Nih toolbox premorbid ability adjustments: Application in a traumatic brain injury sample

Exploring symptom clusters in mild cognitive impairment and dementia with the NIH Toolbox

OBJECTIVE

Symptom clustering research provides a unique opportunity for understanding complex medical conditions. The objective of this study was to apply a variable-centered analytic approach to understand how symptoms may cluster together, within and across domains of functioning in mild cognitive impairment (MCI) and dementia, to better understand these conditions and potential etiological, prevention, and intervention considerations.

METHOD

Cognitive, motor, sensory, emotional, and social measures from the NIH Toolbox were analyzed using exploratory factor analysis (EFA) from a dataset of 165 individuals with a research diagnosis of either amnestic MCI or dementia of the Alzheimer's type.

RESULTS

The six-factor EFA solution described here primarily replicated the intended structure of the NIH Toolbox with a few deviations, notably sensory and motor scores loading onto factors with measures of cognition, emotional, and social health. These findings suggest the presence of cross-domain symptom clusters in these populations. In particular, negative affect, stress, loneliness, and pain formed one unique symptom cluster that bridged the NIH Toolbox domains of physical, social, and emotional health. Olfaction and dexterity formed a second unique cluster with measures of executive functioning, working memory, episodic memory, and processing speed. A third novel cluster was detected for mobility, strength, and vision, which was considered to reflect a physical functioning factor. Somewhat unexpectedly, the hearing test included did not load strongly onto any factor.

CONCLUSION

This research presents a preliminary effort to detect symptom clusters in amnestic MCI and dementia using an existing dataset of outcome measures from the NIH Toolbox.

R2DRV: study protocol for longitudinal assessment of driving after mild TBI in young drivers

BACKGROUND

Mild traumatic brain injury (mTBI) and traffic-related injuries are two major public health problems disproportionately affecting young people. Young drivers, whose driving skills are still developing, are particularly vulnerable to impaired driving due to brain injuries. Despite this, there is a paucity of research on how mTBI impacts driving and when it is safe to return to drive after an mTBI. This paper describes the protocol of the study, R2DRV, Longitudinal Assessment of Driving After Mild TBI in Young Drivers, which examines the trajectory of simulated driving performance and self-reported driving behaviors from acutely post-injury to symptom resolution among young drivers with mTBI compared to matched healthy drivers. Additionally, this study investigates the associations of acute post-injury neurocognitive function and cognitive load with driving among young drivers with and without mTBI.

METHODS

A total of 200 young drivers (ages 16 to 24) are enrolled from two study sites, including 100 (50 per site) with a physician-confirmed isolated mTBI, along with 100 (50 per site) healthy drivers without a history of TBI matched 1:1 for age, sex, driving experience, and athlete status. The study assesses primary driving outcomes using two approaches: (1) high-fidelity driving simulators to evaluate driving performance across four experimental study conditions at multiple time points (within 96 h of injury and weekly until symptom resolution or 8 weeks post-injury); (2) daily self-report surveys on real-world driving behaviors completed by all participants.

DISCUSSION

This study will fill critical knowledge gaps by longitudinally assessing driving performance and behaviors in young drivers with mTBI, as compared to matched healthy drivers, from acutely post-injury to symptom resolution. The research strategy enables evaluating how increased cognitive load may exacerbate the effects of mTBI on driving, and how post-mTBI neurocognitive deficits may impact the driving ability of young drivers. Findings will be shared through scientific conferences, peer-reviewed journals, and media outreach to care providers and the public.

Normative Reference Values for Crystallized-Fluid Discrepancy Scores for the NIH Toolbox Cognition Battery

INTRODUCTION

The purpose of this study was to translate NIH Toolbox Cognition Battery (NIHTB-CB) Crystallized-Fluid discrepancy scores into research and clinical practice with adults by providing normative data for discrepancy scores for both age-adjusted standard scores (SSs) and demographically adjusted T-scores.

METHOD

We included adult participants from the NIHTB-CB standardization sample who denied having neurodevelopmental, medical, psychiatric, or neurological conditions (n = 730; M = 47.4 years old, SD = 17.6, range: 18-85; 64.4% women; 63.1% White). Descriptive statistics were calculated for the Fluid and Crystallized composite scores and Crystallized-Fluid discrepancy score, along with correlations between the composite scores and reliability estimates of the discrepancy score. Percentiles were calculated for the discrepancy score, with stratifications by the gender, education, and Crystallized composite for the age-adjusted SSs and demographically adjusted T-scores (T).

RESULTS

Crystallized-Fluid discrepancy scores ranged from -40 to 44 (M = -0.63, SD = 14.89, Mdn = -1, interquartile range [IQR]: -11 to 10) for age-adjusted SSs and from -29 to 27 (M = -0.39, SD = 10.49, Mdn = -1, IQR = -8 to 7) for demographically adjusted T-scores. Crystallized-Fluid discrepancy scores of SS = 15 and T = 11 were at the 16th percentile (1 SD below the mean) and discrepancy scores of SS = 21 and T = 15 were at the 7th percentile (1.5 SD below the mean).

