Using the NIH Toolbox Cognition Battery (NIHTB-CB) in individuals with traumatic brain injury

PURPOSE/OBJECTIVE

The NIH Toolbox for the Assessment of Neurological Behavior and Function Cognition Battery (NIHTB-CB) is a common data element for use in individuals with traumatic brain injury (TBI). This study evaluates its sensitivity and specificity in distinguishing individuals with complicated mild, moderate, or severe TBI, and provides support for the construct validity of the NIHTB-CB in individuals with TBI.

RESEARCH METHOD

One hundred eighty-two individuals with TBI (n = 83 complicated mild/moderate; n = 99 severe) completed the NIHTB-CB and neuropsychological criterion measures. Complete data were obtained on 158 participants. A control sample of 158 individuals without known neurological impairment was extracted from the NIHTB-CB normative sample. Multivariate analyses of variance determined the sensitivity of the NIHTB-CB measures to TBI and injury severity (complicated mild/moderate TBI, severe TBI, and controls) on the demographically corrected NIHTB-CB composite scores and seven subtests. A descriptive analysis of the sensitivity of each subtest was conducted. Finally, correlations between NIHTB-CB measures and criterion tests assessed convergent and discriminant validity.

RESULTS

Multivariate analyses indicated that there was a main effect for group (complicated mild/moderate vs. severe vs. controls) for fluid scores in the NIHTB-CB as opposed to only marginally significant results for the verbal scores. Moderate to strong relationships were found between the NIHTB-CB measures and their corresponding neuropsychological measures (convergent validity), whereas much smaller correlations were found between measures of different cognitive domains (discriminant validity).

CONCLUSIONS

Findings provide evidence of construct validity and the clinical utility of the NIHTB-CB in individuals with TBI. (PsycINFO Database Record

Creativity Lost

In school settings, students are typically evaluated using group achievement tests, IQ scales, and college entrance exams that focus more on rote-verbal skills (e.g., vocabulary, mathematical facts) than on higher level executive functions (e.g., abstract thinking, problem solving). However, recent neuropsychological findings suggest that rote-knowledge skills and executive functions are divergent cognitive domains that can be dissociated in both adults with frontal lesions and children with neurodevelopmental disorders. New correlational findings obtained from 470 children and adolescents provide additional support for the divergent nature of these cognitive domains and the existence of subgroups of students who exhibit either strengths in abstract, creative thinking with relative weaknesses in rote-verbal skills or vice versa. The results suggest that current school assessment practices may result in academic roadblocks for those students who have strengths in abstract, creative thinking but whose relative weaknesses in rote-verbal skills may hinder their ability to take college entrance exams.

Developing a Cognition Endpoint for Traumatic Brain Injury Clinical Trials

Cognitive impairment is a core clinical feature of traumatic brain injury (TBI). After TBI, cognition is a key determinant of post-injury productivity, outcome, and quality of life. As a final common pathway of diverse molecular and microstructural TBI mechanisms, cognition is an ideal endpoint in clinical trials involving many candidate drugs and nonpharmacological interventions. Cognition can be reliably measured with performance-based neuropsychological tests that have greater granularity than crude rating scales, such as the Glasgow Outcome Scale-Extended, which remain the standard for clinical trials. Remarkably, however, there is no well-defined, widely accepted, and validated cognition endpoint for TBI clinical trials. A single cognition endpoint that has excellent measurement precision across a wide functional range and is sensitive to the detection of small improvements (and declines) in cognitive functioning would enhance the power and precision of TBI clinical trials and accelerate drug development research. We outline methodologies for deriving a cognition composite score and a research program for validation. Finally, we discuss regulatory issues and the limitations of a cognition endpoint.

Normative adjustments to the D-KEFS trail making test: corrections for education and vocabulary level

The Delis-Kaplan Executive Function System (D-KEFS) Trail Making Test (TMT), a modification of the original TMT, was created to isolate set-shifting (Letter-Number Switching) from other component skills. This was accomplished by including four baseline conditions (Visual Scanning, Number Sequencing, Letter Sequencing, and Motor Speed) and by placing equal numbers of stimuli in the three sequencing conditions. Given that some studies with the original TMT demonstrated a significant effect of education and intellectual functioning on performance, we utilized the D-KEFS national standardization sample to examine the effects of education and vocabulary level-i.e., Vocabulary subtest from the Wechsler Abbreviated Scale of Intelligence (WASI)-on the D-KEFS TMT. The results indicate a significant effect of these variables on each D-KEFS TMT condition. Normative tables for education- and vocabulary-adjusted scaled scores based on the database from the D-KEFS national normative study were generated.

