Acute evaluation of sport-related concussion and implications for the Sport Concussion Assessment Tool (SCAT6) for adults, adolescents and children: a systematic review

OBJECTIVES

To systematically review the scientific literature regarding the acute assessment of sport-related concussion (SRC) and provide recommendations for improving the Sport Concussion Assessment Tool (SCAT6).

DATA SOURCES

Systematic searches of seven databases from 2001 to 2022 using key words and controlled vocabulary relevant to concussion, sports, SCAT, and acute evaluation.

ELIGIBILITY CRITERIA

(1) Original research articles, cohort studies, case-control studies, and case series with a sample of >10; (2) ≥80% SRC; and (3) studies using a screening tool/technology to assess SRC acutely (<7 days), and/or studies containing psychometric/normative data for common tools used to assess SRC.

DATA EXTRACTION

Separate reviews were conducted involving six subdomains: Cognition, Balance/Postural Stability, Oculomotor/Cervical/Vestibular, Emerging Technologies, and Neurological Examination/Autonomic Dysfunction. Paediatric/Child studies were included in each subdomain. Risk of Bias and study quality were rated by coauthors using a modified SIGN (Scottish Intercollegiate Guidelines Network) tool.

RESULTS

Out of 12 192 articles screened, 612 were included (189 normative data and 423 SRC assessment studies). Of these, 183 focused on cognition, 126 balance/postural stability, 76 oculomotor/cervical/vestibular, 142 emerging technologies, 13 neurological examination/autonomic dysfunction, and 23 paediatric/child SCAT. The SCAT discriminates between concussed and non-concussed athletes within 72 hours of injury with diminishing utility up to 7 days post injury. Ceiling effects were apparent on the 5-word list learning and concentration subtests. More challenging tests, including the 10-word list, were recommended. Test-retest data revealed limitations in temporal stability. Studies primarily originated in North America with scant data on children.

CONCLUSION

Support exists for using the SCAT within the acute phase of injury. Maximal utility occurs within the first 72 hours and then diminishes up to 7 days after injury. The SCAT has limited utility as a return to play tool beyond 7 days. Empirical data are limited in pre-adolescents, women, sport type, geographical and culturally diverse populations and para athletes.

PROSPERO REGISTRATION NUMBER

CRD42020154787.

A-19 Distress Predicts Poorer Cognitive Performance At Post-Injury In Concussed Athletes

Purpose: This study evaluated the consistency between athletes’ self-reported cognitive symptoms and cognitive test performance. Methods: The sample included 784 Canadian Football League athletes who underwent standardized cognitive testing with cognitive testing (ImPACT) and the Brief Symptom Inventory (BSI-18) at baseline. Over 2 consecutive seasons, 46 players were diagnosed with concussions following assessment with team physicians within 48 hours; 10 were eliminated due to missing data. Five cognitive symptoms (feeling slowed down, feeling in a fog, not feeling right, difficulties concentration, difficulties with memory) were used to create a composite score (Cog). The Cog index, the depression, anxiety, total index scores from the BSI, and the 5 ImPACT cognitive domains were correlated at baseline and post-injury. History of learning disabilities, ADHD, psychiatric diagnosis, and history of concussion were co-variates. Results: There were no significant correlations between Cog, depression, anxiety or total BSI scores and the ImPACT cognitive domains at baseline. At post injury there were no significant correlations between Cog or ImPACT index scores. In contrast, significant negative correlations were found between BSI Anxiety and verbal memory (r = 0.67, p &lt; 0.01), visual memory (r = 0.68, p &lt; 0.01), and visual-motor processing speed (r = 0.48, p &lt; 0.05). In addition, there were significant negative correlations between the BSI total score and visual memory (r = 0.51, p &lt; 0.05) and reaction time (r = 0.55, p &lt; 0.05). Conclusions: Self-reported cognitive difficulties do not correlate with poorer cognitive outcomes in our sample of professional football players. However, distress at post-injury was significantly correlated to performance, suggesting psychological variables may play a role in cognitive functioning.

