Clinical Concussion Research Articles

Determinants of symptom presentation and resolution following concussions in high school sports

ABSTRACT Sport-related concussions (SRCs) are prevalent in high school (HS) sports, though the determinants of, and relationships between concussion symptoms in this population remain relatively unknown. We analysed SRC data captured within the HS RIO injury surveillance system during 2014/15-2018/19. We used Generalized Estimating Equations to simultaneously assess covariate predictors of symptom presentations and identify pairwise symptom associations and employed multivariable ordinal logistic regressions to determine symptom resolution time (SRT) predictors. Among the 8,969 concussions assessed, headaches (94.3%) and dizziness (73.3%) were the most prevalently reported symptoms. In 5,953 boys’ concussion assessed, class year, event type and injury mechanism emerged as determinants of various concussion symptoms, while in 3,016 girls’ concussions assessed, class year, event type, injury mechanism, and sport type emerged as significant symptom determinants. In both groups, difficulty concentrating, sensitivity to light, sensitivity to noise, and disorientation were symptoms with the strongest associations with other symptoms. Odds of longer SRT were higher with greater endorsement (i.e. counts) of the subset of symptoms with strongest cross-domain associations (ORadj. = 1.35; 95% CI = [1.30, 1.40]). Our findings provide valuable information for informing sideline and follow-up clinical concussion assessment algorithms in high school athletes.

Analyzing Dual-Task Paradigms to Improve Postconcussion Assessment and Management.

Dual-task (simultaneous cognitive-motor activities) assessments have been adapted into reliable and valid clinical concussion measures. However, abundant motor and cognitive variations leave researchers and clinicians uncertain about which combinations elicit the intended dual-task effect. Our objective was to examine differences between commonly employed dual-task motor and cognitive combinations among healthy, college-aged individuals. Cross-sectional laboratory study. Twenty participants (age: 21.3 [2.4]y; height: 176.0 [9.1]cm; mass: 76.0 [16.4]kg; 20% with concussion history) completed 4 motor tasks (gait, tandem gait, single-leg balance, and tandem balance) under 5 cognitive conditions (single task, subtraction, month reversal, spelling backward, and visual Stroop) in a research laboratory. The motor performance outcomes were spatiotemporal variables for gait and tandem gait and center of pressure path length (in centimeters) for single-leg and tandem balance. Cognitive outcomes were response rate (responses/second) and cognitive accuracy. We used separate repeated-measures analyses of variance for each motor and cognitive outcome with post hoc Tukey t tests. Gait velocity, gait stride length, and tandem gait velocity demonstrated significant cognitive-motor interactions (P's < .001) such that all dual-task conditions resulted in varyingly slower or shorter movement than single task. Conversely, single-leg balance (P = .627) and tandem balance (P = .434) center of pressure path length did not significantly differ among the dual-task cognitive conditions or relative to single task. Statistically significant cognitive-motor interactions were observed only for spelling backward accuracy (P = .004) and response rates for spelling backward, month reversal, and visual Stroop (P's < .001) such that worse accuracy, but faster response rates, occurred during motor tasks. Gait and tandem gait motor tasks accompanied with spelling backward or subtraction cognitive tasks demonstrated consistently strong dual-task effects and, therefore, may be the best suited for clinical and research use following concussion.

Perceived Stress, Mindfulness, and Clinical Concussion Outcomes in Adults with a Concussion History

ABSTRACT Introduction Higher perceived stress negatively impacts concussion recovery, but there are limited data examining connections between perceived stress and concussion. Additionally, higher mindfulness is associated with lower perceived stress, but there is limited research on how mindfulness impacts concussion outcomes. Therefore, this study aimed to estimate the associations among perceived stress, mindfulness, and clinical concussion outcomes. Methods This was a cross-sectional, observational study in 80 young adults with a concussion history. Participants completed a single study visit measuring the following: 1) demographics, concussion history, and current mindfulness practice; 2) perceived stress (Perceived Stress Scale); 3) mindfulness (Five Facet Mindfulness Questionnaire); and 4) clinical concussion outcomes/symptoms (Rivermead Post-Concussion Symptoms Questionnaire), balance performance (Balance Error Scoring System (BESS) and center of mass), autonomic nervous system function (heart rate variability), vestibular/ocular function (vestibular ocular motor screening), and exertion tolerance (step test). Separate multivariable linear regression models were used to determine the associations among 1) perceived stress and clinical concussion outcomes and 2) mindfulness and clinical concussion outcomes. Next, a perceived stress and mindfulness interaction term was included to test the potential moderation effect of mindfulness on clinical concussion outcomes. Results Higher perceived stress was significantly associated with higher concussion symptom severity (P &lt; 0.001) and higher number of concussion symptoms reported as worse than before injury (P &lt; 0.001). Higher mindfulness was associated with lower concussion symptom severity (P &lt; 0.001), and fewer concussion symptoms reported as worse than before injury (P = 0.002). There were no clinically significant models where the interaction effect was also significant, but the BESS parameter estimate did show statistical significance in the interaction model. Conclusions Our results provide a novel understanding of the association among perceived stress, mindfulness, and clinical concussion outcomes. These data are necessary to inform mechanistic concussion rehabilitation interventions.

