Consensus statement on concussion in sport: the 3rd International Conference on Concussion in Sport held in Zurich, November 2008

Cardiorespiratory fitness assessment and training in the early sub-acute phase of recovery following traumatic brain injury: a systematic review

OBJECTIVES

To examine the safety of cardiorespiratory fitness (CRF) assessment and training in the early sub-acute phase of recovery (≤3 months) following moderate-to-extremely severe traumatic brain injury (TBI).

METHODS

A systematic review was completed in accordance with the PRISMA guidelines. Studies investigating adults and adolescents ≥15 years with moderate-to-extremely severe TBI were considered for inclusion. The methodological quality of the included studies was evaluated according to the McMaster Guidelines for Critical Review Form - Quantitative Studies.

RESULTS

Eleven studies with a total of 380 participants were included in the review. Adverse events (AEs) and symptom monitoring were poorly reported. Only four studies reported on the occurrence of AEs, with a total of eight AEs reported. Three of the reported AEs were concussion-like symptoms with no further exercise-induced symptom exacerbation reported. No serious AEs were reported.

CONCLUSION

There is no evidence to suggest that CRF assessment and training is unsafe in the early sub-acute phase of recovery following moderate-to-extremely severe TBI. However, despite the low AE and symptom exacerbation rates identified, a timeframe for safe commencement was unable to be established due to poor reporting and/or monitoring of exercise-induced symptoms and AEs in the current literature.

Does Headgear Prevent Sport-Related Concussion? A Systematic Review and Meta-Analysis of Randomized Controlled Trials Including 6311 Players and 173,383 Exposure Hours

CONTEXT

A sport-related concussion (SRC) is a traumatic brain injury that is caused by biomechanical stresses and results in a complex pathophysiological process in the brain. Some in the sporting community believe that headgear (HG) can prevent SRC, and several professional Australian sports organizations, including rugby, football, and soccer clubs, recommend its use.

OBJECTIVE

The purpose of this study is to determine whether HG is effective in lowering the prevalence of SRC in sports.

DATA SOURCES

A systematic search for related studies published between 1985 and 2023 was conducted using the following databases: Cochrane Library, AMED, PubMed, Web of Science, and Physiotherapy Evidence Database (PEDro).

STUDY SELECTION

Only randomized controlled trials (RCTs) that investigated the effectiveness of HG in reducing SRC rate were included.

STUDY DESIGN

Systematic review and meta-analysis of RCTs.

LEVEL OF EVIDENCE

Level 1a.

DATA EXTRACTION

Two researchers independently completed the title and abstract search and performed full-text reviews. A third reviewer was consulted to reach a consensus if any discrepancies were noted. The PEDro scale was used to evaluate the quality of the included RCTs. Data recorded from each study included authors, year of publication, type and number of players, study design, duration of the study, injury rate, compliance (%), sports/level, and exposure hours.

RESULTS

The pooled results of 6311 players and 173,383 exposure hours showed 0% SRC reduction per 1000 hours of exposure in the experimental group compared with the control group, with an injury risk ratio of 1.03 (95% CI, 0.82-1.30; P = 0.79).

CONCLUSION

This systematic review and meta-analysis demonstrates that HG does not prevent SRC among soccer and rugby players, and therefore the findings from this meta-analysis do not currently support the use of HG to prevent SRC in soccer or rugby.

A Multimodal Exertional Test for concussion: a pilot study in healthy athletes

Introduction

Exertional tests have become a promising tool to assist clinicians in the management of concussions, however require expensive equipment, extensive spaces, and specialized clinician expertise. As such, we developed a test with minimal resource requirements encompassing key elements of sport and physical activity. The purpose of this study was to pilot test the Multimodal Exertional Test (MET) protocol in a sample of healthy interuniversity athletes.

Methods

The MET comprises four stages, each featuring three distinct tasks. The test begins with engaging in squats, alternating reverse lunges, and hip hinges (Stage 1). The next stage progressively evolves into executing these tasks within specified time limits (Stage 2). Following this, the test advances to a stage that incorporates cognitive tasks (Stage 3), and the final stage demands greater levels of physical exertion, cognition, and multi-directional movements (Stage 4). Heart rate (HR) was obtained during each stage of the MET and participants' symptom severity scores were recorded following each task.

Results

Fourteen healthy interuniversity athletes (n = 8 female, n = 6 male) participated in the study. HR was obtained for 10 of the 14 athletes (females: n = 6, males: n = 4). Increases in average and maximum HR were identified between pre-MET and Stage 1, and between Stages 3 and 4. Consistent with the tasks in each stage, there were no increases in average and maximum HR observed between MET Stages 1 to 3. Female athletes exhibited higher average and maximum HRs compared to male athletes during all four stages. All 14 athletes reported minimal changes in symptom severity following each task.

Conclusion

Among healthy athletes, the MET elicits an increase in average and maximum HR throughout the protocol without symptom provocation. Female athletes exhibit higher HRs during all four stages in comparison to male athletes.

Does Frequency of Baseline Testing Influence Concussion Diagnostic Decision Making Among College Athletes

OBJECTIVE

Concussion is a growing public health concern given the large number of youth and collegiate athletes participating in collision sports. Sport-related concussions can have an adverse impact on student-athletes' health and academic performance. Athletic programs within academic organizations are motivated to employ the most effective and efficient diagnostic and recovery procedures to minimize the duration and impact of these symptoms on student-athletes' functioning. The present study sought to further our understanding regarding the value and frequency of conducting baseline assessments when evaluating sport-related concussions.

METHOD

A total of 41 athletes (24 men, 17 women) between the ages of 18 and 22 were evaluated following suspected concussive injury between 2015 and 2018. Post-injury test results were compared to baselines that had been collected either 1 or 2 years prior, and to normative data, to determine consistency in diagnostic outcomes.

RESULTS

Baseline test/retest reliability using Pearson's bivariate correlations revealed modest correlations on measures of verbal and visual memory (0.437-0.569) and very strong correlations on measures of reaction time and visual-motor speed (0.811-0.821). Meanwhile, minimal if any differences in clinical decision-making regarding the diagnostic outcome was observed when comparing post-injury test results to different baselines and to normative data.

CONCLUSIONS

Findings indicate that yearly baseline testing may not improve diagnostic accuracy, and in many cases, normative data may be adequate for decision-making. Additional research should evaluate the potential benefit of baseline testing in return-to-play decision-making among broader athletic populations.

Current State of Diffusion-Weighted Imaging and Diffusion Tensor Imaging for Traumatic Brain Injury Prognostication

Advanced imaging techniques are needed to assist in providing a prognosis for patients with traumatic brain injury (TBI), particularly mild TBI (mTBI). Diffusion tensor imaging (DTI) is one promising advanced imaging technique, but has shown variable results in patients with TBI and is not without limitations, especially when considering individual patients. Efforts to resolve these limitations are being explored and include developing advanced diffusion techniques, creating a normative database, improving study design, and testing machine learning algorithms. This article will review the fundamentals of DTI, providing an overview of the current state of its utility in evaluating and providing prognosis in patients with TBI.

Does Sleep Quality Influence Recovery Outcomes After Postconcussive Injury in Children and Adolescents?

OBJECTIVE

To determine whether objective parameters of sleep quality differ throughout recovery between children and adolescents who experienced an early return to school (RTS) and those who had a delayed RTS or did not return at all during the study period.

SETTING

Sleep parameters reflective of sleep quality were evaluated in participants' natural sleeping habitat throughout 9 weeks postinjury.

PARTICIPANTS

Ninety-four children and adolescents (aged 5-18 years) with diagnosed concussion.

DESIGN

Prospective cohort. Participants followed RTS protocols.

MAIN MEASURES

Actigraphy-derived estimates of total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), average arousal length (AAL), and number of arousals (NOAs) per hour were assessed. The length of time from injury until RTS was determined for each participant. Participants were categorized into an early RTS or delayed RTS group based on their time to RTS.

RESULTS

Both TST and SE were significantly greater in the early RTS group. WASO duration, AAL, and NOAs were significantly greater in the delayed RTS group. Differences between RTS groups were most apparent during weeks 1 to 5 postinjury.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Participants who returned to school earlier had significantly better objective sleep quality than participants who experienced a delayed RTS. This study provides evidence in support of a relationship between sleep quality and time to RTS in children and adolescents with concussion. Considering early monitoring of sleep, education regarding sleep hygiene, and access to age-appropriate sleep interventions may be helpful in pediatric concussion recovery.

