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

Elevated markers of brain injury as a result of clinically asymptomatic high-acceleration head impacts in high-school football athletes

OBJECTIVE

This prospective observational cohort study of high-school football athletes was performed to determine if high-acceleration head impacts (HHIs) that do not result in clinically diagnosed concussion still lead to increases in serum levels of biomarkers indicating traumatic brain injury (TBI) in asymptomatic athletes and to determine the longitudinal profile of these biomarkers over the course of the football season.

METHODS

Sixteen varsity high-school football athletes underwent baseline neurocognitive testing and blood sampling for the biomarkers tau, ubiquitin C-terminal hydrolase L1 (UCH-L1), neurofilament light protein (NF-L), glial fibrillary acidic protein (GFAP), and spectrin breakdown products (SBDPs). All athletes wore helmet-based accelerometers to measure and record head impact data during all practices and games. At various time points during the season, 6 of these athletes met the criteria for HHI (linear acceleration > 95g and rotational acceleration > 3760 rad/sec2); in these athletes a second blood sample was drawn at the end of the athletic event during which the HHI occurred. Five athletes who did not meet the criteria for HHI underwent repeat blood sampling following the final game of the season. In a separate analysis, all athletes who did not receive a diagnosis of concussion during the season (n = 12) underwent repeat neurocognitive testing and blood sampling after the end of the season.

RESULTS

Total tau levels increased 492.6% ± 109.8% from baseline to postsession values in athletes who received an HHI, compared with 164% ± 35% in athletes who did not receive an HHI (p = 0.03). Similarly, UCH-L1 levels increased 738.2% ± 163.3% in athletes following an HHI, compared with 237.7% ± 71.9% in athletes in whom there was no HHI (p = 0.03). At the end of the season, researchers found that tau levels had increased 0.6 ± 0.2 pg/ml (p = 0.003) and UCH-L1 levels had increased 144.3 ± 56 pg/ml (p = 0.002). No significant elevations in serum NF-L, GFAP, or SBDPs were seen between baseline and end-of-athletic event or end-of-season sampling (for all, p > 0.05).

CONCLUSIONS

In this pilot study on asymptomatic football athletes, an HHI was associated with increased markers of neuronal (UCH-L1) and axonal (tau) injury when compared with values in control athletes. These same markers were also increased in nonconcussed athletes following the football season.

Comparing the Acute Presentation of Sport-Related Concussion in the Pediatric and Adult Populations

Despite growing research on concussion, there is minimal evidence comparing the acute presentation of concussion between pediatric and adult patients. This cross-sectional study compares injury characteristics, symptoms, and neurologic examination in sport-related concussion based on age. Patients presenting to an outpatient sports neurology clinic for initial assessment of concussion within 7 days of injury were divided into 2 groups, 18 and older (n = 28) and 17 and younger (n = 107). There were no significant differences between pediatric and adult patients in any score of the Sport Concussion Assessment Tool-3rd Edition symptom scale, neurologic examination category, pertinent elements of past medical history, or characteristics of the concussion. The pediatric group had higher average hours of sleep (8.1 ± 0.3 vs 7.1 ± 0.58; P = .03) and were less likely to wake refreshed (36.3% vs 65%; P = .02). The initial presentation of concussion within 7 days of injury will likely not differ by age, specifically 18 and older versus 17 and younger.

Mechanisms underlying vulnerabilities after repeat mild traumatic brain injuries

Traumatic brain injury (TBI) has drawn national attention for its high incidence and mechanistic complexity. The majority of TBI cases are "mild" in nature including concussions and mild TBI (mTBI). Concussions are a distinct form of mTBI where diagnosis is difficult, quantification of the incidence is challenging and there is greater risk for subsequent injuries. While concussions occur in the general population, it has become a hallmark injury consistently observed among adolescent and young adult athletes and the risks for repeat TBI (rTBI) is significant. Clinical and experimental evidence shows that the magnitude and duration of deficits is dependent on the number and the interval between injuries. Several studies suggest that metabolic vulnerabilities after injury may contribute to the window for cerebral vulnerability from rTBI. In addition to metabolism, this review addresses how age, sex and hormones also play an important role in the response to repeat concussions. Understanding how these factors collectively contribute to concussion and rTBI recovery is critically important in establishing age/sex appropriate return to play guidelines, injury prevention, therapeutic interventions and mitigation of long-term consequences of rTBI.

The Natural History of Postconcussion Recovery Among High School Athletes

OBJECTIVE

Evaluate postconcussive symptom reporting and recovery.

SETTING

Public high school.

PARTICIPANTS

Unmatched controls (n = 760); students who sustained a sports-related concussion (n = 77); matched controls (gender, grade, sport) (n = 77).

DESIGN

Prospective longitudinal cohort study.

OUTCOME MEASURE

Immediate Postconcussion Assessment and Cognitive Testing.

RESULTS

At baseline, athletes who went on to sustain concussions were more likely than unmatched controls to be younger (P = .02), male (P = .001), and participate in different sports (P < .0001) such as football (concussed = 52%, unmatched controls = 20%). Differences were also noted regarding a previous history of concussion (P = .045; concussed athletes = 26%; unmatched control athletes = 16%) and lifetime number of concussions (P = .05). At baseline, those whose sustained concussions during the study period were more likely than matched controls to report numbness (P = .01) and concentration problems (P = .01) and more likely than unmatched controls to report dizziness (P = .02), sensitivity to light (P = .01), sensitivity to noise (P = .002), and numbness (P = .02). However, when data were reanalyzed and those with a previous history of concussion were removed, differences between those who sustained concussions during the study period and matched controls were no longer significant; when compared to unmatched controls, sensitivity to light (P = .01) and vision problems (P = .04) remained significant. Among those who sustained concussions, median time to recovery was 6 days (95% confidence interval: 4-9), and 71 out of 77 (92%) recovered by the fourth postinjury evaluation (median: 20 days postinjury).

CONCLUSIONS

Course and time frame of recovery were variable. Data also suggest that a previous history of concussion may be contributing to baseline symptom reporting and highlight the potential enduring impact of history of concussion on sensorimotor function. However, further research as to whether preinjury measures of sensorimotor function may increase understanding regarding concussion risk is warranted.

Gender differences in quality of life and symptom expression during recovery from concussion

Pediatric concussion is a significant health concern for parents, medical providers, and schools. This study was designed to gain insight into gender differences in perspectives of children and adolescents recovering from concussion. Specifically, the study explored whether males and females reported different symptom loads for physical symptoms and quality of life after concussion. The Pediatric Life After Concussion Evaluation Scale (PLACES) and the Post Concussion Symptom Scale (PCSS) were completed by 277 participants ages 9-21, with a mean age of 14.8 years. The sample was 47.5% female and 52.5% male. The study showed that overall, females reported more physical and somatic symptoms (Total PCSS, p = .001), worse quality of life during recovery (PLACES, p = .008), difficulty with cognition (p = .001), and elevated emotional symptoms than males (p = .02). When an interaction between gender and time since injury was considered, there were significant interactions for the PCSS, with females experiencing higher physical and cognitive symptom load during the period spanning 1-12 weeks (1-4 weeks: M = 33.18, SD = 27.03; 5-11 weeks: M = 15.0, SD = 16.76). However, for those individuals experiencing symptoms for longer than 12 weeks, males expressed a higher physical and cognitive symptom load (M = 32.36, SD = 26.59). Findings indicate that there are gender differences in the expression of symptoms and perceptions of quality of life after concussion.

