Normative data and validation of a regression based summary score for assessing meaningful neuropsychological change

Cognitive ageing is premature among a community sample of optimally treated people living with HIV

OBJECTIVES

Evidence of premature cognitive ageing amongst people living with HIV (PLHIV) remains controversial due to previous research limitations including underpowered studies, samples with suboptimal antiretroviral access, varying rate of virological control, high rate of AIDS, over-representation of non-community samples, and inclusion of inappropriate controls. The current study addresses these limitations, while also considering mental health and non-HIV comorbidity burden to determine whether PLHIV showed premature cognitive ageing compared with closely comparable HIV-negative controls.

METHODS

This study enrolled 254 PLHIV [92% on antiretroviral therapy; 84% with HIV RNA < 50 copies/mL; 15% with AIDS) and 72 HIV-negative gay and bisexual men [mean (SD) age = 49 (10.2) years] from a single primary care clinic in Sydney, Australia. Neurocognitive function was evaluated with the Cogstate Computerized Battery (CCB) at baseline and 6 months after. Linear mixed-effects (LME) models examined main and interaction effects of HIV status and chronological age on the CCB demographically uncorrected global neurocognitive z-score (GZS), adjusting for repeated testing, and then adjusting sequentially for HIV disease markers, mental health and comorbidities.

RESULTS

HIV status and age interacted with a lower GZS (β = -0.43, P < 0.05). Higher level of anxiety symptoms (β = -0.11, P < 0.01), historical AIDS (β = -0.12, P < 0.05) and historical HIV brain involvement (β = -0.12, P < 0.05) were associated with lower GZS.

CONCLUSIONS

We found a robust medium-sized premature ageing effect on cognition in a community sample with optimal HIV care. Our study supports routine screening of cognitive and mental health among PLHIV aged ≥ 50 years.

The utility of olfactory function in distinguishing early-stage Alzheimer's disease from HIV-associated neurocognitive disorders

OBJECTIVES

Given the rising number of older people with HIV (PWH) and the overlap in cognitive dysfunction profiles in HIV-associated neurocognitive disorders (HAND) and Alzheimer's disease and its precursor, amnestic mild cognitive impairment (aMCI), methods are needed to distinguish aMCI/Alzheimer's disease from HAND. As an early indicator of Alzheimer's disease, we examined whether olfactory dysfunction could help to distinguish between aMCI/Alzheimer's disease and HAND among PWH.

DESIGN

An observational cohort study.

METHODS

Eighty-one older (≥50 years) PWH (83% men, 65% white) from the California NeuroAIDS Tissue Consortium completed the University of Pennsylvania Smell Identification Test (UPSIT; higher scores = better smell identification) and a comprehensive seven-domain neuropsychological test battery and neuromedical evaluation. HAND was classified via Frascati criteria. High aMCI risk was defined as impairment (>1.0 SD below normative mean) on two of four delayed recall or recognition outcomes (at least one recognition impairment required) from the Hopkins Verbal Learning Test-Revised and the Brief Visuospatial Memory Test-Revised. We examined UPSIT scores in relation to aMCI risk and HAND status, and continuous memory scores considering adjustments for demographics and relevant clinical or HIV disease characteristics.

RESULTS

Fifty-seven participants were classified with HAND (70%) and 35 participants were classified as high aMCI risk (43%). UPSIT scores were lower (worse) in the high versus low aMCI risk group [F (1,76) = 10.04, P = 0.002], but did not differ by HAND status [F (1,76) = 0.62, P = 0.43]. UPSIT scores positively correlated with all memory outcomes (Ps < 0.05).

CONCLUSION

Olfactory assessments may help in detecting early aMCI/Alzheimer's disease among PWH and allow for appropriate and early disease intervention.

Chronically elevated depressive symptoms interact with acute increases in inflammation to predict worse neurocognition among people with HIV

We examined the joint effects of depressive symptoms (Beck Depression Inventory-II (BDI-II)) and systemic inflammation (plasma C-reactive protein (CRP)) on longitudinal profiles of neurocognition in a cohort of 143 people with HIV (PWH) on antiretroviral therapy. Global neurocognition, processing speed, motor skills, and attention/working memory all worsened as CRP increased but only among PWH who, on average, exhibited moderate to severe depressive symptoms (BDI-II > 22). Findings suggest that some PWH with chronically elevated depressive symptoms may have an inflammatory subtype of depression and a particular vulnerability to neurocognitive changes that may respond to drugs targeting inflammation or its neural sequelae.

