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Current methods of concussion assessment lack the objectivity and reliability to detect neurological injury. This multi-site study uses combinations of neuroimaging (diffusion tensor imaging and resting state functional MRI) and cognitive measures to train algorithms to detect the presence of concussion in university athletes. Athletes (29 concussed, 48 controls) completed symptom reports, brief cognitive evaluation, and MRI within 72 h of injury. Hierarchical linear regression compared groups on cognitive and neuroimaging measures while controlling for sex and data collection site. Logistic regression and support vector machine models were trained using cognitive and neuroimaging measures and evaluated for overall accuracy, sensitivity, and specificity. Concussed athletes reported greater symptoms than controls (∆R2 = 0.32, p <.001), and performed worse on tests of concentration (∆R2 = 0.07, p <.05) and delayed memory (∆R2 = 0.17, p <.001). Concussed athletes showed lower functional connectivity within the frontoparietal and primary visual networks (p <.05), but did not differ on mean diffusivity and fractional anisotropy. Of the cognitive measures, classifiers trained using delayed memory yielded the best performance with overall accuracy of 71%, though sensitivity was poor at 46%. Of the neuroimaging measures, classifiers trained using mean diffusivity yielded similar accuracy. Combining cognitive measures with mean diffusivity increased overall accuracy to 74% and sensitivity to 64%, comparable to the sensitivity of symptom report. Trained algorithms incorporating both MRI and cognitive performance variables can reliably detect common neurobiological sequelae of acute concussion. The integration of multi-modal data can serve as an objective, reliable tool in the assessment and diagnosis of concussion. [ABSTRACT FROM AUTHOR]

Recent research has yielded multivariate base rates (MBRs) of low scores in healthy populations using a widely adopted concussion screening measure, Immediate Postconcussion and Cognitive Testing (ImPACT). However, the extent to which individuals with concussion obtain reliable changes at divergent frequencies relative to healthy individuals is largely unknown. The present study examined whether MBRs of reliable change accurately discriminated between those with and without concussion. This archival review consisted of 129 healthy individuals and 81 individuals with concussion. MBRs of reliable change scores were examined at varying cutoffs and frequencies between those with and without concussion. Composites showed small to medium effect sizes in differentiating between those with and without concussion. MBRs of reliable change scores on ImPACT provided limited discriminative utility in isolation. Computations of posttest probabilities using Bayes' Theorem yielded evidence for incremental gains when utilizing MBRs of reliable change under certain constraints. [ABSTRACT FROM AUTHOR]

Objective Neuropsychologists commonly use a large battery of tests to inform clinical decisions. Decision analysis can be used to determine which individual tests play a role in the decision-making process. The objective of this project was to conduct quantitative and qualitative decision analysis of decisions by team neuropsychologists with professional hockey players being evaluated as part of the National Hockey League (NHL)/NHL Players Association Concussion Protocol. Method We extracted neuropsychological data from an NHL clinical program database. Team neuropsychologists evaluated concussed players using a hybrid neuropsychological test battery. The neuropsychologists then determined whether players were experiencing concussion-related cognitive difficulties. Logistic regression was used to examine which tests accounted for unique variance in the decision-making process. We also conducted a survey of NHL neuropsychologists, asking them to rate the usefulness of each test in the battery. Results Five of the fifteen measures accounted for unique variance in team neuropsychologists' decisions, including the ImPACT Verbal Memory Composite, Visual Motor Composite, Reaction Time Composite, Symptom Score, and Brief Visuospatial Memory Test—Revised Delayed Recall. Notable discrepancies were uncovered between quantitative indications of usefulness and self-reported qualitative perceptions of test usefulness when making decisions. Qualitatively, clinicians reported that the Hopkins Verbal Learning Test—Revised, Symbol Digit Modalities Test, ImPACT Reaction Time, and Color Trails 2 were the most useful tests when making decisions. Conclusions Along with validation studies, decision analysis can be used as part of a comprehensive evaluation process to inform the development of best-practice batteries for use among athletes with sports concussion. [ABSTRACT FROM AUTHOR]

