Reliability and Concurrent Validity of Select C3 Logix Test Components

Repetitive head impacts among professional fighters: a pilot study evaluating Traumatic Encephalopathy Syndrome and postural balance

OBJECTIVES

Clinical criteria for Traumatic Encephalopathy Syndrome (ccTES) were developed for research purposes to reflect the clinical symptoms of Chronic Traumatic Encephalopathy (CTE). The aims of this study were to 1) determine whether there was an association between the research diagnosis of TES and impaired postural balance among retired professional fighters, and 2) determine repetitive head impacts (RHI) exposure thresholds among both TES positive and TES negative groups in retired professional fighters when evaluating for balance impairment.

METHODS

This was a pilot study evaluating postural balance among participants of the Professional Athletes Brain Health Study (PABHS). Among the cohort, 57 retired professional fighters met the criteria for inclusion in this study. A generalized linear model with generalized estimating equations was used to compare various balance measures longitudinally between fighters with and without TES.

RESULTS

A significant association was observed between a TES diagnosis and worsening performance on double-leg balance assessments when stratifying by RHI exposure thresholds. Additionally, elevated exposure to RHI was significantly associated with increased odds of developing TES; The odds for TES diagnosis were 563% (95% CI = 113, 1963; p-value = 0.0011) greater among athletes with 32 or more professional fights compared to athletes with less than 32 fights when stratifying by balance measures. Likewise, the odds for TES diagnosis were 43% (95% CI = 10, 102; p-value = 0.0439) greater with worsening double leg stance balance in athletes exposed to 32 or more fights.

CONCLUSION

This pilot study provides preliminary evidence of a relationship between declining postural balance and a TES diagnosis among retired professional fighters with elevated RHI exposure. Further research exploring more complex assessments such as the Functional Gait Assessment may be of benefit to improve clinical understanding of the relationship between TES, RHI, and balance.

Immediate post-concussion assessment and cognitive testing Pediatric (ImPACT Pediatric) change scores and factors associated with performance in patients aged 5-9 years following concussion: Preliminary findings

BACKGROUND

Computerized neurocognitive testing is one component of a multidomain assessment of concussion. However, the use of computerized neurocognitive testing has been limited to patients aged 11 years and up, leaving clinicians with few options to evaluate younger children.

PURPOSE

To examine the change in Immediate Post-concussion Assessment and Cognitive Testing Pediatric (ImPACT Pediatric) (ImPACT Applications, 2021) scores and factors associated with performance in children aged 5-9 years following a concussion.

METHODS

Participants included 63 children (42% [n = 27] female) aged 5-9 (M = 7.5 ± 1.0) years within 30 (M = 8.5 ± 5.9) days of a concussion. All participants completed the ImPACT Pediatric at their initial visit and at medical clearance for their return to activity (RTA) visit. The ImPACT Pediatric test is a computerized neurocognitive battery that includes 5 tests that assess memory and visual processing speed. Multivariate and univariate analyses of variance and paired t-tests were used to compare ImPACT Pediatric scores from the initial visit to medical clearance. Multivariate and univariate analyses of covariance and multiple linear regression examined factors associated with ImPACT Pediatric performance.

RESULTS

Participants demonstrated improved overall performance from the initial visit to the medical clearance visit (F(4, 59)=3.08, p = 0.02, Wilks' Λ = 0.83, ηp2=0.17), with significant improvement in Rapid Processing Speed (F(1, 62)=7.48, p < 0.01, ηp2=0.11). When controlling for age, sex, history of ADHD, and days to clinic, the improvement in overall performance remained significant (F(4, 51)=2.99, p = 0.03, Wilks' Λ = 0.81, ηp2=0.19). Older age was significantly associated with the Rapid Processing composite score at the initial visit (F(4, 59)=5.9, p < 0.001, Adj. R2=0.25) and medical clearance visit (F(4, 59)=3.8, p = 0.008, Adj. R2=0.16), with older children associated with better performance at both time points (Initial visit: B = 8.17, p < 0.001; Medical Clearance: B = 3.62, p = 0.03).

CONCLUSION

Our main findings suggest that children aged 5-9 years improved significantly in Rapid Processing on the ImPACT Pediatric from the initial visit to medical clearance. However, no differences were found for the memory components of the ImPACT Pediatric. Older children also performed better on processing speed than younger children. The findings suggest that the processing speed components of ImPACT Pediatric are useful for monitoring improvements in neurocognitive functioning following concussion in children aged 5-9 years, but that age differences need to be considered when interpreting performance.