A-37 Ocular Motor Impairments in Concussion Professional Football Players

Purpose: The purpose of this study was to examine baseline and post-concussion injury characteristics of ocular eye movements using the Sync Think visual eye tracking apparatus in professional football players in the Canadian Football League (CFL). Methods: The visual tracking testing protocol uses an integrated stimulus presentation-eye tracking apparatus (EyeLink CL; SR Research, Ontario, Canada) with which eye movements were recorded at 500 Hz using infrared video-oculography. The standard deviation of radial errors (SDRE) and tangential errors (SDTE) were used to determine poor visual tracking. Participants were (n = 748) rostered players in the Canadian Football League. All participants completed assessments at baseline. Sixteen players completed post-concussion assessments and 98 players completed post-exertional assessments during the 2021 season to evaluate the impact of physical exertion on ocular movement metrics. Results: Participants with diagnosed concussions (n = 16+) demonstrated significantly poorer performance on measures of both gaze stability and smooth pursuit (p &lt; 0.001). The poorer results were correlated with significantly higher subjective ratings of dizziness (p &lt; 0.01) and fogginess (p &lt; 0.001). In contrast, healthy participants who completed the same ocular motor assessments demonstrated no significant differences compared to baseline test performance. Conclusions: Findings suggest that subtle differences in oculomotor functioning arise from sport concussion in professional football players. Further research with larger sample sizes and correlation with other cognitive and physical outcomes is warranted.

A-49 Sideline Concussion Assessment Tool symptoms predict poorer mental health outcomes in college athletes

Purpose: Assessment of emotional functioning is essential in sports-related concussion (SRC) management. This study investigated the prediction of mental health outcomes from the SCAT-3 Symptom Scale. Methods: Canadian university athletes who compete in contact sports participated in a large-scale study (Active Rehabilitation). A total of 235 participants (males = 67%) completed the Brief Symptom Inventory (BSI), Quality of Life Scale (QOLS), and Sideline Concussion Assessment Tool, 3rd edition (SCAT). Step-wise regression analysis using demographic variables (gender, age, history of Learning Disability, history of ADHD, diagnosis of psychiatric condition) and psychological symptoms from the SCAT were used as predictors for the BSI (Depression and Anxiety) and QOLS (Depression and Anxiety). Results: Regression analysis revealed female gender, previous psychiatric diagnosis and Nervousness (SCAT) significantly predicted higher scores on the Depression subscales of BSI (R2 = 0.21, F1,231 = 20.3, p &lt; 0.001) and Quality of Life (R2 = 0.21, F1,231 = 18.0, p &lt; 0.001). Female gender, previous psychiatric diagnosis, Nervousness and Irritability predicted higher scores on both the Anxiety subscales of the BSI (R2 = 0.23, F1,230 = 16.9, p &lt; 0.001) and Quality of Life (R2 = 0.26, F1,230 = 20.2, p &lt; 0.001). Contrary to other findings, history of concussion was not significantly predictive of higher Depression and/or Anxiety scores (although there was a trend between number of concussions and higher symptom report). Conclusions: SCAT symptoms may capture heightened emotional symptom report with more robust scales measuring emotional functioning. In contrast, concussion history did not predict emotional symptoms, a finding contrary to published literature.

