Normative Versus Baseline Paradigms for Detecting Neuropsychological Impairment Following Sports-Related Concussion

Using a novel Reliable Letter-Number Span from the Wechsler Letter-Number Sequencing as an embedded validity indicator in baseline concussion testing for youth athletes

Objective: Few performance validity tests exist for youth undergoing baseline testing for the management of sport-related concussion. This study provides an initial validation of a reliable span calculation from the Wechsler Intelligence Scale for Children-Fourth Edition Letter-Number Sequencing (LNS) subtest as a performance validity indicator for youth baseline testing (Reliable Letter-Number Span; RLNS). Method: Youth athletes (n = 173) underwent baseline concussion testing for the management of sport-related concussion. We classified participants as valid (n = 153) or invalid performance (n = 20) based on several well-established performance validity tests. We calculated RLNS by summing the spans of alphanumeric characters across two items within the Letter-Number Sequencing subtest, similar to the Reliable Digit Span. To better determine the utility of RLNS, we also examined other novel reliable span metrics and established summary scores from the Letter-Number Sequencing as potential validity indicators. Results: Analyses revealed excellent classification accuracy for RLNS, with an area under the curve of .88 (95% CI [.81, .96]). The optimal cutoff for RLNS (≤6) yielded .55 sensitivity and .95 specificity. Results showed similar but slightly lower classification accuracy statistics (areas under the curve of .77-.86) for the other LNS validity indicators. Conclusion: Initial findings support the criterion validity of RLNS as an embedded validity indicator. This measure is among the few extant performance validity tests that may be appropriate for youth baseline concussion testing. RLNS may also be appropriate for other types of pediatric evaluations. However, additional support is necessary before neuropsychologists can use RLNS clinically.

Musculoskeletal injury or Sports-Related Concussion (SRC) in a season of rugby union does not affect performance on concussion battery testing in university-aged student-athletes

BACKGROUND

Sub-concussive and concussive impacts sustained during contact sports such as rugby may affect neurocognitive performance, vestibular-ocular-motor function, symptom burden and academic ability.

METHOD

Student-athletes (n = 146) participating in rugby union British Universities or domestic competitions were assessed on the Immediate Post-Concussion and Cognitive Test, Post-Concussion Symptom Scale, vestibular-oculo-motor screening tool and revised perceived academic impact tool. Individual change from pre-season (July-September 2021) to 2-weeks following last exposure to contact (April-July 2022) was analysed.

RESULTS

Symptom burden significantly worsened (p=0.016) over the season. Significant improvements on verbal memory (p=0.016), visual memory (p=0.008) and motor processing speed (p=0.001) suggest a possible learning effect. Surprisingly, the number of days lost to concussion significantly and positively affected performance on verbal memory (p = 0.018) and reaction time (p = 0.027). Previous concussive events significantly predicted a worsening in symptom burden (p < 0.028), as did in-season concussive events, predicting improved verbal memory (p = 0.033) and symptom burden change (p = 0.047). Baseline performance significantly affected change on several neurocognitive tests, with low-scorers showing more improvement over the season.

CONCLUSION

Participation in rugby union was not associated with deleterious effects on brain function. Previous concussive events and in-season factors, possibly related to learning effects, may explain improvement in cognitive function across the season.

Psychometric Properties of Computerized Cognitive Tools and Standard Neuropsychological Tests Used to Assess Sport Concussion: A Systematic Review

Athletic programs are more frequently turning to computerized cognitive tools in order to increase efficiencies in concussion assessment. However, assessment using a traditional neuropsychological test battery may provide a more comprehensive and individualized evaluation. Our goal was to inform sport clinicians of the best practices for concussion assessment through a systematic literature review describing the psychometric properties of standard neuropsychological tests and computerized tools. We conducted our search in relevant databases including Ovid Medline, Web of Science, PsycINFO, and Scopus. Journal articles were included if they evaluated psychometric properties (e.g., reliability, sensitivity) of a cognitive assessment within pure athlete samples (up to 30 days post-injury). Searches yielded 4,758 unique results. Ultimately, 103 articles met inclusion criteria, all of which focused on adolescent or young adult participants. Test-retest reliability estimates ranged from .14 to .93 for computerized tools and .02 to .95 for standard neuropsychological tests, with strongest correlations on processing speed tasks for both modalities, although processing speed tasks were most susceptible to practice effects. Reliability was improved with a 2-factor model (processing speed and memory) and by aggregating multiple baseline exams, yet remained below acceptable limits for some studies. Sensitivity to decreased cognitive performance within 72 h of injury ranged from 45%-93% for computerized tools and 18%-80% for standard neuropsychological test batteries. The method for classifying cognitive decline (normative comparison, reliable change indices, regression-based methods) affected sensitivity estimates. Combining computerized tools and standard neuropsychological tests with the strongest psychometric performance provides the greatest value in clinical assessment. To this end, future studies should evaluate the efficacy of hybrid test batteries comprised of top-performing measures from both modalities.