Neural Mechanisms Associated With Postural Control in Collegiate Soccer and Non-Soccer Athletes

BACKGROUND AND PURPOSE

Sport-specific training may improve postural control, while repetitive head acceleration events (RHAEs) may compromise it. Understanding the neural mechanisms underlying postural control may contextualize changes due to training and RHAE. The goal of this study was to determine whether postural sway during the Balance Error Scoring System (BESS) is related to white matter organization (WMO) in collegiate athletes.

METHODS

Collegiate soccer ( N = 33) and non-soccer athletes ( N = 44) completed BESS and diffusion tensor imaging. Postural sway during each BESS stance, fractional anisotropy (FA), and mean diffusivity (MD) were extracted for each participant. Partial least squares analyses determined group differences in postural sway and WMO and the relationship between postural sway and WMO in soccer and non-soccer athletes separately.

RESULTS

Soccer athletes displayed better performance during BESS 6, with lower FA and higher MD in the medial lemniscus (ML) and inferior cerebellar peduncle (ICP), compared to non-soccer athletes. In soccer athletes, lower sway during BESS 2, 5, and 6 was associated with higher FA and lower MD in the corticospinal tract, ML, and ICP. In non-soccer athletes, lower sway during BESS 2 and 4 was associated with higher FA and lower MD in the ML and ICP. BESS 1 was associated with higher FA, and BESS 3 was associated with lower MD in the same tracts in non-soccer athletes.

DISCUSSION AND CONCLUSIONS

Soccer and non-soccer athletes showed unique relationships between sway and WMO, suggesting that sport-specific exposures are partly responsible for changes in neurological structure and accompanying postural control performance and should be considered when evaluating postural control after injury.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content, available at: http://links.lww.com/JNPT/A472 ).

Digital neuropsychological test performance in a large sample of uninjured collegiate athletes

Digital neuropsychological test batteries are popular in college athletics; however, well-validated digital tests that are short and portable are needed to expand the feasibility of performing cognitive testing quickly, reliably, and outside standard clinical settings. This study assessed performance on digital versions of Trail Making Test (dTMT) and a modified Symbol Digit Modalities Test (dSDMT) in uninjured collegiate athletes (n = 537; 47% female) using the C3Logix baseline assessment module. Time to complete (dTMT) and the number of correct responses (dSDMT) were computed, transformed into z scores, and compared to age-matched normative data from analogous paper-and-pencil tests. Overall sample performance was compared to normative sample performance using Cohen's d. Sample averages on the dTMT, Part A, and dSDMT were similar to published norms; 97 and 92% of z scores fell within 2 standard deviations of normative means, respectively. The sample averaged faster completion times on dTMT, Part B than published norms, although 98% of z scores were within 2 standard deviations of the normative means. Brief, digitized tests may be useful in populations and testing environments when longer cognitive test batteries are impractical. Future studies should assess the ability of these tests to detect clinically relevant changes following a suspected head injury.

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.

Longitudinal Changes in Regional Brain Volumes and Cognition of Professional Fighters With Traumatic Encephalopathy Syndrome

BACKGROUND AND OBJECTIVES

Due to current limitations in diagnosing chronic traumatic encephalopathy (CTE) clinically, traumatic encephalopathy syndrome (TES) has been proposed as the clinical presentation of suspected CTE. This study aimed to determine whether there was an association between a clinical diagnosis of TES and subsequent temporal decline in cognitive or MRI volumetric measures.

METHODS

This was a secondary analysis of the Professional Athletes Brain Health Study (PABHS), inclusive of active and retired professional fighters older than 34 years. All athletes were adjudicated as TES positive (TES+) or TES negative (TES-) based on the 2021 clinical criteria. General linear mixed models were used to compare MRI regional brain volumes and cognitive performance between groups.

RESULTS

A total of 130 fighters met inclusion criteria for consensus conference. Of them, 52 fighters (40%) were adjudicated as TES+. Athletes with a TES+ diagnosis were older and had significantly lower education. Statistically significant interactions and between-group total mean differences were found in all MRI volumetric measurements among the TES+ group compared with those among the TES- group. The rate of volumetric change indicated a significantly greater increase for lateral (estimate = 5,196.65; 95% CI = 2642.65, 7750.66) and inferior lateral ventricles (estimate = 354.28; 95% CI = 159.90, 548.66) and a decrease for the hippocampus (estimate = -385.04, 95% CI = -580.47, -189.62), subcortical gray matter (estimate = -4,641.08; 95% CI = -6783.98, -2498.18), total gray matter (estimate = -26492.00; 95% CI = -50402.00, -2582.32), and posterior corpus callosum (estimate = -147.98; 95% CI = -222.33, -73.62). Likewise, the rate of cognitive decline was significantly greater for reaction time (estimate = 56.31; 95% CI = 26.17, 86.45) and other standardized cognitive scores in the TES+ group.

