was significantly higher in Ontario than in Quebec: 4.4- vs. 2.2-fold increase.

CONCLUSIONS

The recent increase in rates of mild traumatic brain injuries reported in the scientific literature has also been observed in Quebec. The fact that the rate of visits for mild traumatic brain injury, per person, remained the same from 2003 to 2016 suggests that the increase was not the result of parents seeking more medical services, but that more of them consulted when their child injured his/her head.

High prevalence of prior contact sports play and concussion among orthopedic and neurosurgical department chairs

OBJECTIVE Increased understanding of the consequences of traumatic brain injury has heightened concerns about youth participation in contact sports. This study investigated the prevalence of high school and collegiate contact sports play and concussion history among surgical department chairs. METHODS A cross-sectional survey was administered to 107 orthopedic and 74 neurosurgery chairs. Responses were compared to published historical population norms for contact sports (high school 27.74%, collegiate 1.44%), football (high school 10.91%, collegiate 0.76%), and concussion prevalence (12%). One-proportion Z-tests, chi-square tests, and binary logistic regression were used to analyze differences. RESULTS High school contact sports participation was 2.35-fold higher (65.3%, p < 0.001) for orthopedic chairs and 1.73-fold higher (47.9%, p = 0.0018) for neurosurgery chairs than for their high school peers. Collegiate contact sports play was 31.0-fold higher (44.7%, p < 0.001) for orthopedic chairs and 15.1-fold higher (21.7%, p < 0.001) for neurosurgery chairs than for their college peers. Orthopedic chairs had a 4.30-fold higher rate of high school football participation (46.9%, p < 0.001) while neurosurgery chairs reported a 3.05-fold higher rate (33.3%, p < 0.001) than their high school peers. Orthopedic chairs reported a 28.1-fold higher rate of collegiate football participation (21.3%, p < 0.001) and neurosurgery chairs reported an 8.58-fold higher rate (6.5%, p < 0.001) compared to their college peers. The rate at which orthopedic (42.6%, p < 0.001) and neurosurgical (42.4%, p < 0.001) chairs reported having at least 1 concussion in their lifetime was significantly higher than the reported prevalence in the general population. After correction for worst possible ascertainment bias, all results except high school contact sports participation remained significant. CONCLUSIONS The high prevalence of youth contact sports play and concussion among surgical specialty chairs affirms that individuals in careers requiring high motor and cognitive function frequently played contact sports. The association highlights the need to further examine the relationships between contact sports and potential long-term benefits as well as risks of sport-related injury.

Mild Traumatic Brain Injury Induces Structural and Functional Disconnection of Local Neocortical Inhibitory Networks via Parvalbumin Interneuron Diffuse Axonal Injury

Diffuse axonal injury (DAI) plays a major role in cortical network dysfunction posited to cause excitatory/inhibitory imbalance after mild traumatic brain injury (mTBI). Current thought holds that white matter (WM) is uniquely vulnerable to DAI. However, clinically diagnosed mTBI is not always associated with WM DAI. This suggests an undetected neocortical pathophysiology, implicating GABAergic interneurons. To evaluate this possibility, we used mild central fluid percussion injury to generate DAI in mice with Cre-driven tdTomato labeling of parvalbumin (PV) interneurons. We followed tdTomato+ profiles using confocal and electron microscopy, together with patch-clamp analysis to probe for DAI-mediated neocortical GABAergic interneuron disruption. Within 3 h post-mTBI tdTomato+ perisomatic axonal injury (PSAI) was found across somatosensory layers 2-6. The DAI marker amyloid precursor protein colocalized with GAD67 immunoreactivity within tdTomato+ PSAI, representing the majority of GABAergic interneuron DAI. At 24 h post-mTBI, we used phospho-c-Jun, a surrogate DAI marker, for retrograde assessments of sustaining somas. Via this approach, we estimated DAI occurs in ~9% of total tdTomato+ interneurons, representing ~14% of pan-neuronal DAI. Patch-clamp recordings of tdTomato+ interneurons revealed decreased inhibitory transmission. Overall, these data show that PV interneuron DAI is a consistent and significant feature of experimental mTBI with important implications for cortical network dysfunction.

Assessment of neuro-optometric rehabilitation using the Developmental Eye Movement (DEM) test in adults with acquired brain injury

PURPOSE

This pilot study sought to determine the efficacy of using the Developmental Eye Movement (DEM) test in the adult, acquired brain injury (ABI) population to quantify clinically the effects of controlled, laboratory-performed, oculomotor-based vision therapy/vision rehabilitation.

METHODS

Nine adult subjects with mild traumatic brain injury (mTBI) and five with stroke were assessed before and after an eight-week, computer-based, versional oculomotor (fixation, saccades, pursuit, and simulated reading) training program (9.6h total). The protocol incorporated a cross-over, interventional design with and without the addition of auditory feedback regarding two-dimensional eye position. The clinical outcome measure was the Developmental Eye Movement (DEM) test score (ratio, errors) taken before, midway, and immediately following training.