The role of concussion history and biological sex on baseline concussion clinical profile symptoms in adolescent rugby players

BackgroundAccurate concussion monitoring requires access to preinjury baseline data. This is particularly important in adolescent athletes who have a high risk of concussion and are prone to prolonged recovery. As Rugby Union is governed by similar laws for men and women, it is also an ideal population to rigorously examine the impact of biological sex on concussion symptoms.AimsTo evaluate self-reported concussion symptoms at baseline in adolescent rugby union players, and examine if subtype-specific symptoms are affected by concussion history and biological sex.MethodsAdolescent rugby union players aged 16–18 years were recruited during the 2022–2023 playing season. Participants completed a series of questionnaires covering post-concussion symptoms, concussion clinical profiles, anxiety, depression and fear avoidance behaviours. Independent variables of interest in analysis were biological sex and concussion history.Results149 participants (75% male) were included. 42% (63/149) reported at least one previous concussion (average time since concussion: 18.7 months, range 1–72). Adolescents with a concussion history reported significantly higher scores than those with no history, across two clinical profiles (ocular and sleep), concussion symptom severity, and depression, all based on medium effect sizes (SMD 0.3–0.5). Females had significantly higher scores across cognitive/fatigue, ocular and sleep clinical profiles, concussion symptoms, anxiety and depression, each with large effect sizes (SMD > 0.5).ConclusionsConcussion history and sex are associated with higher baseline scores on specific concussion clinical profile, concussion symptom severity, and anxiety symptoms. These findings highlight the importance of considering baseline differences when interpreting post-injury clinical profile symptoms in adolescent rugby players. (Trial registration: ACTRN12622000931774).

Assessment and management of sport-related concussion in general practice.

Sport-related concussion (SRC) is a traumatic brain injury that occurs during sport or exercise activity. SRC is a growing health concern in Australia, withincreasing public awareness and presentations to general practitioners being increasingly common. This article will focus on the assessment and management of SRC in general practice, including guidance for returning patients to sport. Concussion prevention, potential long-term complications, and the decision-making process regarding retirement from sport are beyond the scope of this article. Recognising concussion can be difficult, asclinical symptoms and signs of SRC can evolve over a period of hours to days. General practitioners should be aware of the range of clinical concussion presentations. The key principles of management include relative rest, followed by a graduated return to cognitive and physical activity. Involvement of a multidisciplinary team can improve symptoms for those patients whose concussion symptoms are prolonged.

Optimizing the Combination of Common Clinical Concussion Batteries to Predict Persistent Postconcussion Symptoms in a Prospective Cohort of Concussed Youth.

