American Medical Society for Sports Medicine position statement on concussion in sport

Does time since concussion alter the factor structure of a multidomain assessment in adolescents?

The utilization of principal component analysis (PCA) approaches to concussion is beneficial to inform the interpretation of clinical outcome data in adolescent patients. While researchers have identified factors using post-concussive symptom scales and cognitive testing, there has yet to be a PCA that incorporates vestibular or oculomotor outcomes, or that focuses exclusively on adolescents. Moreover, the role of time since injury has not been examined in relation to concussion factors in this at-risk population. PCA methods were applied to two independent samples of 237 adolescents who presented to an outpatient concussion clinic: 1) ≤7 days (n = 145), and 2) 8 days-1 month (n = 92). The two separate PCAs included nine clinical assessments comprised of: a) four symptoms factors (cognitive/fatigue/migraine, affective, somatic, sleep), b) memory and speeded cognitive performance, c) near point of convergence (NPC), d) oculomotor, and e) vestibular outcomes. A three-component model including 1) symptoms, 2) cognitive, and 3) vestibular/oculomotor factors that accounted for 69.2% of the variance was supported for the ≤7 days sample. All items except somatic symptoms loaded. A different three-component model was supported for the 8 days-1 month sample, including 1) vestibulo-ocular migraine, 2) visuo-cognitive, and 3) affective-sleep that accounted for 72.1% of the variance, with all items loading. The findings supported two different concussion factor models that highlight the influence of time since injury and importance of considering vestibular and oculomotor outcomes in adolescents. Clinicians should evaluate these different factors using a comprehensive, multi domain approach to better inform assessment and monitor recovery in adolescent patients following concussion.Abbreviations: Principal Components Analysis (PCA), Immediate Post-concussion Assessment and Cognitive Testing (ImPACT), Post-concussion Symptom Scale (PCSS), Vestibular/Ocular Motor Screening (VOMS).

Influence of Aerobic Exercise Volume on Postconcussion Symptoms

BACKGROUND

Aerobic exercise has emerged as a useful treatment to improve outcomes among individuals who experience a concussion. However, compliance with exercise recommendations and the effect of exercise volume on symptom recovery require further investigation.

PURPOSE

To examine (1) if an 8-week aerobic exercise prescription, provided within 2 weeks of concussion, affects symptom severity or exercise volume; (2) whether prescription adherence, rather than randomized group assignment, reflects the actual effect of aerobic exercise in postconcussion recovery; and (3) the optimal volume of exercise associated with symptom resolution after 1 month of study.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Individuals randomized to an exercise intervention (n = 17; mean age, 17.2 ± 2.0 years; 41% female; initially tested a mean of 11.3 ± 2.8 days after injury) or standard of care (n = 20; mean age, 16.8 ± 2.2 years; 50% female; initially tested a mean of 10.7 ± 3.2 days after injury) completed an aerobic exercise test within 14 days of injury. They returned for assessments 1 month and 2 months after the initial visit. The aerobic exercise group was instructed to exercise 5 d/wk, 20 min/d (100 min/wk), at a target heart rate based on an exercise test at the initial visit. Participants reported their exercise volume each week over the 8-week study period and reported symptoms at each study visit (initial, 1 month, 2 months). Because of low compliance in both groups, there was no difference in the volume of exercise between the 2 groups.

RESULTS

There were no significant symptom severity differences between the intervention and standard-of-care groups at the initial (median Post-Concussion Symptom Inventory, 15 [interquartile range = 10, 42] vs 20 [11, 35.5]; P = .26), 1-month (4 [0, 28] vs 5.5 [0.5, 21.5]; P = .96), or 2-month (6.5 [0, 27.5] vs 0 [0, 4]; P = .11) study visits. Exercise volume was similar between groups (median, 115 [54, 225] vs 88 [28, 230] min/wk for exercise intervention vs standard of care; P = .52). Regardless of group, those who exercised <100 min/wk reported significantly higher symptom severity at the 1-month evaluation compared with those who exercised ≥100 min/wk (median, 1.5 [0, 7.5] vs 12 [4, 28]; P = .03). Exercising ≥160 min/wk successfully discriminated between those with and those without symptoms 1 month after study commencement (classification accuracy, 81%; sensitivity, 90%; specificity, 78%).

CONCLUSION

Greater exercise volume was associated with lower symptom burden after 1 month of study, and an exercise volume >160 min/wk in the first month of the study was the threshold associated with symptom resolution after the first month of the study. Because our observation on the association between exercise volume and symptom level is a retrospective and secondary outcome, it is possible that participants who were feeling better were more likely to exercise more, rather than the exercise itself driving the reduction in symptom severity.

The Nocebo Effect and Pediatric Concussion

While placebo effects are well recognized within clinical medicine, "nocebo effects" have received much less attention. Nocebo effects are problems caused by negative expectations derived from information or treatment provided during a clinical interaction. In this review, we examine how nocebo effects may arise following pediatric concussion and how they may worsen symptoms or prolong recovery. We offer several suggestions to prevent, lessen, or eliminate such effects. We provide recommendations for clinicians in the following areas: terminology selection, explicit and implicit messaging to patients, evidence-based recommendations, and awareness of potential biases during clinical interactions. Clinicians should consider the empirically grounded suggestions when approaching the care of pediatric patients with concussion.

Effects of CranioSacral therapy upon symptoms of post-acute concussion and Post-Concussion Syndrome: A pilot study

OBJECTIVE

The purpose of this study was to investigate the utilization of CranioSacral Therapy (CST) in patients with Post-Concussion Syndrome (PCS) and capture patient-reported perceptions of clinical outcomes of lived treatment experiences.

DESIGN

Two-part, longitudinal study conducted through a chart review of target group, followed by a Patient-reported Treatment Outcome Survey (PTOS).

PARTICIPANTS

A convenience sample of 212 patients with a historical incidence of head trauma not requiring hospitalization was obtained through medical records department dating back ten years. Inclusion criteria for further chart review (n = 67) was determined by identifying patients with a confirmed concussion directly correlated with presenting symptoms and for which CST was specifically sought as a treatment option. Demographics and patient-determined treatment duration data were analyzed by comparison groups extensively suggested in existing literature: Recovery time since injury as either Post-acute concussion (<6 months) or Post-Concussion Syndrome (PCS) (≥6 months); Athletes (A) or Non-athletes (NA); and traditional gender. Final PTOS group criteria was determined by eliminating confounding issues reporting (n = 47): (A, n = 24 and NA, n = 23).

RESULTS

Quantitative data was analyzed via Numerical Analysis, and qualitative data was analyzed via Inductive Content Analysis. Symptoms reported in all charts as well as in the PTOS were consistent with identified PCS subtypes. Utilization of CST revealed that most patients determined the treatment effect upon concussion symptoms within 1-3 sessions. Nearly twice as many sessions were attended in the PCS than post-acute groups. Referral sources, studied for a perspective on local concussion after-care discharge planning, ranged from professional to personal recommendation or self-discovery. A majority of patients met goals of reducing post-acute or PCS as reasons cited by self-determined change-in-status or discharge from service. Patients were asked to indicate on the PTOS which pre- and post-treatment symptoms were helped or not helped by this particular intervention.

CONCLUSIONS

Patient-reported changes of PCS symptoms is critical when evaluating treatment options. CST is an experiential treatment that addresses subjective levels of dysfunction, thus it is the patient deciding the value of an intervention. A sizable portion of patients in all groups reported a positive effect upon their symptoms by CST. Patients indicated personal meaning to CST through their utilization of multiple sessions. A high percentage indicated the likelihood of referring others with PCS for CST. Of the 212 patient charts first studied, the 145 not meeting inclusion criteria suggest some chronic conditions may present as long-term effects of older head injuries. CST is a low-risk, conservative treatment option for PCS sub-types worthy of further clinical study.

Pac-12 CARE-Affiliated Program: structure, methods and initial results

Sport-related concussion has garnered increasing scientific attention and research over the last decade. Collegiate student-athletes represent an important cohort in this field. As such, the Pac-12 CARE-Affiliated Program (CAP) was formed in 2017 as a regional hub of the Concussion Assessment, Research and Education (CARE) consortium. CAP is multisite, prospective, longitudinal study that aims to improve student-athlete health by identifying factors associated with concussion incidence and recovery and using this knowledge to inform best clinical practices and policy decisions. CAP employed a staggered rollout across the Pac-12, with the first four institutions enrolling in fall 2018. After receiving institutional review board (IRB) approval, these institutions began consenting student-athletes to share clinical concussion and baseline data for research purposes. Athletes completed baseline testing that included a medical questionnaire, concussion history and a battery for clinical concussion assessments. Concussed student-athletes were given the same battery of assessments in addition to full injury and return to play reports. Clinicians at each university worked with a data coordinator to ensure appropriate reporting, and the Pac-12 Concussion Coordinating Unit at the University of Colorado Boulder provided oversight for quality control of the data study wide. During year 1, CAP consented 2181 student-athletes and tracked 140 concussions. All research was conducted with the appropriate IRB approval across the participating Pac-12 institutions. Data security and dissemination are managed by the Presagia Sports Athlete Electronic Health Record software (Montreal, Quebec, Canada) and QuesGen Systems (San Francisco, California, USA).

