Construct validity of the NIH Toolbox Cognition Battery in individuals with stroke

OBJECTIVE

The National Institutes of Health (NIH) Toolbox (NIHTB) for the Assessment of Behavior and Neurological Function Cognition Battery (NIHTB-CB) provides a brief assessment (approximately 30 min) of key components of cognition. This article examines construct validity to support the clinical utility of the NIHTB-CB in individuals with stroke.

RESEARCH METHOD

A total of 131 individuals with stroke (n = 71 mild stroke; n = 60 moderate/severe stroke) completed the NIHTB-CB. Univariate analyses were conducted to examine the cognitive profiles of the two different stroke groups (mild vs. moderate/severe stroke) on NIHTB-CB measures and composite scores. Pearson correlations were conducted between NIHTB-CB and established measures to examine convergent and discriminant validity. Effect sizes and clinical impairment rates for the different NIHTB-CB measures and composite scores were also examined.

RESULTS

Participants experiencing moderate to severe stroke had poorer performance than did individuals with mild stroke on several of the NIHTB cognition measures. Evidence of convergent validity was provided by moderate to strong correlations between the NIHTB measures and the corresponding standard neuropsychological test (Pearson rs ranged from 0.31 to 0.88; median = .60). Evidence of discriminant validity was provided by smaller correlations between different cognitive domains than correlations of measures within the same domain. Effect sizes for composite and subtest scores regarding stroke severity were generally moderate-to-large. In addition, 42% of the sample were exhibiting mild cognitive impairment (i.e., ≥2 low scores on fluid tests).

CONCLUSIONS

Findings provide support for the construct validity of the NIHTB-CB in individuals with stroke. (PsycINFO Database Record

Motor-free composites from the National Institutes of Health Toolbox Cognition Battery (NIHTB-CB) for people with disabilities

PURPOSE/OBJECTIVE

The National Institutes of Health Toolbox Cognition Battery (NIHTB-CB) includes a group of brief measures (i.e., 30 min) designed to assess language, processing speed, working memory, episodic memory, and executive functioning. These subtests can be combined to create composite scores that reflect fluid and crystallized cognition, as well as overall cognition. The battery is of limited utility with individuals who have impaired upper extremity motor functioning. This manuscript examines the accuracy of the Oral Symbol Digit Modalities Test as a substitute for the Pattern Comparison Processing Speed Test for computing motor-free composite scores. Research Method/Design: Individuals with spinal cord injury (SCI; n = 188), traumatic brain injury (TBI; n = 159), or stroke (n = 180) completed the NIHTB-CB. We used the Oral Symbol Digit Modalities Test to create a Motor-Free Pattern Comparison score; this was used to create revised, Motor-Free Composite scores for Fluid Cognition and Overall Cognition.

RESULTS

Although there were statistically significant overall differences between the two Fluid and Overall Cognition composite scores for some of the clinical groups (scores based on the motor-free approach were significantly higher than the original score), these differences were small and partly because of overclassification of impaired processing speed in participants with motor impairment. There was good to substantial agreement with regard to "impairment" classification between the two sets of Original and Motor-Free composite scores.

CONCLUSIONS/IMPLICATIONS

Although the Motor-Free scores are not a perfect match for the Original Composite scores, they provide a reliable and valid way to examine overall and fluid cognition in individuals with upper extremity motor impairments. (PsycINFO Database Record

Factor structure of the NIH Toolbox Cognition Battery in individuals with acquired brain injury

OBJECTIVE

The National Institutes of Health Toolbox Cognition Battery (NIHTB-CB) measures reading, vocabulary, episodic memory, working memory, executive functioning, and processing speed. While previous research has validated the factor structure in healthy adults, the factor structure has not been examined in adults with neurological impairments. Thus, this study evaluated the NIHTB-CB factor structure in individuals with acquired brain injury.

METHOD

A sample of 392 individuals (ages 18-84) with acquired brain injury (n = 182 TBI, n = 210 stroke) completed the NIHTB-CB along with neuropsychological tests as part of a larger, multisite research project.

RESULTS

Confirmatory factor analyses supported a 5-factor solution that included reading, vocabulary, episodic memory, working memory, and processing speed/executive functioning. This structure generally held in TBI and stroke subsamples as well as in subsamples of those with severe TBI and stroke injuries.