Studies have evaluated individual factors associated with persistent postconcussion symptoms (PPCS) in youth concussion, but no study has combined individual elements of common concussion batteries with patient characteristics, comorbidities, and visio-vestibular deficits in assessing an optimal model to predict PPCS. To determine the combination of elements from 4 commonly used clinical concussion batteries and known patient characteristics and comorbid risk factors that maximize the ability to predict PPCS. Cohort study; Level of evidence, 2. We enrolled 198 concussed participants-87 developed PPCS and 111 did not-aged 8 to 19 years assessed within 14 days of injury from a suburban high school and the concussion program of a tertiary care academic medical center. We defined PPCS as a Post-Concussion Symptom Inventory (PCSI) score at 28 days from injury of ≥3 points compared with the preinjury PCSI score-scaled for younger children. Predictors included the individual elements of the visio-vestibular examination (VVE), Sport Concussion Assessment Tool, 5th Edition (SCAT-5), King-Devick test, and PCSI, in addition to age, sex, concussion history, and migraine headache history. The individual elements of these tests were grouped into interpretable factors using sparse principal component analysis. The 12 resultant factors were combined into a logistic regression and ranked by frequency of inclusion into the combined optimal model, whose predictive performance was compared with the VVE, initial PCSI, and the current existing predictive model (the Predicting and Prevention Postconcussive Problems in Pediatrics (5P) prediction rule) using the area under the receiver operating characteristic curve (AUC). A cluster of 2 factors (SCAT-5/PCSI symptoms and VVE near point of convergence/accommodation) emerged. A model fit with these factors had an AUC of 0.805 (95% CI, 0.661-0.929). This was a higher AUC point estimate, with overlapping 95% CIs, compared with the PCSI (AUC, 0.773 [95% CI, 0.617-0.912]), VVE (AUC, 0.736 [95% CI, 0.569-0.878]), and 5P Prediction Rule (AUC, 0.728 [95% CI, 0.554-0.870]). Among commonly used clinical assessments for youth concussion, a combination of symptom burden and the vision component of the VVE has the potential to augment predictive power for PPCS over either current risk models or individual batteries.

Use of Reactive Balance Assessments With Clinical Baseline Concussion Assessments in Collegiate Athletes.

Current clinical concussion evaluations assess balance deficits using static or dynamic balance tasks while largely ignoring reactive balance. Including a reactive balance assessment might provide a more comprehensive concussion evaluation. To identify redundancy in current clinical baseline assessments of concussion and determine whether reactive balance adds unique information to these evaluations. Cross-sectional study. Clinical assessment. A total of 279 healthy National Collegiate Athletic Association Division I athletes. Two cohorts of data were collected at the beginning of the athletic season. For cohort 1 (n = 191), the Immediate Post-Concussion Assessment and Cognitive Tool, instrumented modified push and release (I-mP&R), and Balance Error Scoring System (BESS) were administered. For cohort 2 (n = 88), the I-mP&R, BESS, timed tandem gait, walking with eyes closed, and clinical reaction time were administered. The strengths of the relationships between the Immediate Post-Concussion Assessment and Cognitive Tool cognitive indices, mP&R clinical score, instrumented measures (BESS sway; I-mP&R time to stability, latency, and step length), BESS score, timed tandem gait, walking time to completion, and clinical reaction time were characterized. The strongest interinstrument correlation value was between single-task time to stability from the I-mP&R and clinical reaction time but was considered weak (r = 0.35, P = .001). The mP&R and I-mP&R clinical scores were weakly associated with the other assessments. Weak correlations between interassessment variables indicated that little redundancy was present in the current clinical evaluations. Furthermore, reactive balance represents a unique domain of function that may improve the comprehensiveness of clinical assessments.

Return-to-Play With R2Play: Protocol for Evaluating Cross-Site Feasibility, Face Validity, and Content Validity of a Multidomain Concussion Assessment Tool for Youth

Context: Clinical concussion assessments do not typically simulate the speed or complexity of sport. Performance changes arising from combined physical, cognitive, and sensory demands of sport may thus remain undetected during rehabilitation. We developed R2Play, a multidomain return-to-play assessment tool for youth with concussions. R2Play involves levels and conditions that vary in physical, cognitive, and sensory load to simulate the multidomain demands of sport. Objectives: To explore cross-site feasibility, face validity, and content validity of R2Play by integrating quantitative and qualitative data. Methods: Convergent mixed-methods feasibility study. Five sites will each recruit 5 clinicians (total nc = 25) and 10 youth sport participants (ages 10–25 y) with a history of concussion in the previous year (total ny = 50). Feasibility will be evaluated using quantitative criteria for acceptability, demand, implementation, practicality, and integration, and qualitative investigated data from content analysis of postassessment interviews with youth and clinician participants. Face validity will be investigated in postassessment interviews. Content validity will be established through (1) changes in performance metrics (time to completion, errors, and heart rate) across R2Play levels, (2) youth-perceived physical and cognitive exertion for each level, and (3) overall clinician perceptions determined through postassessment interviews. Qualitative and quantitative data will be merged through joint display to identify areas of convergence, divergence, and complementarity, and to establish meta-inferences about feasibility, face validity, and content validity. Discussion: This study aims to demonstrate the face and content validity of R2Play, and its feasibility for cross-site implementation. Findings will guide further iteration of R2Play and establish the foundation for a larger multicenter validation study to establish the psychometric properties of R2Play. This work represents an important first step toward the implementation of an ecologically valid multidomain assessment tool designed to support a safe and efficient return-to-play after concussion, ultimately reducing the risk of recurrent concussion and subsequent injury.

