Convergent and discriminant validity of the ImPACT with traditional neuropsychological measures

Minimal Detectable Change for the ImPACT Subtests at Baseline

OBJECTIVE

To establish the minimal detectable change (MDC) of the subtests that comprise the composite scores from remotely administered Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) baselines.

METHOD

Remote ImPACT baseline data from 172 (male = 45, female = 127) National Collegiate Athletic Association Division I student-athletes from the 2020 and 2021 athletic preseasons were used to calculate the MDC at the 95%, 90%, and 80% confidence intervals (CIs) for all subtest scores used to generate the four core composite scores and the impulse control composite.

RESULTS

The MDCs for the verbal memory subtests at the 95% CI were 10.31 for word memory percent correct, 4.68 for symbol match total correct hidden, and 18.25 for three letters percentage correct. Visual memory subtest MDCs were 19.03 for design memory total percent correct and 4.90 for XO total correct memory. Visual motor speed subtest MDCs were 18.89 for XO total correct interference and 5.40 for three letters average counted correctly. Reaction time (RT) MDCs were 0.12 for XO average correct, 0.95 for symbol match average correct RT, and 0.28 for color match average correct. Impulse control MDCs were 5.97 for XO total incorrect and 1.15 for color match total commissions. One-way repeated measures MANOVA, repeated measures ANOVAs, and Wilcoxon signed-ranks test all suggested no significant difference between any subtests across two remote ImPACT baselines.

CONCLUSIONS

The ImPACT subtest scores did not significantly change between athletic seasons. Our study suggests the subtests be evaluated in conjunction with the composite scores to provide additional metrics for clinical interpretation.

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.

Do Differences Exist in Impact Test Domains between Youth Athletes with and without an Anterior Cruciate Ligament Injury?

Poor baseline reaction time, as measured via the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT), has been associated with anterior cruciate ligament (ACL) injury risk in adult athletes. Our study sought to determine whether the reaction time and impulse control ImPACT test domains differed between ACL injured and uninjured pediatric athletes. A total of 140 high-school aged athletes comprising 70 athletes who went on to sustain an ACL injury between 2012 and 2018 and 70 age- and sex-matched uninjured controls were included in the study. Mean reaction times were similar for the injured (0.67 s) and uninjured (0.66 s) athletes (p = 0.432), and the impulse control scores were also similar for those with (5.67) and without (6.07) an ACL injury (p = 0.611). Therefore, neurocognitive risk factors for sustaining an ACL injury in adults cannot necessarily be extrapolated to adolescent athletes. Further research is needed to understand why differences exist between injury risk in youth and adult athletes.

Sensitivity and Specificity of Computer-Based Neurocognitive Tests in Sport-Related Concussion: Findings from the NCAA-DoD CARE Consortium

BACKGROUND

To optimally care for concussed individuals, a multi-dimensional approach is critical and a key component of this assessment in the athletic environment is computer-based neurocognitive testing. However, there continues to be concerns about the reliability and validity of these testing tools. The purpose of this study was to determine the sensitivity and specificity of three common computer-based neurocognitive tests (Immediate Post-Concussion Assessment and Cognitive Testing [ImPACT], CNS Vital Signs, and CogState Computerized Assessment Tool [CCAT]), to provide guidance on their clinical utility.

METHODS

This study analyzed assessments from a cohort of collegiate athletes and non-varsity cadets from the NCAA-DoD CARE Consortium. The data were collected from 2014-2018. Study participants were divided into two testing groups [concussed, n = 1414 (baseline/24-48 h) and healthy, n = 8305 (baseline/baseline)]. For each test type, change scores were calculated for the components of interest. Then, the Normative Change method, which used normative data published in a similar cohort, and the Reliable Change Index (RCI) method were used to determine if the change scores were significant.

RESULTS

Using the Normative Change method, ImPACT performed best with an 87.5%-confidence interval and 1 number of components failed (NCF; sensitivity = 0.583, specificity = 0.625, F1 = 0.308). CNS Vital Signs performed best with a 90%-confidence interval and 1 NCF (sensitivity = 0.587, specificity = 0.532, F1 = 0.314). CCAT performed best when using a 75%-confidence interval and 2 NCF (sensitivity = 0.513, specificity = 0.715, F1 = 0.290). When using the RCI method, ImPACT performed best with an 87.5%-confidence interval and 1 NCF (sensitivity = 0.626, specificity = 0.559, F1 = 0.297).

CONCLUSION

When considering all three computer-based neurocognitive tests, the overall low sensitivity and specificity results provide additional evidence for the use of a multi-dimensional assessment for concussion diagnosis, including symptom evaluation, postural control assessment, neuropsychological status, and other functional assessments.

Tomographic Task-Related Functional Near-Infrared Spectroscopy in Acute Sport-Related Concussion: An Observational Case Study

Making decisions regarding return-to-play after sport-related concussion (SRC) based on resolution of symptoms alone can expose contact-sport athletes to further injury before their recovery is complete. Task-related functional near-infrared spectroscopy (fNIRS) could be used to scan for abnormalities in the brain activation patterns of SRC athletes and help clinicians to manage their return-to-play. This study aims to show a proof of concept of mapping brain activation, using tomographic task-related fNIRS, as part of the clinical assessment of acute SRC patients. A high-density frequency-domain optical device was used to scan 2 SRC patients, within 72 h from injury, during the execution of 3 neurocognitive tests used in clinical practice. The optical data were resolved into a tomographic reconstruction of the brain functional activation pattern, using diffuse optical tomography. Moreover, brain activity was inferred using single-subject statistical analyses. The advantages and limitations of the introduction of this optical technique into the clinical assessment of acute SRC patients are discussed.

Differential Expression of Circulating Inflammatory Proteins Following Sport-Related Traumatic Brain Injury

Sport-related traumatic brain injury (TBI) elicits a multifaceted inflammatory response leading to brain injury and morbidity. This response could be a predictive tool for the progression of TBI and to stratify the injury of which mild TBI is most prevalent. Therefore, we examined the differential expression of serum inflammatory markers overtime and identified novel markers in repetitively concussed athletes. Neuropsychological assessment by Wechsler Adult Intelligence Scale (WAIS) and Immediate Post Concussion Assessment and Cognitive Test (ImPACT) was performed on rugby players and serum was taken from healthy, concussed and repetitively concussed athletes. Serum was also obtained <1 week and >1 week after trauma and analyzed for 92 inflammatory protein markers. Fibroblast growth factor 21 (FGF21) and interleukin-7 (IL-7) differentiated repetitively concussed athletes. Macrophage chemotactic protein-1 (MCP-1), tumor necrosis factor superfamily member 14 (TNFSF14) were significantly reduced >1 week and chemokine (C-X3-C motif) ligand 1 (CX3CL1) upregulated <1 week after injury. FGF21 and MCP-1 negatively correlated with symptoms and their severity. We have identified dynamic changes in the inflammatory response overtime and in different classes of concussion correlating with disease progression. This data supports the use of inflammatory biomarkers as predictors of symptom development due to secondary complications of sport-related mTBI.