Epidemiology of Sport-Related Concussions in High School Athletes: National Athletic Treatment, Injury and Outcomes Network (NATION), 2011-2012 Through 2013-2014

On-field assessment of concussion: clinical utility of the King-Devick test

Sport-related concussion (SRC) is an important public health concern with up to 3.8 million SRCs occurring each year. As the incidence and rate of SRC increases, reliable and valid tools for diagnosis and management are needed. The King-Devick (K-D) test assesses a patient’s visual function based on reading a series of numbers as well as counting both time to completion and errors. Its rapid administration time and simplicity make the K-D test a potentially useful SRC diagnostic tool, though limitations exist in baseline testing and what constitutes an abnormal score. Additionally, the K-D tests should never be used in isolation to diagnose a concussion, but rather as one test in conjunction with additional clinical measures, as part of an individualized approach to each patient. The current review examines the clinical utility of the K-D test.

Lifetime prevalence of concussion among Canadian ice hockey players aged 10 to 25 years old, 2014 to 2017

BACKGROUND

The primary objective of this study was to identify the self-reported lifetime prevalence of diagnosed concussions among Canadian ice hockey players aged 10 to 25 years old.

METHOD

Medical records were identified for n=5223 athletes whom completed comprehensive baseline assessments with a Canada-wide network of private concussion management clinics. Variables extracted included: sex, age, diagnosed history of and number of prior concussions, diagnosed health condition(s), and Post-Concussion Symptom Scale scores.

RESULTS

Approximately 22% of all athletes, 21.7% of females and 21.8% of males reported that they had sustained at least one diagnosed concussion. Age was significantly associated with history of concussion as was having an additional health condition. Sex was not significantly associated with a history of concussion.

CONCLUSION

Lifetime history of concussion prevalence estimates aligned closely with estimates previously published. Future investigations should seek to establish the prevalence of concussions that occur during ice hockey games and practices alone.

Preliminary Evidence for a Window of Increased Vulnerability to Sustain a Concussion in Females: A Brief Report

A difference exists between sexes for the incidence of concussion injuries and severity of post-injury outcomes with females having a higher incidence rate (in comparable sports) and experience more robust symptoms than males. The basis for this disparity has remained largely unresolved. Recent findings point to a potential biological mechanism that may be related to the menstrual cycle as an arbiter of post-injury outcomes. What has not been addressed, is whether the phase of menstrual cycle (inferred fluctuations of ovarian hormones) contributes to an increased vulnerability to sustain a concussion injury. This prospective, observational study sought to determine if concussions occurred at different frequencies throughout the phase of the menstrual cycle. Female athletes who sustained a concussion injury were queried three times over the 7-day study (e.g., within 48 h of injury, and 4 and 7 days after injury) to recall the number of days that have elapsed since the beginning of their most recent menstruation. Twenty female athletes enrolled after sustaining a concussion; 18 were eumenorrheic and 2 amenorrheic. Among eumenorrheic participants at the time of injury, 2 were in the follicular phase, 4 were in the early luteal phase and 9 were in the late luteal phase. Two athletes were injured on the first and 1 was injured on the second day of menstruation. The greatest number of concussions were sustained during the late luteal phase and during the first 2 days of menstruation. This 9-day window accounted for 2/3rd of the sustained concussions in our study.

Concussion - Part I: The need for a multifaceted assessment

INTRODUCTION

Concussion is among the most commonly occurring sport and recreation injuries in today's society. An understanding of the heterogenous nature of concussion will assist in directing a multifaceted and comprehensive interdisciplinary assessment following injury.

PURPOSE

The purpose of this masterclass article is to summarize the current state of the evidence in the area of concussion, describe typical symptom presentations and assessment techniques that may assist in directing appropriate management following concussion.

IMPLICATIONS

A comprehensive assessment including a thoughtful differential diagnosis will assist the clinician to direct care appropriately and efficiently in individuals who have suffered a concussion.

Incidence and Risk of Concussions in Youth Athletes: Comparisons of Age, Sex, Concussion History, Sport, and Football Position

Objective

This study was designed to determine concussion incidence, risk, and relative risk among middle and high school athletes participating in various sports.

Method

Data were retrospectively obtained from 10,334 athletes of 12 different sports in Hawaii. In addition to determining the overall concussion incidence, comparisons of incidence, risk, and relative risk were made according to age, sex, concussion history, sport, and football position.

Results

The overall incidence of concussion among youth athletes was 1,250 (12.1%). The relative risk for a concussion was almost two times greater in 18-year olds than in 13-year-old athletes. In comparable sports, girls had a 1.5 times higher concussion risk than boys. Athletes with a prior concussion had 3-5 times greater risk to sustain a concussion than those with no history of a concussion. Among varied sports, wrestling and martial arts had the highest relative risk of a concussion, followed by cheerleading, football, and track and field. No differences in concussion risks were found among the football players in different positions.

Conclusions

Older youths, females, those with a history of concussion, and those participating in high contact sports were found to have higher risks of sustaining a concussion. The findings increase awareness of concussion patterns in young athletes and raise concerns regarding protective strategies and concussion management in youth sports.