Maximizing the Accuracy of Adolescent Concussion Diagnosis Using Individual Elements of Common Standardized Clinical Assessment Tools.

Multiple clinical evaluation tools exist for adolescent concussion with various degrees of correlation, presenting challenges for clinicians in identifying which elements of these tools provide the greatest diagnostic utility. To determine the combination of elements from 4 commonly used clinical concussion batteries that maximize discrimination of adolescents with concussion from those without concussion. Cross-sectional study. Suburban school and concussion program of a tertiary care academic center. A total of 231 participants with concussion (from a suburban school and a concussion program) and 166 participants without concussion (from a suburban school) between the ages of 13 and 19 years. Individual elements of the visio-vestibular examination (VVE), Sport Concussion Assessment Tool, fifth edition (SCAT5; including the modified Balance Error Scoring System), King-Devick test (K-D), and Postconcussion Symptom Inventory (PCSI) were evaluated. The 24 subcomponents of these tests were grouped into interpretable factors using sparse principal component analysis. The 13 resultant factors were combined with demographic and clinical covariates into a logistic regression model and ranked by frequency of inclusion into the ideal model, and the predictive performance of the ideal model was compared with each of the clinical batteries using the area under the receiver operating characteristic curve (AUC). A cluster of 4 factors (factor 1 [VVE saccades and vestibulo-ocular reflex], factor 2 [modified Balance Error Scoring System double-legged stance], factor 3 [SCAT5/PCSI symptom scores], and factor 4 [K-D completion time]) emerged. A model fit with the top factors performed as well as each battery in predicting concussion status (AUC = 0.816 [95% CI = 0.731, 0.889]) compared with the SCAT5 (AUC = 0.784 [95% CI = 0.692, 0.866]), PCSI (AUC = 0.776 [95% CI = 0.674, 0.863]), VVE (AUC = 0.711 [95% CI = 0.602, 0.814]), and K-D (AUC = 0.708 [95% CI = 0.590, 0.819]). A multifaceted assessment for adolescents with concussion, comprising symptoms, attention, balance, and the visio-vestibular system, is critical. Current diagnostic batteries likely measure overlapping domains, and the sparse principal component analysis demonstrated strategies for streamlining comprehensive concussion assessment across a variety of settings.

Temporal Changes in Fixational Eye Movements After Concussion in Adolescents and Adults: Preliminary Findings.

Concussions often involve ocular impairment and symptoms such as convergence insufficiency, accommodative insufficiency, blurred vision, diplopia, eye strain, and pain. Current clinical assessments of ocular function and symptoms rely on subjective symptom reporting and/or involve lengthy administration time. More objective, brief assessments of ocular function following concussion are warranted. The purpose of this study was to evaluate changes in fixational eye movements (FEMs) and their association with clinical outcomes including recovery time, symptoms, cognitive and vestibular/ocular motor impairment. Thirty-three athletes (13-27 years of age; 54.5% female) within 21 days of a diagnosed concussion participated in the study. A tracking scanning laser ophthalmoscope (TSLO) evaluated FEMs metrics during fixation on a center and corner target. Participants completed symptom (Post-Concussion Symptom Scale [PCSS]), cognitive (Immediate Post-concussion Assessment and Cognitive Testing [ImPACT], and Vestibular/Ocular Motor Screening (VOMS) evaluations. All measures were administered at the initial visit and following medical clearance, which was defined as clinical recovery. Changes in FEMs were calculated using paired-samples t tests. Linear regression (LR) models were used to evaluate the association of FEMs with clinical recovery. Pearson product-moment correlations were used to evaluate the associations among FEMs and clinical outcomes. On the center task, changes across time were supported for average microsaccade amplitude (p = 0.005; Cohen's d = 0.53), peak velocity of microsaccades (p = 0.01; d = 0.48), peak acceleration of microsaccades (p = 0.02; d = 0.48), duration of microsaccade (p < 0.001; d = 0.72), and drift vertical (p = 0.017; d = -0.154). The LR model for clinical recovery was significant (R2 = 0.37; p = 0.023) and retained average instantaneous drift amplitude (β = 0.547) and peak acceleration of microsaccade (β = 0.414). On the corner task, changes across time were supported for drift proportion (p = 0.03; d = 0.43). The LR model to predict clinical recovery was significant (R2 = 0.85; p = 0.004) and retained average amplitude of microsaccades (β = 2.66), peak velocity of microsaccades (β = -15.11), peak acceleration of microsaccades (β = 12.56), drift horizontal (β = 7.95), drift vertical (β = 1.29), drift amplitude (β = -8.34), drift proportion (β = 0.584), instantaneous drift direction (β = -0.26), and instantaneous drift amplitude (β = 0.819). FEMs metrics were also associated with reports of nausea and performance within the domain of visual memory. The FEMs metric were also associated with PCSS, ImPACT, and VOMS clinical concussion outcomes, with the highest magnitude correlations between average saccade amplitude and VOMS symptoms of nausea and average instantaneous drift speed and ImPACT visual memory, respectively. FEMs metrics changed across time following concussion, were useful in predicting clinical recovery, and were correlated with clinical outcomes. FEMs measurements may provide objective data to augment clinical assessments and inform prognosis following this injury.