CONCLUSIONS

The factor structure of the NIHTB-CB is similar in adults with acquired brain injury to adults from the general population. We discuss the implications of these findings for clinical practice and clinical research. (PsycINFO Database Record

A composite of multisystem injury and neurocognitive impairment in HIV infection: association with everyday functioning

The Veterans Aging Cohort Study (VACS) Index is a composite marker of multisystem injury among HIV-infected persons. We aimed to examine its cross-sectional association with functional outcomes, after considering neurocognitive impairment (NCI) and other well-established correlates of everyday functioning among HIV-infected persons. Participants included 670 HIV-infected adults (ages 18-76; 88% male; 63% non-Hispanic White; median current CD4 = 404 cells/mm³; 67% on antiretroviral therapy; AIDS = 63%) enrolled in observational studies at the University of California San Diego HIV Neurobehavioral Research Program. Functional outcomes were assessed via self-report measures of declines in activities of daily living, perceived cognitive symptoms in daily life, and employment status. NCI was assessed via a comprehensive neurocognitive test battery and defined based on established methods. Covariates examined included demographics, HIV disease characteristics not included in the VACS Index, and psychiatric comorbidities. The VACS Index was computed via standard methods and categorized based on its distribution. Results from multivariable regression models showed that both higher VACS Index scores (indicative of worse health) and the presence of NCI were independently associated with declines in activities of daily living, increased cognitive symptoms in daily life, and unemployment. These independent effects remained after adjusting for significant covariates. In conclusion, the VACS Index may be a useful tool for identifying HIV-infected patients at high risk for everyday functioning problems. Considering factors such as NCI, historical HIV disease characteristics, and current mood might be particularly important to enhance the predictive power of the VACS Index for functional status among HIV-infected persons.

NIH Toolbox® Emotion Batteries for Children: Factor-Based Composites and Norms

The recently released National Institutes of Health Toolbox (NIHTB) batteries for neurological and behavioral function were designed to serve as standardized, common measures in clinical and epidemiological research. The current study aimed to examine constructs assessed by the self-report and parental proxy-report scales in the NIHTB Emotion Battery (NIHTB-EB) for Children by using factor analyses on data from the U.S. national normative sample of 2,916 English-speaking children. This battery contains 31 scales designed to assess both positive and negative aspects of social and emotional functioning that are considered developmentally relevant at each of three age ranges (3-7, 8-12, and 13-17 years). Results revealed four similar self-report factors for ages 8 to 12 years and 13 to 17 years. Proxy reports for ages 3 to 7 years revealed three factors, and for ages 8 to 12 years two factors. Based on the standardization sample data, age- and gender-corrected norms are presented for all NIHTB-EB individual scales and factor-based composites.

National Institutes of Health Toolbox Emotion Battery for English- and Spanish-speaking adults: normative data and factor-based summary scores

Background

The National Institutes of Health Toolbox Emotion Battery (NIHTB-EB) is a "common currency", computerized assessment developed to measure the full spectrum of emotional health. Though comprehensive, the NIHTB-EB's 17 scales may be unwieldy for users aiming to capture more global indices of emotional functioning.

Methods

NIHTB-EB was administered to 1,036 English-speaking and 408 Spanish-speaking adults as a part of the NIH Toolbox norming project. We examined the factor structure of the NIHTB-EB in English- and Spanish-speaking adults and developed factor analysis-based summary scores. Census-weighted norms were presented for English speakers, and sample-weighted norms were presented for Spanish speakers.

Results

Exploratory factor analysis for both English- and Spanish-speaking cohorts resulted in the same 3-factor solution: 1) negative affect, 2) social satisfaction, and 3) psychological well-being. Confirmatory factor analysis supported similar factor structures for English- and Spanish-speaking cohorts. Model fit indices fell within the acceptable/good range, and our final solution was optimal compared to other solutions.

Conclusion

Summary scores based upon the normative samples appear to be psychometrically supported and should be applied to clinical samples to further validate the factor structures and investigate rates of problematic emotions in medical and psychiatric populations.

Neurocognitive impairment with hepatitis C and HIV co-infection in Southern Brazil

Although cognitive impairment has been well documented in human immunodeficiency virus (HIV) and hepatitis C virus (HCV) mono-infections, research on neurocognitive effects is limited in the context of HIV/HCV co-infection. The aims of this study were to explore the interplay between HIV and HCV infections in the expression of neurocognitive impairment (NCI), and to examine the differences in test performance between HIV/HCV co-infected and HIV or HCV mono-infected patients. A total of 128 participants from Southern Brazil underwent a comprehensive neuropsychological (NP) battery comprising 18 tests. Participants were grouped according to their serological status: HCV mono-infected (n = 20), HIV mono-infected (n = 48), HIV/HCV co-infected (n = 12), and HIV-/HCV-uninfected controls (n = 48). The frequencies of HIV subtypes B and C between the HIV mono-infected and HIV/HCV co-infected groups were comparable. There was greater prevalence of neuropsychological impairment among all three infection groups compared with the uninfected control group, but no statistically significant differences among mono- and co-infected groups were found. HCV infection was associated with cognitive deficits, independently of liver dysfunction. HCV infection did not show an additive effect on neurocognitive function among HIV+. NCI was independent of HCV RNA on peripheral blood, CSF, and hepatic injury. While we did not find additive global effect, in the present study, there was some evidence of additive HIV/HCV co-infection effects in speed of information processing, executive function, and verbal fluency domains when comparing the co-infected group with the other three groups. NP impairment was not dependent on HCV subtypes.