Modeling sports-related mild traumatic brain injury in animals-A systematic review

Sports-related head trauma has emerged as an important public health issue, as mild traumatic brain injuries (mTBIs) may result in neurodegenerative disorders such as chronic traumatic encephalopathy (CTE). Research into mTBI and CTE pathophysiology are difficult to undertake in athletes, with observational trials and post-mortem analysis the current mainstays. Thus, animal models play an important role in the study of mTBI, however, traditional animal models have focused on acute, severe injuries rather than the more typical mTBI's seen in sport injuries. Recently, a number of animal models have been developed that are both appropriately scaled and biomechanically relevant to the forces sustained by athletes. This review aimed to examine the literature for variables included in these animal models, and the resulting neurotrauma as evidenced by pathology and behavioral deficits. A systematic search of the literature was performed in multiple electronic databases. The inclusion criteria required mimicry of athlete mTBI conditions: freedom of head movement, lack of surgical alteration of the skull, and application of direct contact force. Studies were analyzed for variables including apparatus design features (impact force, change in animal head velocity, and kinetic energy transfer to the head), demonstrated pathology (phosphorylated tau, TDP-43 aggregation, diffuse axonal injury, gliosis, cytokine inflammation response, and genetic integrity), and behavioral changes. These studies suggested that appropriate animal models can assist in understanding the pathological and functional outcomes of athlete mTBI, and could be used as a platform for future studies of diagnostic/prognostic markers and in the development of treatment interventions.

Does soccer headgear reduce the incidence of sport-related concussion? A cluster, randomised controlled trial of adolescent athletes

Background

There have been no large randomised controlled trials to determine whether soccer headgear reduces the incidence or severity of sport-related concussion (SRC) in US high school athletes.

Objective

We aimed to determine whether headgear reduces the incidence or severity (days out from soccer) of SRCs in soccer players.

Methods

2766 participants (67% female, age 15.6±1.2) (who undertook 3050 participant years) participated in this cluster randomised trial. Athletes in the headgear (HG) group wore headgear during the season, while those in the no headgear (NoHG) group did not. Staff recorded SRC and non-SRC injuries and soccer exposures. Multivariate Cox proportional hazards models were used to examine time-to-SRC between groups, while severity was compared with a Wilcoxon rank-sum test.

Results

130 participants (5.3% female, 2.2% male) sustained an SRC. The incidence of SRC was not different between the HG and NoHG groups for males (HR: 2.00 (0.63–6.43) p=0.242) and females (HR: 0.86 (0.54–1.36) p=0.520). Days lost from SRC were not different (p=0.583) between the HG group (13.5 (11.0–018.8) days) and the NoHG group (13.0 (9.0–18.8) days).

Conclusions

Soccer headgear did not reduce the incidence or severity of SRC in high school soccer players.

Trial registration number

NCT02850926.

Hawai'i Concussion Awareness & Management Program (HCAMP): Impact

Concussion, also referred to as mild traumatic brain injury (mTBI), is caused by a direct or indirect blow to the head or body causing the brain to move rapidly within the skull, resulting in immediate, but temporary, brain dysfunction. Developing awareness and promoting concussion education can reduce the number of short and long-term injuries associated with sports and non-sports related concussions in Hawai'i. The purpose of this study was two-fold: (1) to describe the number of concussions in 67 Hawai'i high school athletic programs using the ImPACT database; and (2) to describe which contact and collision sports had the highest rate of concussions in 67 Hawai'i high schools. This was a retrospective study that described the number of concussions generated across school years 2010-2016, concussion data across 14 contact sports, and athletic exposure rating for the 14 contact sports. Data were analyzed and aggregated from a data-bank associated with the Hawai'i Concussion Awareness and Management program. Findings suggest that for Hawai'i high school student athletes' concussions increased from 2010-2013 with a gradual decrease from 2014-2016, specific sports had higher number of concussions (eg, football), and when evaluating concussion rate per 1000 exposures, girls' judo was the highest. These findings stress the need for continued data collection, monitoring, education/awareness and research that will reduce the number of concussions among student athletes.

Concussion Incidence, Duration, and Return to School and Sport in 5- to 14-Year-Old American Football Athletes

OBJECTIVE

To collect prospective data on concussion incidence, risk factors, duration of symptoms, and return to school and sport in 5- to 14-year-old American football participants.

STUDY DESIGN

We conducted a prospective cohort study over 2 years collecting data during two 10-week fall seasons. Youth with concussion were followed to determine time to return to school, sport, and baseline level of symptoms. Logistic regression was used to estimate the risk of sustaining a concussion associated with baseline demographic factors. Time to return to school, sport, and baseline symptoms were analyzed using Kaplan-Meier survival curves.

RESULTS

Of 863 youth followed (996 player-seasons), 51 sustained a football-related concussion, for an athlete-level incidence of 5.1% per season. Youth with history of concussion had a 2-fold increased risk for sustaining an incident concussion (OR, 2.2; 95% CI, 1.1-4.8). Youth with depression had a 5-fold increased risk of concussion (OR, 5.6; 95% CI, 1.7-18.8). After a concussion, 50% of athletes returned to school by 3 days, 50% returned to sport by 13 days, and 50% returned to a baseline level of symptoms by 3 weeks.

CONCLUSIONS

Concussion rates in this study were slightly higher than previously reported, with 5 of every 100 youth sustaining a football-related concussion each season. One-half of youth were still symptomatic 3 weeks after injury. Further research is needed to address the risk of concussion in youth football.