An Attempt to Develop a Model of Brain Waves Using Quantitative Electroencephalography with Closed Eyes in K1 Kickboxing Athletes-Initial Concept

BACKGROUND

Brain injuries are a common problem in combat sports, especially in disciplines such as kickboxing. Kickboxing is a combat sport that has several variations of competition, with the most contact-oriented fights being carried out under the format of K-1 rules. While these sports require a high level of skill and physical endurance, frequent micro-traumas to the brain can have serious consequences for the health and well-being of athletes. According to studies, combat sports are one of the riskiest sports in terms of brain injuries. Among the sports disciplines with the highest number of brain injuries, boxing, mixed martial arts (MMA), and kickboxing are mentioned.

METHODS

The study was conducted on a group of 18 K-1 kickboxing athletes who demonstrate a high level of sports performance. The subjects were between the ages 18 and 28. QEEG (quantitative electroencephalogram) is a numeric spectral analysis of the EEG record, where the data is digitally coded and statistically analysed using the Fourier transform algorithm. Each examination of one person lasts about 10 min with closed eyes. The wave amplitude and power for specific frequencies (Delta, Theta, Alpha, Sensorimotor Rhythm (SMR), Beta 1, and Beta2) were analysed using 9 leads.

RESULTS

High values were shown in the Alpha frequency for central leads, SMR in the Frontal 4 (F4 lead), Beta 1 in leads F4 and Parietal 3 (P3), and Beta2 in all leads.

CONCLUSIONS

The high activity of brainwaves such as SMR, Beta and Alpha can have a negative effect on the athletic performance of kickboxing athletes by affecting focus, stress, anxiety, and concentration. Therefore, it is important for athletes to monitor their brainwave activity and use appropriate training strategies to achieve optimal results.

Deletion of PTEN in microglia ameliorates chronic neuroinflammation following repetitive mTBI

Traumatic brain injury is a leading cause of morbidity and mortality in adults and children in developed nations. Following the primary injury, microglia, the resident innate immune cells of the CNS, initiate several inflammatory signaling cascades and pathophysiological responses that may persist chronically; chronic neuroinflammation following TBI has been closely linked to the development of neurodegeneration and neurological dysfunction. Phosphoinositide 3-kinases (PI3Ks) are a family of lipid kinases that have been shown to regulate several key mechanisms in the inflammatory response to TBI. Increasing evidence has shown that the modulation of the PI3K/AKT signaling pathway has the potential to influence the cellular response to inflammatory stimuli. However, directly targeting PI3K signaling poses several challenges due to its regulatory role in several cell survival pathways. We have previously identified that the phosphatase and tensin homolog deleted on chromosome 10 (PTEN), the major negative regulator of PI3K/AKT signaling, is dysregulated following exposure to repetitive mild traumatic brain injury (r-mTBI). Moreover, this dysregulated PI3K/AKT signaling was correlated with chronic microglial-mediated neuroinflammation. Therefore, we interrogated microglial-specific PTEN as a therapeutic target in TBI by generating a microglial-specific, Tamoxifen inducible conditional PTEN knockout model using a CX3CR1 Cre recombinase mouse line PTEN^fl/fl/CX3CR1^+/CreERT2 (mcg-PTEN^cKO), and exposed them to our 20-hit r-mTBI paradigm. Animals were treated with tamoxifen at 76 days post-last injury, and the effects of microglia PTEN deletion on immune-inflammatory responses were assessed at 90-days post last injury. We observed that the deletion of microglial PTEN ameliorated the proinflammatory response to repetitive brain trauma, not only reducing chronic microglial activation and proinflammatory cytokine production but also rescuing TBI-induced reactive astrogliosis, demonstrating that these effects extended beyond microglia alone. Additionally, we observed that the pharmacological inhibition of PTEN with BpV(HOpic) ameliorated the LPS-induced activation of microglial NFκB signaling in vitro. Together, these data provide support for the role of PTEN as a regulator of chronic neuroinflammation following repetitive mild TBI.

Blood biomarkers of secondary outcomes following concussion: A systematic review

Introduction

Blood biomarkers have been identified as an alternative tool for predicting secondary outcomes following concussion. This systematic review aimed to summarize the literature on blood biomarkers of secondary outcomes following concussion in both pediatric and adult cohorts.

Methods

A literature search of Embase, Medline and PubMed was conducted. Two reviewers independently assessed retrieved studies to determine inclusion in systematic review synthesis.

Results

A total of 1771 unique studies were retrieved, 58 of which were included in the final synthesis. S100B, GFAP and tau were identified as being associated with secondary outcomes following concussion. Seventeen percent of studies were performed in a solely pediatric setting.

Conclusions

Validation of biomarkers associated with secondary outcomes following concussion have been largely limited by heterogeneous study cohorts and definitions of concussion and mTBI, presenting a hurdle for translation of these markers into clinical practice. Additionally, there was an underrepresentation of studies which investigated pediatric cohorts. Adult markers are not appropriate for children, therefore pediatric specific markers of secondary outcomes following concussion present the biggest gap in this field.

ErbB Signaling Pathway Genes Are Differentially Expressed in Monozygotic Twins Discordant for Sports-Related Concussion

Transcriptional changes involved in neuronal recovery after sports-related concussion (SRC) may be obscured by inter-individual variation in mRNA expression and nonspecific changes related to physical exertion. Using a co-twin study, the objective of this study was to identify important differences in mRNA expression among a single pair of monozygotic (MZ) twins discordant for concussion. A pair of MZ twins were enrolled as part of a larger study of concussion biomarkers among collegiate athletes. During the study, Twin A sustained SRC, allowing comparison of mRNA expression to the nonconcussed Twin B. Twin A clinically recovered by Day 7. mRNA expression was measured pre-injury and at 6 h and 7 days postinjury using Affymetrix HG-U133 Plus 2.0 microarray. Changes in mRNA expression from pre-injury to each postinjury time point were compared between the twins; differences >1.5-fold were considered important. Kyoto Encyclopedia of Genes and Genomes identified biologic networks associated with important transcripts. Among 38,000 analyzed genes, important changes were identified in 153 genes. The ErbB (epidermal growth factor receptor) signaling pathway was identified as the top transcriptional network from pre-injury to 7 days postinjury. Genes in this pathway with important transcriptional changes included epidermal growth factor (2.41), epiregulin (1.73), neuregulin 1 (1.54) and mechanistic target of rapamycin (1.51). In conclusion, the ErbB signaling pathway was identified as a potential regulator of clinical recovery in a MZ twin pair discordant for SRC. A co-twin study design may be a useful method for identifying important gene pathways associated with concussion recovery.

Child Sport Concussion Assessment Tool 5th Edition: Normative Reference Values in Demographically Diverse Youth

OBJECTIVES

Examine sociodemographic differences (gender, age, and language spoken at home) on baseline Child Sport Concussion Assessment Tool 5th Edition (Child SCAT5) scores and establish normative reference data for the Child SCAT5 among middle school student athletes.

DESIGN

Cross-sectional study.

SETTING

Nine middle schools in Virginia.

PARTICIPANTS

A sample of 1355 athletes playing competitive school-sponsored sports (ages 11-13, M = 12.3 ± 0.8; 40.1% girls, 59.9% boys) during the 2017 and 2018 school year. Certified athletic trainers administered the Child SCAT5 within the first 2 weeks of the sport season.

INDEPENDENT VARIABLES

Self-reported gender, age, and language spoken at home.

MAIN OUTCOME MEASURES

All Child SCAT5 outcome measures.

RESULTS

Gender, age, and language spoken at home were associated with Child SCAT5 scores, but the magnitude of differences was generally small. Specifically, girls endorsed more symptoms (girls: M = 8.4 ± 5.7, boys: M = 7.5 ± 5.7; P = 0.003) and greater symptom severity (girls: M = 11.6 ± 9.4, boys: M = 10.4 ± 9.3; P = 0.006) than boys and performed slightly better than boys on cognitive and balance tasks. Older students performed slightly better than younger students on tests of cognition (eg, SAC-C: 11-year-olds: M = 21.3 ± 2.1, 13-year-olds: M = 21.7 ± 2.1; P = 0.02). Total symptoms (P = 0.01), symptom severity (P = 0.01), immediate memory (P < 0.001), delayed recall (P = 0.001), and SAC-C total scores (P = 0.002) differed across language groups.