The Clinical Implications of Youth Sports Concussion Laws: A Review

The recent passage of state youth sports concussion laws across the country introduces clinical implications for health care professionals caring for student-athletes. Although the laws were established to provide protections for student-athletes and prevent adverse outcomes, efforts aimed at implementation have uncovered various challenges in concussion diagnosis and management. Some of the most salient issues include medical evaluation, return to play, and return to learn. For this reason, health care professionals play a pivotal role in determining the critical next steps after a student is removed from play with a suspected concussion. Also, state laws may influence an influx of concussion patients to health care facilities and, thereby, present various unforeseen challenges that can be mitigated with adequate clinical preparation. This is key to helping student-athletes recover and resume regular activities in sports, recreation, and education. This review describes the various components of state youth sports concussion laws relevant to clinical practice and nuances that health care professionals should appreciate in this context. Additionally, concussion tools and strategies that can be used in clinical practice are discussed.

Sensorimotor and Physiological Indicators of Impairment in Mild Traumatic Brain Injury: A Meta-Analysis

OBJECTIVE

To systematically review the literature with meta-analysis to determine whether persistence of sensorimotor or physiological impairment exists between 4 weeks to 6 months post mild traumatic brain injury (mTBI), and assign level of evidence to findings.

METHOD

The databases PubMed, pscyINFO, SPORTdiscus, Medline, CINAHL and Embase were searched from inception to November 2016 using a priori inclusion criteria. Critical appraisal was performed, and an evidence matrix established level of evidence. Meta-analysis of pooled results identified standardized mean difference (SMD) and 95% confidence intervals (95% CI) between mTBI and healthy controls for a variety of physiological and sensorimotor indicators.

RESULTS

Eighteen eligible articles, with a mean quality score of 15.67 (SD = 2.33) were included in the final review. Meta-analysis of center of motion variable; maximal mediolateral center of motion/center of pressure separation distance SMD [95% CI] approached significance at (-0.42 [-0.84, -0.00], I² = 0%) for dual task, level walking indicating a potential reduction in maximal mediolateral excursion during gait in the mTBI group compared to healthy controls. Significantly reduced variability in the standard deviation of heart beat intervals was observed in the mTBI group (-0.51 [-0.74, -0.28], I² = 0%). Overall, significant group differences in 36 sensorimotor and physiological variables (eg, balance, gait velocity and motion analysis outcomes, various oculomotor tasks, as well as heart rate variability frequency domains) were identified.

CONCLUSION

Findings demonstrate that persistence of sensorimotor and physiological changes beyond expected recovery times following subacute mTBI in an adult population is possible. These findings have implications for post-injury assessment and management.

The course and prognostic factors of cognitive outcomes after traumatic brain injury: A systematic review and meta-analysis

Despite indications that TBI may be a precursor of cognitive decline and subsequent development of Alzheimer's disease, little is known about the time course of this relationship and the factors involved. This systematic review summarizes the evidence pertinent to this subject matter. All English language studies of longitudinal design, and works cited within them, found in six literature databases, were considered, and their quality assessed. Of 65 articles appraised, 44 studies were selected. Results were organized by timing of assessments, injury severity, and cognitive domains assessed. Differences in the course of cognitive performance were observed across injury severity groups and cognitive domains, with differential proportions of reports of improvement, decline, or no change over time. The evidence for genetic, sex-, age-, and injury-related factors as determinants of cognitive outcome was inconsistent. The non-uniform trajectory of cognitive performance post-TBI supports the notion that this construct is non-homogeneous, and that different factors influence its course. Agreement on a core set of predictors and consideration of psychometric properties of outcome measures is needed.

Using Accelerometers to Record Postural Sway in Adolescents With Concussion: A Cross-Sectional Study

OBJECTIVE

To investigate the magnitude of postural sway induced by different balance tasks in adolescents with concussion and to examine the associations of postural sway with concussion symptoms.

DESIGN

Cross-sectional study.

PATIENTS OR OTHER PARTICIPANTS

Fifty-six adolescents (20 girls, 36 boys) between 13 and 17 years of age who sustained a concussion within the past 44 days and were still symptomatic.

MAIN OUTCOME MEASURE(S)

Anterior-posterior postural sway was measured using an accelerometer attached to the participant's lower back while he or she performed 6 static-balance tasks that varied the visual input, type of surface, and foot stance. Participants self-reported symptoms that occurred at the time of the concussion (eg, dizziness, confusion, amnesia) as well as at the time of balance testing (eg, eye and head movement-induced dizziness).

RESULTS

The normalized path length of postural sway during the different balance tasks was greater with the eyes closed (mean = 19.3 mG/s) compared with the eyes open (mean = 12.4 mG/s; P < .001). Furthermore, sway while standing with the feet together on a foam surface (mean = 17.9 mG/s) or while tandem standing on a firm surface (mean = 19.4 mG/s) was greater than sway while standing with the feet together on a firm surface (mean = 10.3 mG/s; P < .001). Greater sway was associated with dizziness and confusion reported at the time of injury ( P < .05). Dizziness and headache symptoms at rest were positively correlated with sway ( P < .05).

CONCLUSIONS

Using accelerometers to measure postural sway during different challenging balance conditions in adolescents with concussion may provide an objective means of quantifying balance impairments in clinical environments. Furthermore, the association of these measurements with symptoms suggests a need to account for symptom severity at the time of testing.

Bell Ringers: Factors Related to Concussive Events in Children Playing Tackle Football

INTRODUCTION

Sports-related concussion is a significant pediatric health risk, given the number of children involved in sports and the vulnerability of developing brains. Although most research has focused on high school/college athletes, these findings may not be applicable to younger athletes.

METHOD

A mixed-methods analysis examined concussion incidence and sequelae in a cohort of 8- to 13-year-old males (N = 31) playing youth football and their parents. Parents provided background information and completed mood/behavioral questionnaires, and each athlete completed a neuropsychological battery.

RESULTS

Eight athletes (26%) had a history of concussion before assessment. Concussion risk was related to lack of medical evaluation in prior concussions, tackling exposure (in both offensive and defensive positions), and multisport participation. There were no cognitive or psychological differences based on concussion history.

DISCUSSION

Findings identify factors that may contribute to concussion risk in children and show the need for further research in this understudied population.

Risk Factors for Prolonged Symptoms of Mild Traumatic Brain Injury: A Pediatric Sports Concussion Clinic Cohort

OBJECTIVE

To examine predictors of prolonged symptom duration from mild traumatic brain injury (mTBI) in a pediatric sports medicine specialty clinic cohort as these predictors may be distinct in this population.

DESIGN

Retrospective chart review.

SETTING

Outpatient specialty clinic.

PATIENTS

Charts of 549 patients (age range: 10-18 years) with concussions were reviewed in an outpatient clinic that predominantly managed sports-related injuries (77.3%). Patients (n = 431) included in the final analysis met the criteria for mTBI and were symptomatic at their first visit.

ASSESSMENT OF RISK FACTORS

Patient history, injury, and recovery variables were evaluated.

MAIN OUTCOME MEASURES

Predictors of prolonged time to reach self-reported symptom recovery were evaluated using Cox proportional hazards.

RESULTS

Median time to symptom recovery of the 431 patients who presented to clinic with symptoms was 40 days (full clinic sample median = 34 days). Analyses identified 3 unique predictors of symptom recovery: loss of consciousness (LOC) [hazard ratio (HR) = 0.56, P < 0.0001], female sex (HR = 0.57, P < 0.0001), and concussion symptom score at first clinic visit (HR = 0.76, P < 0.0001).