A review of brain regions and associated post-concussion symptoms.

The human brain is an exceptionally complex organ that is comprised of billions of neurons. Therefore, when a traumatic event such as a concussion occurs, somatic, cognitive, behavioral, and sleep impairments are the common outcome. Each concussion is unique in the sense that the magnitude of biomechanical forces and the direction, rotation, and source of those forces are different for each concussive event. This helps to explain the unpredictable nature of post-concussion symptoms that can arise and resolve. The purpose of this narrative review is to connect the anatomical location, healthy function, and associated post-concussion symptoms of some major cerebral gray and white matter brain regions and the cerebellum. As a non-exhaustive description of post-concussion symptoms nor comprehensive inclusion of all brain regions, we have aimed to amalgamate the research performed for specific brain regions into a single article to clarify and enhance clinical and research concussion assessment. The current status of concussion diagnosis is highly subjective and primarily based on self-report of symptoms, so this review may be able to provide a connection between brain anatomy and the clinical presentation of concussions to enhance medical imaging assessments. By explaining anatomical relevance in terms of clinical concussion symptom presentation, an increased understanding of concussions may also be achieved to improve concussion recognition and diagnosis.

Diagnosis, Treatment, and Prevention of Sport-related Concussion

Concussion is a serious injury with potential long-term cognitive complications. Due to the prevalence of undiagnosed concussions and their detriments to health, concussion treatment and prevention are important topics of exploration. By investigating concussion diagnosis and management, the types of treatment, and preventive methods, this study demonstrates the positive role of active rehabilitation in concussion management. It presents opportunities for future studies to focus on more specific types of exercise and possible rule regulations. Results show that concussion symptoms may vary according to severity, from minor headaches and loss of concentration to depression, dementia, and impaired cognitive function. Clinical or syndromic concussion diagnosis is the most used and reliable subjective assessment method in the contemporary health and scientific field. Immediate removal from sport and vigorous exercise is crucial after athletes experience a concussion to avoid exacerbating the symptoms or causing an additional concussion. Contrary to the belief of complete rest after a concussion, early sub-symptom aerobic exercise and a gradual return to sports participation are important and effective measures for concussion treatment. Patients experiencing prolonged symptoms may also benefit from aerobic exercises. Additionally, there is no effective equipment for preventing concussions in the current sports world. Sports rule changes and education could be efficacious in preventing concussions.

Comparison of different approaches to manage multi-site magnetic resonance spectroscopy clinical data analysis.

The effects caused by differences in data acquisition can be substantial and may impact data interpretation in multi-site/scanner studies using magnetic resonance spectroscopy (MRS). Given the increasing use of multi-site studies, a better understanding of how to account for different scanners is needed. Using data from a concussion population, we compare ComBat harmonization with different statistical methods in controlling for site, vendor, and scanner as covariates to determine how to best control for multi-site data. The data for the current study included 545 MRS datasets to measure tNAA, tCr, tCho, Glx, and mI to study the pediatric concussion acquired across five sites, six scanners, and two different MRI vendors. For each metabolite, the site and vendor were accounted for in seven different models of general linear models (GLM) or mixed-effects models while testing for group differences between the concussion and orthopedic injury. Models 1 and 2 controlled for vendor and site. Models 3 and 4 controlled for scanner. Models 5 and 6 controlled for site applied to data harmonized by vendor using ComBat. Model 7 controlled for scanner applied to data harmonized by scanner using ComBat. All the models controlled for age and sex as covariates. Models 1 and 2, controlling for site and vendor, showed no significant group effect in any metabolites, but the vendor and site were significant factors in the GLM. Model 3, which included a scanner, showed a significant group effect for tNAA and tCho, and the scanner was a significant factor. Model 4, controlling for the scanner, did not show a group effect in the mixed model. The data harmonized by the vendor using ComBat (Models 5 and 6) had no significant group effect in both the GLM and mixed models. Lastly, the data harmonized by the scanner using ComBat (Model 7) showed no significant group effect. The individual site data suggest there were no group differences. Using data from a large clinical concussion population, different analysis techniques to control for site, vendor, and scanner in MRS data yielded different results. The findings support the use of ComBat harmonization for clinical MRS data, as it removes the site and vendor effects.