CONCLUSIONS

Crystallized-Fluid discrepancy scores may be, with future research, a useful within-person interpretive approach for detecting a decline from pre-injury or pre-disease levels of cognitive functioning. These normative reference values assist clinicians and researchers in determining the frequency at which given Crystallized-Fluid discrepancy scores occurred among healthy adults in the normative sample.

Age of first exposure to soccer heading: Associations with cognitive, clinical, and imaging outcomes in the Einstein Soccer Study

Introduction

The objective of this study is to assess the role of age at first exposure (AFE) to soccer heading as a predictor of known adverse associations of recent and longer-term heading with brain microstructure, cognitive, and behavioral features among adult amateur soccer players.

Methods

The sample included 276 active amateur soccer players (196 male and 81 female) aged 18-53 years old. AFE to soccer heading was treated as a binary variable, dichotomized at ≤ 10 years vs. >10 years old, based on a recently promulgated US Soccer policy, which bans heading for athletes ages 10 and under.

Results

We found that soccer players who began heading at age 10 or younger performed better on tests of working memory (p = 0.03) and verbal learning (p = 0.02), while accounting for duration of heading exposure, education, sex, and verbal intelligence. No difference in brain microstructure or behavioral measures was observed between the two exposure groups.

Discussion

The findings indicate that, among adult amateur soccer players, AFE to heading before age 10 compared to later start of heading, is not associated with adverse outcomes, and may be associated with better cognitive performance in young adulthood. Cumulative heading exposure across the lifespan, rather than early life exposure, may drive risk for adverse effects and should be the focus of future longitudinal studies to inform approaches to enhance player safety.

Duration of post-traumatic amnesia is uniquely associated with memory functioning in chronic moderate-to-severe traumatic brain injury

BACKGROUND

Disrupted memory circuitry may contribute to post-traumatic amnesia (PTA) after traumatic brain injury (TBI). It is unclear whether duration of PTA (doPTA) uniquely impacts memory functioning in the chronic post-injury stage.

OBJECTIVE

To examine the relationship between doPTA and memory functioning, independent of other cognitive abilities, in chronic moderate-to-severe TBI.

METHODS

Participants were 82 individuals (median chronicity = 10.5 years) with available doPTA estimates and neuropsychological data. Composite memory, processing speed (PS), and executive functioning (EF) performance scores, as well as data on subjective memory (SM) beliefs, were extracted. DoPTA-memory associations were evaluated via linear modeling of doPTA with memory performance and clinical memory status (impaired/unimpaired), controlling for PS, EF and demographic covariates. Interrelationships between doPTA, objective memory functioning, and SM were assessed.

RESULTS

DoPTA was significantly related to memory performance, even after covariate adjustment. Impairment in memory, but not PS or EF, was associated with a history of longer doPTA. SM was associated with memory performance, but unrelated to doPTA.

CONCLUSIONS

Findings suggest a specific association between doPTA-an acute injury phenomenon-and chronic memory deficits after TBI. Prospective studies are needed to understand how underlying mechanisms of PTA shape distinct outcome trajectories, particularly functional abilities related to memory processing.

Predicting military readiness using objective and subjective indices of neuropsychological impairment in service members with mild traumatic brain injury

The military is interested in identifying factors to improve the readiness of service members with traumatic brain injury (TBI). TBI outcome studies have primarily used objective neuropsychological data interpreted using the absolute level of functioning (i.e., high average, average, low average), though research suggests it is also important to consider other objective indices of the relative degree of decline (e.g., mild, moderate, severe) and subjective complaints. The current study determined the predictive ability of objective indices of neuropsychological functioning (i.e., absolute level and the relative degree of decline) and subjective complaints (i.e., Neurobehavioral Symptom Inventory) in terms of military work status (i.e., return to duty, medically disabled, retired) for 113 service members with mild TBI. ANOVAs and post-hoc tests indicated individuals who were able to return to duty had higher absolute indices and lower relative decline scores in working memory and overall intelligence, as well as lower subjective neuropsychological complaints when compared to those who were disabled or retired. Multinomial logistic regression models generally supported these findings, except relative decline scores were not predictive of military work status likely due to issues of collinearity (i.e., relative decline scores are calculated using absolute scores). In conclusion, indices of absolute functioning and subjective neuropsychological impairments appear to be predictors of the ability to return to duty post-TBI in military populations, emphasizing the need to focus on cognitive reserve and emotional resilience as potential interventions.

Comparing indices of objective and subjective neuropsychological impairments in service members with mild traumatic brain injury

Neuropsychological impairments are evaluated using subjective measures and objective tests, although their relationship remains unclear. This is likely because objective data is interpreted in terms of absolute level of functioning (e.g., high average, average, low average) while subjective complaints are interpreted in terms of relative decline from premorbid levels (e.g., mild, moderate, severe). The current study calculated objective indices of estimated degree of relative decline (i.e., difference between current cognitive ability and estimated premorbid level) to compare objective and subjective indices of relative decline for military service members with mild traumatic brain injury (mTBI). Contrary to hypotheses, more indices of absolute level of functioning were significantly correlated with subjective neuropsychological (i.e., Neurobehavioral Symptom Inventory) and psychological complaints (e.g., Personality Assessment Inventory) than relative decline scores. The results suggest stronger cognitive abilities may be associated with greater cognitive reserve or emotional resilience and, thereby, less subjective complaints for individuals with TBI, regardless of the extent of neuropsychological decline experienced.