CONCLUSIONS

Prolonged duration of mTBI symptoms in patients who present to a pediatric sports-based concussion clinic is related to initial symptom severity, female sex, and LOC.

Rehabilitation of an Adolescent Equestrian Athlete With a History of Multiple Concussions: A Case Report Describing an Adapted Return-to-Sport Protocol

BACKGROUND

Equestrian riding is a sport with a high risk of concussion. Currently, the literature guiding rehabilitation for concussions in equestrian athletes is limited, especially for directing return to sport.

CASE DESCRIPTION

In this case report, a 14-year-old female equestrian athlete presented to physical therapy following her third concussion in 3 years. Her primary complaints were headaches, dizziness, difficulty concentrating, light sensitivity, and neck pain. On examination, the patient demonstrated reproduction of symptoms during testing of the vestibular-ocular reflex, showed a 3-line symptomatic loss on the dynamic visual acuity test, and had impairments in the joint position error test (1/5 correct on the left, 4/5 correct on the right) and a Balance Error Scoring System (BESS) score of 38/60 errors. A return-to-riding protocol was adapted from general return-to-sport guidelines and tailored to meet the unique demands of the patient's equestrian sport. The protocol included phased progression through no activity, light aerobic activity, moderate aerobic activity, sport-specific nonjumping skills, sport-specific jumping skills, full practice, and return to competition. During the protocol, the patient participated in 8 physical therapy sessions over 4 weeks for vestibular training, aerobic conditioning, and cervical and core exercises, as well as equestrian exercises at her stables.

OUTCOMES

At the final evaluation, the patient reported no symptoms at rest, with exercise, or when testing vestibular-ocular reflex. Improvements were noted in the dynamic visual acuity test, joint position error, and BESS, with changes in the BESS exceeding minimal detectable change. The patient completed the full return-to-riding protocol in 8 weeks and was able to return to equestrian competition without complaints.

DISCUSSION

This case report describes the physical therapy management of an adapted return-to-sport protocol for an equestrian athlete with a history of multiple sport-related concussions.

LEVEL OF EVIDENCE

Therapy, level 5. J Orthop Sports Phys Ther 2018;48(12):934-942. Epub 27 Jul 2018. doi:10.2519/jospt.2018.8214.

Evaluation of a theory-based concussion education program for secondary school student-athletes in Ireland

Concussion education is an important aspect of concussion prevention. The purpose of this study was to investigate the effect of a novel, theory of planned behavior (TPB)-driven concussion education program on secondary school athletes' concussion-reporting relevant cognitions immediately post-intervention and at 3 months follow-up. Data were collected from 428 secondary school athletes during the 2016-2017 academic year: 229 were assigned to an intervention group of which 59 (25.76%) completed assessments at all timepoints; 199 were assigned to a control group of which 153 (76.88%) completed assessments at all timepoints. Using repeated measures ANOVAs, we examined differences in athletes' concussion-reporting cognitions, by group and gender. The program had a significant positive effect on athletes' knowledge (P < 0.01), perceived behavioral control over concussion recognition and reporting (P < 0.01), and reporting intention (P < 0.01). These results were maintained at 3 months follow-up, with the exception of perceived behavioral control. The program did not have a significant effect on athletes' attitudes toward concussion reporting and subjective reporting norms. Results suggest that the TPB may be a useful framework to inform the development of more effective educational programs. There is a need for multi-layered interventions that aim to create sporting environments that encourage positive concussion care seeking behaviors.

Concussion in adolescent rugby union players: comprehensive acute assessment protocol and development of the SSC concussion passport to monitor long-term health

Introduction

Sports-related concussion (SRC) can be challenging to diagnose, assess and manage. Much of the SRC research is conducted on adults. The assessment of SRC should aim to identify deficits using a detailed multimodal assessment; however, most studies investigating the effects of SRC use diagnostic tools in isolation. It is likely that a combination of diagnostic tests will improve diagnostic accuracy. In this study, we aim to investigate how concussion affects adolescent rugby players and how a variety of diagnostic tools interact with each other as participants recover from their injury. The study will also determine the logistics of recording an individual’s concussion history on a virtual ‘Concussion Passport’ that would remain with the individual throughout their sporting career to allow monitoring of long-term health.

Methods and analysis

All rugby players (n=211) from the Senior Cup Teams of five schools in Dublin, Ireland will be invited to participate in the study. Baseline testing will be performed at the Sports Surgery Clinic, Dublin (SSC) before the rugby season commences. Participants will be followed up over the course of the rugby season. At baseline and at each postconcussion visit, participants will complete the following: Questionnaire, Sports Concussion Assessment Tool 3, Balance Error Scoring System, Computerised Neurocognitive Testing, Vestibulo-ocular assessment, King Devick test, Graded exercise test, Blood tests, Neck strength, FitBit.

Ethics and dissemination

Ethical approval was obtained from the Sports Surgery Clinic Research Ethics Committee (Approval number: SSC 0020). On completion of the study, further papers will be written and published to present the results of the various tests.

Trial registration number

NCT03624634.

A targeted neuropsychological examination of children with a history of sport-related concussion

Experimental research suggests that sport-related concussion can lead to persistent alterations in children's neurophysiology and cognition. However, the search for neuropsychological tests with a similar ability to detect long-term deficits continues.

PRIMARY OBJECTIVE

The current study assessed whether a target battery of neuropsychological measures of higher cognition and academic achievement would detect lingering deficits in children 2 years after injury.

RESEARCH DESIGN

Cross-sectional.

METHODS AND PROCEDURE

A total of 32 pre-adolescent children (16 concussion history, 16 control) completed a targeted battery of neuropsychological and academic tests.

MAIN OUTCOMES AND RESULTS

Children with a history of concussion exhibited selective deficits during the Raven's Coloured Progressive Matrices, Comprehensive Trail-Making Test, and the mathematics sub-section of the WRAT-3. Deficit magnitude was significantly related to age at injury, but not time since injury.

CONCLUSIONS

The current results suggest that neuropsychological measures of higher cognition and academic achievement may be sensitive to lingering deficits, and that children injured earlier in life may exhibit worse neuropsychological and academic performance.

Public Attitudes and Knowledge About Youth Sports Participation and Concussion Risk in an Urban Area

BACKGROUND

Every year, millions of children in the United States participate in youth full-contact sports, which carry concussion risks-the long-term sequelae of which are not well understood. We examined the attitudes and knowledge of adults in Chicago about youth sports participation, concussion risk, and whether physicians should counsel against youth participation in full-contact sports.

METHODS

An anonymous paper survey featuring 13 attitudinal, 13 demographic, and 9 knowledge questions was distributed to a convenience sample of adults ≥18 years in hospital waiting areas and four Chicago parks. Participants were asked to hypothetically consider themselves the parent of a 10-year-old child regarding attitudes towards full-contact sports participation.

RESULTS

Between June 13 and July 27, 2016, 1091 partial or complete valid surveys were collected. Almost half (46%) of respondents would not allow a hypothetical 10-year-old son to play tackle football. The majority (74%) of respondents agreed that it was appropriate for physicians to counsel against youth participation in full-contact sports. Respondents obtained information about concussions from, on average, 2-3 sources, although only 34% received information from physicians. Respondents demonstrated a high concussion knowledge level (average: 6.75 of 9 questions). However, only 39% of respondents correctly answered that the following statement was false: "After a mild concussion, there are usually visible changes on medical imaging".