Insomnia and daytime sleepiness: risk factors for sports-related concussion

OBJECTIVE/BACKGROUND

Poor quality and inadequate sleep are associated with impaired cognitive, motor, and behavioral components of sport performance and increased injury risk. While prior work identifies sports-related concussions as predisposing factors for poor sleep, the role of sleep as a sports-related concussion risk factor is unknown. The purpose of this study was to quantify the effect of poor sleep quality and insomnia symptoms on future sports-related concussion risk.

PATIENTS/METHODS

In this study, 190 NCAA Division-1 athletes completed a survey battery, including the Insomnia Severity Index (ISI) and National Health and Nutrition Examination Survey (NHANES) Sleep module. Univariate risk ratios for future sports-related concussions were computed with ISI and NHANES sleepiness scores as independent predictors. An additional multiple logistic regression model including sport, sports-related concussion history, and significant univariate predictors jointly assessed the odds of sustaining a concussion.

RESULTS

Clinically moderate-to-severe insomnia severity (RR = 3.13, 95% CI: 1.320-7.424, p = 0.015) and excessive daytime sleepiness two or more times per month (RR = 2.856, 95% CI: 0.681-11.977, p = 0.037) increased concussion risk. These variables remained significant and comparable in magnitude in a multivariate model adjusted for sport participation.

CONCLUSION

Insomnia and daytime sleepiness are independently associated with increased sports-related concussion risk. More completely identifying bidirectional relationships between concussions and sleep requires further research. Clinicians and athletes should be cognizant of this relationship and take proactive measures - including assessing and treating sleep-disordered breathing, limiting insomnia risk factors, improving sleep hygiene, and developing daytime sleepiness management strategies - to reduce sports-related concussion risk and support overall athletic performance.

Sport-Related Concussion: Evaluation, Treatment, and Future Directions

Sport-related concussion (SRC) is a highly prevalent injury predominantly affecting millions of youth through high school athletes every year. In recent years, SRC has received a significant amount of attention due to potential for long-term neurologic sequelae. However, the acute symptoms and possibility of prolonged recovery account for the vast majority of morbidity from SRC. Modifying factors have been identified and may allow for improved prediction of a protracted course. Potential novel modifying factors may include genetic determinants of recovery, as well as radiographic biomarkers, which represent burgeoning subfields in SRC research. Helmet design and understanding the biomechanical stressors on the brain that lead to concussion also represent active areas of research. This narrative review provides a general synopsis of SRC, including relevant definitions, current treatment paradigms, and modifying factors for recovery, in addition to novel areas of research and future directions for SRC research.

Management of concussion in soccer

BACKGROUND

When participating in contact sports, (mild) head trauma is a common incident-observed in both professional and amateur sports. When head trauma results in transient neurological impairment, a sports-related concussion has occurred. Acute concussion, repetitive concussions, as well as cumulative "sub-concussive" head impacts may increase the risk of developing cognitive and behavioral deficits for athletes, as well as accelerated cerebral degeneration. While this concept has been well established for classic contact sports like American Football, Rugby, or Boxing, there is still an awareness gap for the role of sports-related concussion in the context of the world's most popular sport-Soccer.

METHODS

Here, we review the relevance of sport-related concussion for Soccer as well as its diagnosis and management. Finally, we provide insight into future directions for research in this field.

RESULTS

Soccer fulfills the criteria of a contact sport and is characterized by a high incidence of concussion. There is ample evidence that these events cause functional and structural cerebral disorders. Furthermore, heading, as a repeat sub-concussive impact, has been linked to structural brain changes and neurocognitive impairment. As a consequence, recommendations for the diagnosis and management of concussion in soccer have been formulated by consensus groups. In order to minimize the risk of repetitive concussion in soccer the rapid and reliable side-line diagnosis of concussion with adoption of a strict remove-from-play protocol is essential, followed by a supervised, graduated return-to-play protocol. Recent studies, however, demonstrate that adherence to these recommendations by players, coaches, clubs, and officials is insufficient, calling for stricter enforcement. In addition, future research to solidify the pathophysiological relevance of concussion for soccer athletes seems to be needed. Advanced neuroimaging and neurochemical biomarker analyses (e.g. S100β, tau and neurofilament light (NfL)) may assist in detecting concussion-related structural brain changes and selecting athletes at risk for irreversible damage.

CONCLUSION

Sports-related concussion represents a genuine neurosurgical field of interest. Given the high socioeconomic relevance, neurosurgeons should get involved in prevention and management of concussion in soccer.

