Clifford A. Smith

The pattern of neuropsychological deficits in Vascular Cognitive Impairment-No Dementia (Vascular CIND).

We examined the pattern of neuropsychological deficits in Vascular Cognitive Impairment-No Dementia (Vascular CIND) by comparing the cognitive and behavioral performance of 41 post-stroke Vascular CIND patients to that of 62 post-stroke patients with no cognitive impairment (NCI). Neuropsychological test scores were grouped into seven cognitive and four behavioral domains, then converted to standardized, weighted principle component scores (PCS) for each domain. Multivariate logistic regression models built on cognitive domains found the immediate recall and psychomotor domains to best predict diagnostic group membership. In a separate model limited to behavioral data, the depressed mood domain best predicted group membership. The combination of immediate memory deficits, psychomotor slowness and depression have also been found in Vascular Dementia (VaD), suggesting that the pattern of deficits in Vascular CIND and VaD neuropsychological deficits are similar. This cognitive and behavioral pattern similarity supports the hypothesis that Vascular CIND lies on a continuum between NCI and VaD.

Performance of Compensation Seeking and Non-Compensation Seeking Samples on the Victoria Symptom Validity Test: Cross-validation and Extension of a Standardization Study

Previous research suggests that the Victoria Symptom Validity Test (VSVT) is effective in confirming or disconfirming the validity of a patients reported cognitive impairments. We sought to cross-validate the findings of the VSVT standardization study, and to determine cut-off scores that are most efficient in discriminating our samples of compensation-seeking patients, primarily with mild traumatic brain injury (CS; n = 53), and non-compensation seeking patients with intractable seizures (NCS; n = 30). All patients in the NCS sample scored in the “valid” range on the VSVT difficult memory items, compared to only 58.5% of the CS sample. We also identified VSVT measures and cut-off scores maximally efficient in discriminating these samples. This study confirms previous research that non-compensation seeking patients do well on the VSVT, but that many compensation seeking patients perform poorly on this measure.

Relationship of ethnicity, age, education, and reading level to speed and executive function among HIV+ and HIV– women: The Women's Interagency HIV Study (WIHS) Neurocognitive Substudy

Use of neuropsychological tests to identify HIV-associated neurocognitive dysfunction must involve normative standards that are well suited to the population of interest. Norms should be based on a population of HIV-uninfected individuals as closely matched to the HIV-infected group as possible and must include examination of the potential effects of demographic factors on test performance. This is the first study to determine the normal range of scores on measures of psychomotor speed and executive function among a large group of ethnically and educationally diverse HIV-uninfected, high-risk women, as well as their HIV-infected counterparts. Participants (n = 1,653) were administered the Trail Making Test Parts A and B (Trails A and Trails B), the Symbol Digit Modalities Test (SDMT), and the Wide Range Achievement Test–3 (WRAT–3). Among HIV-uninfected women, race/ethnicity accounted for almost 5% of the variance in cognitive test performance. The proportions ofvariance in cognitive test performance accounted for by age (13.8%), years of school (4.1%), and WRAT–3 score (11.5%) were each significant, but did not completely account for the effect of race (3%). HIV-infected women obtained lower scores than HIV-uninfected women on time to complete Trails A and B, SDMT total correct, and SDMT incidental recall score, but after adjustment for age, years of education, racial/ethnic classification, and reading level, only the difference on SDMT total correct remained significant. Results highlight the need to adjust for demographic variables when diagnosing cognitive impairment in HIV-infected women. Advantages of demographically adjusted regression equations developed using data from HIV-uninfected women are discussed.

Comparison of Wechsler Memory Scale–Fourth Edition (WMS–IV) and Third Edition (WMS–III) dimensional structures: Improved ability to evaluate auditory and visual constructs

Dimensional structures underlying the Wechsler Memory Scale–Fourth Edition (WMS–IV) and Wechsler Memory Scale–Third Edition (WMS–III) were compared to determine whether the revised measure has a more coherent and clinically relevant factor structure. Principal component analyses were conducted in normative samples reported in the respective technical manuals. Empirically supported procedures guided retention of dimensions. An invariant two-dimensional WMS–IV structure reflecting constructs of auditory learning/memory and visual attention/memory (C1 = .97; C2 = .96) is more theoretically coherent than the replicable, heterogeneous WMS–III dimension (C1 = .97). This research suggests that the WMS–IV may have greater utility in identifying lateralized memory dysfunction.