Neck Symptoms and Associated Clinical Outcomes in Patients Following Concussion.

To examine the frequency and association of neck pain symptoms in patients with a concussion. Three-hundred and thirty-one consecutively enrolled patients aged 9 to 68 years with a diagnosed concussion 1 to 384 days post-injury were enrolled at a concussion clinic from a single integrated healthcare system in Western Pennsylvania between 2019 and 2021. Retrospective cohort analysis of prospectively collected concussion screening tool intake survey responses and clinical outcomes data. The primary outcome was self-reported neck pain or difficulty with neck movement on the Concussion Clinical Profiles Screening (CP Screen) tool, recovery time, and incidence of treatment referral. Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) composite scores, Vestibular/Ocular Motor Screening (VOMS) item scores, type and severity of neck symptoms, mechanism of injury, time from injury to clinic presentation, medical history, and concussion symptom profile were secondary outcomes. Of the 306 consecutively enrolled eligible patients in the registry, 145 (47%) reported neck pain, 68 (22.2%) reported difficulty moving their neck, and 146 (47.7%) reported either symptom. A total of 47 (15.4%) participants reported more severe neck symptoms, and this group took longer to recover (40 ± 27 days) than those not reporting neck symptoms (30 ± 28 days; U = 8316, P < .001). Stepwise logistic regression predicting more severe neck symptoms was significant (Nagelkerke R2 = 0.174, χ 2 = 9.315, P = .316) with older age ( P = .019) and mechanism of injury including motor vehicle collisions (MVCs) ( P = .047) and falls ( P = .044) as risk factors. MVCs and falls were associated with over 4 times and 2 times greater risk, respectively, for reporting more severe neck symptoms. Neck pain and stiffness symptoms are common in patients with a concussion following high-energy mechanisms of injury including MVCs or falls from height. These symptoms are associated with prolonged recovery. Providers should evaluate neck symptoms and consider targeted treatment strategies to limit their effects in patients with a concussion.

Concussion in Ladies Gaelic Football: Self-reported History, Clinical Profiles, and Management Behavior.

To describe the prevalence, characteristics, and management behavior of self-reported sport-related concussion (SRC) in Ladies Gaelic Football (LGF) players. Cross-sectional study. Online survey distributed to LGF clubs throughout Ireland. Elite and nonelite adult LGF players (n = 657). Participants were recruited by convenience sampling and answered an online survey. Questions on demographic characteristics, SRC history, symptoms, injury characteristics, and management behavior after SRCs that occurred while playing LGF during the previous season were included. Overall concussion history, occurrence of an SRC during the previous LGF season, clinical profile scores, characteristics (eg mechanism and setting), and management behavior (eg following a graded RTP program) after SRCs that occurred during the previous season. Approximately one-fifth (17.5%) of participants sustained a suspected or diagnosed SRC during the previous season, which was higher among elite (26.1%) than nonelite (15.3%) players ( P < 0.01). The highest scoring clinical profiles were the ocular and migraine profiles. Only 3.5% of respondents adhered to all SRC management recommendations. Although players who reported a medically diagnosed versus a suspected SRC more often followed these guidelines, SRC management beyond the initial phase of injury remained inadequate. SRC is common in LGF; however, adherence to recommended management guidelines is poor, even among players who receive medical assistance. In particular, few LGF athletes receive clinical concussion care beyond the initial diagnosis and acute management phase. Further research is needed to examine the underlying reasons for poor SRC management in LGF, which will guide the development of future sport-specific interventions.

Relationship and Latent Factors Between Clinical Concussion Assessments and the Functional Standardized Assessment of Reaction Time (StART).