DISCUSSION

The 2021 TES criteria clearly distinguishes group differences in the longitudinal presentation of volumetric loss in select brain regions and cognitive decline among professional fighters 35 years and older. This study suggests that a TES diagnosis may be useful in professional sports beyond football, such as boxing and mixed martial arts. These findings further suggest that the application of TES criteria may be valuable clinically in predicting cognitive decline.

Traumatic encephalopathy syndrome: application of new criteria to a cohort exposed to repetitive head impacts

OBJECTIVE

To examine the characteristics of those who fulfil the recent National Institute of Neurological Disease and Stroke (NINDS) Consensus Diagnostic Criteria for Traumatic Encephalopathy Syndrome (TES) and test whether they show differences in MRI-based regional brain volumes, cognitive domains, and certain plasma biomarkers.

METHODS

Professional fighters 35 years of age or older and/or retired were included. Participants were categorised as either having TES (TES+) or not (non-TES). TES+ participants were further subtyped by their cognitive profile. Multiple linear regression models were used to compare MRI-based regional brain volumes, cognitive performance, plasma tau and neurofilament light levels between TES- and TES+ groups.

RESULTS

176 participants (110 boxers and 66 MMA) were included in the analysis. 72 (41%)/176 were categorised as having TES, the likelihood of TES increasing with age. TES+ participants tended to be boxers, started fighting at a younger age, had more professional fights and knocked out more frequently. The TES+ group had lower regional brain volumes including both grey and white matter structures. TES+ also had lower scores on simple and choice reaction time, psychomotor speed and Trails A .

CONCLUSION

The new TES criteria does distinguish a group of fighters with differences in regional brain volumes and reduced cognitive function. Our findings support the use of the NINDS criteria for TES in further research of the long-term effects of repetitive head impacts.

Multi-Modal Neurorehabilitation for Persisting Post-Concussion Symptoms

Treatment of the chronic sequela that persist after a mild traumatic brain injury has been challenging with limited efficacy. The aim of this work was to report outcomes obtained from persons who met the criteria of persisting post-concussive symptoms (PPCS), utilizing a novel combination of modalities in a structured neurorehabilitation program. This work was designed as a retrospective, pre-post chart review of objective and subjective measures collected from 62 outpatients with PPCS a mean of 2.2 years post-injury, before and after a multi-modal 5-day treatment protocol. The subjective outcome measure was the 27-item modified Graded Symptom Checklist (mGSC). Objective outcome measures were motor speed/reaction time, coordination, cognitive processing, visual acuity, and vestibular function. Interventions included non-invasive neuromodulation, neuromuscular re-education exercises, gaze stabilization exercises, orthoptic exercises, cognitive training, therapeutic exercises, and single/multi-axis rotation therapy. Pre-post differences in measures were analyzed using the Wilcoxon signed-rank test, with effect size determined by the rank-biserial correlation coefficient. Pre-post treatment comparisons for the subjective mGSC overall, combined symptom measures, individual components of the mGSC, and cluster scores significantly improved for all items. Moderate strength relationships were observed for the mGSC composite score, number of symptoms, average symptom score, feeling in a "fog," "don't feel right," irritability, and physical, cognitive, and affective cluster scores. Objective symptom assessment significantly improved for trail making, processing speed, reaction time, visual acuity, and Standardized Assessment of Concussion. Patients suffering from PPCS ∼2 years after injury may have significant benefits with some moderate effect sizes from an intensive, multi-modal neurorehabilitation program.

Ten-Word List Performance in Healthy Athletes and Athletes at 3-to-5 Days Following Concussion

OBJECTIVE

Although the word recall component of the Sport Concussion Assessment Tool (SCAT) was updated from 5-to-10 words, its clinical utility across athletic populations remains unknown. The purpose of this study was to provide normative data on the SCAT-5 10-word test and examine its discriminative ability between healthy university level athletes and those with sport-related concussion (SRC).

DESIGN

Cross-sectional.

SETTING

University.

PARTICIPANTS

Three hundred sixty-three (363, M = 220, F = 153) healthy athletes and 49 (M = 30, F = 19) athletes following SRC.

INDEPENDENT VARIABLE

Healthy athletes measured preseason were compared with athletes following an SRC (median = 4.0 days postinjury).

MAIN OUTCOME MEASURE

Ten-word list performance from the SCAT-5.