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.

Annual Baseline King-Devick Oculomotor Function Testing Is Needed Due to Scores Varying by Age

Objective: To document baseline King-Devick (K-D) oculomotor function scores for male and female participants aged between 4 and 20 years old. Methods: Utilising a cross section of schools, rugby clubs and gymnastic clubs, 1936 participants (1300 male, 636 female) completed the spiral-bound K-D test for the identification of disturbed oculomotor function. Results: This study identified that overall, the baseline scores of the K-D test became faster by 1.4 (0.3 to 4.5) s per year, when compared with the previous age group in the same number of reading card groups. When comparing normative values of the original K-D validation study with the same age groups of the current cohort, participants aged 6 to 11 years recorded a faster baseline time (range 3.5 to 8.6 s), while those in the 12 to 14 years. age group recorded slower baseline times (range −3.9 to −7.9 s). Discussion: In general, there were age group differences, but not sex differences, for K-D test times in the current cohort. Analysis of single card times, across all age groups, showed changes likely due to improved reading time. Conclusion: The results support the need for individualised annual pre-injury baseline testing of the K-D test.

Prospective study with specific Re-Assessment time points to determine time to recovery following a Sports-Related Concussion in university-aged student-athletes

BACKGROUND

Time to recovery for symptom burden and neurocognition following a Sports-Related Concussion (SRC) has previously been determined by consolidating varying re-assessment time points into a singular point, and has not been established for Vestibular-Ocular-Motor (VOM) function or academic ability.

OBJECTIVES

Establish when recovery of symptom burden, neurocognition, VOM function, and academic ability occurs in university-aged student-athletes.

METHODS

Student-athletes completed an assessment battery (Post-Concussion Symptom Scale (PCSS), Immediate Post-Concussion Assessment and Cognitive Test (ImPACT), Vestibular Ocular-Motor Screening (VOMS), Perceived Academic Impairment Tool (PAIT)) during pre-season (n = 140), within 48 hours, 4, 8 and 14 days post-SRC and prior to Return To Play (RTP) and were managed according to the Rugby Football Union' community pathway (n = 42). Student-athletes were deemed recovered or impaired according to Reliable Change Index' (RCI) or compared to their individual baseline.

RESULTS

Symptom burden recovers by four days post-SRC on RCI and to baseline by eight days. VOM function and academic ability recovers by 8 days. Some student-athletes demonstrated worse performance at RTP on all tests by RCI and to baseline, except for on VOMS score and near point convergence by RCI change.

CONCLUSIONS

Variation in individual university-aged student-athletes requires a multi-faceted approach to establish what dysfunctions post-SRC exist and when recovery occurs.

A Normative Reference vs. Baseline Testing Compromise for ImPACT: The CARE Consortium Multiple Variable Prediction (CARE-MVP) Norms

BACKGROUND

Sports medicine clinicians routinely use computerized neurocognitive testing in sport-related concussion management programs. Debates continue regarding the appropriateness of normative reference comparisons versus obtaining individual baseline assessments, particularly for populations with greater likelihood of having below- or above-average cognitive abilities. Improving normative reference methods could offer alternatives to perceived logistical and financial burdens imposed by universal baseline testing.

OBJECTIVES

To develop and validate the Concussion Assessment, Research, and Education (CARE) Consortium Multiple Variable Prediction (MVP) norms for the Immediate Postconcussion Assessment and Cognitive Testing (ImPACT).

METHODS

We developed the CARE-MVP norms for ImPACT composite scores using regression-based equations. Predictor variables included sex, race (white/Caucasian, black/African American, Asian, or Multiple Races), medical history [attention-deficit/hyperactivity disorder (ADHD), learning disorder (LD), prior concussion(s), prior psychiatric diagnosis], and an estimate of premorbid intellect (Wechsler Test of Adult Reading). CARE-MVP norms were first validated in an independent sample of healthy collegiate athletes by comparing predicted and actual baseline test scores using independent-samples t-tests and Cohen's d effect sizes. We then evaluated base rates of low scores in athletes self-reporting ADHD/LD (vs. non-ADHD/LD) and black/African American race (vs. white/Caucasian) across multiple normative reference methods (Chi square, Cramer's V effect size). Lastly, we validated the CARE-MVP norms in a concussed sample (dependent samples t test, Cohen's d effect size).

RESULTS

A total of 5233 collegiate athletes (18.8 ± 1.2 years, 70.5% white/Caucasian, 39.1% female) contributed to the CARE-MVP norms (development N = 2616; internal validation N = 2617). Race and WTAR score were the strongest and most consistent ImPACT score predictors. There were negligible mean differences between observed and predicted (CARE-MVP) baseline scores (Cohen's d < 0.1) for all ImPACT composite scores except Reaction Time (predicted ~ 20 ms faster than observed, d = - 0.28). Low score base rates were similar for athletes across subpopulations when using CARE-MVP norms (ADHD/LD, V = 0.017-0.028; black/African American, V = 0.043-0.053); while, other normative reference methods resulted in disproportionately higher rates of low scores (ADHD/LD, V = 0.062-0.101; black/African American race, V = 0.163-0.221). Acute (24-48 h) postconcussion ImPACT scores were significantly worse than CARE-MVP norms but notably varied as a function of concussion symptom severity.