CONCLUSIONS

Overall, respondents are well-informed about concussions. They are divided about the participation of youth in full-contact sports and are amenable to physician counseling against youth participation in full-contact sports.

The Age Variable in Childhood Concussion Management: A Systematic Review

Background

Sports-related concussion in young children has become a significant international public health issue. This paper reviews the research literature in an effort to shed light on the question, "At what age should young children be managed differently than adults or older adolescents?"

Method

A systematic review, registered with PROSPERO and using PRISMA guidelines, was conducted rendering 37 sports concussion original research studies that examined age as a variable (5-18 years), and which met specific inclusion/exclusion criteria.

Findings

There are no defined, evidence-based age groups for childhood concussion to substantiate differential management across the childhood and adolescent age span. There is evidence to support: (1) concussion may present differently across developmental stages; (2) with increasing age, adolescents may exhibit more symptoms from concussion; (3) the age range of 12-13 is the most frequently used cutoff point between younger and older children; (4) sports concussion research has classified the age variable in children in a number of manners: educational, developmental, sport level, or as a continuous variable, or matter of sample convenience; and (5) four general groupings of young versus pre-puberty child and early versus late adolescent are often utilized.

Conclusions

Due to limited measures and challenges of assessing younger children, current research presents a limited understanding of childhood concussion. Studies in children often lack explained rationales or theories behind age groupings or cutoffs. There is a need for studies dedicated to the question of how concussion varies developmentally from preschool through late adolescence to guide diagnosis and management.

A systematic review of criteria used to define recovery from sport-related concussion in youth athletes

OBJECTIVE

The Concussion in Sport Group guidelines recommend a multifaceted approach to help clinicians make return to sport decisions. The purpose of this study was to identify the most common multifaceted measures used to define clinical recovery from sport-related concussion in young athletes (high school and/or college level) and to summarise existing knowledge of criteria used to make return to sport decisions.

DESIGN

Systematic review.

DATA SOURCES

The PubMed (MEDLINE), SPORTDiscus and Embase electronic databases were searched from 1 January 2000 to 1 March 2017 by three independent reviewers.

ELIGIBILITY CRITERIA

Inclusion criteria: elementary, high school and college age groups, and a specific definition of clinical recovery that required two or more measures.

EXCLUSION CRITERIA

review articles, articles using the same sample population, case studies, non-English language and those that used one measure only or did not specify the recovery measures used.

STUDY QUALITY

Study quality was assessed using the Downs and Black Criteria.

RESULTS

Of 2023 publications, 43 met inclusion criteria. Included articles reported the following measures of recovery: somatic symptom resolution or return to baseline (100%), cognitive recovery or return to baseline (86%), no exacerbation of symptoms on physical exertion (49%), normalisation of balance (30%), normal special physical examination (12%), successful return to school (5%), no exacerbation of symptoms with cognitive exertion (2%) and normalisation of cerebral blood flow (2%). Follow-up to validate the return to sport decision was reported in eight (19%) articles. Most studies were case-control or cohort (level of evidence 4) and had significant risk of bias.

CONCLUSION

All studies of sport-related concussion use symptom reports to define recovery. A minority of studies used multiple measures of outcome or had clearly defined recovery criteria, the most common being a combination of a self-reported symptom checklist and a computerised neurocognitive test. Future studies ideally should define recovery a priori using objective physiological measures in addition to symptom reports.

Modeling the Structure of Acute Sport-Related Concussion Symptoms: A Bifactor Approach

OBJECTIVES

Concussions cause diverse symptoms that are often measured through a single symptom severity score. Researchers have postulated distinct dimensions of concussion symptoms, raising the possibility that total scores may not accurately represent their multidimensional nature. This study examined to what degree concussion symptoms, assessed by the Sport Concussion Assessment Tool 3 (SCAT3), reflect a unidimensional versus multidimensional construct to inform how the SCAT3 should be scored and advance efforts to identify distinct phenotypes of concussion.

METHODS

Data were aggregated across two prospective studies of sport-related concussion, yielding 219 high school and college athletes in the acute (<48 hr) post-injury period. Item-level ratings on the SCAT3 checklist were analyzed through exploratory and confirmatory factor analyses. We specified higher-order and bifactor models and compared their fit, interpretability, and external correlates.

RESULTS

The best-fitting model was a five-factor bifactor model that included a general factor on which all items loaded and four specific factors reflecting emotional symptoms, torpor, sensory sensitivities, and headache symptoms. The bifactor model demonstrated better discriminant validity than the counterpart higher-order model, in which the factors were highly correlated (r=.55-.91).

CONCLUSIONS

The SCAT3 contains items that appear unidimensional, suggesting that it is appropriate to quantify concussion symptoms with total scores. However, evidence of multidimensionality was revealed using bifactor modeling. Additional work is needed to clarify the nature of factors identified by this model, explicate their clinical and research utility, and determine to what degree the model applies to other stages of injury recovery and patient subgroups. (JINS, 2018, 24, 793-804).

Imaging of Concussion in Young Athletes

Conventional neuroimaging examinations are typically normal in concussed young athletes. A current focus of research is the characterization of subtle abnormalities after concussion using advanced neuroimaging techniques. These techniques have the potential to identify biomarkers of concussion. In the future, such biomarkers will likely provide important clinical information regarding the appropriate time interval before return to play, as well as the risk for prolonged postconcussive symptoms and long-term cognitive impairment. This article discusses results from advanced imaging techniques and emphasizes imaging modalities that will likely become available in the near future for the clinical evaluation of concussed young athletes.

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.

Effects of Developmental Age on Symptom Reporting and Neurocognitive Performance in Youth After Sports-Related Concussion Compared to Control Athletes

There is increased necessity to focus research on school-aged athletes with sports-related concussion (SRC). This study assessed differences in symptom reporting and neurocognitive performance in youth athletes who sustained a sports-related concussion. A total of 1345 concussed and 3529 nonconcussed athletes (ages 8-21) completed the Immediate Post-concussive Assessment and Cognitive Testing (ImPACT). Analyses of covariance were conducted in order to assess differences in neurocognitive performance and symptom reporting between the sports-related concussion and control groups across age ranges. Longitudinal hierarchical linear modeling was employed to examine age and its relationship with rates of sports-related concussion recovery in neurocognitive performance. Results revealed athletes aged 13 to 15 had significantly lower neurocognitive performance scores compared to same-aged athletes without a history of sports-related concussion. With respect to the hierarchical linear modeling results, age was identified as a unique predictor of symptom recovery, particularly for ages 8 to 12. Results provide a better understanding of typical symptom reporting and neurocognitive outcomes for younger athletes across different ages.