RESULTS

There were no significant differences in either immediate ( P = 0.228, Cohen's D = 0.18) or delayed ( P = 0.908, Cohen's D = 0.02) recall tests between athletes with SRC and healthy athletes; the null findings extended to both the male and female subset comparisons. Among healthy athletes, females outperformed males on both immediate (mean difference = 1.0, P < 0.001) and delayed (mean difference = 0.5, P = 0.006) recall tasks.

CONCLUSION

Concussion does not seem to impact immediate or delayed recall of the 10-word list in the subacute period following injury. Practitioners should be mindful of sex differences and the time point of administration following injury.

Exploring Vestibular/Ocular and Cognitive Dysfunction as Prognostic Factors for Protracted Recovery in Sports-Related Concussion Patients Aged 8 to 12 Years

OBJECTIVE

To explore the prognostic ability of the vestibular/ocular motor screening (VOMS), King-Devick (K-D) Test, and C3 Logix Trails A and B to identify protracted recovery from sports-related concussion (SRC) in patients aged 8 to 12 years.

DESIGN

Retrospective cohort analysis.

SETTING

Specialty pediatric sports concussion clinic.

PARTICIPANTS

A total of 114 youth athletes aged 8 to 12 years who were diagnosed with an SRC within 7 days of injury.

INDEPENDENT VARIABLES

A positive screen on the VOMS, K-D, and C3 Logix Trails A and Trails B. Combined positive screens on multiple tests (ie, 2, 3, or all 4 positive screens of 4 possible).

MAIN OUTCOME MEASURES

Recovery time in days and protracted recovery (recovery time ≥30-days) were the primary outcomes of interest.

RESULTS

A positive VOMS screen was associated with 1.31 greater days to SRC recovery ( P = 0.02) than a negative VOMS screen. The K-D and C3 Logix tests were not significantly associated with recovery time, nor were any combinations of tests ( P > 0.05). The VOMS demonstrated moderate prognostic ability to predict normal recovery (negative predictive value = 80.78% [95% CI = 63.73-90.95]). Overall predictive accuracy of normal versus protracted recovery was strongest when a participant screened positive on all 4 tests (Accuracy = 76.32% [95% CI = 67.45-83.78]).

CONCLUSIONS

The VOMS was associated with overall recovery time and proved to be a useful test to identify those who would experience a normal recovery time. Combining the 4 tests improved the prognostic accuracy of the protocol in predicting protracted versus normal recovery. These findings suggest that combining multiple, varied assessments of cognition and vestibular/ocular functions may better explain factors contributing to protracted recovery.

The Relationship Between Human-rated Errors and Tablet-based Postural Sway During the Balance Error Scoring System in Military Cadets

BACKGROUND

The Balance Error Scoring System (BESS) is commonly accepted as a valid measure of postural stability. However, reliability values have varied, and subtle changes undetectable with the human eye may exist postinjury. The inertial measurement unit in commercially available tablets has been used to quantify postural sway (instrumented Balance Error Scoring System [iBESS] volume). However, iBESS has not been validated in a military population, and the stability of the tests beyond 1 week is unknown.

HYPOTHESIS

iBESS volume is capable of objectively measuring postural sway during the traditional BESS.

STUDY DESIGN

Prospective repeated-measures study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Eighty-three cadets (40.96% women; age 20.0 ± 1.44 years; height 68.7 ± 4.1 inches; weight 166.7 ± 30.2 lb) with no history of concussion or lower extremity injury agreed to participate. All participants completed the BESS at baseline and 6 months post baseline. During testing, a tablet equipped with an inertial measurement unit was positioned on the participant's sacrum to capture postural sway.

RESULTS

Moderate to strong correlations were exhibited between baseline measurements for single-limb (SL)-firm (r = 0.84; P < 0.01), tandem (TAN)-firm (r = 0.85; P < 0.01), double-limb (DL)-foam (r = 0.50; P < 0.01), SL-foam (r = 0.59; P < 0.01), and TAN-foam (r = 0.79; P < 0.01). Balance improved significantly at 6 months for SL-firm human-rated errors (Effect Size [ES] = 0.32) and for SL-firm (ES = 0.38), DL-foam (ES = 0.21), and SL-foam iBESS volume (ES = 0.35). Moderate to strong correlations were exhibited between human-rated and iBESS change scores for SL-firm (r = 0.71; P < 0.01), TAN-firm (r = 0.75; P < 0.01), and TAN-foam (r = 0.71; P < 0.01), and a weak correlation was exhibited for DL-foam (r = 0.29; P < 0.01) and SL-foam (r = 0.40; P < 0.01).