The Potential Role of the Cervical Spine in Sports-Related Concussion: Clinical Perspectives and Considerations for Risk Reduction

Sports-related concussion (SRC) occurs due to biomechanical forces to the head or neck that can result in pathophysiological changes in the brain. The musculature of the cervical spine has been identified as one potential factor in reducing SRC risk as well as for underlying sex differences in SRC rates. Recent research has demonstrated that linear and rotational head acceleration, as well as the magnitude of force upon impact, is influenced by cervical spine biomechanics. Increased neck strength and girth are associated with reduced linear and rotational head acceleration during impact. Past work has also shown that overall neck strength and girth are reduced in athletes with SRC. Additionally, differences in cervical spine biomechanics are hypothesized as a critical factor underlying sex differences in SRC rates. Specifically, compared to males, females tend to have less neck strength and girth, which are associated with increased linear and rotational head acceleration. Although our ability to detect SRC has greatly improved, our ability to prevent SRC from occurring and decrease the severity of clinical outcomes postinjury is limited. However, we suggest, along with others, that cervical spine biomechanics may be a modifiable factor in reducing SRC risk. In this commentary, we review the role of the cervical spine in reducing SRC risk, and how this risk differs by sex. We discuss clinical considerations for the examination of the cervical spine and the potential clinical relevance for SRC prevention. Additionally, we provide suggestions for future research examining cervical spine properties as modifiable factors in reducing SRC risk. J Orthop Sports Phys Ther 2019;49(3):202-208. Epub 15 Jan 2019. doi:10.2519/jospt.2019.8582.

Head Injury in Soccer: From Science to the Field; summary of the head injury summit held in April 2017 in New York City, New York

There has been an increased focus and awareness of head injury and sport-related concussion (SRC) across all sports from the medical and scientific communities, sports organisations, legislators, the media and the general population. Soccer, in particular, has been a focus of attention due to the popularity of the game, the frequency of SRC and the hypothesised effects of repetitive heading of the ball. Major League Soccer, US Soccer and the National Women’s Soccer League jointly hosted a conference entitled, ‘Head Injury in Soccer: From Science to the Field’, on 21–22 April 2017 in New York City, New York. The mission of this conference was to identify, discuss and disseminate evidence-based science related to the findings and conclusions of the fifth International Conference on Concussion in Sport held by the Concussion in Sport Group and apply them to the sport of soccer. In addition, we reviewed information regarding the epidemiology and mechanism of head injuries in soccer at all levels of play, data regarding the biomechanics and effects of repetitive head impacts and other soccer-specific considerations. We discussed how to release the information raised during the summit to key stakeholders including athletes, parents, coaches and healthcare providers. We identified future areas for research and collaboration to enhance the health and safety of soccer (football) players.

Sport-Related Concussion in Children and Adolescents

Sport-related concussion is an important topic in nearly all sports and at all levels of sport for children and adolescents. Concussion knowledge and approaches to management have progressed since the American Academy of Pediatrics published its first clinical report on the subject in 2010. Concussion's definition, signs, and symptoms must be understood to diagnose it and rule out more severe intracranial injury. Pediatric health care providers should have a good understanding of diagnostic evaluation and initial management strategies. Effective management can aid recovery and potentially reduce the risk of long-term symptoms and complications. Because concussion symptoms often interfere with school, social life, family relationships, and athletics, a concussion may affect the emotional well-being of the injured athlete. Because every concussion has its own unique spectrum and severity of symptoms, individualized management is appropriate. The reduction, not necessarily elimination, of physical and cognitive activity is the mainstay of treatment. A full return to activity and/or sport is accomplished by using a stepwise program while evaluating for a return of symptoms. An understanding of prolonged symptoms and complications will help the pediatric health care provider know when to refer to a specialist. Additional research is needed in nearly all aspects of concussion in the young athlete. This report provides education on the current state of sport-related concussion knowledge, diagnosis, and management in children and adolescents.

Female athletes: managing risk and maximizing benefit

PURPOSE OF REVIEW

The purpose of this review is to provide an updated summary on the unique aspects of caring for female youth and adolescent athletes.

RECENT FINDINGS

Recent research on female athletes has led to a better understanding of injuries and conditions that are more likely to occur in female youth and adolescent athletes, including the frequency and severity of concussions, musculoskeletal injury such as involving the anterior cruciate ligament, and the female athlete triad. Social factors, such as the growing pressure to specialize in a sport particularly at an early age, also put young female athletes at risk for issues such as overuse injuries. Researchers continue to explore the benefits of athletic participation that extend beyond physical fitness.

SUMMARY

Female participation in youth sports has increased dramatically during the past 50 years. This has led to greater research on how to manage risks and maximize benefits for young female athletes, although there is still much to be learned. Providers should educate patients, parents, and coaches on both the increased risks for female athletes and ways to provide better support and accessibility of youth sports to all children.

The Influence of Athletic Trainers on the Incidence and Management of Concussions in High School Athletes

CONTEXT

In many US high schools, the athletic trainer (AT) has the responsibility to identify and manage athletes with concussions. Although the availability of ATs varies a great deal among schools, how the level of AT availability in high schools affects the reported incidence and management of sport-related concussions (SRCs) is unknown.

OBJECTIVE

To determine how the presence of an AT affects the reporting and management of SRCs.

DESIGN

Prospective cohort study.

PATIENTS OR OTHER PARTICIPANTS

A total of 2459 (female = 37.5%, age = 16.1 ± 1.2 years) athletes from 31 Wisconsin high schools were categorized as having low availability (LoAT), mid availability (MidAT), or high availability (HiAT) of ATs. Athletic trainers recorded the incidence, days lost from sport, and postconcussion management through return to sport. The incidence of SRC reporting among categories was examined using a multivariate Cox proportional hazards model. Fisher exact tests were used to determine if postconcussion management differed based on AT availability.