Effect of age and level of education on neurocognitive impairment in HIV positive Zambian adults

OBJECTIVE

Older age and lower education levels are known to be associated with worse neurocognitive (NC) performance in healthy adults, and individuals with HIV infection may experience accelerated brain/cognition aging. However, higher education may possibly protect against HIV-associated neurocognitive disorders (HAND). The aim of the current cross-sectional study was to assess the effect of age and education in an HIV-1 clade C infected adult population in urban Zambia.

METHOD

Demographically corrected Zambian norms on a neuropsychological (NP) test battery were used to correct for normal age and education effects. The study assessed 286 HIV positive (+) males (37.1%) and females (62.9%) with a mean age of 41.35 (SD = 8.56) and mean years of education = 10.16 (SD = 2.18). A comprehensive NP test battery was used to assess cognitive domains frequently affected by HIV: attention/working memory, learning/and delayed recall, executive function, verbal fluency, processing speed, verbal and visual episodic memory, and fine motor skills.

RESULTS

In younger HIV+ Zambians, higher education evidenced protective effects against NC impairments overall, and for the specific domains of executive functions, learning and speed of information processing. Impairment scores did not support accelerated overall brain aging although the restricted age range and relative youth of our total sample may have precluded detection of such tendencies.

CONCLUSIONS

The present study raises the need to investigate factors that could be implicated in the poor neurocognitive performance among the younger, less educated HIV+ individuals in Zambia. (PsycINFO Database Record

Factor Analysis of an Expanded Halstead-Reitan Battery and the Structure of Neurocognition

OBJECTIVE

The structure of neurocognition is explored by examining the neurocognitive domains underlying comprehensive neuropsychological assessment of cognitively healthy individuals.

METHOD

Exploratory factor analysis was conducted on the adult normative dataset of an expanded Halstead-Reitan Battery (eHRB), comprising Caucasian and African American participants. The factor structure contributions of the original HRB, eHRB expansion, and Wechsler intelligence scales were compared. Demographic effects were examined on composite factor scores calculated using confirmatory factor analysis.

RESULTS

The full eHRB had an eight-factor structure, with latent constructs including: 'working memory', 'fluency', 'verbal episodic memory', 'visuospatial cognition' (visuospatial memory and problem solving), 'perceptual-motor speed' (speed for processing visual/tactile material and hand-motor execution), 'perceptual attention' (attention to sensory-perceptual information), 'semantic knowledge' (knowledge acquired through education and culturally-based experiences), and 'phonological decoding' (grapheme-phoneme processing essential for sounding-out words). 'Perceptual-motor speed' and 'perceptual attention' were most negatively associated with age, whereas 'semantic knowledge' and 'phonological decoding' were most resistant to aging. 'Semantic knowledge' showed the greatest dependence on demographic background, including education and ethnicity. Gender differences in cognitive performances were negligible across all domains except 'phonological decoding' with women slightly outperforming men. The original HRB contributed four neurocognitive domains, the eHRB expansion three domains, and the Wechsler scales one additional domain but with restructuring of verbal factors.

CONCLUSION

Eight neurocognitive domains underlie performance of healthy cognitive individuals during comprehensive neuropsychological assessment. These domains serve as framework for understanding the constructs measured by commonly-used neuropsychological tests and may represent the structure of neurocognition.

Differences in Neurocognitive Impairment Among HIV-Infected Latinos in the United States

OBJECTIVES

Human immunodeficiency virus (HIV) disproportionately affects Hispanics/Latinos in the United States, yet little is known about neurocognitive impairment (NCI) in this group. We compared the rates of NCI in large well-characterized samples of HIV-infected (HIV+) Latinos and (non-Latino) Whites, and examined HIV-associated NCI among subgroups of Latinos.