CONCLUSIONS

Gender, age, and language spoken in the home are associated with baseline scores on multiple components of the Child SCAT5 among middle school students, although the magnitudes of observed differences are small. Normative reference values are provided for clinicians when interpreting Child SCAT5 scores.

Biomarkers to aid the return to play decision following sports-related concussion: a systematic review

Premature return to play (RTP) following sports-related concussion (SRC) is associated with significant morbidity including risk of neurological and non-neurological injury, persistent post-concussion symptoms and chronic neurological deficits. Assessing athletes for RTP is critical but these decisions are currently based on clinical assessments that are subject to bias and symptomatic reporting that rely on compliance. An objective and easily obtained biomarker that can indicate recovery following SRC would aid clinicians to make safer RTP decisions. We performed a systematic review to identify potential biomarkers from saliva, urine and blood sources that could inform the clinical RTP decision. The MEDLINE database was searched. Inclusion criteria were studies focusing on adults diagnosed with SRC, fluid biomarkers from blood, saliva or urine and clinical recovery from SRC or at RTP. We assessed each biomarker for their time course post SRC and relationship to clinical recovery. Secondary outcomes included correlation with symptom scores and predictive value for prolonged RTP. We identified 8 studies all investigating blood-based markers of diffuse axonal injury (tau, NFL, SNTF), neuroglial injury (NSE, VLP-1, UCH-L1, S100B, GFAP), inflammation and hormonal disturbances. Tau, SNTF, UCH-1, GFAP, S100B and the inflammatory cytokine MCP-4 are raised post SRC and return to baseline by RTP. Changes in tau, NFL, SNTF, GFAP and MCP-4 post SRC correlate with severity of concussion as measured by symptom severity or RTP duration. There is only preliminary case-reporting for hormonal biomarkers. The evidence is limited by a lack of highly powered studies, variation in use of athletic and Contact sport controls (CSC) and a lack of consistent sampling and assessment protocols. There is promise for biomarkers to aid RTP decisions following SRC, most notably in use alongside clinical assessment in RTP criteria to allow greater precision in identifying mild and severe concussion.

Sports related concussion: an emerging era in digital sports technology

Sports-related concussion (SRC) is defined as a mild traumatic brain injury (mTBI) leading to complex impairment(s) in neurological function with many seemingly hidden or difficult to measure impairments that can deteriorate rapidly without any prior indication. Growing numbers of SRCs in professional and amateur contact sports have prompted closer dialog regarding player safety and welfare. Greater emphasis on awareness and education has improved SRC management, but also highlighted the difficulties of diagnosing SRC in a timely manner, particularly during matches or immediately after competition. Therefore, challenges exist in off-field assessment and return to play (RTP) protocols, with current traditional (subjective) approaches largely based on infrequent snapshot assessments. Low-cost digital technologies may provide more objective, integrated and personalized SRC assessment to better inform RTP protocols whilst also enhancing the efficiency and precision of healthcare assessment. To fully realize the potential of digital technologies in the diagnosis and management of SRC will require a significant paradigm shift in clinical practice and mindset. Here, we provide insights into SRC clinical assessment methods and the translational utility of digital approaches, with a focus on off-field digital techniques to detect key SRC metrics/biomarkers. We also provide insights and recommendations to the common benefits and challenges facing digital approaches as they aim to transition from novel technologies to an efficient, valid, reliable, and integrated clinical assessment tool for SRC. Finally, we highlight future opportunities that digital approaches have in SRC assessment and management including digital twinning and the "digital athlete".

A deep neural network approach for sentiment analysis of medically related texts: an analysis of tweets related to concussions in sports

Annually, over three million people in North America suffer concussions. Every age group is susceptible to concussion, but youth involved in sporting activities are particularly vulnerable, with about 6% of all youth suffering a concussion annually. Youth who suffer concussion have also been shown to have higher rates of suicidal ideation, substance and alcohol use, and violent behaviors. A significant body of research over the last decade has led to changes in policies and laws intended to reduce the incidence and burden of concussions. However, it is also clear that youth engaging in high-risk activities like sport often underreport concussion, while others may embellish reports for specific purposes. For such policies and laws to work, they must operate effectively within a facilitative social context so understanding the culture around concussion becomes essential to reducing concussion and its consequences. We present an automated deep neural network approach to analyze tweets with sport-related concussion context to identify the general public's sentiment towards concerns in sport-related concussion. A single-layer and multi-layer convolutional neural networks, Long Short-Term Memory (LSTM) networks, and Bidirectional LSTM were trained to classify the sentiments of the tweets. Afterwards, we train an ensemble model to aggregate the predictions of our networks to provide a final decision of the tweet's sentiment. The system achieves an evaluation F1 score of 62.71% based on Precision and Recall. The trained system is then used to analyze the tweets in the FIFA World Cup 2018 to measure audience reaction to events involving concussion. The neural network system provides an understanding of the culture around concussion through sentiment analysis.

The Current Status of Concussion Assessment Scales: A Critical Analysis Review

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Concussion is a complex pathophysiologic process that affects the brain; it is induced by biomechanical forces, with alteration in mental status with or without loss of consciousness.

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Concussion assessment tools may be broadly categorized into (1) screening tests such as the SAC (Standardized Assessment of Concussion), the BESS (Balance Error Scoring System), and the King-Devick (KD) test; (2) confirmatory tests including the SCAT (Sport Concussion Assessment Tool), the ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing), and the VOMS (Vestibular Oculomotor Screening); and (3) objective examinations such as brain network activation (BNA) analysis, imaging studies, and physiologic markers.

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The KD, child SCAT3 (cSCAT3), child ImPACT (cImPACT), and VOMS tests may be used to evaluate for concussion in the pediatric athlete.

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Future work with BNA, functional magnetic resonance imaging, diffusion tensor imaging, and serum biomarkers may provide more objective assessment of concussion, neurologic injury, and subsequent recovery.

Sport Concussion Assessment Tool-5th Edition (SCAT5): Normative Reference Values for the National Rugby League Women's Premiership

Objective: To establish normative reference values for the Sport Concussion Assessment Tool-5th Edition (SCAT5) for the new National Rugby League Women's Premiership. Methods: Preseason SCAT5 baseline testing was administered individually to all National Rugby League Women's Premiership players (N = 117). Testing was completed by the medical staff. Normative reference values were calculated for the components of the SCAT5, including the Standardized Assessment of Concussion, modified Balance Error Scoring System, and the Symptom Scale. A small case series of players who sustained concussions were included to illustrate the use of the new normative data. Results: The median Standardized Assessment of Concussion total score was 27.0 (M = 26.9, SD = 2.1). The median modified Balance Error Scoring System score was 2.0 (M = 2.4, SD = 2.2). The median number of symptoms score was 1.0 (M = 3.2, SD = 4.7) and the median symptom severity score was 2.0 (M = 5.4, SD = 8.2). The most common baseline symptom was fatigue or low energy (33%), followed by trouble sleeping (24%), headache (23%), neck pain (22%), and difficulty remembering (21%). In the total sample, 41% reported no symptoms. The clinical interpretation of these new normative data to a case series of women with concussions is provided. Conclusions: Normative reference values are provided for the SCAT5 for women who are professional rugby league players. Using these normative data will improve clinical interpretation of SCAT5 scores following a concussion.

Examining Whether Onfield Motor Incoordination Is Associated With Worse Performance on the SCAT5 and Slower Clinical Recovery Following Concussion

Objective: To examine the relationship between video-identified onfield motor incoordination, the acute assessment of concussion, and recovery time during three seasons of National Rugby League (NRL) play.

Methods: Blows to the head (“head impact events”) were recorded by sideline video operators and medical staff. Any player with a suspected concussion underwent a Head Injury Assessment in which he was taken off the field and medically evaluated, including the administration of the Sports Concussion Assessment Tool, 5th Edition (SCAT5). Video footage was later examined to determine the presence or absence of onfield motor incoordination following the head impact event.