CONCLUSIONS

Results support CARE-MVP norm use in populations typically underrepresented or not adjusted for in traditional normative reference samples, such as those self-reporting ADHD/LD or black/African American race. CARE-MVP norms improve upon prior normative methods and may offer a practical, simple alternative for collegiate institutions concerned about logistical and financial burden associated with baseline testing. An automated scoring program is provided.

Influence of Test Environment, Age, Sex, and Sport on Baseline Computerized Neurocognitive Test Performance

BACKGROUND

Baseline computerized testing is a common component of concussion assessments, and the testing environment has been suggested to influence test performance and validity.

PURPOSE

To compare concussion baseline computerized neurocognitive test performance and validity among adolescent athletes based on testing environment (group, individual), age group (10-12, 13-15, 16-18 years), sex (male, female), and sport type (collision/combat, contact, noncontact).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Through a concussion community outreach program, participants completed baseline computerized neurocognitive testing using Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). A total of 2845 athletes aged 10 to 18 years completed the baseline assessment. A total of 2241 (79%) athletes completed baseline testing in a group environment, and 604 (21%) completed testing in an individual environment. A random subsample of 500 athletes from each group was selected for statistical comparison.

RESULTS

No significant differences were supported in baseline computerized neurocognitive test performance between the group and individual administration environments. Test validity was statistically similar across testing environment, age group, and sex. However, patients of older age (16-18 years), female sex, and collision/combat and contact sports performed better on ImPACT. There were differences in total symptom severity scores (t = 2.19, df = 998, P = .03), with participants in the group testing environment reporting lower total symptom severity scores than those in the individual testing environment. The rates of invalid tests were low across all age groups, averaging from 4.0% in the 10- to 12-year age group to 4.8% in the 13- to 15-year age group.

CONCLUSION

The findings indicated that concussion baseline neurocognitive test performance is similar when administered in group and individual testing environments. However, differences based on age group, sex, and sport type should be considered when interpreting baseline computerized neurocognitive test scores. The finding of higher symptom scores in older adolescents in the individual testing environment suggests that they may be less forthcoming about symptoms in a group setting.

Neurocognitive Performance of 425 Top-Level Football Players: Sport-specific Norm Values and Implications

OBJECTIVE

Concussion diagnosis and management in sports largely relies on neurocognitive testing. In the absence of baseline assessment, only norm values of the general population are available for comparison with scores of concussed athletes. To evaluate whether (elite) sport specific norm values are needed, cognitive performance was compared between top-level football players and the general population.

METHODS

Cognitive performance of 425 top-level football players was evaluated using the computerized test battery CNS Vital Signs. Players were split into two age groups (15-19 and 20-29 years) and test results were compared with a norm sample (n = 268) by means of age-standardized scores using Cohen's d effect size statistics.

RESULTS

The younger age group outperformed the norm sample in all domains, with small to moderate effects on tests of processing speed (d = 0.58, 95% CI = 0.31,0.85), cognitive flexibility (d = 0.27, 95% CI = 0.01,0.53) and psychomotor speed (d = 0.97, 95% CI = 0.69,1.24). In the older age group, no differences were found on four out of six domains; a moderate positive effect was found for psychomotor speed (d = 0.74, 95% CI = 0.54,0.93), a small negative effect for reaction time (d = -0.47, 95% CI = -0.66,-0.28). Relative to the norm, older football players scored lower than younger football players on all test domains.

CONCLUSION

Cognitive performance of elite football players may be different from the general population. It is recommended to use football-specific norm scores for comparison with test results of concussed players, and to choose an adequate control group when investigating effects of contact sport on cognition. Studies with older/retired football players are needed to further analyze potential sport-specific age effects.

C3Logix assessment of neuropsychological performance in athletes and nonathletes

Physical activity (PA) has been shown to enhance physical health, mental health, and cognitive functioning. Adult and older adult research shows that PA positively influences neuropsychological performance and protects against cognitive decline. This study investigated neuropsychological performance in uninjured athletes and nonathletes using an iPad-based neuropsychological battery called C3Logix. Since literature suggests that PA enhances cognitive functioning, athletes may perform better on neurocognitive measures than nonathletes due to athletes' assumed higher level of PA. We hypothesized that collegiate athletes would outperform nonathletes on all cognitive tasks. Ninety-five athletes and 92 nonathletes completed the neurocognitive assessments and results showed that athletes outperformed nonathletes on reaction time tasks, but not in other cognitive domains. The implications of this study included extending the work of previous research using C3Logix and added to our understanding of a possible difference in reaction time between healthy collegiate athletes and nonathletes.