CONCLUSION

Moderate to strong correlations existed between human-rated BESS errors and iBESS volume at baseline and between change scores. In addition, iBESS volume may be more sensitive to balance changes than the human-rated BESS.

CLINICAL RELEVANCE

This evidence supports the use of iBESS volume as a valid measure of postural stability in military cadets. iBESS volume may provide clinicians with an objective and more sensitive measure of postural stability than the traditional human-rated BESS.

Machine learning to predict sports-related concussion recovery using clinical data

OBJECTIVES

Sport-related concussions (SRCs) are a concern for high school athletes. Understanding factors contributing to SRC recovery time may improve clinical management. However, the complexity of the many clinical measures of concussion data precludes many traditional methods. This study aimed to answer the question, what is the utility of modeling clinical concussion data using machine-learning algorithms for predicting SRC recovery time and protracted recovery?

METHODS

This was a retrospective case series of participants aged 8 to 18 years with a diagnosis of SRC. A 6-part measure was administered to assess pre-injury risk factors, initial injury severity, and post-concussion symptoms, including the Vestibular Ocular Motor Screening (VOMS) measure, King-Devick Test and C3 Logix Trails Test data. These measures were used to predict recovery time (days from injury to full medical clearance) and binary protracted recovery (recovery time > 21 days) according to several sex-stratified machine-learning models. The ability of the models to discriminate protracted recovery was compared to a human-driven model according to the area under the receiver operating characteristic curve (AUC).

RESULTS

For 293 males (mean age 14.0 years) and 362 females (mean age 13.7 years), the median (interquartile range) time to recover from an SRC was 26 (18-39) and 21 (14-31) days, respectively. Among 9 machine-learning models trained, the gradient boosting on decision-tree algorithms achieved the best performance to predict recovery time and protracted recovery in males and females. The models' performance improved when VOMS data were used in conjunction with the King-Devick Test and C3 Logix Trails Test data. For males and females, the AUC was 0.84 and 0.78 versus 0.74 and 0.73, respectively, for statistical models for predicting protracted recovery.

CONCLUSIONS

Machine-learning models were able to manage the complexity of the vestibular-ocular motor system data. These results demonstrate the clinical utility of machine-learning models to inform prognostic evaluation for SRC recovery time and protracted recovery.

Reliability and Minimal Detectable Change for a Smartphone-Based Motor-Cognitive Assessment: Implications for Concussion Management

Our purpose was to investigate the reliability and minimal detectable change characteristics of a smartphone-based assessment of single- and dual-task gait and cognitive performance. Uninjured adolescent athletes (n = 17; mean age = 16.6, SD = 1.3 y; 47% female) completed assessments initially and again 4 weeks later. The authors collected data via an automated smartphone-based application while participants completed a series of tasks under (1) single-task cognitive, (2) single-task gait, and (3) dual-task cognitive-gait conditions. The cognitive task was a series of continuous auditory Stroop cues. Average gait speed was consistent between testing sessions in single-task (0.98, SD = 0.21 vs 0.96, SD = 0.19 m/s; P = .60; r = .89) and dual-task (0.92, SD = 0.22 vs 0.89, SD = 0.22 m/s; P = .37; r = .88) conditions. Response accuracy was moderately consistent between assessments in single-task standing (82.3% accurate, SD = 17.9% vs 84.6% accurate, SD = 20.1%; P = .64; r = .52) and dual-task gait (89.4% accurate, SD = 15.9% vs 85.8% accurate, SD = 20.2%; P = .23; r = .81) conditions. Our results indicate automated motor-cognitive dual-task outcomes obtained within a smartphone-based assessment are consistent across a 1-month period. Further research is required to understand how this assessment performs in the setting of sport-related concussion. Given the relative reliability of values obtained, a smartphone-based evaluation may be considered for use to evaluate changes across time among adolescents, postconcussion.

Assessing Clinical Change in Individuals Exposed to Repetitive Head Impacts: The Repetitive Head Impact Composite Index