Results: Motor incoordination was identified in 100/1,706 head impact events (5.9%); 65 of the 100 instances of motor incoordination (65.0%) were ultimately medically diagnosed with a concussion. In 646 athletes for whom SCAT5 data were available, those with motor incoordination were more likely to report both dizziness and balance problems than those without motor incoordination, but there were no group differences on an objective balance test. Additionally, there was no relationship between presence/absence of motor incoordination and number of games missed or time to medical clearance for match play.

Conclusion: In NRL players, motor incoordination is a readily observable onfield sign that is strongly associated with a medical diagnosis of concussion and with self-reported dizziness/balance problems. However, onfield motor incoordination is not associated with objective balance performance and it is not predictive of time to recover following concussion.

Altered physiology of gastrointestinal vagal afferents following neurotrauma

The adaptability of the central nervous system has been revealed in several model systems. Of particular interest to central nervous system-injured individuals is the ability for neural components to be modified for regain of function. In both types of neurotrauma, traumatic brain injury and spinal cord injury, the primary parasympathetic control to the gastrointestinal tract, the vagus nerve, remains anatomically intact. However, individuals with traumatic brain injury or spinal cord injury are highly susceptible to gastrointestinal dysfunctions. Such gastrointestinal dysfunctions attribute to higher morbidity and mortality following traumatic brain injury and spinal cord injury. While the vagal efferent output remains capable of eliciting motor responses following injury, evidence suggests impairment of the vagal afferents. Since sensory input drives motor output, this review will discuss the normal and altered anatomy and physiology of the gastrointestinal vagal afferents to better understand the contributions of vagal afferent plasticity following neurotrauma.

Epidemiology of Concussions in High School Boys' Ice Hockey, 2008/09 to 2016/17 School Years

OBJECTIVE

This study examined the epidemiology of concussions in high school boys' ice hockey during the 2008/09 to 2016/17 school years.

DESIGN

Prospective cohort study. Athletic trainers from an average 33 high schools annually reported boys' ice hockey concussion and athlete-exposure (AE) data for the High School Reporting Information Online system.

SETTING

Convenience sample of high school boys' ice hockey programs during the 2008/09 to 2016/17 school years.

PATIENTS OR OTHER PARTICIPANTS

High school boys' ice hockey players (aged ∼14-18 years).

INDEPENDENT VARIABLES

Concussion data on event type, injury mechanism, symptom resolution time, and time loss were obtained.

MAIN OUTCOME MEASURES

Concussion rates with 95% confidence intervals (CIs) and distributions were calculated.

RESULTS

Overall, 348 concussions were reported in boys' ice hockey during the 2008/09 to 2016/17 academic years, leading to a concussion rate of 0.68/1000 AEs (95% CI, 0.61-0.75). Most occurred in competitions (85.6%), particularly after the first period (72.1% of all competition concussions). Among practice concussions, most occurred after the first hour of practice (60.0%). Most concussions were due to player contact (47.7%) and boards/glass contact (31.9%). Although 69.0% of concussed athletes had symptoms resolve in less than 7 days, only 14.1% returned to activity within a week.

CONCLUSIONS

Most concussions occurred within the second and third periods. Preventive strategies that counter an increased risk of concussion due to a greater intensity of gameplay coupled with increased fatigue may be warranted. Moreover, athletes may further benefit from prevention efforts that focus on anticipating impacts during gameplay.

Effect of Cognitive and Physical Rest on Persistent Postconcussive Symptoms following a Pediatric Head Injury

OBJECTIVE

To evaluate the effect of cognitive and physical rest on persistent postconcussive symptoms in a pediatric population.

STUDY DESIGN

A prospective cohort study of 5- to 18-year-olds diagnosed with an acute concussion in a tertiary care pediatric emergency department was conducted from December 2016 to May 2019. Participants (n = 119) were followed over 1 month to track days off from school and sports and the development of persistent postconcussive symptoms (residual concussion symptoms beyond 1 month). Participants were dichotomized into minimal (≤2) and moderate (>2) rest, based on days off from school and sports after a concussion. Univariate and multivariable logistic regression analyses were completed to examine associations with persistent postconcussive symptoms.

RESULTS

Of the participants in our study, 24% had persistent postconcussive symptoms. Adolescent age, history of prolonged concussion recovery, and headache at presentation were associated with higher odds of persistent postconcussive symptoms in univariate analyses. In a multivariable logistic regression model, only adolescent age was associated with increased odds of persistent postconcussive symptoms. Compared with the minimal cognitive rest group, moderate cognitive rest did not decrease the odds of persistent postconcussive symptoms (aOR, 1.15; 95% CI, 0.44-2.99). Compared with the minimal physical rest group, moderate physical rest also did not decrease the odds of persistent postconcussive symptoms (aOR, 3.17; 95% CI, 0.35-28.78).

CONCLUSIONS

Emerging evidence supports early return to light activity for recovery of acute pediatric concussion. Our study adds to this management approach as we did not find that rest from school and sports resulted in a decreased odds of persistent postconcussive symptoms.

Self-reported concussion history among Icelandic female athletes with and without a definition of concussion

OBJECTIVE

This study examined whether Icelandic female athletes in contact sports, based their self-reported concussion history on adequate medical definitions, by assessing self-reported concussion history with and without a definition of concussion. Another aim was to examine whether currently active athletes were more knowledgeable of concussions than retired athletes.

METHODS

Participants (age = 26.9, SD = 7.1) were 508 former (34.5%) and current (65.5%) elite female athletes in soccer (41%), handball (30.6%), basketball (19.1%), ice hockey (4.5%) and combat sports (4.7%). An online questionnaire (QuestionPro) was distributed to females in contact sports (snowball sampling). Participants later came for an in-person interview where the authenticity of previous responses was confirmed. In the questionnaire, participants answered background questions and questions about concussion history. First, they reported the total number of sustained concussions without a prompt. They reported the number of sustained concussions again after reading a definition of concussion. Participants could not correct their previous answers. Pearson's Chi-square was used for group comparisons.

RESULTS

The prevalence of reported concussions increased from 40.2% to 64.8% following a definition. There was no significant difference in how many participants changed their answer when asked about sustaining SRCs before and after reading the definition based on whether the participants were still competitive or retired X ²(1) = 0.69, p = 0.41.

CONCLUSIONS

Our data suggest that understanding of concussions is inadequate among female athletes. Self-report will continue to be an essential source of clinical information and prompting with a definition can increase the reliability of self-reported concussions.

Effects of College Athlete Life Stressors on Baseline Concussion Measures

CONTEXT

Concussion baseline testing helps injury evaluation by allowing postinjury comparisons to preinjury measures. To facilitate best practice, common neurocognitive, balance, and symptom report metrics used in concussion baseline testing merit examination relative to participant life stressors.

OBJECTIVE

The purpose of this study was to determine if life stressors are associated with college athlete neurocognitive function, postural control, and symptom scores at preseason baseline assessment.

DESIGN

All study variables were collected in a single laboratory session where athletes completed valid and reliable psychometrics as well as a computerized neurocognitive and balance assessments.

SETTING

Sports medicine research center on an American university campus.

PARTICIPANTS

A convenience sample of 123 college student-athletes: 47 females (age = 18.9 [4.3] y) and 76 males (age = 19.4 [1.6] y).

MAIN OUTCOME MEASURES

Participants were categorized into low, moderate, or high life stressors groups using scores from the Social Readjustment Rating Scale-Revised. Dependent variables included outcomes from the CNS Vitals Signs test, the Sensory Organization Test, and the graded symptom checklist indexing neurocognition, balance, and symptom severity, respectfully.

RESULTS

One-way analysis of variance revealed that the moderate life stressors group performed significantly worse than the low life stressors group on the baseline verbal memory domain of the CNS Vital Signs (F2,119 = 3.28; P = .04) only.

CONCLUSION

In the current college athlete sample, few baseline concussion assessment variables were found to be significantly associated with life stressors. Considering the clinical significance of these variables, psychological life stressors may not be a confounding factor in concussion evaluation.

Quality of Psychoeducational Apps for Military Members With Mild Traumatic Brain Injury: An Evaluation Utilizing the Mobile Application Rating Scale

BACKGROUND

Military personnel have an elevated risk of sustaining mild traumatic brain injuries (mTBI) and postconcussion symptoms (PCS). Smartphone apps that provide psychoeducation may assist those with mTBI or PCS to overcome unique barriers that military personnel experience with stigma and access to health care resources.