Collegiate athletes' perceptions of the culture of concussion reporting

The current study was designed to understand the culture of concussion among college student-athletes. Participants: Eight men's lacrosse and seven women's soccer players. Methods: A focus group was conducted to understand thoughts, barriers, team culture, and what was needed to feel safe reporting symptoms. Thematic analysis was conducted to identify key themes. Results: Themes included concerns about being taken out, pushing through, wanting to play, severity influencing reporting, changes about concussion reporting, uncertainty about symptoms, concussion have changed the game, reporting a teammate, wanting someone else to make the call, desire to raise awareness, deception, wanting professors to have more understanding, circumstances influencing reporting, helmets specific for concussion, malingering, and the return to play protocol being too long. Conclusion: Factors ranging from intrinsic to more distal cultural and environmental factors appear to influence reporting concussions. Student-athletes identified factors unique to the college athlete environment.

Measuring optokinetic after-nystagmus: potential for detecting patients with signs of visual dependence following concussion

Concussed patients with chronic symptoms commonly report dizziness during exposure to environments with complex visual stimuli (e.g. supermarket aisles, busy crossroads). Such visual induced dizziness is well-known in patients with vestibular deficits, in whom it indicates an overreliance on visual cues in sensory integration. Considering that optokinetic after-nystagmus (OKAN) reflects the response of the central network integrating visual and vestibular self-motion signals (velocity storage network), we investigated OKAN in 71 patients [17 (23.9%) females, 30.36 ± 9.05 years old] who suffered from persistent symptoms after a concussion and presented clinical signs suggesting visual dependence. Data were retrospectively compared with 21 healthy individuals [13 (61.9%) females, 26.29 ± 10.00 years old]. The median values of the slow cumulative eye position and of the time constant of OKAN were significantly higher in patients than in healthy individuals (slow cumulative eye position: 124.15 ± 55.61° in patients and 77.87 ± 45.63° in healthy individuals-p = 0.012; time constant: 25.17 ± 10.27 s in patients and 13.95 ± 4.92 s in healthy individuals-p = 0.003). The receiving operating curve (ROC) estimated on the time constant had an overall area under the curve of 0.73. Analysis of the ROC suggests that a test measuring the OKAN time constant could obtain a sensitivity of 0.73 and specificity of 0.72 in determining the origin of the visual-related disturbances in those patients (threshold 16.6 s). In a subset of 43 patients who also performed the Sensory Organization Test (SOT), the proposed OKAN test was twice as sensitive as the SOT. This study suggests that concussed patients with persisting visual symptoms may have an underlying impairment of the velocity storage mechanism and that measuring the OKAN time constant can objectify such impairment.

Are you missing a concussion by watching American football? Video analysis of ball location in a Division 1 football program

OBJECTIVE

Action in a football game occurs quickly. Medical staff can miss a sport-related concussion (SRC) if they do not observe it directly. The objective of this study is to determine if SRCs occur more frequently at ball than away from ball during gameplay. Game-specific concussion statistics can enhance medical provider care of athletes.

METHODS

We used gameplay videos of an NCAA Division I football program to analyze SRCs and determine the primary tackler or ball handler during each concussion play. We compared the relative risk of SRCs for the primary ball handlers/tacklers to that of the other 10 players on the same team during that play.

RESULTS

Over 10 seasons, 26 SRCs occurred at ball for the primary ball handler/tackler position (0.22 SRCs/game) versus 16 away from ball (0.13 SRCs/game). The relative risk of an SRC according to exposure (at ball) vs. no exposure (away from ball) was 16.2 (CI 8.7-30.2, P < .05). Special teams had more SRCs away from ball than at ball, but this was not significant (relative risk 3.32, CI 0.90-12.3, P > .05).

CONCLUSIONS

The study provides medical staff guidance to more efficiently identify in-game SRCs and supports evidence for rules changes.

Diagnostic accuracy and reliability of sideline concussion evaluation: a prospective, case-controlled study in college athletes comparing newer tools and established tests

OBJECTIVE

To assess diagnostic accuracy and reliability of sideline concussion tests in college athletes.

METHODS

Athletes completed baseline concussion tests including Post-Concussion Symptom Scale, Standardised Assessment of Concussion (SAC), modified Balance Error Scoring System (m-BESS), King-Devick test and EYE-SYNC Smooth Pursuits. Testing was repeated in athletes diagnosed acutely with concussion and compared to a matched teammate without concussion.

RESULTS

Data were collected on 41 concussed athletes and 41 matched controls. Test-retest reliability for symptom score and symptom severity assessed using control athletes was 0.09 (-0.70 to 0.88) and 0.08 (-1.00 to 1.00) (unweighted kappa). Intraclass correlations were SAC 0.33 (-0.02 to 0.61), m-BESS 0.33 (-0.2 to 0.60), EYE-SYNC Smooth Pursuit tangential variability 0.70 (0.50 to 0.83), radial variability 0.47 (0.19 to 0.69) and King-Devick test 0.71 (0.49 to 0.84). The maximum identified sensitivity/specificity of each test for predicting clinical concussion diagnosis was: symptom score 81%/94% (3-point increase), symptom severity score 91%/81% (3-point increase), SAC 44%/72% (2-point decline), m-BESS 40%/92% (5-point increase), King-Devick 85%/76% (any increase in time) and EYE-SYNC Smooth Pursuit tangential variability 48%/58% and radial variability 52%/61% (any increase). Adjusted area under the curve was: symptom score 0.95 (0.89, 0.99), symptom severity 0.95 (95% CI 0.88 to 0.99), SAC 0.66 (95% CI 0.54 to 0.79), m-BESS 0.71 (0.60, 0.83), King-Devick 0.78 (0.69, 0.87), radial variability 0.47 (0.34, 0.59), tangential variability 0.41 (0.30, 0.54) CONCLUSION: Test-retest reliability of most sideline concussion tests was poor in uninjured athletes, raising concern about the accuracy of these tests to detect new concussion. Symptom score/severity had the greatest sensitivity and specificity, and of the objective tests, the King-Devick test performed best.

Head injury assessment in rugby union: clinical judgement guidelines

Background/aim

Clinical judgement is a recognised component of a complete off-field concussion assessment. This study identifies guidance criteria for team medical staff when using clinical judgement in their decision-making process during the World Rugby off-field concussion-assessment screen (HIA1).

Methods

Retrospective study of examining doctor clinical judgement in 1149 HIA1 assessments after a meaningful head impact event completed on rugby union players participating in elite-level international and national competitions between September 2015 and June 2018. We assessed (1) an abnormal subtest result as worse performance compared with preseason baseline values; (2) the proportion of cases where clinicians overruled abnormal HIA1 assessment subtest results and (3) made recommendations on how clinical judgement decisions may be made more safely based on the accuracy of clinical judgement decisions assessed against the final concussion diagnosis.

Results

One or more subtests were abnormal compared with baseline values in 857 of 1149 HIA1 assessments. Clinical judgement was used to return players to the game despite abnormal subtest results on 424 out of 857 occasions (49%). In a significant majority of cases 356/424 (84%), clinical judgement decisions were correct, with players later cleared of a concussion. An application of guided clinical judgement potentially decreased false negative assessments by 33% (21/63).

Conclusions

Clinical judgement should be applied in the diagnosis of concussion but done so cautiously. We propose doctors should only use clinical judgement to overrule either one of; or a combination of (1) an abnormal tandem gait and (2) one abnormal cognitive test.

Developing Insights for Possible and Probable Acute Concussions Using Cluster Analysis

Few studies have analyzed the Sport Concussion Assessment Tool's (SCAT) utility among athletes whose concussion assessment is challenging. Using a previously published algorithm, we identified possible and probable concussions at <6 h (n = 393 males, n = 265 females) and 24-48 h (n = 323 males, n = 236 females) post-injury within collegiate student-athletes and cadets from the Concussion Assessment, Research, and Education (CARE) Consortium. We applied cluster analysis to characterize performance on the Standard Assessment of Concussion (SAC), Balance Error Scoring System (BESS), and the SCAT symptom checklist for these athletes. Among the cluster sets that best separated acute concussions and normal performances, total symptom number raw score and change and post-traumatic migraine raw score and change score were the most frequent clustering variables across males and females at <6 h and 24-48 h. Similarly, total symptom number raw score and change score and post-traumatic migraine raw score and change score were most significantly different between clusters for males and females at <6 h and 24-48 h. Our results suggest that clinicians should focus on total symptom number, post-traumatic migraine symptoms, and cognitive-fatigue symptoms when assessing possible and probable concussions, followed by the SAC and BESS scores.