Mild Traumatic Brain Injury in Adolescent Mice Alters Skull Bone Properties to Influence a Subsequent Brain Impact at Adulthood: A Pilot Study

Mild traumatic brain injuries (mTBI) are common during adolescence, and limited clinical evidence suggests that a younger age at first exposure to a mTBI may lead to worse long-term outcomes. In this study, we hypothesized that a mTBI during adolescence would predispose toward poorer neurobehavioral and neuropathological outcomes after a subsequent injury at adulthood. Mice received a mild weight drop injury (mTBI) at adolescence (postnatal day 35; P35) and/or at adulthood (P70). Mice were randomized to 6 groups: 'sham' (sham-surgery at P35 only); 'P35' (mTBI at P35 only); 'P35 + sham' (mTBI at P35 + sham at P70); 'sham + P70' (sham at P35 + mTBI at P70); 'sham + sham' (sham at both P35 and P70); or 'P35 + P70' (mTBI at both P35 and P70). Acute apnea and an extended righting reflex time confirmed a mTBI injury at P35 and/or P70. Cognitive, psychosocial, and sensorimotor function was assessed over 1-week post-injury. Injured groups performed similarly to sham controls across all tasks. Immunofluorescence staining at 1 week detected an increase in glial activation markers in Sham + P70 brains only. Strikingly, 63% of Sham + P70 mice exhibited a skull fracture at impact, compared to 13% of P35 + P70 mice. Micro computed tomography of parietal skull bones found that a mTBI at P35 resulted in increased bone volume and strength, which may account for the difference in fracture incidence. In summary, a single mTBI to the adolescent mouse brain did not exacerbate the cerebral effects of a subsequent mTBI in adulthood. However, the head impact at P35 induced significant changes in skull bone structure and integrity. These novel findings support future investigation into the consequences of mTBI on skull bone.

What factors must be considered in ‘return to school’ following concussion and what strategies or accommodations should be followed? A systematic review

Objective

To evaluate the evidence regarding (1) factors affecting return to school (RTS) and (2) strategies/accommodations for RTS following a sport-related concussion (SRC) in children and adolescents.

Design

A systematic review of original studies specifically addressing RTS following concussion in the paediatric and sporting context.

Data sources

MEDLINE (Ovid), Embase (Ovid), PsycInfo (Ovid) electronic databases and the grey literature OpenGrey, ClinicalTrials.gov and Google Advanced.

Eligibility criteria

Studies were included if they were original research on RTS following SRC in children aged 5–18 years published in English between 1985 and 2017.

Results

A total of 180 articles were identified; 17 articles met inclusion criteria. Several factors should be considered for RTS after concussion, including: symptomatology; rest following injury; age/grade; and course load. On RTS after concussion, 17%–73% of students were provided academic accommodations or experienced difficulty with RTS. Students were more likely to obtain academic accommodations in schools with a concussion policy if they had a medical RTS letter and had regular medical follow-up after concussion.

Conclusions

Schools should have a concussion policy and offer individualised academic accommodations to students recovering from SRC on RTS; a medical letter should be provided to facilitate provision/receipt of academic accommodations; students should have early, regular medical follow-up following SRC to help with RTS and monitor recovery; students may require temporary absence from school after SRC; clinicians should assess risk factors/modifiers that may prolong recovery and require more intensive academic accommodations.

PROSPERO registration number

CRD42016039184.

MRI Evidence of Neuropathic Changes in Former College Football Players

OBJECTIVE

To examine effects of participating in collegiate football on neural health several years after retirement. We hypothesized that relative cortical thinning and loss of white matter integrity would be observed in former players.

DESIGN

Former NCAA Division I football players were compared with demographically similar track-and-field athletes with regard to cortical thickness and white matter integrity.

SETTING

Participants participated in MRI scans at the Center for Imaging Research at the University of Cincinnati.

PARTICIPANTS

Eleven former football players and 10 demographically similar track-and-field athletes.

MAIN OUTCOME MEASURES

Normalized cortical thickness was compared between groups using 2-tailed Student t test. As a secondary analysis, Spearman correlation coefficient was calculated between cortical thickness and number of concussions. Fractional anisotropy for regions-of-interest placed in frontal white matter tracts and internal capsule were compared between groups using 2-tailed Student t test.

RESULTS

Football players showed significantly lower cortical thickness within portions of both the frontal and temporal cortex. Affected frontal regions included left frontal pole and right superior frontal gyrus. Affected temporal regions included portions of the superior temporal gyrus, left inferior temporal gyrus, and right middle and superior temporal gyri. Cortical thickness inversely correlated with number of reported concussions over most of these regions. In addition, fractional anisotropy was lower in the right internal capsule of former football players, relative to controls.

CONCLUSIONS

These findings suggest that at least some consequences of high-level collegiate football play persist even after the cessation of regular head blows. Longer-term studies are warranted to examine potential cognitive and functional implications of sustained cortical atrophy.

Detection of Acute and Long-Term Effects of Concussion: Dual-Task Gait Balance Control Versus Computerized Neurocognitive Test

OBJECTIVE

To examine the acute (within 72h of injury) and long-term (2mo postinjury) independent associations between objective dual-task gait balance and neurocognitive measurements among adolescents and young adults with a concussion and matched controls.

DESIGN

Longitudinal case-control.

SETTING

Motion analysis laboratory.

PARTICIPANTS

A total of 95 participants completed the study: 51 who sustained a concussion (mean age, 17.5±3.3y; 71% men) and 44 controls (mean age, 17.7±2.9y; 72% men). Participants who sustained a concussion underwent a dual-task gait analysis and computerized neurocognitive testing within 72 hours of injury and again 2 months later. Uninjured controls also completed the same test protocol in similar time increments.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

We compared dual-task gait balance control and computerized neurocognitive test performance between groups using independent samples t tests. Multivariable binary logistic regression models were then constructed for each testing time to determine the association between group membership (concussion vs control), dual-task gait balance control, and neurocognitive function.

RESULTS

Medial-lateral center-of-mass displacement during dual-task gait was independently associated with group membership at the initial test (adjusted odds ratio [aOR], 2.432; 95% confidence interval [CI], 1.269-4.661) and 2-month follow-up test (aOR, 1.817; 95% CI, 1.014-3.256) tests. Visual memory composite scores were significantly associated with group membership at the initial hour postinjury time point (aOR, .953; 95% CI, .833-.998). However, the combination of computerized neurocognitive test variables did not predict dual-task gait balance control for participants with concussion, and no single neurocognitive variable was associated with dual-task gait balance control at either testing time.

CONCLUSIONS

Dual-task assessments concurrently evaluating gait and cognitive performance may allow for the detection of persistent deficits beyond those detected by computerized neurocognitive deficits alone.

Assessment of Sleep Quantity and Sleep Disturbances During Recovery From Sports-Related Concussion in Youth Athletes

OBJECTIVE

To determine the relation between sleep quantity and sleep disturbances on symptoms and neurocognitive ability during the acute phase (<7d) and after sports-related concussion (SRC; >21d).

DESIGN

Prospective inception cohort study.

SETTING

General community setting of regional middle and high schools.

PARTICIPANTS

A sample (N=971) including youth athletes with SRC (n=528) and controls (n=443) (age, 10-18y).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Athletes completed the Immediate Post-Concussion Assessment and Cognitive Testing battery. Partial correlation analyses and independent t tests were conducted to assess sleep quantity the night before testing. Multivariate analysis of covariance was used to assess sleep disturbances and their interaction with age.

RESULTS

Less sleep quantity was correlated with greater report of cognitive (P=.001) and neuropsychological (P=.024) symptoms specific to prolonged recovery from SRC. Sleep disturbances significantly affect each migraine, cognitive, and neuropsychological symptoms (P<.001). A significant interaction was found between sleep disturbances and age (P=.04) at >21 days post-SRC.

CONCLUSIONS

Findings emphasize that the continued presence of low sleep quantity and sleep disturbances in youth athletes with SRC should be a specific indicator to health professionals that these athletes are at an increased risk of protracted recovery. Further research should identify additional factors that may interact with sleep to increase the risk of protracted recovery.