METHODS

Participants included English-speaking HIV+ adults assessed at six U.S. medical centers (194 Latinos, 600 Whites). For overall group, age: M=42.65 years, SD=8.93; 86% male; education: M=13.17, SD=2.73; 54% had acquired immunodeficiency syndrome. NCI was assessed with a comprehensive test battery with normative corrections for age, education and gender. Covariates examined included HIV-disease characteristics, comorbidities, and genetic ancestry.

RESULTS

Compared with Whites, Latinos had higher rates of global NCI (42% vs. 54%), and domain NCI in executive function, learning, recall, working memory, and processing speed. Latinos also fared worse than Whites on current and historical HIV-disease characteristics, and nadir CD4 partially mediated ethnic differences in NCI. Yet, Latinos continued to have more global NCI [odds ratio (OR)=1.59; 95% confidence interval (CI)=1.13-2.23; p<.01] after adjusting for significant covariates. Higher rates of global NCI were observed with Puerto Rican (n=60; 71%) versus Mexican (n=79, 44%) origin/descent; this disparity persisted in models adjusting for significant covariates (OR=2.40; CI=1.11-5.29; p=.03).

CONCLUSIONS

HIV+ Latinos, especially of Puerto Rican (vs. Mexican) origin/descent had increased rates of NCI compared with Whites. Differences in rates of NCI were not completely explained by worse HIV-disease characteristics, neurocognitive comorbidities, or genetic ancestry. Future studies should explore culturally relevant psychosocial, biomedical, and genetic factors that might explain these disparities and inform the development of targeted interventions. (JINS, 2018, 24, 163-175).

Uncorrected versus demographically-corrected scores on the NIH Toolbox Cognition Battery in persons with traumatic brain injury and stroke

OBJECTIVE

The association between demographic characteristics and neurocognitive performance is well established; however, clinicians may have difficulty selecting when to use uncorrected versus demographically corrected scores. We compared these score types in individuals with traumatic brain injury (TBI) and stroke, on the National Institutes of Health Toolbox-Cognition Battery (NIHTB-CB).

RESEARCH METHOD

Adults with TBI and stroke were demographically matched to controls, and completed the NIHTB-CB. Published "corrected scores" are adjusted for age, education, sex, and race/ethnicity; "uncorrected scores" were created using census data to represent the average adult in the U.S.

POPULATION

RESULTS

Effect sizes for the TBI and stroke groups versus controls were larger using corrected scores compared with uncorrected scores for the fluid composite (uncorrected to corrected effect sizes: TBI: d = 0.66, p < .001 to 0.83, p < .001; stroke d = 0.97, p < .001 to 1.10, p < .001). For the crystallized composite, effect sizes for the TBI and stroke groups versus controls were smaller and nonsignificant using corrected scores (uncorrected to corrected effect sizes: TBI d = 0.23, p = .03 to 0.20, p = .06; stroke d = 0.40, p < .001 to 0.17, p = .09). In the injury groups, demographic characteristics accounted for up to 33% of variance in uncorrected scores (p < .001), but <5% of variance in corrected scores (p > .06).

CONCLUSIONS

Corrected scores were more sensitive to neurocognitive impairments in the brain-injured groups. Corrected scores have the advantage of controlling for variance associated with premorbid factors rather than changes in neurological functioning; are more helpful in characterizing acquired neurocognitive changes; and can aid in the interpretation of test performance. (PsycINFO Database Record

Racial Differences in Neurocognitive Outcomes Post-Stroke: The Impact of Healthcare Variables

OBJECTIVES

The present study examined differences in neurocognitive outcomes among non-Hispanic Black and White stroke survivors using the NIH Toolbox-Cognition Battery (NIHTB-CB), and investigated the roles of healthcare variables in explaining racial differences in neurocognitive outcomes post-stroke.

METHODS

One-hundred seventy adults (91 Black; 79 White), who participated in a multisite study were included (age: M=56.4; SD=12.6; education: M=13.7; SD=2.5; 50% male; years post-stroke: 1-18; stroke type: 72% ischemic, 28% hemorrhagic). Neurocognitive function was assessed with the NIHTB-CB, using demographically corrected norms. Participants completed measures of socio-demographic characteristics, health literacy, and healthcare use and access. Stroke severity was assessed with the Modified Rankin Scale.

RESULTS

An independent samples t test indicated Blacks showed more neurocognitive impairment (NIHTB-CB Fluid Composite T-score: M=37.63; SD=11.67) than Whites (Fluid T-score: M=42.59, SD=11.54; p=.006). This difference remained significant after adjusting for reading level (NIHTB-CB Oral Reading), and when stratified by stroke severity. Blacks also scored lower on health literacy, reported differences in insurance type, and reported decreased confidence in the doctors treating them. Multivariable models adjusting for reading level and injury severity showed that health literacy and insurance type were statistically significant predictors of the Fluid cognitive composite (p<.001 and p=.02, respectively) and significantly mediated racial differences on neurocognitive impairment.