One size fits none: neurobiologic-specific modifications for the assessment, diagnosis, and treatment of sport-related concussion (SRC)

PRIMARY OBJECTIVE

- To discuss how the underlying neuroanatomy and neurobiology of five sport-related concussion (SRC) clinical profiles impacts assessment and treatment.

RESEARCH DESIGN

- Narrative review.

METHODS AND PROCEDURES

- Based on the current literature and clinical experience, arguments against the traditional SRC protocol and for a clinical profiles-based SRC protocol are made.

MAIN OUTCOMES AND RESULTS

- While the clinical profiles-based SRC protocol is widely used and accepted, there has been little published regarding the link to the underlying neuropathology. Our narrative review describes the five SRC clinical profiles: vestibular, ocular, mood, post-traumatic migraine, and cognitive/fatigue. For these profiles, the underlying neuroanatomy and neurobiology is outlined, as well as how that anatomy and biology impact the profiles' etiology, assessment, and treatment. The cervical and sleep modifiers are also briefly covered.

CONCLUSIONS

- Utilizing this model, clinicians are able to provide an individualized assessment, conceptualization, and treatment plan for SRC, leading to improved outcomes and clinical experiences for athletes.

Musculoskeletal and Sports Medicine Curriculum Guidelines for Pediatric Residents

ABSTRACT

Musculoskeletal (MSK) and sports-related conditions are relatively common in the pediatric population. Pediatric residencies should provide residents with the knowledge and skills to assess and manage both acute and chronic MSK and sports injuries and complaints. Residents should develop the competencies and attitudes to safeguard and promote a healthy and active lifestyle for youth. Programs can use a variety of educational tools, both in the clinic and on the field, to provide a well-rounded MSK curriculum throughout the residency years. This article provides a review of general pediatric sports medicine curriculum guidelines and suggested implementation strategies.

Concussion assessment potentially aided by use of an objective multimodal concussion index

Objective

Prompt, accurate, objective assessment of concussion is crucial as delays can lead to increased short and long-term consequences. The purpose of this study was to derive an objective multimodal concussion index (CI) using EEG at its core, to identify concussion, and to assess change over time throughout recovery.

Methods

Male and female concussed ( N = 232) and control ( N = 206) subjects 13–25 years were enrolled at 12 US colleges and high schools. Evaluations occurred within 72 h of injury, 5 days post-injury, at return-to-play (RTP), 45 days after RTP (RTP + 45); and included EEG, neurocognitive performance, and standard concussion assessments. Concussed subjects had a witnessed head impact, were removed from play for ≥ 5 days using site guidelines, and were divided into those with RTP < 14 or ≥14 days. Part 1 describes the derivation and efficacy of the machine learning derived classifier as a marker of concussion. Part 2 describes significance of differences in CI between groups at each time point and within each group across time points.

Results

Sensitivity = 84.9%, specificity = 76.0%, and AUC = 0.89 were obtained on a test Hold-Out group representing 20% of the total dataset. EEG features reflecting connectivity between brain regions contributed most to the CI. CI was stable over time in controls. Significant differences in CI between controls and concussed subjects were found at time of injury, with no significant differences at RTP and RTP + 45. Within the concussed, differences in rate of recovery were seen.

Conclusions

The CI was shown to have high accuracy as a marker of likelihood of concussion. Stability of CI in controls supports reliable interpretation of CI change in concussed subjects. Objective identification of the presence of concussion and assessment of readiness to return to normal activity can be aided by use of the CI, a rapidly obtained, point of care assessment tool.

Concussion in the Athletic Training Room: a Team Physician Narrative

PURPOSE OF THE REVIEW

Concussion evaluation and management has changed significantly. Understanding proper recognition, evaluation, and management allows for improved provision of care to patients. This paper will approach this topic from a sideline to training room management versus the traditional clinic evaluation RECENT FINDINGS: Research is continuing to refine and examine tools to assist in proper concussion evaluation. Concussion recovery protocols are becoming more conservative as patients are taking longer to recover than previously thought. Treatment of concussion is becoming more sophisticated and patient involved. Concussion research has increased dramatically over the last 30 years changing our approach to diagnosis and treatment. The area of concussion will continue to evolve as research continues to look at effective tools and markers for diagnosis and effective treatment protocols become substantiated through research.

Head Impact Situations in Professional Football (Soccer)

To assess head impact incidents (HIIs) and to distinguish diagnosed head injuries from other incidents, a video observation analysis of match HIIs was conducted in the German Bundesliga (2017/18 season). Video recordings of each match were screened to identify the respective events. Head injury data were identified by a prospective injury registry. HII and head injury incidence rates (IR) were calculated with 95% CIs. The total number of HIIs was 1,362 corresponding to an IR of 134.9/1000 match hours (95% CI 127.9–142.2). In 123 HII (IR 12.2, 95% CI 10.2–14.5) the contact was classified as severe. Head contact with the opponent was the most frequent cause (85%). The most frequent mechanism was in 44% (combined) the arm and elbow-to-head, followed by head-to-head and hand-to-head contacts (each 13%). In 58%, the HIIs occurred during header duels. Twenty-nine head injuries were recorded (IR 2.9, 95% CI 2.0–4.1). Concussions/traumatic brain injuries accounted for 48%, head/facial fractures 24%, head/facial contusions 21%, and lacerations/abrasions 7%. The number of HIIs not classified as concussions/more severe trauma was high. Identification of HIIs and head injury severity should be improved during on-field assessment as many head injuries might go unrecognised based on the large number of HIIs.

A cross-sectional study reporting concussion exposure, assessment and management in Western Australian general practice

Background

General Practitioners (GPs) may be called upon to assess patients who have sustained a concussion despite limited information being available at this assessment. Information relating to how concussion is actually being assessed and managed in General Practice is scarce. This study aimed to identify characteristics of current Western Australian (WA) GP exposure to patients with concussion, factors associated with GPs’ knowledge of concussion, confidence of GPs in diagnosing and managing patients with concussion, typical referral practices and familiarity of GPs with guidelines.

Methods

In this cross-sectional study, GPs in WA were recruited via the RACGP WA newsletter and shareGP and the consented GPs completed an electronic survey. Associations were performed using Chi-squared tests or Fisher’s Exact test.

Results

Sixty-six GPs in WA responded to the survey (response rate = 1.7%). Demographics, usual practice, knowledge, confidence, identification of prolonged recovery as well as guideline and resource awareness of GPs who practised in regional and metropolitan areas were comparable (p > 0.05). Characteristics of GPs were similar between those who identified all symptoms of concussion and distractors correctly and those who did not (p > 0.05). However, 84% of the respondents who had never heard of concussion guidelines were less likely to answer all symptoms and distractors correctly (p = 0.039). Whilst 78% of the GPs who were confident in their diagnoses had heard of guidelines (p = 0.029), confidence in managing concussion was not significantly associated with GPs exposure to guidelines. It should be noted that none of the respondents correctly identified signs of concussion and excluded the distractors.

Conclusions

Knowledge surrounding concussion guidelines, diagnosis and management varied across GPs in WA. Promotion of available concussion guidelines may assist GPs who lack confidence in making a diagnosis. The lack of association between GPs exposure to guidelines and confidence managing concussion highlights that concussion management may be an area where GPs could benefit from additional education and support.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-021-01384-1.

Discrepancies in child and parent reporting of concussion symptoms

Objective: To assess discrepancies between child and parent symptom reports following concussion.Methods: Prospective cohort study involving 61 patients, age 7-21 years, diagnosed with a concussion within the previous 14 days. Children/parents completed the Child SCAT-3 symptom inventory at enrollment and 4 weeks post-injury. A within-subjects t-test was used to compare differences in child/parent response for each of 20 individual symptoms, 4 symptom domains, and total symptom severity. Pearson correlations were used to measure agreement between child/parent responses. A repeated measures analysis of variance assessed the effect of time on child/parent symptom discrepancy.Results: At enrollment, children reported higher symptom severity for 'distracted easily' (adj. p = .015) and 'confused' (adj. p = .015). There was moderate-to-high (r > 0.3) agreement between children and parents for more individual symptoms at enrollment (18/20) than at 4 weeks post-injury (14/20). Age had no effect (p > .05) on the discrepancy between child/parent reports.Conclusions: Although there was moderate-to-strong agreement between child/parent reports of concussion symptoms, discrepancies in individual cognitive symptom reports exist, in both children and adolescents. Therefore, collection of parent scales may provide useful information when tracking cognitive symptoms in adolescent patients, who may under-report or under-recognize cognitive deficits.