Background: There is a current lack of any composite measure for the effective tracking and monitoring of clinical change in individuals exposed to repetitive head impacts (RHI). The aim of this study is to create a composite instrument for the purposes of detecting change over time in cognitive and behavioral function in individuals exposed to RHI. Methods: The data to derive the composite instrument came from the Professional Fighters Brain Health Study (PFBHS), a longitudinal study of active and retired professional fighters [boxers and mixed martial arts (MMA) fighters] and healthy controls. Participants in the PFBHS underwent assessment on an annual basis that included computerized cognitive testing and behavioral questionnaires. Multivariate logistic regression models were employed to compare active fighters (n = 117) with controls (n = 22), and retired fighters (n = 26) with controls to identify the predictors that could be used to differentiate the groups over time. In a second step, linear discriminant analysis was performed to derive the linear discriminant coefficients for the three groups by using the predictors from the two separate logistic regression models. Results: The composite scale is a weighted linear value of 12 standardized scores consisting of both current and yearly change scores in domains including: processing speed, choice reaction time, semantic fluency, letter fluency, and Barrett Impulsiveness Scale. Because the weighting of values differed between active and retired fighters, two versions emerged. The mean and standard deviation ratio (MSDR) showed that the new index had better sensitivity compared to the individual measures, with the ratio of MSDR of the new index to that of the existing measures of at least 1.84. Conclusion: With the increasing need for tools to follow individuals exposed to RHI and the potential of clinical trials on the horizon for CTE, the RHICI is poised to serve as an initial approach to a composite clinical measure.

Insular Connectivity Is Associated With Self-Appraisal of Cognitive Function After a Concussion

Concussion is associated with acute cognitive impairments, with declines in processing speed and reaction time being common. In the clinical setting, these issues are identified via symptom assessments and neurocognitive test (NCT) batteries. Practice guidelines recommend integrating both symptoms and NCTs into clinical decision-making, but correlations between these measures are often poor. This suggests that many patients experience difficulties in the self-appraisal of cognitive issues. It is presently unclear what neural mechanisms give rise to appraisal mismatch after a concussion. One promising target is the insula, which regulates aspects of cognition, particularly interoception and self-monitoring. The present study tested the hypothesis that appraisal mismatch is due to altered functional connectivity of the insula to frontal and midline structures, with hypo-connectivity leading to under-reporting of cognitive issues and hyper-connectivity leading to over-reporting. Data were collected from 59 acutely concussed individuals and 136 normative controls, including symptom assessments, NCTs and magnetic resonance imaging (MRI) data. Analysis of resting-state functional MRI supported the hypothesis, identifying insular networks that were associated with appraisal mismatch in concussed athletes that included frontal, sensorimotor, and cingulate connections. Subsequent analysis of diffusion tensor imaging also determined that symptom over-reporting was associated with reduced fractional anisotropy and increased mean diffusivity of posterior white matter. These findings provide new insights into the mechanisms of cognitive appraisal mismatch after a concussion. They are of particular interest given the central role of symptom assessments in the diagnosis and clinical management of concussion.

Neuropsychological Assessment of Sport-Related Concussion

Neuropsychological assessment is a key component in a comprehensive, multidisciplinary approach to assessment of sport-related concussion (SRC). Currently computerized tests are the most commonly used modality of neurocognitive testing and involve both baseline and postinjury assessments. A comprehensive neuropsychological assessment should not only include neurocognitive testing but also incorporate symptom inventories, vestibular-ocular screening, and a psychological evaluation. Neuropsychological assessments are most effective when completed by a Clinical Neuropsychologist, given their specialized training in test interpretation and conceptualization of the psychological, cognitive, behavioral, physiologic, as well as neurologic principals when treating and managing SRC.

An iPad-based Measure of Processing Speed in Older Adults Hospitalized for Heart Failure

BACKGROUND

In older adults hospitalized with heart failure (HF), cognitive impairment is associated with increased hospital readmission and mortality risk. There is no consensus on an objective, scalable method of cognitive screening in this population.

OBJECTIVE

The aim of this project was to determine the feasibility, test-retest reliability, and convergent validity of the Processing Speed Test (PST), a test of information processing, attention, and working memory administered on an iPad in older adults hospitalized with HF.

METHODS

Patients hospitalized with HF (n = 30) and age-, sex-, and education-matched controls (n = 30) participated in the study. To determine test-retest reliability, the PST was administered on an iPad on 2 occasions, separated by 12 to 48 hours. The Symbol Digit Modalities Test was administered at the first testing time point to determine convergent validity.

RESULTS

Test-retest reliability of the PST was 0.80 and 0.92 in individuals with HF and controls, respectively. Convergent validity was 0.72 and 0.90 for individuals with HF and controls, respectively. Time to complete the PST was similar for both individuals with HF and controls (<5 minutes).

CONCLUSION

The iPad-based deployment of the PST was a feasible, reliable, and valid cognitive screen for older adults hospitalized with HF. Using a tablet-based self-administered cognitive screen in older adults with HF provides a method of cognitive assessment that is amenable to widespread clinical utilization.

Reliability of Objective Eye-Tracking Measures Among Healthy Adolescent Athletes

OBJECTIVE

To determine the test-retest correlation of an objective eye-tracking device among uninjured youth athletes.

DESIGN

Repeated-measures study.