A-12 Mental Health Outcomes for CFL Athletes with ADHD

Purpose: Current research suggests that athletes with Attention Deficit Hyperactivity Disorder (ADHD) are at risk for poorer outcomes arising from sport related concussions (SRC). There is limited research related evaluating mental health outcomes in athletes diagnosed with ADHD. The purpose of the study is to evaluate mental health outcomes among Canadian Football League (CFL) athletes with (ADHD) and to measure outcomes based upon a history of concussion. Methods: Professional football players from the CFL (n = 784) were administered a baseline mental health measure, the Health-Related Quality of Life (HRQL), as a component of pre-season evaluations as part of a larger cohort study (Active Rehabilitation). Diagnosis of ADHD was the independent variable and HRQL index scores measuring physical functioning, depression, cognitive functioning, were dependent variables. A second analysis compared ADHD athletes with no history of concussion to those with a history of concussion on the HRQL indexes. Results: Participants diagnosed with ADHD (n = 80) had statistically significant differences on the Physical Functioning (t(782) = −3.359, p &lt; 0.001), Depression ((t(782) = −2.820, p = 0.002) and Cognitive (t(782) = −3.570, p &lt; 0.001) domains of the HRQL, compared to athletes without ADHD. Among the athletes who are diagnosed with ADHD, no mental health differences were found between those who have at least one concussion and those who do not. Conclusions: This study did not find a significant effect of concussion on mental health outcomes in participants with ADHD. However, athletes with ADHD present with higher mental health symptoms which may merit closer monitoring.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

The Influence of Time of Season on Injury Rates and the Epidemiology of Canadian Football Injuries

OBJECTIVE

To describe injury rates and injury patterns in the Canadian Football League (CFL) according to time during the season, player position, injury type, and injury location.

DESIGN

Prospective, cohort study.

SETTING AND PARTICIPANTS

Eight seasons from CFL injury surveillance database.

INDEPENDENT VARIABLES

Depending on the analysis, time of season (preseason, regular, and playoffs), player position, injury type, and injury location.

MAIN OUTCOME MEASURES

Medical attention and time-loss injury rates per 100 athletes at risk (AAR), and prevalence of time-loss injuries per week.

RESULTS

The average game injury rate was 45.2/100 AAR medical attention injuries and 30.7/100 AAR time-loss injuries. Injury rates declined by 1% per week over the season for both medical attention (rate ratio = 0.99) and time-loss (rate ratio = 0.99) injuries, with a substantial decline during the playoffs compared with preseason (rate ratio = 0.70-0.77). The number of ongoing time-loss injuries increased over the course of the regular season. Quarterbacks, offensive backs, and linebackers had the highest game injury rates. Joint/ligament and muscle/tendon injuries were the most common injury types for games and practices, respectively. The lower extremity was the most commonly affected area, specifically the lower leg/ankle/foot and hip/groin/thigh.

CONCLUSIONS

There was a 1% decline in injury rate per week during the season and a 30% decline during the playoffs. The number of ongoing time-loss injuries increased over the regular season. Current results can aid league officials and medical staff in making evidence-based decisions concerning player safety and health.

A-23 Mental Health Outcomes of Elite Athletes Following Sport Related Concussion

Objective

Investigation of anxiety and depression symptoms at baseline and following sport related concussion in a population of professional and collegiate football players.

Method

A quasi-experimental prospective longitudinal design was implemented. Participants included 198 Canadian Football League and University of Alberta varsity football players at baseline. Additionally, this study tracked 13 concussed athletes, 12 orthopaedic control athletes, and 15 healthy control athletes over approximately a 2 month period. Statistical analysis included an ANOVA and repeated measures ANOVA to identify differences in mental health at baseline as well as after injury at 3 time points (24-48 hours post injury, asymptomatic, and 1 month post return to play).