Impaired motor control after sport-related concussion could increase risk for musculoskeletal injury: Implications for clinical management and rehabilitation

This review presents a conceptual framework and supporting evidence that links impaired motor control after sport-related concussion (SRC) to increased risk for musculoskeletal injury. Multiple studies have found that athletes who are post-SRC have higher risk for musculoskeletal injury compared to their counterparts. A small body of research suggests that impairments in motor control are associated with musculoskeletal injury risk. Motor control involves the perception and processing of sensory information and subsequent coordination of motor output within the central nervous system to perform a motor task. Motor control is inclusive of motor planning and motor learning. If sensory information is not accurately perceived or there is interference with sensory information processing and cognition, motor function will be altered, and an athlete may become vulnerable to injury during sport participation. Athletes with SRC show neuroanatomic and neurophysiological changes relevant to motor control even after meeting return to sport criteria, including a normal neurological examination, resolution of symptoms, and return to baseline function on traditional concussion testing. In conjunction, altered motor function is demonstrated after SRC in muscle activation and force production, movement patterns, balance/postural stability, and motor task performance, especially performance of a motor task paired with a cognitive task (i.e., dual-task condition). The clinical implications of this conceptual framework include a need to intentionally address motor control impairments after SRC to mitigate musculoskeletal injury risk and to monitor motor control as the athlete progresses through the return to sport continuum.

Predictive Accuracy of the Sport Concussion Assessment Tool 3 and Vestibular/Ocular-Motor Screening, Individually and In Combination: A National Collegiate Athletic Association-Department of Defense Concussion Assessment, Research and Education Consortium Analysis

BACKGROUND

Vestibular and ocular symptoms in sport-related concussions are common. The Vestibular/Ocular-Motor Screening (VOMS) tool is a rapid, free, pen-and-paper tool that directly assesses these symptoms and shows consistent utility in concussion identification, prognosis, and management. However, a VOMS validation study in the acute concussion period of a large sample is lacking.

PURPOSE

To examine VOMS validity among collegiate student-athletes, concussed and nonconcussed, from the multisite National Collegiate Athletic Association-Department of Defense Concussion Assessment, Research and Education (CARE) Consortium. A secondary aim was to utilize multidimensional machine learning pattern classifiers to deduce the additive power of the VOMS in relation to components of the Sport Concussion Assessment Tool 3 (SCAT3).

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

Preseason and acute concussion assessments were analyzed for 419 student-athletes. Variables in the analysis included the VOMS, Balance Error Scoring System, Standardized Assessment of Concussion, and SCAT3 symptom evaluation score. Descriptive statistics were calculated for all tools, including Kolmogorov-Smirnov significance and Cohen d effect size. Correlations between tools were analyzed with Spearman r, and predictive accuracy was evaluated through an Ada Boosted Tree machine learning model's generated receiver operating characteristic curves.

RESULTS

Total VOMS scores and SCAT3 symptom scores demonstrated significant increases in the acute concussion time frame (Cohen d = 1.23 and 1.06; P < .0001), whereas the Balance Error Scoring System lacked clinical significance (Cohen d = 0.17). Incorporation of VOMS into the full SCAT3 significantly boosted overall diagnostic ability by 4.4% to an area under the curve of 0.848 (P < .0001) and produced a 9% improvement in test sensitivity over the existing SCAT3 battery.

CONCLUSION

The results from this study highlight the relevance of the vestibular and oculomotor systems to concussion and the utility of the VOMS tool. Given the 3.8 million sports-related and 45,121 military-related concussions per year, the addition of VOMS to the SCAT3 is poised to identify up to an additional 304,000 athletes and 3610 servicemembers annually who are concussed, thereby improving concussion assessment and diagnostic rates. Health care providers should consider the addition of VOMS to their concussion assessment toolkits, as its use can positively affect assessment and management of concussions, which may ultimately improve outcomes for this complex and common injury.

Network Analysis of Sport-Related Concussion Research During the Past Decade (2010-2019)

CONTEXT

Research into sport-related concussion (SRC) has grown substantially over the past decade, yet no authors to date have synthesized developments over this critical time period.

OBJECTIVE

To apply a network-analysis approach in evaluating trends in the SRC literature using a comprehensive search of original, peer-reviewed research articles involving human participants published between January 1, 2010, and December 15, 2019.

DESIGN

Narrative review.

MAIN OUTCOME MEASURE(S)

Bibliometric maps were derived from a comprehensive search of all published, peer-reviewed SRC articles in the Web of Science database. A clustering algorithm was used to evaluate associations among journals, organizations or institutions, authors, and key words. The online search yielded 6130 articles, 528 journals, 7598 authors, 1966 organizations, and 3293 key words.

RESULTS

The analysis supported 5 thematic clusters of journals: (1) biomechanics/sports medicine (n = 15), (2) pediatrics/rehabilitation (n = 15), (3) neurotrauma/neurology/neurosurgery (n = 11), (4) general sports medicine (n = 11), and (5) neuropsychology (n = 7). The analysis identified 4 organizational clusters of hub institutions: (1) University of North Carolina (n = 19), (2) University of Toronto (n = 19), (3) University of Michigan (n = 11), and (4) University of Pittsburgh (n = 10). Network analysis revealed 8 clusters for SRC key words, each with a central topic area: (1) epidemiology (n = 14), (2) rehabilitation (n = 12), (3) biomechanics (n = 11), (4) imaging (n = 10), (5) assessment (n = 9), (6) mental health/chronic traumatic encephalopathy (n = 9), (7) neurocognition (n = 8), and (8) symptoms/impairments (n = 5).

CONCLUSIONS

The findings suggest that during the past decade SRC research has (1) been published primarily in sports medicine, pediatric, and neuro-focused journals, (2) involved a select group of researchers from several key institutions, and (3) concentrated on new topical areas, including treatment or rehabilitation and mental health.

Loss of Consciousness is Associated with Elevated Cognitive Intra-Individual Variability Following Sports-Related Concussion

OBJECTIVE

The purpose of this study was to evaluate whether loss of consciousness (LOC), retrograde amnesia (RA), and anterograde amnesia (AA) independently influence a particular aspect of post-concussion cognitive functioning-across-test intra-individual variability (IIV), or cognitive dispersion.

METHOD

Concussed athletes (N = 111) were evaluated, on average, 6.04 days post-injury (SD = 5.90; Mdn = 4 days; Range = 1-26 days) via clinical interview and neuropsychological assessment. Primary outcomes of interest included two measures of IIV-an intra-individual standard deviation (ISD) score and a maximum discrepancy (MD) score-computed from 18 norm-referenced variables.

RESULTS

Analyses of covariance (ANCOVAs) adjusting for time since injury and sex revealed a significant effect of LOC on the ISD (p = .018, ηp2 = .051) and MD (p = .034, ηp2 = .041) scores, such that athletes with LOC displayed significantly greater IIV than athletes without LOC. In contrast, measures of IIV did not significantly differ between athletes who did and did not experience RA or AA (all p > .05).

CONCLUSIONS

LOC, but not RA or AA, was associated with greater variability, or inconsistencies, in cognitive performance acutely following concussion. Though future studies are needed to verify the clinical significance of these findings, our results suggest that LOC may contribute to post-concussion cognitive dysfunction and may be a risk factor for less efficient cognitive functioning.

Case report: Manual therapies promote resolution of persistent post-concussion symptoms in a 24-year-old athlete

This case report illustrates the treatment outcomes of a collegiate athlete presenting with an 18-month history of post-concussion syndrome who received a series of mixed manual therapies in isolation of other therapy. Persistent symptoms were self-reported as debilitating, contributing to self-removal from participation in school, work, and leisure activities. Patient and parent interviews captured the history of multiple concussions and other sports-related injuries. Neurological screening and activities of daily living were baseline measured. Post-Concussion Symptom Checklist and Headache Impact Test-6™ were utilized to track symptom severity. Treatments applied included craniosacral therapy, manual lymphatic drainage, and glymphatic techniques. Eleven treatment sessions were administered over 3 months. Results indicated restoration of oxygen saturation, normalized pupil reactivity, and satisfactory sleep. Post-concussion syndrome symptom severity was reduced by 87% as reflected by accumulative Post-Concussion Symptom Checklist scores. Relief from chronic headaches was achieved, reflected by Headache Impact Test-6 scores. Restoration of mood and quality of life were reported. A 6-month follow-up revealed symptoms remained abated with full re-engagement of daily activities. The author hypothesized that post-concussion syndrome symptoms were related to compression of craniosacral system structures and lymphatic fluid stagnation that contributed to head pressure pain, severe sleep deprivation, and multiple neurological and psychological symptoms. Positive outcomes over a relatively short period of time without adverse effects suggest these therapies may offer viable options for the treatment of post-concussion syndrome.

Do rugby league players under-report concussion symptoms? A cross-sectional study of elite teams based in Australia

Objective

To determine the rate of under-reporting of concussion and its symptoms in elite rugby league players in Australia.

Methods

The study was conducted in the preseason of the 2020 National Rugby League (NRL) competition.

A total of 151 male, NRL club contracted rugby league players across three professional clubs participated.

The participants completed a voluntary, anonymous survey exploring player demographics, concussion data, under-reporting instances and reasons for under-reporting over the 2018 and 2019 rugby league seasons.