Background: Concussion subtypes are typically organized into commonly affected symptom areas or a combination of affected systems, an approach that may be flawed by bias in conceptualization or the inherent limitations of interdisciplinary expertise. Objective: The purpose of this study was to determine whether a bottom-up, unsupervised, machine learning approach, could more accurately support concussion subtyping. Methods: Initial patient intake data as well as objective outcome measures including, the Patient-Reported Outcomes Measurement Information System (PROMIS), Dizziness Handicap Inventory (DHI), Pain Catastrophizing Scale (PCS), and Immediate Post-Concussion Assessment and Cognitive Testing Tool (ImPACT) were retrospectively extracted from the Advance Concussion Clinic's database. A correlation matrix and principal component analysis (PCA) were used to reduce the dimensionality of the dataset. Sklearn's agglomerative clustering algorithm was then applied, and the optimal number of clusters within the patient database were generated. Between-group comparisons among the formed clusters were performed using a Mann-Whitney U test. Results: Two hundred seventy-five patients within the clinics database were analyzed. Five distinct clusters emerged from the data when maximizing the Silhouette score (0.36) and minimizing the Davies-Bouldin score (0.83). Concussion subtypes derived demonstrated clinically distinct profiles, with statistically significant differences (p < 0.05) between all five clusters. Conclusion: This machine learning approach enabled the identification and characterization of five distinct concussion subtypes, which were best understood according to levels of complexity, ranging from Extremely Complex to Minimally Complex. Understanding concussion in terms of Complexity with the utilization of artificial intelligence, could provide a more accurate concussion classification or subtype approach; one that better reflects the true heterogeneity and complex system disruptions associated with mild traumatic brain injury. [ABSTRACT FROM AUTHOR]

Previous research has reported lower cognitive test scores on baseline testing in athletes reporting multiple previous concussions or a history of learning disability (LD). Age also has an important influence on cognitive performance. While these factors have been considered individually in previous studies, the present study is the first to explore the interaction of age, self-reported LD, and history of concussion on baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT®) in a nationwide study of adolescent athletes. ImPACT® was administered to 1823 Finnish male ice hockey players (aged 12-21 years old) prior to the 2015-2016 or 2016-2017 playing seasons. Linear regressions and simple slopes analyses were used for clarifying the impact of LD and previous concussion history on maturational trajectories. In comparison to typically developing athletes, athletes with LD had lower neurocognitive scores in all composites and differing maturational trajectory in verbal memory and visual motor speed. The number of previous concussions did not impair neurocognitive performance at baseline assessment. Application of standard age-based norms to adolescent athletes with a history of LD has the potential to negatively skew clinical decision-making. Separate reference values for LD athletes are warranted due to their unique developmental cognitive trajectories. The reference values for the Finnish participants in this study are presented. [ABSTRACT FROM AUTHOR]

Objective:The Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) is commonly used to assess baseline and post-injury cognition among athletes in North America. Despite this, several studies have questioned the reliability of ImPACT when given at intervals employed in clinical practice. Poor test–retest reliability reduces test sensitivity to cognitive decline, increasing the likelihood that concussed athletes will be returned to play prematurely. We recently showed that the reliability of ImPACT can be increased when using a new composite structure and the aggregate of two baselines to predict subsequent performance. The purpose of the present study was to confirm our previous findings and determine whether the addition of a third baseline would further increase the test–retest reliability of ImPACT.Methods:Data from 97 English speaking professional hockey players who had received at least 4 ImPACT baseline evaluations were extracted from a National Hockey League Concussion Program database. Linear regression was used to determine whether each of the first three testing sessions accounted for unique variance in the fourth testing session.Results:Results confirmed that the aggregate baseline approach improves the psychometric properties of ImPACT, with most indices demonstrating adequate or better test–retest reliability for clinical use.Conclusions:The aggregate baseline approach provides a modest clinical benefit when recent baselines are available – and a more substantial benefit when compared to approaches that obtain baseline measures only once during the course of a multi-year playing career. Pending confirmation in diverse samples, neuropsychologists are encouraged to use the aggregate baseline approach to best quantify cognitive change following sports concussion. [ABSTRACT FROM PUBLISHER]

There is no accepted clinical imaging modality for concussion, and current imaging modalities including fMRI, DTI, and PET are expensive and inaccessible to most clinics/patients. Functional near-infrared spectroscopy (fNIRS) is a non-invasive, portable, and low-cost imaging modality that can measure brain activity. The purpose of this study was to compare brain activity as measured by fNIRS in concussed and age-matched controls during the performance of cognitive tasks from a computerized neurocognitive test battery. Participants included nine currently symptomatic patients aged 18-45 years with a recent (15-45 days) sport-related concussion and five age-matched healthy controls. The participants completed a computerized neurocognitive test battery while wearing the fNIRS unit. Our results demonstrated reduced brain activation in the concussed subject group during word memory, (spatial) design memory, digit-symbol substitution (symbol match), and working memory (X's and O's) tasks. Behavioral performance (percent-correct and reaction time respectively) was lower for concussed participants on the word memory, design memory, and symbol match tasks than controls. The results of this preliminary study suggest that fNIRS could be a useful, portable assessment tool to assess reduced brain activation and augment current approaches to assessment and management of patients following concussion. [ABSTRACT FROM AUTHOR]