The MMPI-2 Fake Bad Scale: Concordance and Specificity of True and Estimated Scores

A number of recent studies have supported the use of the MMPI-2 Fake Bad Scale (FBS) as a measure of negative response bias, the scale at times demonstrating greater sensitivity to negative response bias than other MMPI-2 validity scales. However, clinicians may not always have access to True FBS (T-FBS) scores, such as when True-False answer sheets are unavailable or published research studies do not report FBS raw scores. Under these conditions, Larrabee (2003a) suggests a linear regression formula that provides estimated FBS (E-FBS) scores derived from weighted validity and clinical T-Scores. The present study intended to validate this regression formula of MMPI-2 E-FBS scores and demonstrate its specificity in a sample of non-litigating, clinically referred, medically intractable epilepsy patients. We predicted that the E-FBS scores would correlate highly (>.70) with the T-FBS scores, that the E-FBS would show comparable correlations with MMPI-2 validity and clinical scales relative to the T-FBS, and that the E-FBS would show an adequate ability to match T-FBS scores using a variety of previously suggested T-FBS raw score cutoffs. Overall, E-FBS scores correlated very highly with T-FBS scores (r = .78, p < .0001), though correlations were especially high for women (r = .85, p < .0001) compared to men (r = .62, p < .001). Thirty-one of 32 (96.9%) comparisons made between E-FBS/T-FBS correlates with other MMPI-2 scales were nonsignificant. When matching to T-FBS “high” and “low” scores, the E-FBS scores demonstrated the highest hit rate (92.5%) through use of Lees-Haleys (1992) revised cutoffs for men and women. These same cutoffs resulted in excellent overall specificity for both the T-FBS scores (92.5%) and E-FBS scores (90.6%). The authors conclude that the E-FBS represents an adequate estimate of T-FBS scores in the current epilepsy sample. Use of E-FBS scores may be especially useful when clinicians conduct the MMPI-2 short form, which does not include all of the 43 FBS items but does include enough items to compute each of the validity and clinical T-Scores. Future studies should examine E-FBS sensitivity in compensation-seekers with incomplete effort.

Gender Effects on HIV-Associated White Matter Alterations: A Voxel-Wise DTI Study

Sexual dimorphisms within the human brain are well-documented. Human immunodeficiency virus (HIV) infection is associated with atrophy and microstructural white matter alterations, yet sex-specific dimorphic brain alterations in persons living with HIV have not been systematically examined. To address this issue, we evaluated regional differences in normal-appearing white matter (NAWM) in adults with and without HIV utilizing diffusion tensor imaging. Through a voxel-by-voxel analytic approach, sexual dimorphisms in NAWM anisotropy and diffusivity were identified. In comparison to seronegative men and women, HIV infection contributed to a decline in the distribution of anisotropic differences between the sexes. Alterations in diffusivity were more complex, with seropositive women demonstrating an increase in regional diffusivity, while seropositive men demonstrated a reduction in regional differences. Sex by serostatus interactions within the left frontal lobe and bilateral thalamic region were identified. These results suggest that HIV contributes to sex-specific microstructural NAWM alterations, such that sex and serostatus differentially alter the integrity of the neuronal matrix.

Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and Depressive Complaints in Older Adults

The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) is a commonly administered test used to identify cognitive impairment in geriatric patients. To date, no published studies have examined the relationship between depressive symptoms and performance on the RBANS in older adults. Using a clinical sample of 45 older adults, we found a significant negative correlation between depression scores (measured by Geriatric Depression Scale-15) and RBANS Immediate Memory Index. Further examination showed that the List Learning subtest was associated with depression, but Story Memory was not. All other RBANS indices and related subtests were not associated with depression scores. Clinical implications are discussed.