Effect of atomoxetine on executive function impairments in adults with ADHD

OBJECTIVE

To assess the effect of atomoxetine on ADHD-related executive functions over a 6-month period using the Brown Attention-Deficit Disorder Scale (BADDS) for Adults, a normed, 40-item, self-report scale in a randomized, double-blind, placebo-controlled clinical trial.

METHOD

In a randomized, double-blind clinical trial, adults with ADHD received either atomoxetine 25 to 100 mg/day or placebo for 6 months. Patients completed the BADDS to report their current daily functioning in 5 clusters of ADHD-related impairments of executive functioning: (1) Organizing and Activating to Work; (2) Focusing for Tasks; (3) Regulating Alertness and Effort; (4) Modulating Emotions; and (5) Utilizing Working Memory.

RESULTS

Mean scores were significantly more improved in the atomoxetine group compared to the placebo group: total score, -27.0 versus -19.0 (p < .001); all 5 cluster scores, p < .01.

CONCLUSIONS

Once-daily atomoxetine can improve executive function impairments in adults with ADHD as assessed by the BADDS.

Social perception and WAIS-IV Performance in adolescents and adults diagnosed with Asperger's Syndrome and Autism

Previous research using the Wechsler scales has identified areas of cognitive weaknesses in children, adolescents, and adults diagnosed with Autism or Asperger's syndrome. The current study evaluates cognitive functioning in adolescents and adults diagnosed with Autism or Asperger's syndrome using the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) and the Social Perception subtest from the Advanced Clinical Solutions. Deficits in social perception, verbal comprehension, and processing speed were found in the Autism sample. Additionally, they exhibited inconsistent performance on auditory working memory and perceptual reasoning tasks. The Asperger's syndrome group had better overall cognitive skills than the Autism group, but compared with controls, they had weaknesses in processing speed, social perception, and components of auditory working memory. Both groups had relatively low scores on the WAIS-IV Comprehension subtest compared with the other verbal comprehension subtests. Clinical application and utility of the WAIS-IV and Social Perception in Autism Spectrum Disorders are discussed.

Rapidly-administered short forms of the Wechsler Adult Intelligence Scale—3rd edition

Although the Wechsler Full Scale IQ (FSIQ) is a common component of most neuropsychological evaluations, there are many clinical situations where the complete administration of this battery is precluded by various constraints, including limitations of time and patient compliance. These constraints are particularly true for dementia evaluations involving elderly patients. The present study reports data on two short forms particularly suited to dementia evaluations, each requiring less than 20min of administration time. One of the short forms was previously validated in dementia for the WAIS-R [Randolph, C., Mohr, E., & Chase, T. N. (1993). Assessment of intellectual function in dementing disorders: Validity of WAIS-R short forms for patients with Alzheimer's, Huntington's, and Parkinson's disease. Journal of Clinical and Experimental Neuropsychology, 15, 743-753]; the second was developed specifically for patients with motor disabilities. These short forms were validated using the WAIS-III normative standardization sample (N=2450), neurologic sample (N=63), and matched controls (N=49), and a separate mixed clinical sample (N=70). The results suggest that each short form provides an accurate and reliable estimate of WAIS-III FSIQ, validating their use in appropriate clinical contexts. The present data support the use of these short forms for dementia evaluations, and suggests that they may be applicable for the evaluation of other neurological and neuropsychiatric disorders that involve acquired neurocognitive impairment.

Reliability and validity of the Delis-Kaplan Executive Function System: an update

A critical endeavor in every health-related field is the continued development of new technologies and instrumentation for improving diagnosis and treatment. For example, the field of neuroimaging has made astonishing advances with procedures such as functional MRI, MR spectroscopy, and MR diffusion tensor imaging. The field of neuropsychology has also recognized the importance of continually striving to develop new, more sensitive clinical measures. At the same time, the development of new tests or procedures does not guarantee that the instruments represent improvements in diagnosis or treatment. For this reason, ongoing studies of reliability and validity of new diagnostic instruments are also an important part of research in all health-related fields.