Results

17.2% of surveyed players reported sustaining a likely concussion over the past 2 years and not reporting to medical staff. 22% of NRL first grade players admitted to not reporting at least one concussion during the 2018 and 2019 seasons. The most common reason not to report was the player ‘not wanting to be ruled out of the game or training session’ (57.7%), followed by ‘not wanting to let down the coaches or teammates’ (23.1%). 85.4% of surveyed players reported having concussion education by their club in the previous two seasons.

Conclusions

17.2 % of elite rugby league players in Australia chose not to report likely concussive episodes and concussion-related symptoms during the 2018 and 2019 seasons. Clinicians need to be aware of under-reporting in athletes when assessing players following head injuries. The findings highlight the need for development of validated, objective testing for concussion following sports-associated head injury.

Factors Associated with Symptom Reporting in U.S. Service Academy Cadets and NCAA Student Athletes without Concussion: Findings from the CARE Consortium

BACKGROUND

Symptom resolution is a key marker in determining fitness for return to activity following concussion, but in some cases, distinguishing persistent symptoms due to concussion versus symptoms related to other factors can be challenging.

OBJECTIVE

To determine base rates of postconcussional syndrome (PCS) diagnostic categorization in healthy cadets and student athletes with no recent concussion.

METHODS

13,009 cadets and 21,006 student athletes completed baseline preseason testing. After inclusion/exclusion criteria were applied, the final sample included 12,039 cadets [9123 men (75.8%); 2916 women (24.2%)] and 18,548 student athletes [10,192 men (54.9%); 8356 women (45.1%)]. Participants completed the Sport Concussion Assessment Tool-3rd Edition (SCAT3) symptom evaluation as part of baseline preseason testing. The PCS diagnostic categorization was classified by the International Classification of Diseases, 10th Revision (ICD-10) symptom criteria for PCS.

RESULTS

In the absence of recent concussion, subgroups of cadets (17.8% of men; 27.6% of women) and student athletes (11.4% of men; 20.0% of women) reported a cluster of symptoms that would meet the ICD-10 symptom criteria for PCS. Participants with insufficient sleep and/or preexisting conditions (e.g., mental health problems), freshmen cadets, and cadets at the U.S. Coast Guard Academy and at the U.S. Air Force Academy (freshmen were tested during basic cadet training) were more likely to report a cluster of symptoms that would meet the ICD-10 symptom criteria for PCS.

CONCLUSION

The ICD-10 symptom criteria for PCS can be mimicked by preexisting conditions, insufficient sleep, and/or stress. Findings support person-specific assessment and management of symptoms following concussion.

The association of concussion history and symptom presentation in combat sport athletes

OBJECTIVE

The purpose of this study was to describe the concussion-related symptoms reported among combat sport athletes with and without a history of concussion, and a history of neck injury.

DESIGN

Cross-sectional survey.

SETTING

Data were collected using an online survey instrument.

PARTICIPANTS

Three hundred and nine adult combat sport athletes.

MAIN OUTCOME MEASURES

Self-reported 12-month concussion history and neck injury history and a 22-item symptom checklist.

RESULTS

A history of concussion was reported by 19.1% of athletes, a history of neck injury was reported by 23.0%, and 13.6% reported both injuries. Neck pain was the most frequently reported symptom. Athletes with a history of injury had significantly greater proportions of 'high' total symptoms and symptom severity scores compared with athletes with no history of injury. Athletes with a history of concussion had 2.35 times higher odds of reporting 'high' total symptoms and symptoms severity scores.

CONCLUSION

Athletes with a history of concussion or neck injury have greater odds of presenting with higher symptom scores. The presence of high total symptom scores and high symptom severity scores may indicate a need for further investigation into domains commonly associated with concussion.

It is time to rewrite state youth sports concussion laws

Between 2009 and 2014, all 50 states and the District of Columbia passed legislation to improve the recognition and management of youth concussed in sports. These laws can include requirements for concussion training for school athletic personnel, concussion education for children and their parents, return-to-play (RTP) procedures, and medical clearance to for RTP. Concussion can impact academic learning and performance in children and adolescents. Postconcussion academic accommodations during recovery can be an important component of secondary prevention for mitigating the sequalae of head injury. Few state youth concussion laws, however, include provision of postconcussion return-to-learn (RTL) accommodations and most of those that do address RTL apply to student athletes only. Concussions may occur in youth who are not participating in organised sports (eg, falls, traffic crashes) and thus may not be subjected to RTL accommodations, even if the state mandates such procedures for athletes. Low income and students of colour may be more likely to have non-sports concussions than their more affluent and white peers, thus potentially creating demographic disparities in the benefits of RTL procedures. State youth sports concussion laws should be revised so that they include RTL provisions that apply to all students, athletes and non-athletes alike.

Predictive Value of Subacute Heart Rate Variability for Determining Outcome Following Adolescent Concussion

Objective assessments of concussion recovery are crucial for facilitating effective clinical management. However, predictive tools for determining adolescent concussion outcomes are currently limited. Research suggests that heart rate variability (HRV) represents an indirect and objective marker of central and peripheral nervous system integration. Therefore, it may effectively identify underlying deficits and reliably predict the symptomology following concussion. Thus, the present study sought to evaluate the relationship between HRV and adolescent concussion outcomes. Furthermore, we sought to examine its predictive value for assessing outcomes. Fifty-five concussed adolescents (12–17 years old) recruited from a local sports medicine clinic were assessed during the initial subacute evaluation (within 15 days postinjury) and instructed to follow up for a post-acute evaluation. Self-reported clinical and depressive symptoms, neurobehavioral function, and cognitive performance were collected at each timepoint. Short-term HRV metrics via photoplethysmography were obtained under resting conditions and physiological stress. Regression analyses demonstrated significant associations between HRV metrics, clinical symptoms, neurobehavioral function, and cognitive performance at the subacute evaluation. Importantly, the analyses illustrated that subacute HRV metrics significantly predicted diminished post-acute neurobehavioral function and cognitive performance. These findings indicate that subacute HRV metrics may serve as a viable predictive biomarker for identifying underlying neurological dysfunction following concussion and predict late cognitive outcomes.

The use of inertial measurement units to assess gait and postural control following concussion

BACKGROUND

Impairments in gait and balance function are typical after concussion. There is evidence that these neuromuscular deficits persist past the typical time of symptom resolution. The ability to quantify these changes in gait and balance may provide useful information when making return to play decisions in clinical settings.

RESEARCH QUESTION

Are changes in gait function and postural control evident across the course of a concussion management program?

METHODS

A retrospective analysis of a convenience sample of 38 patients who were seen for concussion between October 2017 and May 2019 was performed. Gait and balance measures were assessed at their initial clinic visit post-injury and at their clearance visit using inertial measurement units. During dual-task walking trials, the medial-lateral motion of the center of mass and gait velocity were measured. Postural sway complexity and jerk index were measured during both eyes-open and eyes-closed balance trials.

RESULTS

Paired samples t-tests and Wilcoxon signed rank tests were used to determine whether statistically significant changes occurred for the gait and balance variables, respectively. Medial-lateral sway decreased (4.4 ± 1.3 cm to 4.0 ± 1.2 cm, p = 0.018) and gait velocity increased (0.78 ± 0.23 m/s to 0.91 ± 0.18 m/s, p <  0.001) from initial to clearance testing. Jerk index decreased (6.41 ± 11.06 m²/s⁵ to 5.73 ± 4.28 m²/s⁵, p = 0.031) and (11.87 ± 26.42 m²/s⁵ to 7.87 ± 8.38 m²/s⁵, p = 0.003) from initial to clearance testing for the eyes-open and eyes-closed conditions, respectively. Complexity index increased (2.38 ± 1.08-2.86 ± 0.72, p = 0.010) from initial to clearance testing for the eyes-closed condition. There was no change in complexity index for the eyes-open condition.

SIGNIFICANCE

These preliminary results support the potential use of measures of gait and postural control to assess recovery following a concussion in a clinical setting.

First-time sports-related concussion recovery revisited: management changes and impact on recovery

Context

Concussion is among the most common injuries in athletes. Over the past 10 years, concussion knowledge has expanded, and guidelines for management have changed. Recent changes include recommendations against strict mental and physical rest after sustaining a concussion, a better recognition of preexisting conditions predisposing protracted concussion recovery, and the addition of preliminary patient counseling and education about the expected course of concussion recovery.

Objective

To assess the impact of changes in concussion management on the duration of symptoms in middle school and high school athletes after sustaining a first-time, sports-related concussion.

Methods

A retrospective review was performed of medical records of athletes who sustained a concussion between 2016 and 2018 and were treated by the same primary care physician (J.M.N) using the revised approach to concussion management described. Patients were included if they were 11 to 18 years old and had a diagnosis of first-time concussion sustained while playing organized sports. Athletes who sustained a concomitant injury or sustained a concussion outside of organized sports were excluded from the study; athletes lost to follow-up or with incomplete forms were also excluded. Each athlete's length of symptomatic time from his or her concussion was calculated. This data was then compared with a previously-published data set of athletes who sustained a concussion between 2011 and 2013, with the same inclusion criteria but a different approach to concussion management.