OBJECTIVE

This study aims to (1) use the Mobile Application Rating Scale (MARS) to evaluate smartphone apps purporting to provide psychoeducation for those who have sustained an mTBI or a PCS; (2) explore the relevance, utility, and effectiveness of these apps in facilitating symptom management and overall recovery from mTBI and PCS among military personnel; and (3) discuss considerations pertinent to health care professionals and patients with mTBI when considering the use of mobile health (mHealth), including apps for mTBI psychoeducation.

METHODS

A five-step systematic search for smartphone apps for military members with mTBI or PCS was conducted on January 31, 2020. Cost-free apps meeting the inclusion criteria were evaluated using the MARS and compared with evidence-based best practice management protocols for mTBI and PCS.

RESULTS

The search yielded a total of 347 smartphone apps. After applying the inclusion and exclusion criteria, 13 apps were subjected to evaluation. Two apps were endorsed by the US Department of Veterans Affairs and the US Department of Defense; all the others (n=11) were developed for civilians. When compared with evidence-based best practice resources, the apps provided various levels of psychoeducational content. There are multiple considerations that health care professionals and those who sustain an mTBI or a PCS have to consider when choosing to use mHealth and selecting a specific app for mTBI psychoeducation. These may include factors such as the app platform, developer, internet requirement, cost, frequency of updates, language, additional features, acknowledgment of mental health, accessibility, military specificity, and privacy and security of data.

CONCLUSIONS

Psychoeducational interventions have a good evidence base as a treatment for mTBI and PCS. The use of apps for this purpose may be clinically effective, cost-effective, confidential, user friendly, and accessible. However, more research is needed to explore the effectiveness, usability, safety, security, and accessibility of apps designed for mTBI management.

Sex Differences in Circulating T-Tau Trajectories After Sports-Concussion and Correlation With Outcome

Sex differences in molecular biomarkers after sports-related concussion (SRC) could steadily advance our understanding of injury heterogeneity and complexity, and help capture phenotypic characteristics, by unveiling sex-dependent pathobiological processes and disease mechanisms. Such knowledge will help improve diagnosis, clinical management, and prognosis. Total-tau (t-tau) has recently emerged as a promising blood marker showing sex-associated differences in neurodegenerative diseases. Nonetheless, to date, little is known about the potential influence of sex on its injury-related concentration and dynamics after SRC. We hypothesized that measurements of circulating levels of t-tau over time would reflect a differential vulnerability signature, providing insights into the sex-related phenotypes and their relationship with clinical outcomes. To test this hypothesis, plasma levels of t-tau were measured using an ultrasensitive immunoassay up to 7 days after injury, in 46 concussed athletes (20 males, 26 females). We used trajectory analysis to generate two distinct temporal profiles of t-tau, which were then compared with gender and return to play (RTP). The majority of subjects (~63%) started with low t-tau concentrations that further declined within the first 48 h; while the remaining (“maximal decliners”) started with concentrations comparable to the baseline levels that also fell over time, but persisting markedly higher compared with the first profile. The maximal decliner group was primarily composed of female subjects (p = 0.007) and was significantly associated with poor outcome (RTP ≥ 10 days after concussion) (p = 0.011). Taken together, our data provide evidence for the existence of sex-related biosignatures following sports-related concussions, possibly indicating a differential effect as a result of distinct brain vulnerability and inherent injury response. Future studies will be required to further elucidate underlying sex-based biological and pathophysiological mechanisms, and determine the value of t-tau signatures for management and therapeutic decision-making in sports-related concussions.

Early Aerobic Exercise for the Treatment of Acute Pediatric Concussions

Sport-related concussion is a common injury that has garnered the attention of the media and general public because of the potential for prolonged acute symptoms and increased risk for long-term impairment. Currently, a growing body of evidence supports the use of various therapies to improve recovery after a concussion. A contemporary approach to managing concussion symptoms is to use aerobic exercise as treatment. To date, several studies on both pediatric and adult patients have established that controlled aerobic exercise is a safe and effective way to rehabilitate patients experiencing delayed recovery after concussion. However, less is known about the utility of an early exercise protocol for optimizing recovery after acute concussion and reducing the risk for persistent postconcussive symptoms, particularly in pediatric populations. Thus, the purpose of our paper was to review and evaluate the available literature on the implementation of aerobic exercise for the treatment of acute pediatric concussion.

Differences in Postinjury Psychological Symptoms Between Collegiate Athletes With Concussions and Orthopedic Injuries

OBJECTIVE

To describe the differences in postinjury psychological symptoms among Division I collegiate student athletes who sustained concussions versus orthopedic injures and to examine the effects of injury type on postinjury psychological symptoms during the course of recovery.

DESIGN

A prospective cohort study with repeated measures.

SETTING

Two Big 10 Conference universities.

PARTICIPANTS

Student athletes who were at least 18 years old and participated in one of 9 National Collegiate Athletic Association (NCAA) Division I-sponsored sports during the 2007 to 2011 seasons.

MAIN OUTCOME MEASURES

Baseline depressive symptoms and anxiety were measured at enrollment. On identification of an eligible injury, follow-up surveys were conducted among injured athletes at multiple intervals until the injured athlete returned to play. Depressive symptoms, anxiety, fear of return-to-play, and fear of reinjury were measured at the postinjury follow-ups.

RESULTS

The concussion group had significantly lower scores of fear of return-to-play (B = -0.94, P = 0.0278) and fear of reinjury (B = -1.11, P = 0.0152) compared with the orthopedic injury group. The concussion group scored higher on depressive symptoms than the orthopedic injury group at 1 month after injury (P = 0.0264), although both groups scored similarly at baseline (P = 0.9729) and at 1 week after injury (P = 0.1475).

CONCLUSIONS

Patterns of psychological disturbance differ after concussions and orthopedic injures. Further research is warranted to identify the factors contributing to these differences and to develop effective intervention programs to prevent these symptoms.

Injury patterns in synchronized skating: a growing and evolving sport

BACKGROUND

Data about injuries among synchronized skating athletes are lacking while physical demands in this sport discipline continue to grow. No injury data among junior synchronized skaters exist. The purpose of this study was to investigate the frequency and pattern of injuries in junior and senior synchronized skaters.

METHODS

In this descriptive epidemiology study anonymous questionnaires were distributed to synchronized junior and senior skaters. 708 synchronized skaters (393 juniors and 315 seniors) completed the questionnaire. Male skaters were excluded from analysis.

RESULTS

Spinal conditions were reported by 148 (37.7%) juniors compared to 149 (47.3%) of senior skaters with statistically significant cumulative incidence (P=0.01); 23% of juniors and 30.2% of senior skaters reported problems with more than one spinal region; 64.4% juniors and 72.1% senior skaters reported at least one non-spinal injury during their synchronized skating career. There were 380 unique injuries reported by junior skaters and 363 by senior skaters. Lower extremity injuries were the most common injuries in both groups of skaters, followed by upper extremity, head and trunk injuries. From all the anatomical regions mentioned, there was only statistically significant difference between the groups in the occurrence of head injuries with senior skaters having 1.9 greater odds ratio to have head injury.

CONCLUSIONS

This study presents new data on the current injury pattern seen in synchronized skating since the inclusion of new skills. The number of head injuries and spinal conditions show statistically significant cumulative incidence in senior compared to junior skaters.

Postconcussion Exertion Evolution: Clinical and Behavioral Considerations

The philosophy and practices concerning concussion management have evolved from passive to active strategies that incorporate immediate, guided rest followed by early integration of physical and cognitive activity as tolerated by symptoms. Recent research and clinical evidence support guidance that symptom tolerable and clinically guided activity is beneficial postconcussion both acutely and in the longer term. Furthermore, recent studies illustrate benefits of targeted deficit-based therapies (vestibular, cervicogenic, visual, psychological, etc.) postconcussion subacutely and in those with persistent symptoms. The dissemination of this new information occurs at a fast pace and is often difficult to rapidly integrate into clinical practice due to necessary policy and behavior changes. This review will outline recent evidence concerning both rest and exertion postconcussion through the lens of the socioecological model to more rapidly promote policy and practice changes.