Results

At baseline, players who had a history of 1 or more concussions reported a greater number of anxiety and depression symptoms in comparison to players who did not have a history of concussion (F(2, 197) = 66.75, (p =.000)). At the group level, there were no differences in anxiety and depression symptoms between players who sustained a concussion, orthoepic injury, or no injury across the four time points measured (depression (F(3, 58) = 1.05, (p =.404); anxiety (F(3, 58) = 1.65, (p =.151)). However, individuals who sustained a concussion displayed significant changes in symptoms of anxiety (F(3, 12) = 9.004, (p =.000)) and depression (F(3, 12) = 11.396, (p =.000)) over time. Specifically, concussed players reported an increase in anxiety related symptoms between baseline report and 24-48 hours post injury (p = .042), a decrease between 24-48 hours and 1 month post return to play (p = .002) and a decrease between asymptomatic and 1 month post return to play (p = .036) time points. Additionally, players who sustained a concussion reported a significant increase in depressive symptoms between 24-48 hours post injury and 1 month post return to play (p = .029) and a decrease between asymptomatic and 1 month post return to play (p = .014) time points. This change over time was not found in the orthopaedic injury (depression (F(3, 11) = 2.467, (p =.14); anxiety (F(3, 11) = 2.242, (p =.15)) or healthy control groups (depression; (F(3, 14) = 2.177, (p =.17); anxiety; F(3, 14) = 1.435, (p =.30)).

Conclusions

Results from this study suggest that a history of concussion impacts baseline self-report of anxiety and depression symptoms. Furthermore, players who sustained a concussion experienced subtle increases in anxiety and depressive symptoms in the short term and not in the long term. Players with who sustained an orthopaedic injury and healthy players did not show these changes in anxiety and depression symptom report. It appears that in this small sample concussion produced unique outcomes related to mental health functioning in the short term.

Methodology and Implementation of a Randomized Controlled Trial (RCT) for Early Post-concussion Rehabilitation: The Active Rehab Study

Background: Sports-related concussion (SRC) is a complex injury with heterogeneous presentation and management. There are few studies that provide guidance on the most effective and feasible strategies for recovery and return to sports participation. Furthermore, there have been no randomized studies of the feasibility, safety, and efficacy of early rehabilitation strategies across multiple sports and age groups. This international cluster-randomized pragmatic trial evaluates the effectiveness of early multi-dimensional rehabilitation integrated with the current return to sport strategy vs. the current return to sport strategy alone.

Methods: The study is a cluster-randomized pragmatic trial enrolling male and female athletes from 28 sites. The sites span three countries, and include multiple sports, levels of play (high school, college, and professional), and levels of contact. The two study arms are Enhanced Graded Exertion (EGE) and Multidimensional Rehabilitation (MDR). The EGE arm follows the current return to sport strategy and the MDR arm integrates early, MDR strategies in the context of the current return to sport strategy. Each arm employs a post-injury protocol that applies to all athletes from that site in the event they sustain a concussion during their study enrollment. Participants are enrolled at pre-season baseline. Assessment timepoints include pre-season baseline, time of injury (concussion), 24–48 h post-injury, asymptomatic, and 1-month post-injury. Symptoms and activity levels are tracked post injury through the return to play process and beyond. Injury and recovery characteristics are obtained for all participants. Primary endpoints include time to medical clearance for full return to sport and time to become asymptomatic. Secondary endpoints include symptom, neurocognitive, mental status, balance, convergence insufficiency, psychological distress, and quality of life trajectories post-injury.

Discussion: Outputs from the trial are expected to inform both research and clinical practice in post-concussion rehabilitation across all levels of sport and extend beyond civilian medicine to care for military personnel.

Ethics and Dissemination: The study is approved by the data coordinating center Institutional Review Board and registered at clinicaltrials.gov. Dissemination will include peer-reviewed publications, presentation to patients and public groups, as well as dissemination in other healthcare and public venues of interest.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT02988596

Trial Funding: National Football League.

Does an individual's fitness level affect baseline concussion symptoms?

CONTEXT

Variables that may influence baseline concussion symptoms should be investigated.

OBJECTIVE

To evaluate the effect of physical fitness on self-report of baseline concussion symptoms in collegiate athletes and students.

DESIGN

Controlled laboratory study.

PATIENTS OR OTHER PARTICIPANTS

A total of 125 undergraduates, including 95 collegiate athletes and 30 recreational athletes (83 males, 42 females).