Psychometric Properties of the NIH Toolbox Cognition Battery in Healthy Older Adults: Reliability, Validity, and Agreement with Standard Neuropsychological Tests

OBJECTIVE

Few independent studies have examined the psychometric properties of the NIH Toolbox Cognition Battery (NIHTB-CB) in older adults, despite growing interest in its use for clinical purposes. In this paper we report the test-retest reliability and construct validity of the NIHTB-CB, as well as its agreement or concordance with traditional neuropsychological tests of the same construct to determine whether tests could be used interchangeably.

METHODS

Sixty-one cognitively healthy adults ages 60-80 completed "gold standard" (GS) neuropsychological tests, NIHTB-CB, and brain MRI. Test-retest reliability, convergent/discriminant validity, and agreement statistics were calculated using Pearson's correlations, concordance correlation coefficients (CCC), and root mean square deviations.

RESULTS

Test-retest reliability was acceptable (CCC = .73 Fluid; CCC = .85 Crystallized). The NIHTB-CB Fluid Composite correlated significantly with cerebral volumes (r's = |.35-.41|), and both composites correlated highly with their respective GS composites (r's = .58-.84), although this was more variable for individual tests. Absolute agreement was generally lower (CCC = .55 Fluid; CCC = .70 Crystallized) due to lower precision in fluid scores and systematic overestimation of crystallized composite scores on the NIHTB-CB.

CONCLUSIONS

These results support the reliability and validity of the NIHTB-CB in healthy older adults and suggest that the fluid composite tests are at least as sensitive as standard neuropsychological tests to medial temporal atrophy and ventricular expansion. However, the NIHTB-CB may generate different estimates of performance and should not be treated as interchangeable with established neuropsychological tests.

Comparability of iPad and Web-Based NIH Toolbox Cognitive Battery Administration in Veterans

OBJECTIVE

The purpose of this study was to evaluate the comparability of National Institutes of Health Toolbox Cognitive Battery test scores across iPad application and web-based personal computer administration platforms. Original test norms were developed using a personal computer-based administration and no previous studies assessing platform comparability have been published.

METHOD

Participants (N = 62; final analyzed sample n = 49) were combat-exposed post-deployment veterans without neurologic disorder, severe mental illness, current substance use disorder, or a history of moderate or severe traumatic brain injury. All participants completed both iPad and web-based versions of tests on the same day in an experimental within-subjects crossover design. Standalone validity measures were incorporated to exclude invalid performance. Outcome measures included the Dimensional Change Card Sort Test, Flanker Inhibitory Control and Attention Test, List Sorting Working Memory Test, and Pattern Comparison Processing Speed Test.

RESULTS

Score differences between platforms were found on the Flanker Inhibitory Control and Attention Test. Scores were moderately correlated across tests, with the exception of low correlations for the Pattern Comparison Processing Speed Test. Most participants preferred iPad to web administration, regardless of administration order.

CONCLUSIONS

Results suggest caution when interpreting iPad-acquired scores, particularly for the Flanker Inhibitory Control and Attention Test. iPad-based testing offers valuable improvements; however, the development of iPad-specific norms may be necessary to ensure valid interpretation of acquired data.

The clinical utility and construct validity of the NIH Toolbox Cognition Battery (NIHTB-CB) in individuals with disabilities

A State-of-the-Science conference on measurement with disability populations recommended "...the development of cognitive and psychosocial outcome measures, using computer-adaptive testing...that are low in respondent burden and valid across patient populations," (Clohan et al., 2007, p. 1537). Following this recommendation, the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR) prioritized the development of measures of cognitive functioning for individuals with disabilities, noting that measures of cognitive functioning "have not been developed for systemic application in the field of medical rehabilitation. Cognition is both a rehabilitation outcome and a factor related to broader functional and community outcomes for individuals with a wide variety of disabling conditions" (Office of Special Education & Rehabilitation Services, 2009, p. 37193). From this came the NIH Toolbox for the Assessment of Neurological and Behavioral Function project (NIH Toolbox) which provides a comprehensive set of cognitive, motor, sensory, and emotional health and function measures for use in clinical, longitudinal, and epidemiological research. The nine papers comprising this special section of Rehabilitation Psychology reflect the sustained collaborative efforts of more than two dozen investigators working at six sites over the past 8 years. They are an initial attempt to validate the NIHTB-CB in disability samples, and they provide initial evidence that the NIHTB-CB can be used with individuals who have TBI, SCI, or stroke. The articles published here reflect the fulfillment of recommendations made during a state-of-the-science conference in 2007. (PsycINFO Database Record