The value of the identification of predisposing factors for post-traumatic amnesia in management of mild traumatic brain injury

OBJECT

To identify the risk factors for post-traumatic amnesia (PTA) and to document the incidence of PTA after mild traumatic brain injuries.

METHODS

This was a prospective study, affecting mild TBI (mTBI) (Glasgow Coma Scale 14-15) cases attending to the Emergency Department between January 2009 and April 2012 (40 months duration). Patients were divided into two groups (Group A: without PTA, and Group B: with PTA, and they were assessed according to the risk factors.

RESULTS

A total of 1762 patients (males: 1002, 56.8%) were meeting study inclusion criteria [Group A: n = 1678 (83.8%), Group B: n = 84 (4.2%)]. Age, CT findings: (traumatic focal HCs in the frontal and temporal lobes or more diffuse punctate HCs, and skull base fractures), anticoagulation therapy and seizures were independent factors of PTA. There was no statistically significant correlation between PTA and sex, convexity fractures, stroke event, mechanism of mTBI (fall +/or beating), hypertension, coronary heart disease, chronic smokers and diabetes (p > 0.005).

CONCLUSION

CT findings: (traumatic focal HCs in the frontal and temporal lobes or more diffuse punctate HCs and skull base fractures), age, seizures and anticoagulation/antiplatelet therapy, were independent factors of PTA and could be used as predictive factors after mTBI.

The Association Between Premorbid Conditions in School-Aged Children With Prolonged Concussion Recovery

The association between preexisting anxiety, depression, and/or neurodevelopmental disorders and symptom duration among younger children who sustain concussions is not well known. The authors conducted a prospective cohort study of 569 patients presenting to a pediatric neurology clinic with the diagnosis of concussion. The authors measured associations between symptom duration and premorbid conditions, as well as gender, age, mechanism of injury, and other factors. Premorbid conditions were common in both age groups. On univariate modeling female gender, age >12 years, and premorbid conditions were associated with longer symptom duration. On multivariable modeling, females and patients ≤12 years old with a history of headaches, migraines, or a history of psychiatric conditions took significantly longer to recover than those without such conditions. Premorbid conditions are associated with a prolonged recovery from concussion among those patients ≤12 years old.

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.

Investigating the Variability in Mild Traumatic Brain Injury Definitions: A Prospective Cohort Study

OBJECTIVE

To prospectively compare the proportion of traumatic brain injuries (TBIs) that would be classified as mild by applying different published definitions of mild TBI to a large prospectively collected dataset, and to examine the variability in the proportions included by various definitions.

DESIGN

Prospective observational study.

SETTING

Hospital emergency departments.

PARTICIPANTS

Children (N=11,907) aged 3 to 16 years (mean age, 8.2±3.9y). Of the participants, 3868 (32.5%) were girls, and 7374 (61.9%) of the TBIs were the result of a fall. Median Glasgow Coma Scale score was 15.

MAIN OUTCOME MEASURES

We applied 17 different definitions of mild TBI, identified through a published systematic review, to children aged 3 to 16 years. Adjustments and clarifications were made to some definitions. The number and percentage identified for each definition is presented.

RESULTS

Adjustments had to be made to the 17 definitions to apply to the dataset: none in 7, minor to substantial in 10. The percentage classified as mild TBI across definitions varied from 7.1% (n=841) to 98.7% (n=11,756) and varied by age group.

CONCLUSIONS

When applying the 17 definitions of mild TBI to a large prospective multicenter dataset of TBI, there was wide variability in the number of cases classified. Clinicians and researchers need to be aware of this variability when examining literature concerning children with mild TBI.

Cortical thickness and subcortical brain volumes in professional rugby league players

Purpose

The purpose of this study was to examine cortical thickness and subcortical volumes in professional rugby players with an extensive history of concussions compared to control subjects.

Method

Participants included 24 active and former professional rugby league players [Age M(SD) = 33.3(6.3); Range = 21–44] with an extensive history of concussion and 18 age- and education-matched controls with no history of neurotrauma or participation in contact sports. Participants underwent T1-weighted imaging and completed a neuropsychological battery, including two tests of memory. Whole brain cortical thickness analysis and structural volume analysis was performed using FreeSurfer version 6.0.

Results

Professional rugby league players reported greater alcohol consumption (p < .001) and had significantly worse delayed recall of a visually complex design (p = .04). They did not differ from controls on other clinical outcome measures. There were no differences in cortical thickness between the groups. Professional players had smaller whole brain (p = .003), bilateral hippocampi (ps = .03), and left amygdala volumes (p = .01) compared to healthy controls. Within the players group, there were significant associations between greater alcohol use and smaller bilateral hippocampi and left amygdala volumes. There were no associations between structural volumes and history of concussions or memory performance.

Conclusions

The literature examining cortical thickness in athletes with a history of multiple concussions is mixed. We did not observe differences in cortical thickness in professional rugby league players compared to controls. However, smaller subcortical volumes were found in players that were, in part, associated with greater alcohol consumption.

•

No differences in cortical thickness were observed in rugby players compared to controls.

•

Smaller hippocampal and amygdala volumes were observed in rugby players.

•

Greater alcohol use was associated with smaller bilateral hippocampi and left amygdala volumes in rugby players.

Safety and Prognostic Utility of Provocative Exercise Testing in Acutely Concussed Adolescents: A Randomized Trial

OBJECTIVE

To evaluate (1) systematic assessment of exercise tolerance in adolescents shortly after sport-related concussion (SRC) and (2) the prognostic utility of such assessment.

DESIGN

Prospective randomized controlled trial.

SETTING

University and community sports medicine centers.

PARTICIPANTS

Adolescents with SRC (1-9 days from injury). Sixty-five were randomized and 54 completed the study (mean age 15 years, 4 days after injury).

INTERVENTIONS

Buffalo Concussion Treadmill Test (BCTT, n = 27) or not (controls, n = 27) on visit day #1. Heart rate threshold (HRt) at symptom exacerbation represented level of exercise tolerance. Participants reported symptoms daily for 14 days and then had follow-up BCTT (n = 54). Recovery was defined as returning to normal level of symptoms and exercise tolerance, verified by independent physician examination.

MAIN OUTCOME MEASURES

Days to recovery and typical (≤21 days) versus prolonged recovery (>21 days). Mixed effects linear models and linear regression techniques examined symptom reports and time to recovery. Linear regression assessed the association of HRt with recovery time.

RESULTS

Days to recovery (P = 0.7060) and typical versus prolonged recovery (P = 0.1195) were not significantly different between groups. Symptom severity scores decreased in both groups over 14 days (P < 0.0001), were similar (P = 0.2984), and did not significantly increase the day after the BCTT (P = 0.1960). Lower HRt on visit day #1 was strongly associated with prolonged recovery time (P = 0.0032).

CONCLUSIONS

Systematic evaluation of exercise tolerance using the BCTT within 1 week after SRC did not affect recovery. The degree of early exercise intolerance after SRC was important for prognosis. This has implications for school academic and team preparation.

What do coaches want to know about sports-related concussion? A needs assessment study

PURPOSE

This study aims to identify the concussion-related training and education needs of Gaelic Athletic Association (GAA) coaches in Ireland, as well as the preferred method of concussion education delivery.