RESULTS

The incidence of reported SRCs was lower for the LoAT schools (2.4%) compared with the MidAT (5.6%, hazard ratio = 2.59, P = .043) and HiAT (7.0%, hazard ratio = 3.33, P = .002) schools. The median time before the first AT interaction was longer for LoAT schools (24.0 hours) than for MidAT (0.5 hours, post hoc P = .012) and HiAT (0.2 hours, post hoc P = .023) schools. The number of post-SRC interactions was different in all groups (LoAT = 2 interactions, MidAT = 3, and HiAT = 4; all post hoc P values < .05). Days lost were greater for MidAT and HiAT (both 14 days lost) schools compared with LoAT schools (11.5 days lost, post hoc P = .231 and P = .029, respectively). Athletes at LoAT schools were less likely to undergo a return-to-play protocol (9/18 SRCs, 50.0%) than athletes at MidAT (44/47 SRCs, 93.6%; post hoc P = .001) or HiAT (64/64 SRCs, 100%; post hoc P < .001) schools.

CONCLUSIONS

The level of AT availability positively influenced the reported incidence of SRCs as well as postconcussion management activities in this sample of high schools.

Prognostic Factors in Pediatric Sport-Related Concussion

PURPOSE OF REVIEW

Sport-related concussion (SRC) and mild traumatic brain injury (mTBI) have been thrust into the national spotlight, with youth athletes bearing the burden of this public health problem. The current review aims to provide a practical summary of pediatric SRC, including key terminology, return to play/school, and risk factors for post-concussion syndrome (PCS).

RECENT FINDINGS

While the majority of youth athletes recover within 2 to 4 weeks, approximately 10% of athletes experience a protracted recovery with symptoms lasting months, impacting social, scholastic, and sporting activities. In the pediatric population, the strongest predictors of PCS are initial symptom burden and prior concussion, with mixed results behind the factors of gender, headaches, and learning disability. The role of psychiatric, family history, sports, and socioeconomic factors remain in their infancy.

No change in plasma tau and serum neurofilament light concentrations in adolescent athletes following sport-related concussion

Sport-related concussion (SRC), a mild form of traumatic brain injury (TBI), is a common injury in contact sports. Health care professionals rely on subjective criteria (e.g., symptoms), as there is no objective marker for identification of athletes with SRC. Blood-based biomarkers have shown promise as diagnostic and prognostic tools following TBI and SRC. In the present study, we examined plasma tau and serum NF-L, two biomarkers for neuronal/axonal injury, concentrations at preseason and following SRC in contact sport athletes (n = 11) using ultrasensitive single molecule array (Simoa) assays. Preseason baseline samples were collected, and post-concussion samples were obtained at 6- and 14-days following injury. We found no difference between baseline, 6-day and 14-day post-concussion concentrations of tau (p = 0.14) or NF-L (p = 0.53). Further, no difference was found between preseason baseline and all post-SRC samples for tau (p = 0.22) or NF-L (p = 0.98). The total number of symptoms reported on the Standardized Assessment of Concussion– 3^rd Edition (SCAT3) and associated symptom severity scores increased from preseason to 6-days post-SRC but returned to baseline values at 14-days (p = 0.02 and p = 0.003, respectively). These results suggest that the severity of neuronal injury in this cohort of contact sport athletes with clinical uncomplicated SRC was too low to be detected by tau and NF-L measurements in blood samples obtained at 6- and 14-days post-injury.

Peripheral Vestibular System Histopathologic Changes following Head Injury without Temporal Bone Fracture

Objective

Vestibular symptoms such as dizziness and vertigo are common after head injury and may be due to trauma to the peripheral vestibular system. The pathophysiology of peripheral vestibular symptoms following head injury without temporal bone (TB) fracture, however, is not well understood. Herein, we investigate the histopathology of the peripheral vestibular system of patients who sustained head injury without a TB fracture.

Study Design

Otopathology study.

Setting

Otopathology laboratory.

Subjects and Methods

TB of subjects with a history of head injury without TB fractures were included and evaluated by light microscopy. Specimens were assessed for qualitative and quantitative characteristics, such as number of Scarpa’s ganglion cells in the superior and inferior vestibular nerves, vestibular hair cell and/or dendrite degeneration in vestibular end organs, presence of vestibular hydrops, and obstruction of the endolymphatic duct.

Results

Five cases (n = 5 TBs) had evidence of vestibular pathology. There was a decrease of 48.6% (range, 40%-59%) in the mean count of Scarpa’s ganglion cells as compared with that of normative historical age-matched controls. Moderate to severe degeneration of the vestibular membranous labyrinth was identified in the posterior, superior, and lateral canals in several cases (50%, n = 4 TBs). The maculae utriculi and sacculi showed mild to severe degeneration in 2 cases. Additional findings include vestibular hydrops (25%, n = 2 TBs) and blockage of the endolymphatic duct (n = 1 TB).

Conclusions

Otopathologic analysis of patients with a history of head injury without TB fracture demonstrated peripheral vestibular otopathology. Future studies are necessary to determine if otopathology findings are directly attributable to head injury.