Pre-frontal Cortex Oxygenation Changes During Aerobic Exercise in Elite Athletes Experiencing Sport-Related Concussion

Aims: Recent research suggests that aerobic exercise can be performed safely within the first week following a concussion injury and that early initiation of exercise may speed recovery. To better understand the physiological changes during a concussion, we tested the hypothesis that mild-to-intense exercise testing can be performed within days immediately following injury, and can be used to discern differences between the concussed and normal healthy state. Thus, the purpose was to observe the cerebral hemodynamic responses to incremental exercise testing performed acutely post-concussion in high-performance athletes. Methods: This study was a within- and between-experimental design, with seven male university ice hockey teams participating. A subgroup of five players acted as control subjects (CON) and was tested at the same time as the 14 concussed (mTBI) players on Day 2, 4, and 7 post-concussion. A 5-min resting baseline and 5-min exercise bouts of mild (EX1), moderate (EX2), and high (EX3) intensity exercise were performed on a cycle ergometer. Near-infrared spectroscopy was used to monitor pre-frontal cortex oxy-haemoglobin (HbO2), deoxy-haemoglobin (HHb), and total blood volume (tHb) changes. Results: ANOVA compared differences between testing days and groups, and although large percentage changes in HbO2 (20-30%), HHb (30-40%), and tHb (30-40%) were recorded, no significant (p ≤ 0.05) differences in cerebral hemodynamics occurred between mTBI vs. CON during aerobic exercise testing on any day post-injury. Furthermore, there was a linear relationship between exercise intensity vs. cerebral hemodynamics during testing for each day (r 2 = 0.83-0.99). Conclusion: These results demonstrate two novel findings: (1) mild-to-intense aerobic exercise testing can be performed safely as early as Day 2 post-concussion injury in a controlled laboratory environment; and (2) evidence-based objective measures such as cerebral hemodynamics can easily be collected using near-infrared spectroscopy (NIRS) to monitor physiological changes during the first-week post-injury. This research has important implications for monitoring physiological recovery post-injury and establishing new rehabilitation guidelines.

In-clinic event related potentials after sports concussion: A 4-year study

PURPOSE

Electrophysiological event-related potentials (ERP's) have been reported to change after concussion. The objective of this study is to use a simple 2-tone auditory P300 ERP in routine clinical settings to measure changes from baseline after concussion and to determine if these changes persist at return to play when other standard measures have normalized.

METHODS

Three-hundred sixty-four (364) student athletes, aged 17-23 years, participating in contact sports were tracked over consecutive years. In this blinded study P300, plus physical reaction times and Trail Making tests, were collected alongside standard clinical evaluations. Changes in these measures after concussion were compared to clinical outcomes over various stages of post-injury recovery.

RESULTS

Concussed players experienced significant reaction time and/or P300 amplitude changes compared to pre-concussion baseline measurements (p< 0.005). P300 changes persisted in 38% of the players after standard measures, including reaction times, had cleared. Many of those players slow to normalize were part of the sub-concussive symptom group and/or appeared more prone to repeat concussions.

CONCLUSION

These data suggest significant P300 amplitude changes after concussion that are quantifiable and consistent. These changes often normalized slower than other standard assessments. More data are needed to determine if slow normalization relates to sub-concussive or repeated events.

Concussion Recovery Timeline of High School Athletes Using A Stepwise Return-to-Play Protocol: Age and Sex Effects

CONTEXT

Implementation of a stepwise return-to-play (RTP) protocol has become the standard management strategy for high school athletes to ensure a safe RTP after concussion. The detailed characteristics of the recovery timeline throughout the steps of an RTP protocol have not been delineated among the adolescent population.

OBJECTIVE

To investigate the days spent in each step of the stepwise RTP protocol in an adolescent population and examine the effects of age and sex on recovery time.

DESIGN

Cross-sectional study.

SETTING

Local schools.

PATIENTS OR OTHER PARTICIPANTS

Student-athletes from 57 schools.

INTERVENTION(S)

A total of 726 patients with concussion (age = 15.5 ± 1.2 years, males = 454, females = 272) were included. The 7-step RTP protocol consists of the following steps: (1) complete cognitive rest, (2) full return to school, (3) light exercise, (4) running progression, (5) noncontact training drills and weight training, (6) full-contact practice or training, and (7) return to game play. The data were obtained by certified athletic trainers as a part of the statewide standardized concussion-management protocol.

MAIN OUTCOME MEASURE(S)

Days spent in steps 0 to 6 as well as a breakdown of days by sex and age.

RESULTS

The average total RTP days were 20.2 ± 13.9. Half of this time was spent in the return-to-school phase (steps 2-3: 10.2 ± 10.0 days). Compared with 17-year-old participants, younger participants (age = 14-16 years) took 3 or 4 days longer to start step 3 and to reach step 6 (P < .05). Females took longer to reach step 6 than males (21.6 ± 15.5 versus 19.3 ± 12.7 days) because they took longer to reach step 3 (14.7 ± 11.4 days) than males (13.0 ± 10.0 days; P < .05).

CONCLUSIONS

Our study provides an estimated stepwise concussion recovery timeline for adolescent student-athletes. Clearance to start step 3 was the benchmark for the recovery timeline, as the duration of the exercise portion of the protocol was consistent across the age and sex groups.

Concussion Symptom Profiles Among Child, Adolescent, and Young Adult Athletes

OBJECTIVES

(1) To examine how age influences initial symptom presentation following concussion; and (2) to determine whether specific symptom profiles are associated with duration of postconcussion symptoms, and whether they vary by age group.

DESIGN

A total of 689 patients (20% children 7-12 years of age, 69% adolescents 13-18 years of age, and 11% young adults 19-30 years of age) were seen and diagnosed with a concussion within 21 days after injury. Patients completed the Post-Concussion Symptom Scale (PCSS) and were followed until they no longer required care.

SETTING

Two specialty care sport concussion clinical practices.

MAIN OUTCOME MEASURES

Overall PCSS score was obtained, as well as severity ratings from somatic, vestibular-ocular, cognitive, sleep, and emotional symptom domains. We also calculated total symptom duration time.

RESULTS

No significant main effect of age, or age by sex associations were identified among the symptom domains. Females endorsed a higher somatic symptom severity rating than males (9.8 ± 6.7 vs 8.1 ± 6.7; P = 0.03). For patients between 7 and 12 years of age, higher somatic [β-coefficient = 1.57, 95% confidence interval (CI), 1.47-1.67] and cognitive (β-coefficient = 2.50, 95% CI, 2.32-2.68) symptom severities were associated with longer duration of concussion symptoms. Among adolescents, longer total symptom duration was associated with more severe somatic (β-coefficient = 1.25, 95% CI, 0.34-2.15) and vestibular-ocular (β-coefficient = 2.36, 95% CI, 1.49-3.23) symptoms.

CONCLUSIONS

Within 21 days after concussion, symptom-reporting behavior seems to be similar across the age spectrum, but the relationship between symptom profiles and time to symptom resolution varies by age. Although overall symptom ratings are beneficial in determining clinical pathways, symptom domain use may provide a beneficial method to determine individualized patient care that differs between children and adolescents after concussion.

Time-Dependent Changes in Microglia Transcriptional Networks Following Traumatic Brain Injury

The neuroinflammatory response to traumatic brain injury (TBI) is critical to both neurotoxicity and neuroprotection, and has been proposed as a potentially modifiable driver of secondary injury in animal and human studies. Attempts to broadly target immune activation have been unsuccessful in improving outcomes, in part because the precise cellular and molecular mechanisms driving injury and outcome at acute, subacute, and chronic time points after TBI remain poorly defined. Microglia play a critical role in neuroinflammation and their persistent activation may contribute to long-term functional deficits. Activated microglia are characterized by morphological transformation and transcriptomic changes associated with specific inflammatory states. We analyzed the temporal course of changes in inflammatory genes of microglia isolated from injured brains at 2, 14, and 60 days after controlled cortical impact (CCI) in mice, a well-established model of focal cerebral contusion. We identified a time dependent, injury-associated change in the microglial gene expression profile toward a reduced ability to sense tissue damage, perform housekeeping, and maintain homeostasis in the early stages following CCI, with recovery and transition to a specialized inflammatory state over time. This later state starts at 14 days post-injury and is characterized by a biphasic pattern of IFNγ, IL-4, and IL-10 gene expression changes, with concurrent proinflammatory and anti-inflammatory gene changes. Our transcriptomic data sets are an important step to understand microglial role in TBI pathogenesis at the molecular level and identify common pathways that affect outcome. More studies to evaluate gene expression at the single cell level and focusing on subacute and chronic timepoint are warranted.