METHODS

We used a self-report questionnaire to collect data from a convenience sample of 108 GAA coaches in Ireland. Data were captured on (1) informational needs and desires, (2) preferred methods of delivery, and (3) concussion practices and procedures. Questionnaires were completed electronically from June 3rd-September 29th, 2015.

RESULTS

Coaches indicated that they were most interested in receiving information about the (1) signs and symptoms of concussion, (2) assessment of concussion, and (3) return-to-play guidelines. Over two-thirds of participants indicated that in-person training would be the most effective mode of delivery of concussion education for this population. Additionally, only 10% coaches reported that before the start of the season they talked to their athletes about concussion management and safety, and this was more common among coaches who reported being formally educated about concussion.

CONCLUSION

Our findings reveal a disconnect between the concussion education needs and the education that is currently provided to GAA coaches, in terms of content and delivery modality. Our results suggest a need for a multifaceted approach to concussion education, tailored to the needs and learning preferences of the target population.

Age at First Exposure to Repetitive Head Impacts Is Associated with Smaller Thalamic Volumes in Former Professional American Football Players

Thalamic atrophy has been associated with exposure to repetitive head impacts (RHI) in professional fighters. The aim of this study is to investigate whether or not age at first exposure (AFE) to RHI is associated with thalamic volume in symptomatic former National Football League (NFL) players at risk for chronic traumatic encephalopathy (CTE). Eighty-six symptomatic former NFL players (mean age = 54.9 ± 7.9 years) were included. T1-weighted data were acquired on a 3T magnetic resonance imager, and thalamic volumes were derived using FreeSurfer. Mood and behavior, psychomotor speed, and visual and verbal memory were assessed. The association between thalamic volume and AFE to playing football and to number of years playing was calculated. Decreased thalamic volume was associated with more years of play (left: p = 0.03; right: p = 0.03). Younger AFE was associated with decreased right thalamic volume (p = 0.014). This association remained significant after adjusting for total years of play. Decreased left thalamic volume was associated with worse visual memory (p = 0.014), whereas increased right thalamic volume was associated with fewer mood and behavior symptoms (p = 0.003). In our sample of symptomatic former NFL players at risk for CTE, total years of play and AFE were associated with decreased thalamic volume. The effect of AFE on right thalamic volume was almost twice as strong as the effect of total years of play. Our findings confirm previous reports of an association between thalamic volume and exposure to RHI. They suggest further that younger AFE may result in smaller thalamic volume later in life.

Neurocognitive Deficits of Concussed Adolescent Athletes at Self-reported Symptom Resolution in the Zurich Guidelines Era

Background:

Previous studies have evaluated high school and collegiate athletes in the pre–Zurich guidelines era; whether adolescent athletes demonstrate similar neurocognitive decrements in the current concussion management era remains unclear.

Purpose:

To assess for the presence of neurocognitive deficits in adolescents with a sport-related concussion at the time of self-reported symptom resolution.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

We conducted a prospective cohort study of 32 patients, aged 13 to 18 years, who sustained concussions during ice hockey and who were referred to 3 sports medicine clinics between September 1, 2012, and March 31, 2015. Demographic, anthropometric, and injury data were collected at the time of the initial postconcussion evaluation. To document symptoms, patients completed the Post-Concussion Symptom Scale (PCSS) at initial and follow-up visits. Baseline and postinjury neurocognitive function were assessed using computerized neurocognitive testing (Immediate Post-Concussion Assessment and Cognitive Test [ImPACT]), and a reliable change index was used to determine significant changes in composite scores. Statistical comparisons were conducted using the Student t test and Mann-Whitney U test.

Results:

A total of 9 of 32 athletes (28.1%; 95% CI, 14.8%-46.9%) demonstrated continued neurocognitive impairment on ≥1 composite score when no longer reporting concussion-related symptoms, while only 2 of 32 athletes (6.3%; 95% CI, 1.4%-23.2%) demonstrated continued neurocognitive impairment on ≥2 composite scores.

Conclusion:

Neurocognitive deficits persist in adolescent athletes who no longer report concussion-related symptoms, at rates similar to those of collegiate athletes but at longer time intervals. This finding provides further evidence that adolescent athletes with a sport-related concussion demonstrate a protracted recovery and resolution of neurocognitive deficits compared with collegiate and professional athletes. Computer-based neurocognitive testing as part of a multifaceted approach continues to play an important role in return-to-play decision making after a sport-related concussion in adolescent athletes. Test-taking strategies may erroneously identify asymptomatic athletes as exhibiting neurocognitive impairment.

Self-reported history of seizure and baseline neurocognitive test performance in student-athletes: an initial investigation

OBJECTIVES

Baseline neurocognitive assessment data can be critical in return to play (RTP) decision-making following a sport-related concussion (SRC). The literature indicates that many modifying factors of SRC have been studied empirically; however, there has been little investigation into the effect of a self-reported history of seizure(s) on baseline neurocognitive test data. The objective of this investigation was to determine whether a self-reported history of seizure(s) is associated with differences in baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) performance.

METHODS

A retrospective analysis of 18,245 adolescent and young adult athletes' ImPACT scores was performed. After application of inclusion and exclusion criteria, 7,391 participants were dichotomized into groups based on the presence or absence of a self-reported history of seizure. Participants reporting a history of seizure (n = 60) were matched on multiple variables in a 1:3 ratio with controls (n = 180) without a history of self-reported seizure. Baseline ImPACT composite scores were then compared between groups using either a 2-tailed t-test or a Mann-Whitney U-Test.

RESULTS

A significant between-group difference was observed in ImPACT visual motor speed composite scores (35.28 vs. 37.64, p = 0.029, Hedge's g = 0.327), with the group self-reporting a history of seizure performing at inferior average scores. No significant between-group differences were detected in verbal memory, visual memory, reaction time, impulse control, or total symptom scores.

CONCLUSION

Athletes with a history of self-reported seizure scored significantly lower on ImPACT visual motor speed compared to matched controls. As a solitary finding with a small effect size, the clinical significance of this difference is unclear. Apart from the decrease in visual-motor speed, this preliminary analysis suggests that athletes with a history of seizure might not have significantly different neurocognitive baseline test scores when compared with matched controls. Further empirical investigation is warranted to determine if a history of seizure is a modifying factor for SRC.

Hyperarousal Symptoms Explain the Relationship Between Cognitive Complaints and Working Memory Performance in Veterans Seeking PTSD Treatment

OBJECTIVE

Comorbidity and symptom overlap between traumatic brain injury and posttraumatic stress disorder (PTSD) in veterans returning from deployment present challenges with respect to differential diagnosis and treatment. Both conditions frequently manifest with attention and working memory deficits, though the underlying neuropsychological basis differs. This study evaluated whether hyperarousal symptoms explain the relationship between subjective and objective measures of cognition in a veteran sample.

PARTICIPANTS AND PROCEDURES

One-hundred three veterans completed the military version of the PTSD Checklist (PCL), the Neurobehavioral Symptom Inventory, and the Wechsler Memory Scale, 3rd edition digit span task with adequate effort.

RESULTS

Hierarchical regression suggested that hyperarousal, but not other PTSD symptoms, explained the relationship between neurobehavioral symptoms and cognitive functioning. This relationship was present regardless of whether veterans met full PTSD diagnostic criteria or screened positive on a traumatic brain injury screener and was robust to other moderators.

CONCLUSION

These findings highlight the importance of considering traumatic brain injury and PTSD symptom overlap, particularly the relationship between hyperarousal symptoms and attention and working memory deficits, in conceptualizing cases and treatment planning.

