Changes in ImPACT Cognitive Subtest Networks Following Sport-Related Concussion.

OBJECTIVE: High school athletes are administered ImPACT at the start of the academic year or sport season and again after suspected concussion. Concussion management involves the comparison of baseline and post-injury cognitive scores with declines in scores providing evidence for concussive injury. A network framework may provide additional information about post-concussive cognitive changes and expand characterization of sport-related concussion (SRC) recovery. DESIGN: Retrospective cohort study. SETTING: High school. PARTICIPANTS: High school athletes (n = 1553) were administered ImPACT at baseline (T1), post-SRC (T2 = 72 h of injury), and prior to return to play (T3 = within two weeks post-injury). INDEPENDENT VARIABLES: ImPACT cognitive subtest scores. MAIN OUTCOME MEASURES: Cognitive networks were calculated and compared over three time points. Centrality indices were calculated to determine the relative importance of cognitive variables within networks. RESULTS: Network connectivity increased from T1 to T2 and remained hyperconnected at T3. There was evidence of network reorganization between T1 and T3. Processing speed was central within each network, and visual memory and impulsivity became more central over time. CONCLUSIONS: The results suggest potential evidence of cognitive network change over time. Centrality findings suggest research specific to visual memory and impulse control difficulties during the post-concussion recovery period is warranted. Network analysis may provide additional information about cognitive recovery following SRC and could potentially serve as an effective means of monitoring persisting cognitive symptoms after concussion.

Characterizing the Network Structure of Post-Concussion Symptoms.

OBJECTIVE: Assessment of post-concussion symptoms is implemented at secondary, post-secondary, and professional levels of athletics. Network theory suggests that disorders can be viewed as a set of interacting symptoms that amplify, reinforce, and maintain one another. Examining the network structure of post-concussion symptoms may provide new insights into symptom comorbidity and may inform targeted treatment. We used network analysis to examine the topology of post-concussion symptoms using the Post-Concussion Symptom Scale (PCSS) in high school athletes with recent suspected sport-related concussion. METHOD: Using a cross-sectional design, the network was estimated from Post Concussion Symptom Scale scores from 3,292 high school athletes, where nodes represented symptoms and edges represented the association between symptoms. Node centrality was calculated to determine the relative importance of each symptom in the network. RESULTS: The network consisted of edges within and across symptom domains. "Difficulty concentrating" and "dizziness" were the most central symptoms in the network. Although not highly central in the network, headaches were the highest rated symptom. CONCLUSIONS: The interconnectedness among symptoms supports the notion that post-concussion symptoms are interrelated and mutually reinforcing. Given their central role in the network, "difficulty concentrating" and "dizziness" are expected to affect the activation and persistence of other post-concussion symptoms. Interventions targeting difficulties with concentration and dizziness may help alleviate other symptoms. Our findings could inform the development of targeted treatment with the aim of reducing overall symptom burden. Future research should examine the trajectory of post-concussion symptom networks to advance the clinical understanding of post-concussive recovery.

Cognitive profiles following sport-related concussion in high school athletes.

OBJECTIVE: Heterogeneity is common following traumatic brain injury (TBI) with important implications for clinical outcome. Research in moderate to severe TBI identifies differentiated cognitive profiles. There is little research investigating potential clusters following sport concussion. METHODS: Cluster analysis was used to determine patterns of Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) performance at three time points (72 hr, 4-7 days, and 8-30 days postconcussion). Participants included 1,817 high-school athletes (Mage = 15.5; 37.9% female) who completed ImPACT following concussion. RESULTS: Separate cluster analyses of cognitive scores were conducted at each postconcussion timepoint. Results indicated three clusters of cognitive performance within 1 week postinjury, while a two-cluster solution was identified at longer intervals (8-30 days). Clusters differed primarily by level of performance and also exhibited stratified differences in symptom severity and magnitude of change in cognitive function and symptom-reporting from pre- to postconcussion. The lowest performing cluster in each PC group was Mildly-to-Moderately Impaired and exhibited the highest rates of complicated recovery, suggesting an association between the current clusters and protracted recovery. CONCLUSIONS: Results provide preliminary evidence that ImPACT can identify clusters of athletes based on cognitive performance postconcussion that differ in clinically meaningful ways, including symptoms, magnitude of change from baseline, and concussion recovery outcomes. Discriminant functions can classify athletes into clusters based on postconcussion scores and a supplemental excel calculator is provided for such purposes. Absence of full demographic data regarding race/ethnicity and socioeconomic status may limit generalizability. Future work should investigate whether these clusters may assist in return-to-play decision-making by identifying at-risk athletes who may benefit from targeted intervention. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Confirmatory factor analysis of imPACT cognitive tests in high school athletes.