Sex Differences in Common Sports Injuries

Common sports injuries include bone stress injuries (BSIs), anterior cruciate ligament (ACL) injuries, and concussions. Less commonly recognized are the specific sex differences in epidemiology, risk factors, and outcomes of these conditions by sex. An understanding of these factors can improve their clinical management, from prescribing appropriate prehabilitation to guiding postinjury rehabilitation and return to play. This narrative review summarizes the sex differences in the diagnosis and management of BSIs, ACL injuries, and concussions. Although BSIs are more common in female athletes, risk factors for both sexes include prior injury and relative energy deficiency in sport (RED-S). Risk factors in female athletes include smaller calf girth, femoral adduction, and higher rates of loading. Female athletes are also at greater risk for developing ACL injuries in high school and college, but their injury rate is similar in professional sports. Increased lateral tibial slope, smaller ACL size, and suboptimal landing mechanics are additional risk factors more often present in female athletes. Male athletes are more likely to have ACL surgery and have a higher rate of return to sport. Concussions occur more commonly in female athletes; however, female athletes are also more likely to report concussions. Male athletes more commonly sustain concussion through contact with another player. Female athletes more commonly sustain injury from contact with playing equipment. Managing post-concussion symptoms is important, and female athletes may have prolonged symptoms. An understanding of the sex-specific differences in these common sports injuries can help optimize their prehabilitation and rehabilitation. LEVEL OF EVIDENCE: IV.

Using opinion leaders to address intervention gaps in concussion prevention in youth sports: key concepts and foundational theory

Behavioral interventions to increase disclosure and proper management of concussion in youth sports have unrealized potential when it comes to preventing concussion. Interventions have focused on changing individual athlete behavior and have fallen short of the potential for sustained systemic behavioral change. One potentially critical reason for this shortfall is that other key determinants of risk behaviors at all levels of the socio-ecological model (e.g. interpersonal, community, policy) are not addressed in extant programming. There is a critical need for theory-driven interventions that address concussion prevention and education at the community level and target sustainable culture change. The Popular Opinion Leader (POL) intervention, a multi-level intervention model previously successfully employed in multiple public health contexts, is theoretically well positioned to affect such change. POL is based on the Diffusion of Innovations framework and involves identifying, recruiting, and training well-respected and trusted individuals to personally endorse prevention and risk-reduction within their social networks. Critical behavioral changes related to concussion disclosure and management have been shown to diffuse to others if enough opinion leaders endorse and support the behaviors. This article summarizes the concepts and principles of POL and describes how it could be adapted for and implemented in youth sport settings. For optimal impact, POL needs to adapt to several factors unique to youth sports settings and culture. First, adult involvement may be important, given their direct involvement in the athlete's medical care. However, parents and coaches' opinions on injury care-seeking, competition, and safety may affect their perceptions of POL. Second, youth sports are structured settings both physically and socioculturally. Games and practices may provide opportunities for the informal interactions that are critical to the success of POL. However, youth sport setting membership is transient as players get older and move to other sport settings; POL approaches need to be self-sustaining despite this turnover. Moreover, stakeholder value placed on athlete development and competition, alongside safety, must be considered. Formative research is needed to ensure that POL principles are translated into the youth sport setting while maintaining fidelity to the concepts and principles that have made POL successful for other health outcomes.

Season and Sport-Specific Adolescent Concussions via Online Surveillance in New Jersey Public High Schools 2015–2017

Despite increased awareness of concussions among student-athletes, local epidemiologic surveillance efforts are limited, especially among adolescents. We analyzed data reported through a state public-school-based online surveillance tool during the fall (summer preseason and regular season), winter, and spring seasons of the 2015–2017 school years at seven participating public high schools across New Jersey. Concussions were sustained during interscholastic and intramural sports and in physical education classes. There were 208 concussions: 142 in fall (123 regular season), 22 in winter (21 regular season), and 44 in spring. Reports stated 75% were first concussions, but 17% were second and 2% were third concussions.

Sex Differences in the Clinical Incidence of Concussions, Missed School Days, and Time Loss in High School Student-Athletes: Part 1

BACKGROUND

Sports-related concussion (SRC) injury rates are well established in collegiate athletics through epidemiological studies using the National Collegiate Athletic Association Injury Surveillance System. However, few studies have examined sex differences, time loss, and missed school days in high school athletes, especially at the state level.

PURPOSE

To identify sex differences in the clinical incidence of SRCs, missed school days, and time loss in high school student-athletes.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

A total of 193,757 (116,434 male and 77,323 female) student-athletes (10th grade ± 1.1) participating in Michigan High School Athletic Association (MHSAA)-sponsored athletic activities were recorded in the Head Injury Reporting System. Certified athletic trainers, school athletic administrators, and coaches from MHSAA high schools reported SRC data and overall participation for the 2015-2016 academic year. Total concussive injuries, as well as missed school days and time loss for each concussive injury, were reported. The clinical incidence was calculated by dividing the number of SRCs in a particular category by the number of participants in that category and presented with 95% CIs. Relative risk ratios (RRs) were determined for sex-comparable sports.

RESULTS

The overall clinical incidence for all sports was 1.7 per 100 player-seasons (95% CI, 1.6-1.8) and 1.9 (95% CI, 1.8-2.0) for male sports and 1.5 (95% CI, 1.4-1.6) for female sports. Female athletes were at a 1.9 (95% CI, 1.8-2.2) times greater risk for enduring SRCs than male athletes in sex-comparable sports, with a greater risk in baseball/softball (RR, 2.7 [95% CI, 1.9-3.8]), basketball (RR, 2.5 [95% CI, 2.1-2.9]), and soccer (RR, 1.6 [95% CI, 1.4-1.9]). Female student-athletes had significantly longer time loss than male student-athletes ( P < .001). The mean number of missed school days did not differ between sexes ( P = .70).