SETTING

Sports-medicine clinic.

PARTICIPANTS

Healthy youth athletes (mean age = 14.6 ± 2.2 years; 39% women) completed a brief, automated, and objective eye-tracking assessment.

INDEPENDENT VARIABLES

Participants completed the eye-tracking assessment at 2 different testing sessions.

MAIN OUTCOME MEASURES

During the assessment, participants watched a 220-second video clip while it moved around a computer monitor in a clockwise direction as an eye tracker recorded eye movements. We obtained 13 eye movement outcome variables and assessed correlations between the assessments made at the 2 time points using Spearman's Rho (rs).

RESULTS

Thirty-one participants completed the eye-tracking evaluation at 2 time points [median = 7 (interquartile range = 6-9) days between tests]. No significant differences in outcomes were found between the 2 testing times. Several eye movement variables demonstrated moderate to moderately high test-retest reliability. Combined eye conjugacy metric (BOX score, rs = 0.529, P = 0.008), the variance of the ratio for both eye movements in the horizontal (rs = 0.497, P = 0.013) and vertical (rs = 0.446; P = 0.029) movement planes along the top/bottom of the computer screen, and the variance of the left and right eye movement along the bottom segment of the computer screen (rs = 0.565; P = 0.004) each demonstrated moderate between-test correlations.

CONCLUSIONS

Automated and quantitative eye movement and conjugacy metrics provide relatively stable measurements among a group of healthy youth athletes. Thus, their inclusion as a visual tracking metric may be complementary to other visual examination techniques when monitoring concussion recovery across time.

Mitigating the Consequences of Subconcussive Head Injuries

Subconcussive head injury represents a pathophysiology that spans the expertise of both clinical neurology and biomechanical engineering. From both viewpoints, the terms injury and damage, presented without qualifiers, are synonymously taken to mean a tissue alteration that may be recoverable. For clinicians, concussion is evolving from a purely clinical diagnosis to one that requires objective measurement, to be achieved by biomedical engineers. Subconcussive injury is defined as subclinical pathophysiology in which underlying cellular- or tissue-level damage (here, to the brain) is not severe enough to present readily observable symptoms. Our concern is not whether an individual has a (clinically diagnosed) concussion, but rather, how much accumulative damage an individual can tolerate before they will experience long-term deficit(s) in neurological health. This concern leads us to look for the history of damage-inducing events, while evaluating multiple approaches for avoiding injury through reduction or prevention of the associated mechanically induced damage.

Reliability, Validity and Utility of Inertial Sensor Systems for Postural Control Assessment in Sport Science and Medicine Applications: A Systematic Review

BACKGROUND

Recent advances in mobile sensing and computing technology have provided a means to objectively and unobtrusively quantify postural control. This has resulted in the rapid development and evaluation of a series of wearable inertial sensor-based assessments. However, the validity, reliability and clinical utility of such systems is not fully understood.

OBJECTIVES

This systematic review aims to synthesise and evaluate studies that have investigated the ability of wearable inertial sensor systems to validly and reliably quantify postural control performance in sports science and medicine applications.

METHODS

A systematic search strategy utilising the PRISMA guidelines was employed to identify eligible articles through ScienceDirect, Embase and PubMed databases. In total, 47 articles met the inclusion criteria and were evaluated and qualitatively synthesised under two main headings: measurement validity and measurement reliability. Furthermore, studies that investigated the utility of these systems in clinical populations were summarised and discussed.

RESULTS

After duplicate removal, 4374 articles were identified with the search strategy, with 47 papers included in the final review. In total, 28 studies investigated validity in healthy populations, and 15 studies investigated validity in clinical populations; 13 investigated the measurement reliability of these sensor-based systems.

CONCLUSIONS

The application of wearable inertial sensors for sports science and medicine postural control applications is an evolving field. To date, research has primarily focused on evaluating the validity and reliability of a heterogeneous set of assessment protocols, in a laboratory environment. While researchers have begun to investigate their utility in clinical use cases such as concussion and musculoskeletal injury, most studies have leveraged small sample sizes, are of low quality and use a variety of descriptive variables, assessment protocols and sensor-mounting locations. Future research should evaluate the clinical utility of these systems in large high-quality prospective cohort studies to establish the role they may play in injury risk identification, diagnosis and management. This systematic review was registered with the International Prospective Register of Systematic Reviews on 10 August 2018 (PROSPERO registration: CRD42018106363): https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=106363 .