To examine the relationships and latent factors within the Standardized Assessment of Reaction Time (StART), and between StART and current clinical assessments. Cross-sectional study. Clinical medicine facility. Eighty-nine healthy collegiate student-athletes (63% male, age: 19.5 ± 0.9 years, 28% ≥1 concussion history). Student-athletes completed StART and clinical assessments during preinjury testing. Standardized Assessment of Reaction Time consisted of 3 conditions (standing, single-leg balance, cutting) under 2 cognitive states (single task and dual task) for 3 trials each condition. Clinical assessments were the Sport Concussion Assessment Tool (SCAT) symptom checklist, Standardized Assessment of Concussion (SAC), tandem gait (single task and dual task), and Immediate PostConcussion Assessment and Cognitive Testing (ImPACT). We used Pearson- r correlation coefficients and exploratory factor analysis (EFA) to examine relationships and latent factors between StART and clinical assessments. Null to moderate correlations presented among the StART outcomes (r range: 0.06-0.70), and null to small correlations between StART and clinical assessments (r range: -0.16 to 0.34). The three-factor EFA for solely StART explained 70.6% total variance: functional movement (cutting), static dual-task (standing and single-leg balance), and static single task (standing and single-leg balance). The five-factor EFA for StART and clinical assessments explained 65.8% total variance: gait (single-task and dual-task tandem gait), functional movement (StART single-task and dual-task cutting), static dual-task (StART standing, single-leg balance), neurocognitive (ImPACT verbal memory, visual memory, visual-motor speed), and static single task (StART standing, single-leg balance). No other outcomes met the factor loading threshold. StART displayed 3 distinct categories and had minimal redundancy within its subtests. StART did not meaningfully correlate with clinical assessments, suggesting that StART provides unique information by examining more functional, reactive movement.

Eye Tracking Metrics Differences among Uninjured Adolescents and Those with Acute or Persistent Post-Concussion Symptoms.

Eye tracking assessments that include pupil metrics can supplement current clinical assessments of vision and autonomic dysfunction in concussed adolescents. This study aimed to explore the utility of a 220-second eye tracking assessment in distinguishing eye position, saccadic movement, and pupillary dynamics among uninjured adolescents, those with acute post-concussion symptoms (≤28 days since concussion), or those with persistent post-concussion symptoms (>28 days since concussion). Two hundred fifty-six eye tracking metrics across a prospective observational cohort of 180 uninjured adolescents recruited from a private suburban high school and 224 concussed adolescents, with acute or persistent symptoms, recruited from a tertiary care subspecialty concussion care program, 13 to 17 years old, from August 2017 to June 2021 were compared. Kruskal-Wallis tests were used, and Bonferroni corrections were applied to account for multiple comparisons and constructed receiver operating characteristic curves. Principal components analysis and regression models were applied to determine whether eye tracking metrics can augment clinical and demographic information in differentiating uninjured controls from concussed adolescents. Two metrics of eye position were worse in those with concussion than uninjured adolescents, and only one metric was significantly different between acute cases and persistent cases. Concussed adolescents had larger left and right mean, median, minimum, and maximum pupil size than uninjured controls. Concussed adolescents had greater differences in mean, median, and variance of left and right pupil size. Twelve metrics distinguished female concussed participants from uninjured; only four were associated with concussion status in males. A logistic regression model including clinical and demographics data and transformed eye tracking metrics performed better in predicting concussion status than clinical and demographics data alone. Objective eye tracking technology is capable of quickly identifying vision and pupillary disturbances after concussion, augmenting traditional clinical concussion assessments. These metrics may add to existing clinical practice for monitoring recovery in a heterogeneous adolescent concussion population.

Machine learning to predict sports-related concussion recovery using clinical data.