RESULTS

For the DEM ratio parameter, improvements were found in 80-89% of the subjects. For the DEM error parameter, improvements were found in 100% of the subjects. Incorporation of the auditory feedback component revealed a trend toward enhanced performance. The findings were similar for both DEM parameters, as well as for incorporation of the auditory feedback, in both diagnostic groups.

DISCUSSION

The results of the present study demonstrated considerable improvements in the DEM test scores following the oculomotor-based training, thus reflecting more time-optimal and accurate saccadic tracking after the training. The DEM test should be considered as another clinical test of global saccadic tracking performance in the ABI population.

Increased Myo-Inositol in Primary Motor Cortex of Contact Sports Athletes without a History of Concussion

The objective of the study was to determine whether repetitive hits to the head at a subclinical level are associated with structural and functional brain abnormalities and whether these effects are influenced by high levels of fitness associated with intense physical activity. Seventy-two college students were recruited: 24 nonathletic, 24 athletes practicing a varsity contact sport, and 24 athletes practicing a varsity noncontact sport. They were recruited for a neuropsychological evaluation and a magnetic resonance imaging session that included magnetic resonance spectroscopy of primary motor cortex (M1) and prefrontal cortex and susceptibility-weighted imaging. There was no evidence for reduced cognitive performance or presence of micro bleeds in contact sports athletes. Abnormalities in contact sports athletes were found for myo-inositol concentration (mIns) in M1, where levels were significantly higher compared with noncontact sports athletes (p = 0.016) and nonathletes (p = 0.029). In prefrontal cortex, glutamate + glutamine (Glx) was significantly reduced in contact sports athletes compared with noncontact sports athletes (p = 0.016), and a similar reduction was observed for gamma-aminobutyric acid (GABA) levels (p = 0.005). Varsity contact sports are associated with area-specific alterations in mIns concentration in the primary motor cortex. In the prefrontal cortex, high levels of fitness could modulate the effects of head impact exposure on prefrontal metabolite concentration. Indeed, although athletes in contact and noncontact sports show different neurometabolic profiles, they do not differ from sedentary controls.

Bibliometric analysis of military trauma publications: 2000-2016

INTRODUCTION

Bibliometric tools can be used to identify the authors, topics and research institutions that have made the greatest impact in a field of medicine. The aim of this research was to analyse military trauma publications over the last 16 years of armed conflict in order to highlight the most important lessons that have translated into civilian practice and military doctrine as well as identify emerging areas of importance.

METHODS

A systematic search of research published between January 2000 and December 2016 was conducted using the Thompson Reuters Web of Science database. Both primary evidence and review publications were included. Results were categorised according to relevance and topic and the 30 most cited publications were reviewed in full. The h-index, impact factors, citation counts and citation analysis were used to evaluate results.

RESULTS

A plateau in the number of annual publications on military trauma was found, as was a shift away from publications on wound and mortality epidemiology to publications on traumatic brain injury (TBI), neurosurgery or blast injury to the head. Extensive collaboration networks exist between highly contributing authors and institutions, but less collaboration between authors from different countries. The USA produced the majority of recent publications, followed by the UK, Germany and Israel.

CONCLUSIONS

In recent years, the number of publications on TBI, neurosurgery or blast injury to the head has increased. It is likely that the lessons of recent conflicts will continue to influence civilian medical practice, particularly regarding the long-term effects of blast-related TBI.

Neurotrauma

Traumatic brain injury remains a major cause of morbidity and mortality throughout the world, affecting young and old alike. Pathologic data have been developed through observations of human autopsies and developing animal models to investigate mechanisms, although animal models do not represent the polypathology of human brain injury and there are likely to be significant differences in the anatomic basis of injury and cellular responses between species. Traumatic brain injury can be defined pathologically as either focal or diffuse, and can be considered to be either primary, directly related to the force associated with the neurotrauma, or secondary, developing as a downstream consequence of the neurotrauma. While neuropathology has traditionally focused on severe head injury, there is increasing recognition of the long-term consequences of traumatic brain injury, particularly repetitive mild traumatic brain injury, and a possible long-term association with chronic traumatic encephalopathy.