Results

A total of 110 male and 72 female athletes (N=182) met the study's eligibility criteria. Collectively, athletes of both sexes from the 2016-2018 data set reported a higher incidence of preexisting conditions associated with prolonged concussion recovery compared with the data set of 2011-2013 athletes. However, both sexes from the 2016-2018 data set also reported a shorter median duration of concussion symptoms compared with the 2011-2013 athletes (median duration 5 vs. 11 days for male athletes and 7 vs. 28 days for female athletes, respectively; p<0.001).

Conclusion

Recent changes in concussion management have led to decreased duration of symptoms among 11- to 18-year-old athletes with first-time, sports-related concussions. These management changes include advocating for early activity, recognizing preexisting conditions, and educating athletes about the realities of concussion recovery.

Youth Soccer Parents' Attitudes and Perceptions About Concussions

PURPOSE

Parents are important figures in properly managing youth sport concussions. Although media attention has predominantly centered on concussions in contact/collision sports, evidence suggests that the concussion rate in soccer is comparable to those found in contact/collision sports. Given the high rate of concussions in youth soccer, this study aimed to examine parents of youth soccer athletes' attitudes and perceptions about concussions and associated factors.

METHODS

A cross-sectional study was conducted by surveying parents of youth soccer athletes from the five largest organized youth soccer programs across the U.S. The researchers developed a questionnaire after an extensive literature review and by modifying previously used instruments.

RESULTS

Overall, 419 parents completed the survey. The vast majority (85%) agreed that a concussion is a serious injury, but only 27.9% believed that their child could suffer a concussion during the next season. Parents were most concerned about permanent brain damage when their child suffers a concussion. The vast majority (4.37 ± .89) perceived concussion reporting as an important injury prevention strategy. Greater appreciation and perceived risk about concussions was found particularly among parents who received concussion education and those who had witnessed or heard about a concussive incidence(s).

CONCLUSIONS

Findings suggest that youth soccer parents have high appreciation and perceived risk about concussions. However, the need for more targeted education was noted, as improvements to better manage and reduce concussions can be made. Future research should continue examining youth sport parents' belief and understanding about concussions as well as factors affecting them.

Medicine in the Sport of Horse Racing

Horseracing is among the most popular and increasingly lucrative industry sports in the nation. The average jockey must control a thoroughbred horse 10 times their weight that may act unpredictably whether at rest or full gallop resulting in falls, kicks, or even biting injuries. Despite the risks, jockeys do not have access to the same quality of medical care that is standard in similarly profitable sports organizations. Beyond the mental and physical demands of training and performance endured by any professional athlete, jockeys are confronted with health challenges unique to their sport. In this review of the literature, we aim to educate sports medicine physicians regarding the underlying causes of injuries, describe injury management, and make recommendations for appropriate preventive strategies. Overall, there is a void of literature, and so our authors offer expert opinion and encourage others to get involved in making this a safer sport.

Dual-Task Gait Recovery after Concussion among Female and Male Collegiate Athletes

PURPOSE

Few studies have investigated recovery between sexes using objective outcome measures. Our purpose was to examine the independent association between biological sex and recovery of postconcussion gait among collegiate athletes.

METHODS

We evaluated participants with a diagnosed concussion <7 d postinjury, and approximately 1.5 months and 3.5 months postinjury. Participants completed a single/dual-task gait evaluation and symptom inventory. During dual-task trials, they completed a mental task (backward subtraction, spelling, or month recitation). The primary outcome measure was height-adjusted gait velocity recovery, defined as achieving normal gait velocity using established values: >0.56 and >0.50 gait velocity (m·s)/height (m) under single and dual-task conditions, respectively. We used a multivariable Cox proportional hazard model to identify associations between sex and dual-task recovery, controlling for age, concussion history, symptom severity, and loss of consciousness at the time of injury.

RESULTS

Ninety-four individuals participated in the study: 47 (50%) were female athletes (mean age = 20.1, SD = 1.3 yr) and 47 (50%) were male athletes (mean age = 20.3, SD = 1.3 yr). Sex was not independently associated with height-adjusted single-task gait velocity recovery after controlling for potential confounders (hazard ratio = 1.62, 95% confidence interval = 0.87-3.01). However, male sex was independently associated with longer dual-task gait recovery time after controlling for potential confounders (hazard ratio = 2.43, 95% confidence interval = 1.11-5.35).

CONCLUSION

Male athletes required a longer duration of time after concussion to achieve dual-task gait recovery than female athletes. Thus, functional dual-task abilities after concussion may be affected differentially by sex and should be accounted for within individualized concussion management strategies.

Time to Authorized Clearance from Sport-Related Concussion: The Influence of Healthcare Provider and Medical Facility

CONTEXT

Return-to-play following sport-related concussion(SRC) requires authorized clearance from a healthcare provider(HCP). Variability in HCPs and facilities where athletes seek care may influence return time.

OBJECTIVE

Determine the initial examiner, HCPs that authorize clearance, and medical facilities authorizing clearance among high school student-athletes following SRC, and compare authorized clearance time by HCPs and medical facilities.

DESIGN

Prospective Cohort Study.

SETTING

High school.

PATIENTS OR OTHER PARTICIPANTS

Student-athletes(n=16,001) with SRC participating in STATE-XXX High School Athletic Association(XHSAA)-sponsored athletics.

MAIN OUTCOME MEASURE(S)

Frequencies of initial examiner and authorized clearance for each HCP(Doctor of Osteopathic Medicine(DO), Doctor of Medicine(MD), Nurse Practitioner(NP), Physician Assistant(PA)) and medical facility (Neurologist's Office, Team Physician, Primary Care Physician or Pediatrician's Office(PCP), Hospital, Urgent/Ready Care) for each SRC case. Kaplan-Meier curves and Peto tests evaluated differences in median time to authorized clearance between HCPs and facilities. Only cases with a follow-up authorized clearance date(80.3%, n=12,856) were included in authorized clearance and time to return analyses.

RESULTS

An athletic trainer was at least one of the initial examiners for 71.3%(n=11,404) of cases; 80.2%(n=12,990) had only one initial examiner. There was an association between initial examiner and medical facility providing clearance for athletic director(χ2=52.6, p≤.001, V=.06), athletic trainer(χ2=172.0, p≤.001, V=.12), coach(χ2=161.5, p≤.001, V=.11), DO(χ2=59.4, p≤.001, V= 07), and NP(χ2=10.0, p .03, V=.12). The majority(n=8,218, 63.9%) received clearance by an MD; 70.8%(n=9,099) were cleared at a PCP. Median time to authorized clearance varied by facility(Urgent/Ready Care: 7 days[4,11], Hospital: 9 days[6,14], PCP: 10 days[6,14], Team Physician: 12 days[8,16], Neurologist Office: 13 days[9,20]; p ≤ .001).

CONCLUSIONS

Clearance was frequently provided by an MD and at a PCP. Median time to return to unrestricted participation following SRC varied by HCP and medical facility. Future research should elucidate why differences exist and determine why athletes seek care at different medical facilities.

Neuromodulation for Mild Traumatic Brain Injury Rehabilitation: A Systematic Review

Background: Mild traumatic brain injury (mTBI) results from an external force to the head or body causing neurophysiological changes within the brain. The number and severity of symptoms can vary, with some individuals experiencing rapid recovery, and others having persistent symptoms for months to years, impacting their quality of life. Current rehabilitation is limited in its ability to treat persistent symptoms and novel approaches are being sought to improve outcomes following mTBI. Neuromodulation is one technique used to encourage adaptive neuroplasticity within the brain. Objective: To systematically review the literature on the efficacy of neuromodulation in the mTBI population. Method: A systematic review was conducted using Medline, Embase, PsycINFO, PsycARTICLES and EBM Review. Preferred Reporting Items for Systematic Reviews and the Synthesis Without Meta-analysis reporting guidelines were used and a narrative review of the selected studies was completed. Fourteen articles fulfilled the inclusion criteria which were published in English, investigating an adult sample and using a pre- and post-intervention design. Studies were excluded if they included non-mild TBI severities, pediatric or older adult populations. Results: Thirteen of fourteen studies reported positive reductions in mTBI symptomatology following neuromodulation. Specifically, improvements were reported in post-concussion symptom ratings, headaches, dizziness, depression, anxiety, sleep disturbance, general disability, cognition, return to work and quality of life. Normalization of working memory activation patterns, vestibular field potentials, hemodynamics of the dorsolateral prefrontal cortex and excessive delta wave activity were also seen. The studies reviewed had several methodological limitations including small, heterogenous samples and varied intervention protocols, limiting generalisability. Further research is required to understand the context in which neuromodulation may be beneficial. Conclusions: While these positive effects are observed, limitations included unequal representation of neuromodulation modalities in the literature, and lack of literature describing the efficacy of neuromodulation on the development or duration of persistent mTBI symptoms. Better clarity regarding neuromodulation efficacy could have a significant impact on mTBI patients, researchers, clinicians, and policy makers, facilitating a more productive post-mTBI population. Despite the limitations, the literature indicates that neuromodulation warrants further investigation. PROSPERO registration number: CRD42020161279.