CONCLUSIONS

We replicated prior work showing that Blacks are at increased risk for poorer neurocognitive outcomes post-stroke than Whites. Health literacy and insurance type might be important modifiable factors influencing these differences. (JINS, 2017, 23, 640-652).

Lower CSF Aβ is Associated with HAND in HIV-Infected Adults with a Family History of Dementia

BACKGROUND

Both family history of dementia (FHD) and lower levels of Aβ-42 are indepentently associated with worse neurocognitive functioning in HIVinfected patients.

OBJECTIVE

To examine the relationships between cerebrospinal fluid (CSF) Aβ-42 and FHD with HIV-associated neurocognitive disorders (HAND).

METHODS

One hundred eighty-three HIV+ adults underwent neuropsychological and neuromedical assessments, and determination of CSF Aβ-42 concentration and FHD (defined as a self-reported first or second-degree relative with a dementia diagnosis). Univariate analyses and multivariable logistic regressions were used.

RESULTS

FHD was not associated with HAND (p = 0.24); however, CSF Aβ-42 levels were lower (p = 0.03) in the HAND group, but were not associated with FHD (p = 0.89). Multivariable models showed a main effect of CSF Aβ-42 (p = 0.03) and a trend-level (p = 0.06) interaction between FHD and CSF Aβ-42, such that lower CSF Aβ-42 was associated with HAND in those with FHD (p < 0.01) compared to those without FHD (p = 0.83). An analysis in those with follow-up data showed that higher baseline CSF Aβ-42 was associated with lower risk of neurocognitive decline (p = 0.02). While we did not find an FHD X CSF Aβ-42 interaction (p = 0.83), when analyses were stratified by FHD, lower CSF Aβ-42 was associated at the trend-level with neurocognitive decline in the FHD group (p = 0.08) compared to the no FHD group (p = 0.15).

CONCLUSION

FHD moderates the relationship between of CSF Aβ-42 and HAND. The findings highlight the complexities in interpreting the relationships between biomarkers of age-related neurodegeneration and HAND.

Feasibility and Acceptability of Ecological Momentary Assessment of Daily Functioning Among Older Adults with HIV

OBJECTIVE

This study aimed to examine the feasibility, acceptability, and initial validity of using smartphone-based ecological momentary assessment (EMA) to assess daily functioning and other behavioral factors among older HIV+ adults.

METHODS

Twenty older HIV+ adults (mean age: 59 years) completed laboratory-based neurobehavioral and functional assessments then completed EMA surveys via smartphones five times per day for one week.

RESULTS

Excellent EMA adherence (86.4%) was found, and participants rated their experience with EMA methods positively. Time-use data indicated participants were spending 74% of their waking-sampled time at home, 63% of their time alone, and 32% of their time engaged in passive leisure activities (e.g., watching TV). Better neurocognitive and functional capacity abilities were correlated with less time spent in passive leisure activities. Lastly, mood and cognitive symptom data collected via EMA were significantly associated with scores from laboratory-based assessments of these same constructs.

CONCLUSIONS

EMA via smartphones is a feasible and acceptable data collection method among older HIV+ adults and appears to be a promising mobile tool to assess daily functioning behaviors in HIV. These preliminary findings indicate older HIV+ adults are spending a considerable amount of time at home, alone, and engaged in passive leisure activities, primarily watching TV. EMA may contribute to future research examining functional disability among the growing population of older HIV+ adults.

Genome-wide association study of HIV-associated neurocognitive disorder (HAND): A CHARTER group study