INTERVENTION(S)

Participants completed the Standardized Concussion Assessment Tool 2 (SCAT2; symptom report) at baseline, within 10 minutes of completing the Leger test, and within 24 hours of the initial baseline test. The Leger (beep) test is a shuttle-run field test used to predict maximal aerobic power.

MAIN OUTCOME MEASURE(S)

The total symptom score on the SCAT2 was calculated and analyzed with a repeated-measures analysis of variance. A linear regression analysis was used to determine if 3 variables (sport type, sex, or fitness level) accounted for a significant amount of the variance in the baseline symptom report.

RESULTS

Participants reported more symptoms postactivity but fewer symptoms at 24 hours compared with baseline, representing a time effect in our model (F2,234 = 47.738, P < .001). No interactions were seen among the independent variables. We also found an effect for fitness level, with fitter individuals reporting fewer symptoms at all 3 time intervals. The regression analysis revealed that fitness level accounted for a significant amount of the variance in SCAT2 symptoms at baseline (R (2) = 0.22, F3,121 = 11.44, P < .01).

CONCLUSIONS

Fitness level affected the baseline concussion symptom report. Exercise seems to induce concussion symptom reporting, and symptom severity may be a function of an athlete's level of conditioning. Sports medicine professionals should consider an athlete's level of fitness when conducting baseline concussion symptom assessments.

Frequency domain surface EMG sensor fusion for estimating finger forces

Extracting or estimating skeletal hand/finger forces using surface electro myographic (sEMG) signals poses many challenges due to cross-talk, noise, and a temporal and spatially modulated signal characteristics. Normal sEMG measurements are based on single sensor data. In this paper, array sensors are used along with a proposed sensor fusion scheme that result in a simple Multi-Input-Single-Output (MISO) transfer function. Experimental data is used along with system identification to find this MISO system. A Genetic Algorithm (GA) approach is employed to optimize the characteristics of the MISO system. The proposed fusion-based approach is tested experimentally and indicates improvement in finger/hand force estimation.

Towards smart prosthetic hand: Adaptive probability based skeletan muscle fatigue model

Skeletal muscle force can be estimated using surface electromyographic (sEMG) signals. Usually, the surface location for the sensors is near the respective muscle motor unit points. Skeletal muscles generate a spatial EMG signal, which causes cross talk between different sEMG signal sensors. In this study, an array of three sEMG sensors is used to capture the information of muscle dynamics in terms of sEMG signals. The recorded sEMG signals are filtered utilizing optimized nonlinear Half-Gaussian Bayesian filters parameters, and the muscle force signal using a Chebyshev type-II filter. The filter optimization is accomplished using Genetic Algorithms. Three discrete time state-space muscle fatigue models are obtained using system identification and modal transformation for three sets of sensors for single motor unit. The outputs of these three muscle fatigue models are fused with a probabilistic Kullback Information Criterion (KIC) for model selection. The final fused output is estimated with an adaptive probability of KIC, which provides improved force estimates.

Control strategies for smart prosthetic hand technology: an overview

A chronological overview of the applications of control theory to prosthetic hand is presented. The overview focuses on hard computing or control techniques such as multivariable feedback, optimal, nonlinear, adaptive and robust and soft computing or control techniques such as artificial intelligence, neural networks, fuzzy logic, genetic algorithms and on the fusion of hard and soft control techniques. This overview is not intended to be an exhaustive survey on this topic and any omissions of other works is purely unintentional.

Characterization of a three-component vanillate O-demethylase from Moorella thermoacetica

The Moorella thermoacetica aromatic O-demethylase was characterized as an inducible three-component system with similarity to the methanogenic methanol, methylamine, and methanethiol methyltransferases and to the O-demethylase system from Acetobacterium dehalogenans. MtvB catalyzes methyl transfer from a phenylmethylether to the cobalt center of MtvC, a corrinoid protein. MtvA catalyzes transmethylation from MtvC to tetrahydrofolate, forming methyltetrahydrofolate. Cobalamin can substitute for MtvC.