CONCLUSION

High school female student-athletes have a higher risk for an SRC in all sex-comparable sports except lacrosse. This may be because of biomechanical differences of the head-neck segment, hormonal differences, and the fact that female athletes are more likely to report symptoms after a suspected SRC.

CLINICAL RELEVANCE

Despite sex differences in the clinical incidence of SRCs and time loss from participation in high school sports, the numbers of missed school days are relatively similar between sexes.

Comparison of Head Impact Exposure Between Male and Female High School Ice Hockey Athletes

BACKGROUND

Concussion incidence rates are higher among female than male athletes in sports played by both sexes. Biomechanical factors may play a role in observed sex-based differences in concussion incidence.

PURPOSE

To compare head impact counts and magnitudes during sports participation between male and female high school ice hockey athletes.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Over 2 seasons, a total of 21 male and 19 female ice hockey athletes from a single high school were instrumented with impact-sensing adhesive skin patches worn over the mastoid process while participating in games and practices. The impact sensors recorded the number, magnitude (peak linear acceleration [PLA, g] and peak angular acceleration [PAA, rad/s²] of the head; Head Impact Telemetry severity profile [HITsp]), and location of impacts sustained during each instrumented session. Head impact counts, magnitudes, and locations were compared between the sexes.

RESULTS

Males experienced more head impacts than females during games (mean ± SD: 7.7 ± 3.0 vs 5.3 ± 2.0, P < .001) as well as practices (4.3 ± 1.6 vs 3.8 ± 1.1, P = .002). Mean impact magnitudes were greater for females for PLA (18.8 g ± 1.7 g vs 17.1 g ± 1.6 g, P < .001) and HITsp (19.7 ± 1.5 vs 17.7 ± 1.4, P < .001), while mean PAA was greater for males (3057.6 ± 2.0 rad/s² vs 2778.3 ± 2.7 rad/s², P < .001). Female athletes experienced higher PLA, PAA, and HITsp magnitudes for the top 10%, 5%, and 1% of impacts (all P < .050). Males experienced more impacts to the front (34.3%) and back (31.7%) of the head, while females experienced more impacts to the side (43.1%) and top (4.1%) (χ² = 295.70, df = 3, P < .001).

CONCLUSION

While male high school ice hockey athletes experienced more head impacts than females, impact magnitudes tended to be higher for females.

A football helmet prototype that reduces linear and rotational acceleration with the addition of an outer shell

OBJECTIVE

Amid the public health controversy surrounding American football, a helmet that can reduce linear and rotational acceleration has the potential to decrease forces transmitted to the brain. The authors hypothesized that a football helmet with an outer shell would reduce both linear and rotational acceleration. The authors' objectives were to 1) determine an optimal material for a shock-absorbing outer shell and 2) examine the ability of an outer shell to reduce linear and/or rotational acceleration.

METHODS

A laboratory-based investigation was undertaken using an extra-large Riddell Revolution football helmet. Two materials (Dow Corning Dilatant Compound and Sorbothane) were selected for their non-Newtonian properties (changes in viscosity with shear stress) to develop an outer shell. External pads were attached securely to the helmet at 3 locations: the front boss, the side, and the back. The helmet was impacted 5 times per location at 6 m/sec with pneumatic ram testing. Two-sample t-tests were used to evaluate linear/rotational acceleration differences between a helmet with and a helmet without the outer shell.

RESULTS

Sorbothane was superior to the Dow Corning compound in force reduction and recovered from impact without permanent deformation. Of 5 different grades, 70-duro (a unit of hardness measured with a durometer) Sorbothane was found to have the greatest energy dissipation and stiffness, and it was chosen as the optimal outer-shell material. The helmet prototype with the outer shell reduced linear acceleration by 5.8% (from 75.4g to 71.1g; p < 0.001) and 10.8% (from 89.5g to 79.8g; p = 0.033) at the side and front boss locations, respectively, and reduced rotational acceleration by 49.8% (from 9312.8 rad/sec2 to 4671.7 rad/sed2; p < 0.001) at the front boss location.

CONCLUSIONS

Sorbothane (70 duro) was chosen as the optimal outer-shell material. In the outer-shell prototype helmet, the results demonstrated a 5%-10% reduction in linear acceleration at the side and front boss locations, and a 50% reduction in rotational acceleration at the front boss location. Given the paucity of publicly reported helmet-design literature and the importance of rotational acceleration in head injuries, the substantial reduction seen in rotational acceleration with this outer-shell prototype holds the potential for future helmet-design improvements.

Initial symptom presentation after high school football-related concussion varies by time point in a season: an initial investigation

Background

Schedule-based and in-season factors (e.g., competition type) have been shown to be associated with symptom reporting patterns and injury severity in sport-related concussion (SRC). To determine if acute neurocognitive and symptom presentation following SRC differ by time point within a high school football season.