HIV-associated neurocognitive disorder (HAND) often complicates HIV infection despite combination antiretroviral therapy (ART) and may be influenced by host genomics. We performed a genome-wide association study (GWAS) of HAND in 1,050 CNS HIV Anti-Retroviral Therapy Effects Research (CHARTER) Study participants. All participants underwent standardized, comprehensive neurocognitive, and neuromedical assessments to determine if they had cognitive impairment as assessed by the Global Deficit Score (GDS), and individuals with comorbidities that could confound diagnosis of HAND were excluded. Neurocognitive outcomes included GDS-defined neurocognitive impairment (NCI; binary GDS, 366 cases with GDS ≥ 0.5 and 684 controls with GDS < 0.5, and GDS as a continuous variable) and Frascati HAND definitions that incorporate assessment of functional impairment by self-report and performance-based criteria. Genotype data were obtained using the Affymetrix Human SNP Array 6.0 platform. Multivariable logistic or linear regression-based association tests were performed for GDS-defined NCI and HAND. GWAS results did not reveal SNPs meeting the genome-wide significance threshold (5.0 × 10-8 ) for GDS-defined NCI or HAND. For binary GDS, the most significant SNPs were rs6542826 (P = 8.1 × 10-7 ) and rs11681615 (1.2 × 10-6 ), both located on chromosome 2 in SH3RF3. The most significant SNP for continuous GDS was rs11157436 (P = 1.3 × 10-7 ) on chromosome 14 in the T-cell-receptor alpha locus; three other SNPs in this gene were also associated with binary GDS (P ≤ 2.9 × 10-6 ). This GWAS, conducted among ART-era participants from a single cohort with robust neurological phenotyping, suggests roles for several biologically plausible loci in HAND that deserve further exploration. © 2017 Wiley Periodicals, Inc.

Use of Western Neuropsychological Test Battery in Detecting HIV-Associated Neurocognitive Disorders (HAND) in Zambia

This is a study of neuroAIDS in sub-Saharan Africa, involving 266 Zambian adults infected with the human immunodeficiency virus (HIV), clade C. All HIV+ participants were receiving combination antiretroviral therapy (CART), and were administered a comprehensive neuropsychological (NP) test battery covering seven ability domains that are frequently affected by neuroAIDS. The battery was developed in the U.S. but has been validated in other international settings and has demographically-corrected normative standards based upon 324 healthy Zambian adults. Compared to the healthy Zambian controls, the HIV+ sample performed worse on the NP battery with a medium effect size (Cohen's d = 0.64). 34.6 % of the HIV+ individuals had global NP impairment and met criteria for HIV associated neurocognitive disorder (HAND). The results indicate that the Western-developed NP test battery is appropriate for use in Zambia and can serve as a viable HIV and AIDS management tool.

Everyday functional ability in HIV and methamphetamine dependence

BACKGROUND

Methamphetamine (METH) use is a risk factor for the transmission of HIV. Each is associated with neurocognitive impairment and subsequent problems in everyday functioning, yet additive effects of HIV and METH are not consistently observed. This study used the UCSD Performance-Based Skills Assessment (UPSA-2) to assess whether METH use disorder and HIV together resulted in poorer functional outcome than either condition alone.

METHOD

Participants in the Translational Methamphetamine AIDS Research Center (TMARC) cohort were stratified based upon HIV infection and METH use disorder: HIV-/METH- (n=49), HIV-/METH+ (n=48), HIV+/METH- (n=37), and HIV+/METH+ (n=38). They were administered the UPSA-2 which measures abilities in six domains of everyday functioning. Main effects and interactions of HIV and METH were examined, as were relationships between UPSA-2 scores and disease characteristics.

RESULTS

Significant HIV-by-METH interactions were observed for the UPSA-2 total score and Comprehension/Planning and Financial subscales such that METH was associated with lower scores in HIV- participants but not HIV+ participants. METH was associated with lower scores on the Communications subscale. All three risk groups had lower scores than HIV-/METH- participants. Recency and frequency of METH use were associated with lower scores. Lower Medication Management scores were related to lower nadir CD4 counts.

CONCLUSIONS

METH use disorder and HIV each impair functional performance, but there is no additive effect when the two conditions occur together. The neurocognitive sequelae of combined HIV infection and METH use are complex and warrant further study, as do the potential effects of compensatory strategies and other factors.

Performance of Hispanics and Non-Hispanic Whites on the NIH Toolbox Cognition Battery: the roles of ethnicity and language backgrounds

OBJECTIVE

This study examined the influence of Hispanic ethnicity and language/cultural background on performance on the NIH Toolbox Cognition Battery (NIHTB-CB).

METHOD

Participants included healthy, primarily English-speaking Hispanic (n = 93; Hispanic-English), primarily Spanish-speaking Hispanic (n = 93; Hispanic-Spanish), and English speaking Non-Hispanic white (n = 93; NH white) adults matched on age, sex, and education levels. All participants were in the NIH Toolbox national norming project and completed the Fluid and Crystallized components of the NIHTB-CB. T-scores (demographically-unadjusted) were developed based on the current sample and were used in analyses.