The Effect of Pretest Exercise on Baseline Computerized Neurocognitive Test Scores

Background:

Baseline neurocognitive assessment plays a critical role in return-to-play decision making following sport-related concussions. Prior studies have assessed the effect of a variety of modifying factors on neurocognitive baseline test scores. However, relatively little investigation has been conducted regarding the effect of pretest exercise on baseline testing.

Purpose/Hypothesis:

The aim of our investigation was to determine the effect of pretest exercise on baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) scores in adolescent and young adult athletes. We hypothesized that athletes undergoing self-reported strenuous exercise within 3 hours of baseline testing would perform more poorly on neurocognitive metrics and would report a greater number of symptoms than those who had not completed such exercise.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

The ImPACT records of 18,245 adolescent and young adult athletes were retrospectively analyzed. After application of inclusion and exclusion criteria, participants were dichotomized into groups based on a positive (n = 664) or negative (n = 6609) self-reported history of strenuous exercise within 3 hours of the baseline test. Participants with a positive history of exercise were then randomly matched, based on age, sex, education level, concussion history, and hours of sleep prior to testing, on a 1:2 basis with individuals who had reported no pretest exercise. The baseline ImPACT composite scores of the 2 groups were then compared.

Results:

Significant differences were observed for the ImPACT composite scores of verbal memory, visual memory, reaction time, and impulse control as well as for the total symptom score. No significant between-group difference was detected for the visual motor composite score. Furthermore, pretest exercise was associated with a significant increase in the overall frequency of invalid test results.

Conclusion:

Our results suggest a statistically significant difference in ImPACT composite scores between individuals who report strenuous exercise prior to baseline testing compared with those who do not. Since return-to-play decision making often involves documentation of return to neurocognitive baseline, the baseline test scores must be valid and accurate. As a result, we recommend standardization of baseline testing such that no strenuous exercise takes place 3 hours prior to test administration.

Anthropometrics and maturity status: A preliminary study of youth football head impact biomechanics

CONTEXT

There is a paucity of head impact biomechanics research focusing on youth athletes. Little is known about how youth subconcussive head impact tolerances are related to physical size and maturation.

OBJECTIVE

To examine the effects of age, anthropometric and maturational status variability on head impact biomechanics.

DESIGN

Cross-sectional.

SETTING

Outdoor youth football facilities in South Carolina.

PARTICIPANTS

Thirty-four male recreational youth football players, 8 to 13yrs.

INTERVENTIONS

Categorized by CDC standards, independent variables were: age, height, mass, BMI, and estimated peak height velocity (PHV). Participants wore a designated head impact sensor (xPatch) on their mastoid process during practices and games.

MAIN OUTCOME MEASURES

Linear acceleration (g) and rotational acceleration (rad/s²).

RESULTS

Boys in the older age category had a greater linear (F=17.72; P<0.001) and rotational acceleration (F=10.74; P<0.001) than those in the younger category. Post-PHV boys had higher linear (F=9.09, P=0.002) and rotational (F=5.57, P=0.018) accelerations than those who were pre-PHV. Rotational, but not linear acceleration differed by height category with lowest impacts found for the tallest category, whereas both linear and rotational accelerations by mass differences favored average and heavy categories. BMI overweight boys, had the greatest linear (F=5.25; P=0.011) and rotational acceleration (F=4.13; P=0.260) means.

CONCLUSION

Post-PHV boys who were older, taller and had longer legs, but who were not heavier, had higher impacts perhaps due to the type of impacts sustained. Taller boys' heads are above their peers possibly encouraging hits in the torso region resulting in lower impact accelerations. Obese boys did not have sequential results compared to boys in the other BMI categories probably due to league rules, player position, and lack of momentum produced.

Preliminary evidence of reduced brain network activation in patients with post-traumatic migraine following concussion

Post-traumatic migraine (PTM) (i.e., headache, nausea, light and/or noise sensitivity) is an emerging risk factor for prolonged recovery following concussion. Concussions and migraine share similar pathophysiology characterized by specific ionic imbalances in the brain. Given these similarities, patients with PTM following concussion may exhibit distinct electrophysiological patterns, although researchers have yet to examine the electrophysiological brain activation in patients with PTM following concussion. A novel approach that may help differentiate brain activation in patients with and without PTM is brain network activation (BNA) analysis. BNA involves an algorithmic analysis applied to multichannel EEG-ERP data that provides a network map of cortical activity and quantitative data during specific tasks. A prospective, repeated measures design was used to evaluate BNA (during Go/NoGo task), EEG-ERP, cognitive performance, and concussion related symptoms at 1, 2, 3, and 4 weeks post-injury intervals among athletes with a medically diagnosed concussion with PTM (n = 15) and without (NO-PTM) (n = 22); and age, sex, and concussion history matched controls without concussion (CONTROL) (n = 20). Participants with PTM had significantly reduced BNA compared to NO-PTM and CONTROLS for Go and NoGo components at 3 weeks and for NoGo component at 4 weeks post-injury. The PTM group also demonstrated a more prominent deviation of network activity compared to the other two groups over a longer period of time. The composite BNA algorithm may be a more sensitive measure of electrophysiological change in the brain that can augment established cognitive assessment tools for detecting impairment in individuals with PTM.

Underreporting of Concussions and Concussion-Like Symptoms in Female High School Athletes

Underreporting of concussions and concussion-like symptoms in athletes continues to be a serious medical concern and research focus. Despite mounting worry, little evidence exists examining incidence of underreporting and documenting characteristics of head injury in female athletes participating in high school sports. This study examined the self-reporting behaviors of female high school athletes. Seventy-seven athletes participated, representing 14 high school sports. Nearly half of the athletes (31 participants) reported a suspected concussion, with 10 of the 31 athletes refraining from reporting symptoms to training staff after injury. Only 66% reported receiving concussion education. Concussion education appeared to have no relationship with diagnosed concussion rates in athletes, removing athletes from play, or follow-up medical care after injury. In conclusion, female high school athletes underreport signs and symptoms of concussions. Concussion education should occur at higher rates among female athletes to influence reporting behaviors.

Recovery progression and symptom resolution in sport-related mild traumatic brain injury

OBJECTIVE

To characterize the recovery progression of a group of athletes who participated in a concussion management program based on (1) group analysis and (2) individual analysis.

SETTING

Concussion management clinic.

PARTICIPANTS

Thirty athletes (22 males, 8 females; baseline age = 16.23 ± 2.40 years) who had undergone four assessments: one baseline and three post-injury assessments at 3, 8, 15 days post-injury.

DESIGN

Retrospective clinical.

MAIN MEASURES

Four neurocognitive scores of the Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) including verbal memory, visual memory, speed of processing and reaction time and also a total symptom score.

RESULTS

Group-analysis showed a clear decline in verbal memory (F(3, 87) = 7.36, p < 0.000) and an increase in self-reported symptoms (χ²(3, N = 30) = 48.703, p < 0.000), 3 days post-injury. By day 8, athletes had returned to their baseline levels for verbal memory and were not experiencing symptoms. When athletes' scores were examined individually, at 3 days post-injury, 60% of the athletes showed deficits on two or more of the ImPACT variables. This rate dropped to 23% at 8 days post-injury and remained the same (23%) 15 days post-injury.

CONCLUSIONS

In concussion recovery, variability is the rule, rather than the exception, with regard to both impaired neurocognitive functions and recovery duration.