Methods

Multicenter ambispective cohort of high school football players who sustained a SRC (N = 2594). Timing (early, mid, and late season) of SRC was based on median dates for the start of the pre-season, regular season, and playoffs of each states’ football schedules. Analysis of covariance (ANCOVA) investigated differences across season period groups for: (1) neurocognitive test scores, (2) total symptom scores (TSS), and (3) individual symptom increases from baseline within 1-week post-injury.

Results

Significant group differences were observed in TSS, F(2, 2589) = 15.40, p <  0.001, η_p² = 0.01, and individual symptom increases from baseline, F(2, 2591) = 16.40, p <  0.001, η_p² = 0.01. Significant increases were seen from baseline to both midseason and late season in both TSS, χ² = 24.40, p <  0.001, Φ = 0.10 and individual symptoms, χ² = 10.32, p = 0.006, Φ = 0.10. Post hoc tests indicated a linear trend, with late-season injured athletes reporting approximately twice the TSS (13.10 vs. 6.77) and new symptoms (5.70 vs. 2.68) as those with early-season injuries.

Conclusion

In a cohort of American high school football student-athletes, those suffering SRC in the late-season time period had increased acute symptom burden. SRC sustained later in-season may require more conservative management.

Female adolescent elite handball players are more susceptible to shoulder problems than their male counterparts

PURPOSE

Shoulder problems are frequent among senior elite handball players. The objective of this study was to assess the prevalence of shoulder problems among adolescent elite handball players and to investigate potential differences in gender, school grade, playing position and playing level.

METHODS

During the 2014 and 2015 pre-season periods, 471 players (age 15-18 years, 54% female) completed a comprehensive baseline questionnaire regarding history of any shoulder pain and shoulder problems experienced during the past season. The players were monitored weekly for one competition season (September-April) regarding shoulder problems and the amount of match and training. Generalised linear models with a binomial link function were used to calculate a prevalence ratio (PR) with 95% confidence interval (CI) to compare the subgroups of players.

RESULTS

In total, 110 players (23%) reported having substantial shoulder problems (defined as moderate/severe reduction in training volume, or moderate/severe reduction in performance, or complete inability to participate) at some point during the follow-up season, of which almost half reported complete inability to participate. Of those players reporting substantial problems, 43% (95% CI 39-48) did so for at least 3 consecutive weeks during the season. The prevalence was significantly higher in female players (PR 1.46, 95% 1.04-2.06) and in backcourt players (PR 1.58, 95% CI 1.08-2.32), but no differences were found for school grade (PR 1.21 95% CI 0.88-1.67) or playing level (PR 1.09 95% CI 0.76-1.56).

CONCLUSIONS

The prevalence of substantial shoulder problems in adolescent elite handball players is high, especially among females, and this warrants further studies on risk factors for shoulder injury and the development of prevention strategies in handball players already before the age of 15. These findings also highlight the importance of introducing a clinical monitoring programme on a routine basis and improving the medical support, taking gender-related aspects into consideration, at handball-profiled secondary schools.

LEVEL OF EVIDENCE

II.

School Nurses' Perceived Challenges With Concussion Management Procedures in the Secondary School Setting

School nurses have an integral role in managing student health concerns throughout the school day, yet little is known about their specific role in concussion management. Therefore, the purpose of this study was to explore the challenges encountered by school nurses regarding concussion management in the secondary school setting. Twenty-two school nurses employed in the secondary school setting were interviewed via phone. We analyzed the data via the consensual qualitative research paradigm. Overall, we found school nurses face consistent challenges with their role on the concussion management team, specifically related to education of school personnel, parents, and community health-care providers. Challenging topics included the inconsistency of community health-care provider recommendations and others' perceptions of school nurses' preparation and training to be important members of the concussion management team. Efforts to increase concussion education and improve communication across all stakeholders of the concussion management team should be implemented.

When in doubt, sit it out! Pediatric concussion-an update

Concussion is a major public health issue that has received much publicity in recent years. Reported concussions are increasing across all ages, including the highest rates in pediatric age ranges. Due to the age-related physiological responses and differential recovery of symptoms after concussion, special consideration must be given to youth concussions. Concussion can affect each child differently and likely affects children differently than adults. Until the past decade, there has been a scarcity of scientifically rigorous studies examining concussions in children. This increasing amount of research and consensus has begun to influence the definition, evaluation, management, return to school and play recommendations, prevention, and education relating to pediatric concussion. The purpose of this article is a review of relevant research published in the last few years (2015-2017) with highlights of these updates summarized for clinical use.

Post-concussion recovery in children and adolescents: A narrative review

Objectives

To determine if current evidence supports a slower recovery from concussion in children and adolescents when compared to adults, and to assess current management guidelines in view of this evidence.

Design

Narrative review.

Methods

We examined key recent research studies relating to the question “do children take longer to recover from concussion than adults?” Concussion management strategies and a sample of guidelines from different organisations were analysed in view of the current literature.

Results

Recovery has been defined as return to baseline on self-reported concussion symptoms or measures of cognitive deficit. Some studies have compared measures of recovery between children and young adults, and a number of cross-sectional studies have compared groups of children of different ages. The findings varied; however, most studies suggested that children may take longer to recover than adults. Age-related differences have been considered when designing guidelines for the management of concussion.

Conclusions

In view of the differences in time to recovery in children, this review supports the use of more conservative concussion management guidelines in children than in adults.