Concussion: A Global Perspective

Concussion, also referred to as mild traumatic brain injury (MTBI), is a common pediatric condition. This article reviews global perspectives on the epidemiology, treatment, and prognosis of concussion in children. A Pubmed search was conducted using Clinical Queries with the key terms "concussion" and "mild traumatic brain injury," and the search was limited to "children." The search strategy included meta-analyses, randomized controlled trials, clinical trials, and reviews. The majority of publications were from Canada and the United States. Prevalence estimates vary widely according to case definition and studied population. Due to under-reporting and to the widely varying definitions of concussion, it is difficult to estimate how common the condition is. Common causes of concussions include sports injuries, motor vehicle collisions, bicycle accidents, falls, and assaults. Diagnosis is mainly clinical. Because concussion results from a disturbance in brain function rather than structural injury, neuroimaging studies, such as computed tomography and magnetic resonance imaging, are not routinely recommended. Treatment generally involves physical and cognitive rest, with a gradual return to activities, whereas prolonged rest may actually worsen outcomes. Helmets when bicycling, skiing, snowboarding, motor biking, placing age limits on certain types of contact sports, and encouragement of fair play are recommended to decrease the impact of head injuries but they do not prevent concussions. Overall outcomes are generally favorable. The symptoms and signs of concussion usually resolve within 10 days; most patients recover in 48-72 hours. Global perspectives on management and prognosis are lacking. Concussions or MTBIs are common childhood injuries and the prognosis is good but information is predominantly from Canada and the USA. Research in other countries in particular low and middle income countries is vital to have a global perspective on MTBI.

Activity Level During Acute Concussion May Predict Symptom Recovery Within an Active Duty Military Population

OBJECTIVE

To evaluate the impact on symptom resolution of activity acutely following a concussion and the role of acute-phase symptoms on this relationship among active duty service members (SMs).

SETTING

Three military installations.

PARTICIPANTS

Sixty-two SMs aged 18 to 44 years who sustained a concussion within 72 hours of enrollment.

DESIGN

Longitudinal design with data collected within 72 hours of injury (baseline, n = 62) and at 1 week (n = 57), 1 month (n = 50), 3 months (n = 41), and 6 months (n = 40) postinjury.

MAIN MEASURES

Baseline activity level using a 60-item Activity Questionnaire. Symptom level at baseline and during follow-up using Neurobehavioral Symptoms Inventory.

RESULTS

Significant interaction (Pi < .05) was found, with significant main effects (P < .05) limited to SMs with elevated baseline symptomatology. Among these participants, greater baseline total activity was significantly related to greater vestibular symptoms at 1, 3, and 6 months (β = .61, .63, and .59, respectively). Significant associations were also found for particular types of baseline activity (eg, physical; vestibular/balance; military-specific) and symptoms at 1, 3, and/or 6 months postinjury.

CONCLUSION

These results provide support for clinical guidance that symptomatic SMs, particularly those with high levels of acute symptoms, may need to avoid excessive activity acutely following concussion.

Activity Level and Type During Post-acute Stages of Concussion May Play an Important Role in Improving Symptoms Among an Active Duty Military Population

Background: Previous research demonstrates that early rest and gradual increases in activity after concussion can improve symptoms; however, little is known about the intensity and type of activity during post-acute time periods-specifically months post-injury-that may promote optimal recovery in an active duty service member (SM) population. Objective: The objectives of this study were to investigate how activity level and type at the post-acute stages of concussion (at 1 and 3 month[s] post-injury) impact subsequent symptoms among SMs, and how this relationship might differ by the level of symptoms at the time of injury. Methods: Participants included 39 SMs ages 19-44 years from 3 military installations who were enrolled within 72 h after sustaining a concussion. Linear regression was used to evaluate whether the association between activity level at 1 or 3 month(s) post-injury (as measured by a multi-domain Activity Questionnaire) and subsequent symptoms at 3 and/or 6 months (as measured by the Neurobehavioral Symptom Inventory) varied by the level of symptoms at acute stages of concussion. Partial correlation was used to evaluate relationships that did not differ by acute symptom level. Symptoms at the time of activity assessment (1 or 3 month[s]) were accounted for in all models, as well as activity level at acute stages of concussion. Results: Greater physical and vestibular/balance activity at 1 month were significantly correlated with lower symptoms at 3 months, but not at 6 months post-injury. There were no significant associations found between activity (total or by type) at 3 months and symptoms at 6 months. The association between activity level at either 1 or 3 months and subsequent symptoms at 3 and/or 6 months did not differ by the level of acute symptoms. Conclusion: The intensity and type of activities in which SMs engage at post-acute stages of concussion may impact symptom recovery. Although low levels of activity have been previously shown to be beneficial during the acute stage of injury, higher levels of activity may provide benefit at later stages. These findings provide support for the importance of monitoring and managing activity level beyond the acute stage of concussion.

Effects of Exercise on EEG Activity and Standard Tools Used to Assess Concussion

A variety of cognitive assessment tools are used to determine the functional status of the brain before and after injury in athletes. Questionnaires, neuropsychological tests, and electroencephalographic (EEG) measures have been recently used to directly assess brain function on and near the playing field. However, exercise can affect cognitive performance and EEG measures of cortical activity. To date, little empirical evidence exists on the effects of acute exercise on these measures of neurological function. We therefore quantified athlete performance on a standardized battery of concussion assessment tools and EEG measurements immediately before and after acute exercise to simulate conditions of athletic competition. Heart rate and arterial oxygen levels were collected before and after the exercise challenge consisting of a 1-mile run. Together these data, from a gender-balanced cohort of collegiate athletes, demonstrated that moderate to hard levels of acute exercise improved performance on the King-Devick test (K-D test) and Standardized Assessment of Concussion (SAC) component of the Sport Concussion Assessment Tool (SCAT3). Gender played an important role in these effects, and performance was most affected by exercise in female athletes. EEG activity in the theta band (4-8 Hz) was decreased during periods of quiet resting with eyes open or eyes closed. Additionally, exercise produced a slowing of the EEG during the K-D test and a shift to higher frequencies during the balance assessment of the SCAT3. Together, these data indicate that exercise alone can influence outcome measures of cognitive assessment tools used to assess brain function in athletes. Finally, care must be taken to acquire postinjury measurements during a comparable physiologic state to that in which baseline assessment data were measured, and further research is needed into the factors influencing outcome measures of these tests.

Sideline assessment of concussion

The recognition and sideline evaluation of possible sport-related concussion are difficult tasks for a physician and other clinicians. Sideline assessment tools have continued to evolve over the years, but objective biomarkers of concussion do not currently exist. Sideline video review programs may aid in the recognition of possible concussion as additional information for the sideline athletic medicine staff. Additional investigational assessments include visual oculomotor processing, reaction time, and rapid eye movements and attention. As the presentation of concussion is variable and symptoms may evolve over time, it is important that athletes with possible concussion are followed with serial assessments. If the diagnosis is unclear, it is advised to err on the side of caution and not allow the athlete to return to competition on the day of the injury. This chapter will review the current issues regarding the sideline assessment of concussion.

An experimental study of the effect on activity intentions of postconcussion recovery advice

This study tested the effect of issuing return-to-activity advice on activity intentions at Day 2 and Day 10 days post simulated mild traumatic brain injury. One hundred and twenty-eight volunteers were randomly allocated to one of two groups who received ( n =  65) or did not receive standardized post-injury advice ( n =  63). To prime the simulation, the participants read a mild traumatic brain injury vignette about a person who is concussed while playing sport. Then the participants role-played the injured person and reported activity intentions for three activity types (cognitive, physical and restful) twice, once for each time frame (i.e. Day 2 and Day 10). The advice was to rest for the first 24–48 h and then gradually resume normal activities. There was no significant group by activity-type interaction ( p > .05) at Day 2. When both time frames were considered, there was no significant group × time frame interaction for any activity type or any item, except for an increase in non-manual (clerical) work and weight training at Day 10 compared to Day 2 in the group with the advice. In general, the intentions for all activity types were consistent with the recovery advice (i.e., rest then increasing activity), even when the advice was not given. However, at Day 10, cognitive and physical activity levels were still expected to be lower than usual (pre-injury), and many participants were uncertain about the concept of cognitive rest. These factors, along with individual patient circumstances, should be taken into account in rehabilitation planning.