'As easy as riding a bike': a systematic review of injuries and illness in road cycling

OBJECTIVES

To allow the implementation of effective injury and illness prevention programmes for road cyclists, we wanted to first identify the injury/illness burden to this group of athletes. We, therefore, undertook a systematic review of all reported injuries/illness in road cycling.

DESIGN

Systematic review.

DATA SOURCES

Identification of articles was achieved through a comprehensive search of: MEDLINE, Embase, PsycINFO, Web of Science and Cochrane Library from inception until January 2020.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies reporting injuries/illness in adults participating in road cycling. Cycling commuter studies were excluded from the analysis.

METHOD

Two review authors independently screened titles and abstracts for eligibility and trial quality. Initial search criteria returned 52 titles and abstracts to be reviewed, with 12 studies included after reviewing the full text articles.

RESULTS

The most common injuries sustained were abrasions, lacerations and haematomas accounting for 40-60% of the total injuries recorded. Fractures (6-15%) were the second most frequent type of injury. Head injuries (including concussions) accounted for 5-15% of injuries with musculotendinous injuries accounting for 2-17.5%. The upper limb was more frequently affected by injuries than the lower limb, with amateurs appearing to be at higher risk of injury/illness than professionals. Clavicle was the prevalent fracture, with patellofemoral syndrome the number one overuse diagnosis. No meta-analysis of the results was undertaken due to the inconsistent methods of reporting.

CONCLUSION

This is the first systematic review of road cycling injuries. Injuries most often affected the upper limb, with clavicle being the most prevalent fracture and the most common overuse injury being patellofemoral syndrome.

Using functional movement tests to investigate the presence of sensorimotor impairment in amateur athletes following sport-related concussion: A prospective, longitudinal study

OBJECTIVE

To longitudinally investigate the presence of sensorimotor impairments in amateur athletes following sport-related concussion using two functional movement tests.

DESIGN

Prospective, longitudinal study.

SETTING

Human movement analysis laboratory.

PARTICIPANTS

Athletes who presented to a hospital emergency department and were diagnosed with sport-related concussion, and sex-, age-, and activity-matched non-concussed, control athletes. Concussed participants were assessed within one-week following sport-related concussion, upon clearance to return-to-sporting activity (RTA), and two weeks after RTA. Control participants were assessed at an initial time-point and approximately two and four weeks following their initial study assessment.

MAIN OUTCOMES MEASURES

At each laboratory assessment, participants completed two functional movement tests: the Star Excursion Balance Test to evaluate anterior reach distance (normalised for leg length) and fractal dimension (centre of pressure path complexity), and the Multiple Hop Test to evaluate corrective postural strategies and time-to-stabilisation.

RESULTS

Fifty concussed athletes and 50 control athletes completed the study. There were no significant differences at any study assessment between the concussion and control group on the Star Excursion Balance Test anterior reach distance or fractal dimension (centre of pressure path complexity). During the Multiple Hop Test, the concussion group used a significantly greater number of corrective postural strategies than the control group one-week following sport-related concussion and upon clearance to RTA, but not two weeks following RTA.

CONCLUSION

Recently concussed athletes made a greater number of corrective postural strategies than control participants during the Multiple Hop Test upon clearance to RTA but not two weeks after RTA. The Multiple Hop Test may offer a clinically useful tool for practitioners to examine the recovery of subtle sensorimotor impairments and related RTA readiness.

A Within-Subjects Comparison of Clinical Outcomes for Patients' First and Second Concussions

OBJECTIVES

To examine the difference between an individual's first and second concussion using a comprehensive, multidomain assessment including symptoms, neurocognitive, vestibular, ocular, and individual demographic and medical history risk factors associated with protracted recovery.

SETTING

Concussion Specialty Clinic.

PARTICIPANTS

Seventy-three patients (aged 13-21 years; 57% female) diagnosed with 2 separate concussions (380.5 ± 278.7 days between injuries) from August 2016 to August 2018.

DESIGN

Retrospective within-subjects cohort study.

MAIN MEASURES

ImPACT, PCSS, and Vestibular-Ocular Motor Screen (VOMS) at each visit. Patients were divided into "normal" (≤30 days) and "protracted" recovery (>30 days) for χ2 analyses.

RESULTS

There were no differences between the first and second injuries in recovery time, VOMS, visual and verbal memory, or reaction time. Visual motor speed scores were higher at the second injury time point and reported sleep symptoms were higher at the first injury time point. In addition, participants reported to the clinic on average 3 days earlier for an evaluation for their second injury. Results from χ2 analyses indicated that female sex predicted protracted recovery (>30 days) from concussion at the first injury time point (OR = 4.1; 95% CI, 1.5-11.6; P = .006).

CONCLUSIONS

The findings provide preliminary evidence that there is no clinical difference between patients' first and second concussions when both injuries were treated through a concussion specialty clinic.

Neuropsychological Assessment of Sport-Related Concussion

Neuropsychological assessment is a key component in a comprehensive, multidisciplinary approach to assessment of sport-related concussion (SRC). Currently computerized tests are the most commonly used modality of neurocognitive testing and involve both baseline and postinjury assessments. A comprehensive neuropsychological assessment should not only include neurocognitive testing but also incorporate symptom inventories, vestibular-ocular screening, and a psychological evaluation. Neuropsychological assessments are most effective when completed by a Clinical Neuropsychologist, given their specialized training in test interpretation and conceptualization of the psychological, cognitive, behavioral, physiologic, as well as neurologic principals when treating and managing SRC.

The Molecular Pathophysiology of Concussion

After a concussion, a series of complex, overlapping, and disruptive events occur within the brain, leading to symptoms and behavioral dysfunction. These events include ionic shifts, damaged neuronal architecture, higher concentrations of inflammatory chemicals, increased excitatory neurotransmitter release, and cerebral blood flow disruptions, leading to a neuronal crisis. This review summarizes the translational aspects of the pathophysiologic cascade of postconcussion events, focusing on the role of excitatory neurotransmitters and ionic fluxes, and their role in neuronal disruption. We review the relationship between physiologic disruption and behavioral alterations, and proposed treatments aimed to restore the balance of disrupted processes.

Considerations for Athlete Retirement After Sport-Related Concussion

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

Future Directions in Sports-Related Concussion Management

This article focuses on 3 concepts that continue to be investigated in the search for the holy grail of concussion-a valid diagnostic test. Imaging advances are discussed with optimism that functional MRI and diffusion tensor imaging may be available clinically. Biomarkers and the use of genetic tests are covered. Sideline accelerometer use may help steer discussions of head trauma risk once technology exists to accurately estimate acceleration of the brain. In the meantime, strategies including allowing athletes to be substituted out of games for an evaluation and video review in elite sports can improve recognition of sports-related concussion.

Understanding concussion knowledge and behavior among mixed martial arts, boxing, kickboxing, and Muay Thai athletes and coaches

Objectives: In combat sports, strikes to the head are not just incidental but a deliberate and clear determinant of success. Concussion is a complex injury that is poorly understood and inappropriate practices are often observed among athletes and coaches. The purpose of this study was to investigate concussion knowledge and behavior as well as address recommendations for combat sports athletes and coaches. Methods: 70 athletes and 35 coaches from combat sports disciplines completed an online-validated survey and a personal questionnaire about concussion knowledge, training experience, and knowledge translation. Athletes were divided into subgroups for analysis according to sex (male n = 55, female n = 15), skill level (amateur n = 52, professional n = 18), and weight classes (<66.2 kg: n = 25, 66.6 to 77.5 kg: n = 30, and >78 kg: n = 15). Results: The likely absence of health-care professionals during training was confirmed by 68.5% of coaches, and athletes declared that self-diagnosis (79%) and coaches' diagnosis (43.3%) were the most used method of suspected concussion assessment. Merely 5.7% of coaches properly recognized the level of traumatic brain injury a concussion represents, 68.8% were unfamiliar with any sideline assessment tools, and only 14.3% often seek out concussion knowledge. Athletes who were aware of the level of brain injury a concussion represents performed fewer sparring sessions per week (mild: 1.27 ± 1.1; severe: 3.17 ± 2.81; p = .05, d = .89) and had a greater likelihood of reporting concussive episodes. Most professional (55.5%), female (54.5%), and under 66.2 kg (50%) athletes returned to full practice within 1 week following a concussion diagnosis. Conclusions: Relevant key gaps of knowledge and behavior were verified in combat sports athletes and coaches. The awareness of basic concepts may improve injury reporting and safer behavior in athletes. Knowledge translation strategies with accessible language are recommended for coaches, in particular on how to identify acute symptoms and perform basic assessment.