ImPACT is the most commonly utilized computerized neurocognitive assessment for the clinical management of sport concussion. The cognitive composite scores that ImPACT currently reports include Verbal Memory, Visual Memory, Visual Motor Speed, Reaction Time, and Impulse Control. However, exploratory factor analytic studies report that two or more factors may better represent ImPACT's latent structure, suggesting that the current cognitive composites may not adequately represent the cognitive constructs ImPACT assesses. The latent structure of ImPACT cognitive baseline scores was examined using exploratory (EFA) and confirmatory factor analysis (CFA) of valid baseline ImPACT scores for 36,091 high school athletes. These athletes were randomly divided into two samples. The first sample was a calibration sample used for EFA and the second sample was a cross-validation sample used for CFA to estimate the best model identified in the calibration phase, along with other models that were reported in the literature or based on theoretical considerations, including hierarchical and bifactor models. EFA identified a first-order four-factor solution consisting of Visual Memory, Visual Reaction Time, Verbal Memory, and Working Memory constructs. CFA indicated that this four-factor model provided superior fit for the data, while the current five-composite structure of ImPACT provided a poor fit for the data. The latent constructs identified in this study using CFA do not map well onto the composite scores that are currently used to interpret ImPACT performance. Future research should investigate whether interpretation of ImPACT based on the constructs identified here will be more useful for clinical decision making than current approaches. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Influence of Autism and Other Neurodevelopmental Disorders on Cognitive and Symptom Profiles: Considerations for Baseline Sport Concussion Assessment.

OBJECTIVE: The presence of neurodevelopmental disorders (ND) such as attention-deficit/hyperactivity disorder (ADHD) and learning disorders (LD) have demonstrated effects on Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) performance. No current research has directly examined whether autism spectrum disorder (ASD) has similar effects. The current study compared ImPACT cognitive and symptom profiles in athletes with self-reported ASD to other NDs and healthy controls using case-control matching. METHOD: The current study compared ImPACT baselines of high school athletes with ASD to athletes with other NDs (ADHD, LD, and co-occurring ADHD/LD) and healthy controls on cognitive composites and symptom reporting. Participants included 435 athletes (87 controls, 87 with ASD, 87 with ADHD, 87 with LD, and 87 with ADHD/LD) selected from a larger naturalistic sample. Athletes were matched to the ASD group based on age, sex, and sport using randomized case-matched selection from the larger database. RESULTS: Results revealed that athletes with ASD performed more poorly than healthy controls on the Visual Motor Speed composite. No differences were found for Post-concussion Symptom Scale (PCSS) domain scores. Differences in cognitive and symptom profiles among the athletes with other NDs were also found. CONCLUSIONS: Results elucidate patterns of baseline performance for athletes with ASD, demonstrating that there may not be significant differences between ASD and healthy controls on four of the five ImPACT composites, and no symptom reporting differences. Cognitive and symptom differences found for other NDs should be considered when interpreting baseline performance and for making return-to-play decisions in the absence of baseline assessment.

Influence of Special Education, ADHD, Autism, and Learning Disorders on ImPACT Validity Scores in High School Athletes.

OBJECTIVE: The Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) is commonly used to assist with post-concussion return-to-play decisions for athletes. Additional investigation is needed to determine whether embedded indicators used to determine the validity of scores are influenced by the presence of neurodevelopmental disorders (NDs). METHOD: This study examined standard and novel ImPACT validity indicators in a large sample of high school athletes (n = 33,772) with or without self-reported ND. RESULTS: Overall, 7.1% of athletes' baselines were judged invalid based on standard ImPACT validity criteria. When analyzed by group (healthy, ND), there were significantly more invalid ImPACT baselines for athletes with an ND diagnosis or special education history (between 9.7% and 54.3% for standard and novel embedded validity criteria) when compared to athletes without NDs. ND history was a significant predictor of invalid baseline performance above and beyond other demographic characteristics (i.e., age, sex, and sport), although it accounted for only a small percentage of variance. Multivariate base rates are presented stratified for age, sex, and ND. CONCLUSIONS: These data provide evidence of higher than normal rates of invalid baselines in athletes who report ND (based on both the standard and novel embedded validity indicators). Although ND accounted for a small percentage of variance in the prediction of invalid performance, negative consequences (e.g., extended time out of sports) of incorrect decision-making should be considered for those with neurodevelopmental conditions. Also, reasons for the overall increase noted here, such as decreased motivation, "sandbagging", or disability-related cognitive deficit, require additional investigation.

Using heart rate as a physical activity metric.

Physical activity (PA) is critical for a healthy lifestyle. The current study assessed heart rate (HR) as a primary measure of moderate and vigorous PA with four typically developing children. First, individualized HR assessments were conducted to determine moderate and vigorous HR zones. Next, participants engaged in various exercises at a local YMCA facility (i.e., biking, elliptical, basketball, and exergame boxing) to determine how HR during these activities aligned with their individualized HR zones. During exercise bouts, HR was typically above moderate, but below vigorous HR zones for all participants. Additionally, exercises that restricted range of motion (i.e., biking and elliptical) engendered generally lower HR than exercises with greater range of motion. Vocal instructions to exercise at vigorous levels were effective at increasing HR to vigorous levels for one participant. The advantages of using HR as a metric of PA during assessment and intervention are discussed.