Preliminary evidence from a prospective DTI study suggests a posterior-to-anterior pattern of recovery in college athletes with sports-related concussion

OBJECTIVES

We compared the integrity of white matter (WM) microstructure to the course of recovery in athletes who sustained one sports-related concussion (SRC), assessing individual longitudinal changes in WM fiber tracts following SRC using pre- and post-injury measurements.

MATERIALS AND METHODS

Baseline diffusion tensor imaging (DTI) scans and neuropsychological tests were collected on 53 varsity contact-sport college athletes. Participants (n = 13) who subsequently sustained an SRC underwent DTI scans and neuropsychological testing at 2 days, 2 weeks, and 2 months following injury.

RESULTS

Relying on tract-based spatial statistics (TBSS) analyses, we found that radial diffusivity (RD) and mean diffusivity (MD) were significantly increased at 2 days post-injury compared to the same-subject baseline (corrected p < 0.02). These alterations were visible in anterior/posterior WM regions spanning both hemispheres, demonstrating a diffuse pattern of injury after concussion. Implicated WM fiber tracts at 2 days include the following: right superior/inferior longitudinal fasciculus; right/left inferior fronto-occipital fasciculus; right corticospinal tract; right acoustic radiation; right/left anterior thalamic radiations; right/left uncinate fasciculus; and forceps major/minor. At 2 weeks post-injury, persistently elevated RD and MD were observed solely in prefrontal portions of WM fiber tracts (using same-subject contrasts). No significant differences were found for FA in any of the post-injury comparisons to baseline. Plots of individual subject RD and MD in prefrontal WM demonstrated homogenous increases from baseline to just after SRC; thereafter, trajectories became more variable. Most subjects' diffusivity values remained elevated at 2 months post-injury relative to their own baseline. Over the 2-month period after SRC, recovery of WM fiber tracts appeared to follow a posterior-to-anterior trend, paralleling the posterior-anterior pattern of WM maturation previously identified in the normal population.

CONCLUSION

These results suggest greater vulnerability of prefrontal regions to SRC, underline the importance of an individualized approach to concussion management, and show promise for using RD and MD for imaging-based diagnosis of SRC.

Service and support needs following pediatric brain injury: perspectives of children with mild traumatic brain injury and their parents

OBJECTIVE

To provide a qualitative examination of the service and support needs of children who have had a mild traumatic brain injury (mTBI), and their parents, in order to improve clinical services.

METHODS

Semi-structured interviews were conducted with 9 children (8-12 years; M = 10.6 years, SD = 0.8) and their parents (n = 9) 29-55 days (M = 34 days; SD = 9.3) after presenting to an Australian Paediatric Emergency Department (PED) for mTBI. Children's post-concussive symptoms (PCS) were additionally measured using the Post-Concussive Symptom Inventory (PCSI). Audio recordings were transcribed, and a thematic analysis was conducted.

RESULTS

Post-injury needs were reflected in four main themes: Communication; Family Burden; Continuity of Care; and Social and Community Support. These themes reflected children's and parents' needs for information, emotional/social/community support, and follow-up care. Both the children's and parents' needs, and the extent to which they were met, appeared to be related to the severity and duration of the child's PCS.

CONCLUSIONS

Dedicated pediatric mTBI follow-up services that build on family's resources and meet their individual needs for information, emotional support, and referral may assist in optimizing post-injury outcomes.

Clinical Findings in a Multicenter MRI Study of Mild TBI

Background: Uncertainty continues to surround mild traumatic brain injury (mTBI) diagnosis, symptoms, prognosis, and outcome due in part to a lack of objective biomarkers of injury and recovery. As mTBI gains recognition as a serious public health epidemic, there is need to identify risk factors, diagnostic tools, and imaging biomarkers to help guide diagnosis and management. Methods: One hundred and eleven patients (15-50 years old) were enrolled acutely after mTBI and followed with up to four standardized serial assessments over 3 months. Each encounter included a clinical exam, neuropsychological assessment, and magnetic resonance imaging (MRI). Chi-square and linear mixed models were used to assess changes over time and determine potential biomarkers of mTBI severity and outcome. Results: The symptoms most frequently endorsed after mTBI were headache (91%), not feeling right (89%), fatigue (86%), and feeling slowed down (84%). Of the 104 mTBI patients with a processed MRI scan, 28 (27%) subjects had white matter changes which were deemed unrelated to age, and 26 of these findings were deemed unrelated to acute trauma. Of the neuropsychological assessments tested, 5- and 6-Digit Backward Recall, the modified Balance Error Scoring System (BESS), and Immediate 5-Word Recall significantly improved longitudinally in mTBI subjects and differentiated between mTBI subjects and controls. Female sex was found to increase symptom severity scores (SSS) at every time point. Age ≥ 25 years was correlated with increased SSS. Subjects aged ≥ 25 also did not improve longitudinally on 5-Digit Backward Recall, Immediate 5-Word Recall, or Single-Leg Stance of the BESS, whereas subjects < 25 years improved significantly. Patients who reported personal history of depression, anxiety, or other psychiatric disorder had higher SSS at each time point. Conclusions: The results of this study show that 5- and 6-Digit Backward Recall, the modified BESS, and Immediate 5-Word Recall should be considered useful in demonstrating cognitive and vestibular improvement during the mTBI recovery process. Clinicians should take female sex, older age, and history of psychiatric disorder into account when managing mTBI patients. Further study is necessary to determine the true prevalence of white matter changes in people with mTBI.

Concussion in University Level Sport: Knowledge and Awareness of Athletes and Coaches

Using a cross-sectional survey concussion knowledge was evaluated among forty university-level athletes (n = 20, rugby union players; n = 20, Gaelic football players) and eight experienced team coaches (n = 2, rugby union; n = 2, Gaelic football; n = 1, soccer; n = 1, hockey; n = 1, netball; n = 1, basketball). Levels of knowledge of concussion were high across all participants. Coaches had higher knowledge scores for almost all areas; however, there was evidence of important gaps even in this group. Knowledge was not sufficient in identifying concussion, and when it is safe to return to play following a concussion. Impaired knowledge of how to recognise a concussion, and misunderstanding the need for rest and rehabilitation before return to play presents a hazard to health from second impact and more catastrophic brain injury. We discuss reasons for these guideline misconceptions, and suggest that attitude issues on the significance of concussion may underlie a willingness to want to play with a concussion. This suggests the current education on sport-related concussion needs to be expanded for the appropriate management of university-level contact sports.

The First Decade of Web-Based Sports Injury Surveillance (2004-2005 Through 2013-2014): Methods of the National Collegiate Athletic Association Injury Surveillance Program and High School Reporting Information Online

OBJECTIVE: 

To describe the methods of the National Collegiate Athletic Association (NCAA) Injury Surveillance Program (ISP) and High School Reporting Information Online (HS RIO) system as a complement to the sport-specific manuscripts that will follow.

BACKGROUND: 

The NCAA-ISP and HS RIO collect injury and exposure data from samples of collegiate and high school sports programs, respectively. The NCAA-ISP, which the NCAA has maintained since 1982, was relaunched as a Web-based platform at the beginning of the 2004-2005 academic year. In 2005, the HS RIO was introduced to capture data on high school athletes and modeled after the NCAA-ISP. Relevant data are shared with the NCAA and high school sport and policy committees to develop evidence-based rules and programs that help protect the health and safety of student-athletes.

DESCRIPTION: 

The NCAA-ISP and HS RIO monitor participation in school-sanctioned competitions and practices that occur from the first preseason practice to the final postseason contest for more than 25 sports. For this series of publications in the Journal of Athletic Training, injury information on 13 sports at the collegiate level during the 2004-2005 through 2013-2014 academic years and the high school level during the 2005-2006 through 2013-2014 academic years was evaluated.

CONCLUSIONS: 

Athletic trainers have been a vital source of data collection over the past decade to help produce the largest datasets of collegiate and high school sports injuries. Such data have helped various sport and policy committees advance protocols that aim to increase sports safety. This series of publications will aid by continuing to provide data to stakeholders in the sports community.