Sport-related concussions (SRCs) are a concern for high school athletes. Understanding factors contributing to SRC recovery time may improve clinical management. However, the complexity of the many clinical measures of concussion data precludes many traditional methods. This study aimed to answer the question, what is the utility of modeling clinical concussion data using machine-learning algorithms for predicting SRC recovery time and protracted recovery? This was a retrospective case series of participants aged 8 to 18 years with a diagnosis of SRC. A 6-part measure was administered to assess pre-injury risk factors, initial injury severity, and post-concussion symptoms, including the Vestibular Ocular Motor Screening (VOMS) measure, King-Devick Test and C3 Logix Trails Test data. These measures were used to predict recovery time (days from injury to full medical clearance) and binary protracted recovery (recovery time > 21 days) according to several sex-stratified machine-learning models. The ability of the models to discriminate protracted recovery was compared to a human-driven model according to the area under the receiver operating characteristic curve (AUC). For 293 males (mean age 14.0 years) and 362 females (mean age 13.7 years), the median (interquartile range) time to recover from an SRC was 26 (18-39) and 21 (14-31) days, respectively. Among 9 machine-learning models trained, the gradient boosting on decision-tree algorithms achieved the best performance to predict recovery time and protracted recovery in males and females. The models' performance improved when VOMS data were used in conjunction with the King-Devick Test and C3 Logix Trails Test data. For males and females, the AUC was 0.84 and 0.78 versus 0.74 and 0.73, respectively, for statistical models for predicting protracted recovery. Machine-learning models were able to manage the complexity of the vestibular-ocular motor system data. These results demonstrate the clinical utility of machine-learning models to inform prognostic evaluation for SRC recovery time and protracted recovery.

The Effect of Soccer and Lacrosse Participation and Video Verified Head Impact Biomechanics on Clinical Concussion Measures

Neurocognitive changes have been found in participants of contact sports without documented concussions, raising concerns regarding the long-term consequences of subconcussive head impacts in sport. However, sex comparisons of neurocognitive change without reported concussions have not been completed for soccer or lacrosse athletes. Our purpose was to determine changes in clinical measures of cognitive function in uninjured collegiate lacrosse and soccer players. Men’s soccer (N=23), women’s soccer (N=36), men’s lacrosse (N=28) and women’s lacrosse (N=31) players wore xPatch head impact monitoring sensors for all practices and games. Sensors measured peak linear accelerations and peak rotational accelerations, allowing for daily density calculations. Participants completed the Sport Concussion Assessment Tool 3 and Immediate Post-Concussion and Cognitive Testing at the beginning and end of the season. For women, multiple statistically significant relationships were identified [decreased reaction time with increased cumulative peak linear acceleration (rs=-0.30, P=0.03), peak linear acceleration daily density (rs=-0.31, P=0.04), and peak rotational acceleration daily density (rs=-0.31, P=0.03) and also Immediate Post-Concussion and Cognitive Testing symptom change increased with increased cumulative peak linear acceleration (rs=-0.38, P=0.008) and cumulative peak rotational acceleration (rs=-0.37, P=0.009)]. For men, cognitive change scores, specifically concentration, had the only statistically significant relationship with cumulative peak rotational acceleration (rs=0.32, P=0.02). Men had a greater number of changes over the course of the season compared to women; however, the changes did not appear related to head impact biomechanics. Women had many statistically significant correlations between head impacts and deterioration in some constructs, especially symptoms.

The Effect of Sex, Sport, and Preexisting Histories on Baseline Concussion Test Performance in College Lacrosse and Soccer Athletes.

To study sex and sport differences in baseline clinical concussion assessments. A secondary purpose was to determine if these same assessments are affected by self-reported histories of (1) concussion; (2) learning disability; (3) anxiety and/or depression; and (4) migraine. Prospective cohort. National Collegiate Athletic Association D1 Universities. Male and female soccer and lacrosse athletes (n = 237; age = 19.8 ± 1.3 years). Sport, sex, history of (1) concussion; (2) learning disability; (3) anxiety and/or depression; and (4) migraine. Sport Concussion Assessment Tool 22-item symptom checklist, Standardized Assessment of Concussion, Balance Error Scoring System (BESS), Generalized Anxiety Disorder 7-item scale, and Patient Health Questionnaire. Female athletes had significantly higher total symptoms endorsed (P = 0.02), total symptom severity (P < 0.001), and BESS total errors (P = 0.01) than male athletes. No other sex, sport, or sex-by-sport interactions were observed (P > 0.05). Previous concussion and migraine history were related to greater total symptoms endorsed (concussion: P = 0.03; migraine: P = 0.01) and total symptom severity (concussion: P = 0.04; migraine: P = 0.02). Athletes with a migraine history also self-reported higher anxiety (P = 0.004) and depression (P = 0.01) scores. No other associations between preexisting histories and clinical concussion outcomes were observed (P > 0.05). Our findings reinforce the need to individualize concussion assessment and management. This is highlighted by the findings involving sex differences and preexisting concussion and migraine histories. Clinicians should fully inventory athletes' personal and medical histories to better understand variability in measures, which may be used to inform return-to-participation decisions following injury.