RESULTS

Spanish-speaking Hispanics performed worse than English-speaking Hispanics and NH whites on demographically unadjusted NIHTB-CB Fluid Composite scores (ps < .01). Results on individual measures comprising the Fluid Composite showed significant group differences on tests of executive inhibitory control (p = .001), processing speed (p = .003), and working memory (p < .001), but not on tests of cognitive flexibility or episodic memory. Test performances were associated with language/cultural backgrounds in the Hispanic-Spanish group: better vocabularies and reading were predicted by being born outside the U.S., having Spanish as a first language, attending school outside the U.S., and speaking more Spanish at home. However, many of these same background factors were associated with worse Fluid Composites within the Hispanic-Spanish group.

CONCLUSIONS

On tests of Fluid cognition, the Hispanic-Spanish group performed the poorest of all groups. Socio-demographic and linguistic factors were associated with those differences. These findings highlight the importance of considering language/cultural backgrounds when interpreting neuropsychological test performances. Importantly, after applying previously published NIHTB-CB norms with demographic corrections, these language/ethnic group differences are eliminated.

Depressive symptoms in HIV-infected and seronegative control subjects in Cameroon: Effect of age, education and gender

Depression is a leading cause of HIV/AIDS disease burden; it worsens health outcomes and quality of life. Addressing this problem requires accurate quantification of the extra burden of depression to HIV/AIDS in a given population, and knowledge of the baseline depression prevalence in the general population. There has been no previous study of depression in the general Cameroonian population. The current study attempts to address that important need. We used the Beck Depression Inventory-II to assess the prevalence and severity of depressive symptoms in 270 HIV-infected and seronegative Cameroonians. Univariate analyses showed a trend toward higher depressive symptoms among cases, compared to controls (p = 0.055), and among older subjects (>40 years), compared to younger subjects (≤40 years) (p = 0.059). Analysis of depression severity showed that 33.73% of cases had moderate-to-severe depressive symptoms, compared to 19.8% of controls (p<0.01). However, multivariable negative binomial regression analyses showed no effect of age, HIV status, CD4 levels, viral loads, ART, or opportunistic infections on the risk of depressive symptoms. Both univariate and multivariable regression analyses showed significantly higher risk of depressive symptoms among females compared to males; this was significant for both female controls and female cases. Female cases had significantly higher CD4 cell counts and lower viral loads, compared to males. Both univariate and multivariable regression analyses showed that lower education (≤10 years) was associated with increased risk of depressive symptoms. This study shows a high prevalence of depressive symptoms among seronegative controls and HIV-infected Cameroonians. Integrating care for mental disorders such as depression into primary health care and existing HIV/AIDS treatment programs in Cameroon may improve the wellbeing of the general population and could lower the HIV/AIDS burden.

Altered reward expectancy in individuals with recent methamphetamine dependence

BACKGROUND

Chronic methamphetamine use may lead to changes in reward-related function of the ventral striatum and caudate nucleus. Whether methamphetamine-dependent individuals show heightened reactivity to positively valenced stimuli (i.e. positive reinforcement mechanisms), or an exaggerated response to negatively valenced stimuli (i.e. driven by negative reinforcement mechanisms) remains unclear. This study investigated neural functioning of expectancy and receipt for gains and losses in adults with (METH+) and without (METH-) histories of methamphetamine dependence.

METHODS

Participants (17 METH+; 23 METH-) performed a probabilistic feedback expectancy task during blood-oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI). Participants were given visual cues probabilistically associated with monetary gain, loss, or neutral outcomes. General linear models examined the BOLD response to: (1) anticipation of gains and losses, and (2) gain and loss monetary outcomes.

RESULTS

METH+ had less BOLD response to loss anticipation than METH- in the ventral striatum and posterior caudate. METH+ also showed more BOLD response to loss outcomes than to gain outcomes in the anterior and posterior caudate, whereas METH- did not show differential responses to the valence of outcomes.

DISCUSSION

METH+ individuals showed attenuated neural response to anticipated gains and losses, but their response to loss outcomes was greater than to gain outcomes. A decreased response to loss anticipation, along with a greater response to loss outcomes, suggests an altered ability to evaluate future risks and benefits based upon prior experience, which may underlie suboptimal decision-making in METH+ individuals that increases the likelihood of risky behavior.

Latent Toxoplasma Infection and Higher Toxoplasma gondii Immunoglobulin G Levels Are Associated With Worse Neurocognitive Functioning in HIV-Infected Adults

BACKGROUND

 Human immunodeficiency virus (HIV)-associated neurocognitive disorders persist despite suppressive antiretroviral therapy (ART). Because latent Toxoplasma infection (LTI) may adversely impact brain function, we investigated its impact on neurocognitive impairment (NCI) in people living with HIV disease.

METHODS

 Two hundred sixty-three HIV-infected adults underwent comprehensive neurocognitive assessments and had anti-Toxoplasma gondii immunoglobulin G (anti-Toxo IgG) measured by qualitative and quantitative enzyme-linked immunosorbent assays.