The Relationship Between Fighting Style, Cognition, and Regional Brain Volume in Professional Combatants: A Preliminary Examination Using Brief Neurocognitive Measures

OBJECTIVE

Repetitive head impacts (RHIs) in combat sports are associated with cognitive decline and brain volume reduction. While fighting style differences between boxers, mixed martial artists (MMAs), and martial artists (MAs) have resulted in a broader spectrum of injury, the effects of RHIs on MAs relative to other fighters have not yet been explored. This study aimed to determine a differential effect of fighting style on cognition and brain.

SETTING

A large outpatient medical center specializing in neurological care.

PARTICIPANTS, DESIGN, AND MAIN MEASURES

In total, 40 MAs, 188 boxers, and 279 MMAs were compared on baseline measures of subcortical regional brain volumes, after controlling for total brain volumes, and cognitive performance.

RESULTS

Significant differences between MAs, MMAs, and boxers were observed in subcortical brain structure volumes and cognitive measures. MMAs and MAs consistently had larger volumes and higher scores than boxers. Fighting style significantly moderated the relationship between the number of professional fights and the volumes of various subcortical brain structures and performance on a measure of processing speed at baseline.

CONCLUSIONS

Differences in RHIs across fighting styles may be of clinical significance. Exploring changes over time within the MA, boxer, and MMA cohorts may provide insight into longer-term discrepancies in subcortical regional brain volumes and cognitive functioning across fighting styles.

Tandem Gait Test-Retest Reliability Among Healthy Child and Adolescent Athletes

CONTEXT

The tandem gait test is a method for assessing dynamic postural control and part of the Sport Concussion Assessment Tool, versions 3 and 5. However, its reliability among child and adolescent athletes has yet to be established.

OBJECTIVE

To examine the test-retest reliability of the single-task and dual-task tandem gait test among healthy child and adolescent athletes.

DESIGN

Descriptive laboratory study.

SETTING

Sports injury-prevention center.

PATIENTS OR OTHER PARTICIPANTS

Uninjured and healthy athletes between the ages of 9 and 18 years.

INTERVENTION(S)

Tandem gait measures repeated 3 times across the period of approximately 1 month.

MAIN OUTCOME MEASURE(S)

Participants completed the tandem gait test under single-task and dual-task (ie, while simultaneously executing a cognitive task) conditions. Our primary outcome measure was completion time during the single-task and dual-task conditions. We also assessed cognitive accuracy and response rate while participants completed the dual-task tandem gait test.

RESULTS

Thirty-two child and adolescent athletes completed the study (mean age = 14.3 ± 2.4 years; females = 16). Single-task tandem gait times were similar across the 3 testing sessions (14.4 ± 4.8, 13.5 ± 4.2, and 13.8 ± 4.8 seconds; P = .45). Dual-task tandem gait times steadily improved across the test timeline (18.6 ± 6.9, 16.6 ± 4.5, and 15.8 ± 4.7 seconds; P = .02). Bivariate correlations indicated moderately high to high agreement from test 1 to test 2 (single-task r = .627; dual-task r = 0.655) and from test 2 to test 3 (single-task r = 0.852; dual-task r = 0.775). Both the single-task (intraclass correlation coefficient; ICC [3,1] = 0.86; 95% confidence interval [CI] = 0.73, 0.93) and dual-task (ICC [3,1] = 0.84; 95% CI = 0.69, 0.92) conditions demonstrated high reliability across testing sessions.

CONCLUSIONS

Tandem gait outcome measures demonstrated high test-retest reliability in both the single- and dual-task conditions. The overall reliability was within the acceptable range for clinical practice, but improvements across tests suggested a moderate practice effect. Tandem gait represents a reliable, dynamic, postural-control test that requires minimal space, cost, and time.

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.

Assessing the effects of concussion using the C3Logix Test Battery: An exploratory study

The C3Logix is a computerized concussion assessment tool that measures a wider array of symptoms (i.e., balance and oculomotor functioning) than other computerized batteries. Although the C3Logix has been used increasingly by athletic organizations at all levels of play, its utility within the concussion population has not been extensively examined. The current study aimed to determine whether the C3Logix is sensitive to the effects of concussion. A total of 54 student-athletes enrolled at a large southern university completed the C3Logix at baseline and within days following a suspected concussion (mean = 2.93, SD = 3.14). Dependent-samples t-tests revealed that relative to their baselines, following concussion, athletes both reported significantly greater postconcussive symptoms and performed more poorly on measures of reaction time and computer-measured balance. Decrements in processing speed, visual acuity, and clinician-observed errors on tests of balance also trended toward significance. Results suggest that inclusion of measures of balance and oculomotor functioning in the assessment of concussion may provide additional clinical utility above and beyond domains typically measured by computerized concussion assessments.