We compared classification accuracy of post-concussion test data against baseline and normative data, accounting for baseline level of performance. Athletes (N = 250) completed baseline and post-concussion ImPACT assessments, within 7 days of concussion (verified by sports medicine professionals and self-reported symptoms). Athletes were classified as “below average,” “average,” or “above average” at baseline. Change from baseline was calculated using reliable change indices (RCIs) and regression-based measures (RBz), and comparison to normative data was achieved using z-scores. Normative comparisons identified fewer symptomatic, concussed athletes than RCIs and RBz. Both RCIs and RBz consistently identified “impairment” at 1 and 1.5 SD, regardless of baseline level, whereas normative comparisons identified 46–48% fewer athletes performing “above average” at baseline using a cut-off of 1 SD and 36-38% fewer using a cut-off of 1.5 SD. The use of normative comparisons may differentially classify concussed, symptomatic athletes who are outside the “average” range at baseline. [ABSTRACT FROM PUBLISHER]

This study documented baseline neurocognitive performance of 23,815 athletes on the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) test. Specifically, 9,733 Hispanic, Spanish-speaking athletes who completed the ImPACT test in English and 2,087 Hispanic, Spanish-speaking athletes who completed the test in Spanish were compared with 11,955 English-speaking athletes who completed the test in English. Athletes were assigned to age groups (13–15, 16–18). Results revealed a significant effect of language group (p < .001; partial η2 = 0.06) and age (p < .001; partial η2 = 0.01) on test performance. Younger athletes performed more poorly than older athletes, and Spanish-speaking athletes completing the test in Spanish scored more poorly than Spanish-speaking and English-speaking athletes completing the test in English, on all Composite scores and Total Symptom scores. Spanish-speaking athletes completing the test in English also performed more poorly than English-speaking athletes completing the test in English on three Composite scores. These differences in performance and reported symptoms highlight the need for caution in interpreting ImPACT test data for Hispanic Americans. [ABSTRACT FROM AUTHOR]

Objective: The purpose of the present study was to examine if concussion symptoms worsened immediately (i.e. 20 minutes) following performance on a scomputerized neurocognitive test. Research design: Cross-sectional study; Level of evidence, 2. Methods and procedures: A total of 165 athletes with a concussion participated in the study. Participants completed the Immediate Post-concussion Assessment and Cognitive Test (ImPACT) and Post-concussion Symptom Scale (PCSS) at baseline, 3 and 10 days post-concussion. Participants completed a second PCSS following the ImPACT test at 3 and 10 days post-injury. Main outcomes and results: Athletes with a concussion exhibited greater symptoms post-neurocognitive test 3 days post-concussion on headache ( p = 0.01), nausea ( p = 0.03), dizziness ( p = 0.03), sadness ( p = 0.005), mentally foggy ( p = 0.002) and visual problems ( p = 0.007). Athletes with a concussion demonstrated increased symptoms on sadness ( p = 0.00) and difficulty remembering ( p = 0.03) at 10 days post-injury. Athletes also demonstrated neurocognitive impairments in verbal memory ( p = 0.009) and slower reaction time ( p = 0.01) 10 days post-concussion and visual memory ( p = 0.000) and motor processing speed ( p = 0.000) impairments at 3 days post-injury. Conclusion: The current study suggests that there may be an increase in concussion symptoms following a 20-minute cognitive task. Thus, it illustrates the need for clinicians to make sure they are symptom free with both physical and cognitive testing. [ABSTRACT FROM AUTHOR]

We present the initial validation of a two-factor structure of Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) using ImPACT composite scores and document the reliability and validity of this factor structure. Factor analyses were conducted for baseline (N = 21,537) and post-concussion (N = 560) data, yielding “Memory” (Verbal and Visual) and “Speed” (Visual Motor Speed and Reaction Time) Factors; inclusion of Total Symptom Scores resulted in a third discrete factor. Speed and Memory z-scores were calculated, and test–retest reliability (using intra-class correlation coefficients) at 1 month (0.88/0.81), 1 year (0.85/0.75), and 2 years (0.76/0.74) were higher than published data using Composite scores. Speed and Memory scores yielded 89% sensitivity and 70% specificity, which was higher than composites (80%/62%) and comparable with subscales (91%/69%). This emergent two-factor structure has improved test–retest reliability with no loss of sensitivity/specificity and may improve understanding and interpretability of ImPACT test results. [ABSTRACT FROM AUTHOR]

A commentary to the article "Clinical utility of ImPACT assessment for postconcussion return-to-play counseling: Psychometric issues," published in a 2012 issue, is presented. It points out a failure to document any detailed inclusion criteria for identifying published articles to guide the review of the current literature. It contends that the use of Pearson's correlation coefficients as a measure of test-retest reliability is hampered by the kind of data obtained from the measurement.