Cis P-tau is induced in clinical and preclinical brain injury and contributes to post-injury sequelae

Traumatic brain injury (TBI) is characterized by acute neurological dysfunction and associated with the development of chronic traumatic encephalopathy (CTE) and Alzheimer's disease. We previously showed that cis phosphorylated tau (cis P-tau), but not the trans form, contributes to tau pathology and functional impairment in an animal model of severe TBI. Here we found that in human samples obtained post TBI due to a variety of causes, cis P-tau is induced in cortical axons and cerebrospinal fluid and positively correlates with axonal injury and clinical outcome. Using mouse models of severe or repetitive TBI, we showed that cis P-tau elimination with a specific neutralizing antibody administered immediately or at delayed time points after injury, attenuates the development of neuropathology and brain dysfunction during acute and chronic phases including CTE-like pathology and dysfunction after repetitive TBI. Thus, cis P-tau contributes to short-term and long-term sequelae after TBI, but is effectively neutralized by cis antibody treatment.Induction of the cis form of phosphorylated tau (cis P-tau) has previously been shown to occur in animal models of traumatic brain injury (TBI), and blocking this form of tau using antibody was beneficial in a rodent model of severe TBI. Here the authors show that cis P-tau induction is a feature of several different forms of TBI in humans, and that administration of cis P-tau targeting antibody to rodents reduces or delays pathological features of TBI.

Moving concussion care to the next level: The emergence and role of concussion clinics in the UK

Concussion is a worldwide issue in sports medicine at present, and in recent years has evolved into a major consideration for sports in the United Kingdom (UK). Governing bodies, sports clinicians, and indeed athletes themselves are dealing with the implications that this injury brings. In parallel with this, innovative means of managing this condition are emerging. The creation of specialized concussion clinics (which mirror those present in the United States and Canada) is one means of enhancing concussion care in the UK. In this chapter, the emergence of concussion clinics in the UK will be discussed. The specific roles of the multidisciplinary teams working in these clinics will be outlined (including the disciplines of sports medicine, radiology, neurology, physiotherapy, and psychology/psychiatry), and the approaches used in the management of concussion in this setting will be explored. Future recommendations for the growth and development of clinic-based concussion care in the UK will also be discussed.

Mild Traumatic Brain Injury Evokes Pyramidal Neuron Axon Initial Segment Plasticity and Diffuse Presynaptic Inhibitory Terminal Loss

The axon initial segment (AIS) is the site of action potential (AP) initiation, thus a crucial regulator of neuronal activity. In excitatory pyramidal neurons, the high density of voltage-gated sodium channels (NaV1.6) at the distal AIS regulates AP initiation. A surrogate AIS marker, ankyrin-G (ankG) is a structural protein regulating neuronal functional via clustering voltage-gated ion channels. In neuronal circuits, changes in presynaptic input can alter postsynaptic output via AIS structural-functional plasticity. Recently, we showed experimental mild traumatic brain injury (mTBI) evokes neocortical circuit disruption via diffuse axonal injury (DAI) of excitatory and inhibitory neuronal systems. A key finding was that mTBI-induced neocortical electrophysiological changes involved non-DAI/ intact excitatory pyramidal neurons consistent with AIS-specific alterations. In the current study we employed Thy1-yellow fluorescent protein (YFP)-H mice to test if mTBI induces AIS structural and/or functional plasticity within intact pyramidal neurons 2 days after mTBI. We used confocal microscopy to assess intact YFP+ pyramidal neurons in layer 5 of primary somatosensory barrel field (S1BF), whose axons were continuous from the soma of origin to the subcortical white matter (SCWM). YFP+ axonal traces were superimposed on ankG and NaV1.6 immunofluorescent profiles to determine AIS position and length. We found that while mTBI had no effect on ankG start position, the length significantly decreased from the distal end, consistent with the site of AP initiation at the AIS. However, NaV1.6 structure did not change after mTBI, suggesting uncoupling from ankG. Parallel quantitative analysis of presynaptic inhibitory terminals along the postsynaptic perisomatic domain of these same intact YFP+ excitatory pyramidal neurons revealed a significant decrease in GABAergic bouton density. Also within this non-DAI population, patch-clamp recordings of intact YFP+ pyramidal neurons showed AP acceleration decreased 2 days post-mTBI, consistent with AIS functional plasticity. Simulations of realistic pyramidal neuron computational models using experimentally determined AIS lengths showed a subtle decrease is NaV1.6 density is sufficient to attenuate AP acceleration. Collectively, these findings highlight the complexity of mTBI-induced neocortical circuit disruption, involving changes in extrinsic/presynaptic inhibitory perisomatic input interfaced with intrinsic/postsynaptic intact excitatory neuron AIS output.

Wearable Devices for Sports: New Integrated Technologies Allow Coaches, Physicians, and Trainers to Better Understand the Physical Demands of Athletes in Real time

Elite-level athletes and professional sports teams are continually searching for opportunities to improve athletic performance and gain a competitive advantage on the field. Advances in technology have provided new avenues to maximize player health and safety. Over the last decade, time?motion analysis systems, such as video recording and computer digitization, have been used to measure human locomotion and improve sports performance. While these techniques were state of the art at the time, their usefulness is inhibited by the questionable validity of the acquired data, the labor-intensive nature of collecting data with manual hand-notation techniques, and their inability to track athlete position, movement, displacement, and velocity.