RESULTS

 Participants were mostly middle-aged white men who were taking ART (70%). LTI was detected in 30 (11.4%) participants and was associated with a significantly greater prevalence of global NCI (LTI positive [LTI⁺] = 57% and LTI negative [LTI^-] = 34%) (odds ratio, 1.67; 95% confidence interval, 1.17-2.40; P = .017). Deficits were more prevalent in the LTI⁺ vs the LTI^- group in 6 of 7 cognitive domains with statistical significance reached for delayed recall (P < .01). The probability of NCI increased with higher CD4⁺ T-cell counts among LTI⁺ individuals but with lower CD4⁺ T-cell counts in LTI^- persons. A strong correlation (r = .93) between anti-Toxo IgG levels and global deficit score was found in a subgroup of 9 patients. Biomarkers indicative of central nervous system inflammation did not differ between LTI⁺ and LTI^- participants.

CONCLUSIONS

 In this cross-sectional analysis, LTI was associated with NCI, especially in those with higher CD4⁺ T-cell counts. Longitudinal studies to investigate the role of neuroinflammation and neuronal injury in LTI patients with NCI and trials of anti-Toxoplasma therapy should be pursued.

Prevalence and Correlates of Persistent HIV-1 RNA in Cerebrospinal Fluid During Antiretroviral Therapy

BACKGROUND

 Neurocognitive disorders remain common among human immunodeficiency virus (HIV)-positive adults, perhaps owing to persistent HIV-1 RNA in cerebrospinal fluid (CSF) during antiretroviral therapy (ART).

METHODS

 Using a single-copy assay, we measured HIV-1 RNA levels in CSF and plasma specimens from 220 HIV-positive adults who were taking suppressive ART. Fifty-five participants were tested twice.

RESULTS

 HIV-1 RNA was detected in 42.3% of CSF and 65.2% of plasma samples. Correlates of higher CSF HIV-1 RNA levels included higher nadir and current CD4⁺ T-cell counts, a plasma HIV-1 RNA level of ≥ 1 copy/mL, and a lower central nervous system penetration-effectiveness score (model P < .001). Worse neurocognitive performance was associated with discordance in HIV-1 RNA detection between plasma and CSF, lower overall CSF HIV-1 RNA level, and longer ART duration, among others (model P < .001). In the longitudinal subgroup, CSF HIV-1 RNA persisted in most participants (69%) over 7 months.

CONCLUSIONS

 Low-level HIV-1 RNA in CSF is common during suppressive ART and is associated with low-level HIV-1 RNA in blood, better immune status, and lower ART drug distribution into CSF. The association between HIV-1 RNA discordance and HIV-associated neurocognitive disorder (HAND) may reflect compartmentalization. The relationship between HAND, lower HIV-1 RNA levels in CSF, and lower CD4⁺ T-cell counts may reflect disturbances in the immune response to HIV-1 in the CNS.

Evaluating the accuracy of self-report for the diagnosis of HIV-associated neurocognitive disorder (HAND): defining "symptomatic" versus "asymptomatic" HAND

The criteria for differentiating symptomatic from asymptomatic HIV-associated neurocognitive disorder require evaluation of (1) cognitive impairment, (2) daily functioning declines, and (3) whether the functional declines are attributable to cognitive versus physical problems. Many providers rely only on self-report to evaluate these latter criteria. However, the accuracy of patient-provided information may be limited. This study evaluated the validity of self-assessment for HIV-associated neurocognitive disorder (HAND) diagnoses by comparing objective findings with self-report of criteria 2 and 3 above. Self-reports were used to stratify 277 cognitively impaired HIV+ individuals into functionally dependent (n = 159) and independent (n = 118) groups, followed by group comparisons of objective functional problems. The dependent group was then divided into those who self-attributed their functional dependence to only cognitive (n = 80) versus only physical (n = 79) causes, for further comparisons on objective findings. The functionally dependent group was significantly worse than the independent group on all objective disability characteristics except severity of cognitive impairment, while those who attributed their dependence to physical (versus cognitive) factors were similar on all objective physical, cognitive, and functioning variables. Of note, 28 % of physical attributors showed no physical abnormalities on neuromedical examinations. Results suggest that patient report is consistently associated with objective measures of functional loss; in contrast, patient identification of physical versus cognitive causes is poorly associated with objective criteria. These findings caution against relying solely on patient self-report to determine whether functional disability in cognitively impaired HIV+ individuals can be attributed to strictly physical causes.