Computerized neuropsychological testing is commonly utilized in the management of sport-related concussion. In particular, the Immediate Postconcussion Assessment and Cognitive Testing 2.0 program (ImPACT) is widely used to assess the cognitive functioning of athletes before and after a concussion. We review the evidence for the clinical utility of this program in terms of validity, reliability, and use in return-to-play decisions. We conclude that the empirical evidence does not support the use of ImPACT testing for determining the time of postconcussion return to play. [ABSTRACT FROM AUTHOR]

Over the past 20 years, clinical neuropsychologists have been at the forefront of both scientific and clinical initiatives aimed at developing evidence-based approaches to the evaluation and management of sport-related concussion (SRC). These efforts have directly impacted current policy on strategies for injury assessment and return-to-play by athletes after concussion. Many states are considering legislation requiring (a) education of athletes, parents, coaches, and school/organization officials on the recognition, evaluation, and management of SRCs; (b) removal from play of any youth athlete that is suspected of having sustained a concussion; and (c) not allowing the student to return to participation until the student is evaluated and cleared for return to participation in writing by an appropriate healthcare professional. It is the official position of the American Academy of Clinical Neuropsychology (AACN), American Board of Professional Neuropsychology (ABN), Division 40 (Neuropsychology) of the American Psychological Association (APA), and the National Academy of Neuropsychology (NAN) that neuropsychologists should be included among the licensed healthcare professionals authorized to evaluate, clinically manage, and provide return to play clearance for athletes who sustain a SRC. [ABSTRACT FROM PUBLISHER]

Over the past 20 years, clinical neuropsychologists have been at the forefront of both scientific and clinical initiatives aimed at developing evidence-based approaches to the evaluation and management of sport-related concussion. These efforts have directly impacted current policy on strategies for injury assessment and return-to-play by athletes after concussion. Many states are considering legislation requiring (a) education of athletes, parents, coaches, and school/organization officials on the recognition, evaluation, and management of sport-related concussions; (b) removal from play of any youth athlete that is suspected of having sustained a concussion; and (c) not allowing the student to return to participation until the student is evaluated and cleared for return to participation in writing by an appropriate healthcare professional. It is the official position of the American Academy of Clinical Neuropsychology (AACN), American Board of Neuropsychology (ABN), Division 40 (Neuropsychology) of the American Psychological Association (APA), and the National Academy of Neuropsychology (NAN) that neuropsychologists should be included among the licensed health care professionals authorized to evaluate, clinically manage, and provide return to play clearance for athletes who sustain a sport-related concussion. [ABSTRACT FROM PUBLISHER]

This article reviews current issues in the following areas of pediatric sports-related concussion: incidence of concussion, potential long-term effects, return to play, and the emergence of legislation regarding concussion education and management programs. Incidence of concussion is presented in context of emergency room visits, as well as under-reporting of concussions. The literature on history of concussion is reviewed, for high school, collegiate, and professional athletes, with respect to potential long-term effects of cerebral concussion. Specific discussions of effects include: decreased cognition and increased symptom reporting following multiple concussions, and recent diagnoses of chronic traumatic encephalopathy in non-professional and youth athletes. Recent legislative and advocacy efforts are reviewed, including mandated programs in specific states. [ABSTRACT FROM AUTHOR]

Subjective feedback about distractions or problems encountered during computerized assessment was provided by 538 out of a pool of 1659 high-school athletes who completed baseline testing using ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing). Three types of feedback were included: (a) environmental, (b) computer-based (mechanical), and (c) instruction-based (associated with difficulty understanding test instructions). One-way analyses of variance were conducted and revealed relationships between greater symptom reporting and any type of feedback, environmental feedback, and instruction-based feedback. Increased symptom reporting was noted for female students. Additional relationships were noted between providing computer-based feedback and faster reaction time; and between history of concussion and providing instruction-based feedback. Athletes endorsing more symptoms at baseline scored significantly worse on ImPACT, as reflected in decreased visual memory performance. Results suggest that feedback provided during computerized assessment may yield information about symptom reporting and test-taking style, which may also be of particular interpretive utility when athletes minimize their symptoms. [ABSTRACT FROM PUBLISHER]