Athletic trainer employment, physician access and care delivery in secondary schools

Objective: To evaluate the source of employment of athletic trainers (ATs), access to team physicians, and usage of up-to-date (implementation of the most current international sports medicine societies' position statements and evidence-based literature policy and procedure manuals in secondary schools. Methods: We conducted a cross-sectional study among National Athletic Trainers' Association (NATA) members. NATA 'Research Survey Request' was contacted to obtain 1,000 e-mail addresses of ATs who actively worked in the secondary school setting. We evaluated AT employment, access to team physicians, and usage of up-to-date policy and procedure manuals within different residential areas (urban, suburban, and rural) and school distinctions (public vs. private). Results: Two-hundred ninety-six responses were received (30% response rate). The majority (72%) of ATs reported having an assigned team physician for their school. Approximately one-third (36%) of ATs reported being employed by a hospital, clinic, or outreach facility. Fifty-one percent of ATs reported having a policy and procedure manual that was developed and reviewed with their team physician. There was a significantly greater amount of suburban ATs who reported having an up-to-date policy and procedure manual (urban 45% vs. suburban 60% vs. rural 39%; p = 0.007). Significantly more ATs who were employed in a public school setting reported conducting annual policy and procedure manual reviews than those employed in private school settings (public 63% vs. private 49%; p = 0.045). Conclusions: The majority of ATs have assigned team physicians and a third is employed by a medical group. A high number of ATs reported not having a policy and procedure manual that was developed and reviewed with their team physician. Sports medicine teams within secondary schools, particularly in private schools, should strive to develop and maintain an up-to-date policy and procedure manual that is frequently reviewed with their team physician.

Assessment of Postural Stability During an Upper Extremity Rapid, Bimanual Motor Task After Sport-Related Concussion

CONTEXT

Sport-related concussion (SRC) often presents with multidimensional and subtle neurologic deficits that are difficult to detect with standard clinical tests. New assessment approaches that efficiently quantify deficits across multiple neurologic domains are needed.

OBJECTIVE

To quantify impairments in postural movements during an assessment of rapid, bimanual motor ability in athletes within 10 days of experiencing an SRC and evaluate relationships between impairments in upper extremity and postural performance.

DESIGN

Cohort study.

SETTING

Sports medicine clinic.

PATIENTS OR OTHER PARTICIPANTS

Initial baseline assessments were completed for 711 athletes. Seventy-five athletes (age = 15.8 ± 3.3 years at baseline) sustained SRCs and were reassessed within 10 days. Seventy-eight athletes (age = 15.5 ± 2.0 years) completed 2 assessments in a healthy state.

MAIN OUTCOME MEASURE(S)

Athletes stood on force plates and performed a rapid, bimanual motor task, termed the object-hit task, delivered using a Kinesiological Instrument for Normal and Altered Reaching Movements endpoint robot. Measures of postural stability that quantified center-of-pressure movements and measures of upper extremity performance were used to characterize task performance.

RESULTS

Performance changes across assessments were converted to reliable change indices. We observed a difference in reliable change indices values between athletes with SRC and healthy control athletes on the combined postural measures (P = .01). Using measures to evaluate the change in postural movements from the early, easier portion of the task to the later, more difficult portion, we identified the highest levels of impairment (19%-25% of the sample impaired). We also noted a difference between individuals with concussion and healthy individuals on the combined upper extremity measures (P = .003), but these impairments were largely unrelated to those identified in the postural movements.

CONCLUSIONS

Measurement of postural movements during the object-hit task revealed impairments in postural stability that were not related to impairments in upper extremity performance. The findings demonstrated the benefits of using assessments that simultaneously evaluate multiple domains of neurologic function (eg, upper extremity and postural control) after SRC.

High Energy Side and Rear American Football Head Impacts Cause Obvious Performance Decrement on Video

The objective of this study was to compare head impact data acquired with an impact monitoring mouthguard (IMM) to the video-observed behavior of athletes' post-collision relative to their pre-collision behaviors. A total of n = 83 college and high school American football players wore the IMM and were video-recorded over 260 athlete-exposures. Ex-athletes and clinicians reviewed the video in a two-step process and categorized abnormal post-collision behaviors according to previously published Obvious Performance Decrement (OPD) definitions. Engineers qualitatively reviewed datasets to check head impact and non-head impact signal frequency and magnitude. The ex-athlete reviewers identified 2305 head impacts and 16 potential OPD impacts, 13 of which were separately categorized as Likely-OPD impacts by the clinical reviewers. All 13 Likely-OPD impacts were in the top 1% of impacts measured by the IMM (ranges 40-100 g, 3.3-7.0 m/s and 35-118 J) and 12 of the 13 impacts (92%) were to the side or rear of the head. These findings require confirmation in a larger data set before proposing any type of OPD impact magnitude or direction threshold exists. However, OPD cases in this study compare favorably with previously published impact monitoring studies in high school and college American football players that looked for OPD signs, impact magnitude and direction. Our OPD findings also compare well with NFL reconstruction studies for ranges of concussion and sub-concussive impact magnitudes in side/rear collisions, as well as prior theory, analytical models and empirical research that suggest a directional sensitivity to brain injury exists for single high-energy impacts.

Concussion among soccer players in the 2017 Brazilian championship - the gap between protocol and medical practice

Background

The present study aims to report traumatic brain injury (TBI) among soccer players in the 2017 Brazilian Soccer Championship and discuss the protocols for concussion evaluation.

Materials & methods

This is an observational study utilizing video analysis of 380 matches. TBI was considered as any event in which one or more soccer player(s) had a head trauma. For potential concussion diagnosis, we analyzed players with one of the following signs: slowness to get up, disorientation, motor incoordination, loss of consciousness, head clutching and impact seizure.

Results

There were 374 TBIs in total. The average time for medical assessment was 1'35". 13 players had concussion with an average time of 3'19″ for medical evaluation. Four players were replaced after having a concussion.

Conclusion

There is a gap between concussion protocols and medical practices in Brazilian elite soccer. Further discussion about soccer replacement rules are imperative.

Prospective study of the association between sport-related concussion and brain morphometry (3T-MRI) in collegiate athletes: study from the NCAA-DoD CARE Consortium

OBJECTIVES

To determine the acute and early long-term associations of sport-related concussion (SRC) and subcortical and cortical structures in collegiate contact sport athletes.

METHODS

Athletes with a recent SRC (n=99) and matched contact (n=91) and non-contact sport controls (n=95) completed up to four neuroimaging sessions from 24 to 48 hours to 6 months postinjury. Subcortical volumes (amygdala, hippocampus, thalamus and dorsal striatum) and vertex-wise measurements of cortical thickness/volume were computed using FreeSurfer. Linear mixed-effects models examined the acute and longitudinal associations between concussion and structural metrics, controlling for intracranial volume (or mean thickness) and demographic variables (including prior concussions and sport exposure).

RESULTS

There were significant group-dependent changes in amygdala volumes across visits (p=0.041); this effect was driven by a trend for increased amygdala volume at 6 months relative to subacute visits in contact controls, with no differences in athletes with SRC. No differences were observed in any cortical metric (ie, thickness or volume) for primary or secondary analyses.

CONCLUSION

A single SRC had minimal associations with grey matter structure across a 6-month time frame.

A preliminary cross-sectional assessment of postural control responses to continuous platform rotations following a sport-related concussion

BACKGROUND

Individuals suffering a sport-related concussion typically recover within 1 month; however, persistent post-concussive symptoms are known to occur beyond this period. Clinical guidelines may not be sufficient to determine if dynamic postural control is still impaired at the point of the return to play decision.

RESEARCH QUESTION

Do individuals with a previous sport-related concussion who have returned to play show differences in postural control compared to individuals without a previous concussion, in response to continuous platform perturbations?

METHODS

Eight previously concussed and eight age- and position-matched participants completed six one-minute trials (three with eyes open/closed) whilst stood on a moving platform that rotated about the pitch axis with a peak-to-peak amplitude of 4° at a frequency of 0.8 Hz. Six trials were also captured during static quiet stance for comparison. Reactive and anticipatory stages of postural control were analysed by determining anteroposterior margins of stability (MoS) as a measure of whole-body postural control and head-to-trunk anchoring index as an indication of the head-trunk segmental coupling strategy.

RESULTS

Posterior MoS during platform rotations reduced for both groups during eyes closed trials, but previously concussed participants exhibited a significantly greater reduction (1.97 cm) in comparison to matched-controls (0.34 cm). Participants, regardless of group, showed a preference towards a head-stabilised-to-trunk strategy during platform rotations. There were no differences during static trials.

SIGNIFICANCE

This preliminary study suggests previously concussed athletes demonstrate a greater reduction in postural control whilst undergoing continuous platform rotations with eyes closed, which could indicate possible lingering deficits to other sensory systems such as the vestibular system, though participants were not likely to lose their balance.