Neurocognitive impairment in Spanish-speaking Latinos living with HIV in the US: Application of the neuropsychological norms for the US-Mexico border region in Spanish (NP-NUMBRS)

Objective Latinos in the US are at increased risk for HIV-associated neurocognitive impairment (NCI). Most studies of US Latinos living with HIV have included primarily English-speakers only. We investigated the rate, pattern, and correlates of HIV-associated NCI in native Spanish-speaking Latinos living in the US near the Mexican border. Methods Participants included 407 native Spanish-speaking Latinos (Age: M = 37.65, SD = 10.0; Education: M = 10.75, SD = 4.1; 53% male): 153 persons living with HIV (PLWH; 56% AIDS) and 254 healthy controls. All participants completed comprehensive neuropsychological assessments in Spanish. Raw neuropsychological test scores from seven domains were converted to demographically-adjusted T-scores using norms developed with healthy controls. Global and domain NCI were defined per established criteria. Among PLWH we applied norms developed for non-Hispanic (NH) Whites and Blacks, and investigated correlates of global NCI, including HIV disease characteristics and psychiatric comorbidities. Results Utilizing population specific norms, rates of global NCI were significantly higher among PLWH (39%) than healthy controls (17%), comparable to previously published rates. In contrast, rates of global NCI in the same group of PLWH were significantly different when NH White norms (63%, p < 0.0001) and NH Black norms were used (18%, p < 0.0001). Among PLWH without a history of lifetime substance use disorder, more years of antiretroviral exposure were significantly associated with decreased rates of global NCI. Conclusions Present findings lend support to the validity of newly developed norms for native Spanish-speakers living near the US-Mexico border, and underscore the importance of utilizing appropriate norms to accurately identify HIV-associated NCI.

Cumulative Burden of Depression and Neurocognitive Decline Among Persons With HIV: A Longitudinal Study

BACKGROUND

Higher cumulative burden of depression among people with HIV (PWH) is associated with poorer health outcomes; however, longitudinal relationships with neurocognition are unclear. This study examined hypotheses that among PWH, (1) higher cumulative burden of depression would relate to steeper declines in neurocognition, and (2) visit-to-visit depression severity would relate to fluctuations in neurocognition within persons.

SETTING

Data were collected at a university-based research center from 2002 to 2016.

METHODS

Participants included 448 PWH followed longitudinally. All participants had >1 visit (M = 4.97; SD = 3.53) capturing depression severity (Beck Depression Inventory-II) and neurocognition (comprehensive test battery). Cumulative burden of depression was calculated using an established method that derives weighted depression severity scores by time between visits and total time on study. Participants were categorized into low (67%), medium (15%), and high (18%) depression burden. Multilevel modeling examined between- and within-person associations between cumulative depression burden and neurocognition over time.

RESULTS

The high depression burden group demonstrated steeper global neurocognitive decline compared with the low depression burden group (b = -0.100, P = 0.001); this was driven by declines in executive functioning, delayed recall, and verbal fluency. Within-person results showed that compared with visits when participants reported minimal depressive symptoms, their neurocognition was worse when they reported mild (b = -0.12, P = 0.04) or moderate-to-severe (b = -0.15, P = 0.03) symptoms; this was driven by worsened motor skills and processing speed.

CONCLUSIONS

High cumulative burden of depression is associated with worsening neurocognition among PWH, which may relate to poor HIV-related treatment outcomes. Intensive interventions among severely depressed PWH may benefit physical, mental, and cognitive health.

Asymptomatic neurocognitive impairment is a risk for symptomatic decline over a 3-year study period

OBJECTIVE

To examine whether persons with asymptomatic neurocognitive impairment (ANI) were more likely to show progression to mild neurocognitive disorder or HIV-associated dementia than those who were neuropsychologically normal (NP-N).

DESIGN

Longitudinal observational cohort study.

METHODS

Study sample included 720 HIV-1 seropositive persons (317 with ANI and 403 NP-N) receiving care in Toronto, Canada [83% were on antiretroviral treatment; 71% had undetectable (<50 copies/ml) plasma HIVRNA]. Neuropsychological assessments were conducted at 12 months intervals for a median follow-up time of 34 months. Neuropsychological data were corrected for age, education, sex, and race/ethnicity, and corrected for practice effect at follow-ups. Progression to mild neurocognitive disorder and HIV-associated dementia at each time point was determined using the Global Deficit Score and presence of cognitive symptoms.

RESULTS

Over the follow-up period, 170 individuals (24%) progressed to symptomatic HIV-associated neurocognitive disorders (HAND). Persons with ANI were more likely to progress to symptomatic HAND than persons with NP-N after adjusting for baseline and time-varying confounders (adjusted hazards ratio: 1.88; 95% confidence interval: 1.37-2.60; P < 0.001). Female sex, depression, and cigarette smoking were associated with higher risk of progression to symptomatic HAND, but traditional HIV markers and antiretroviral treatment were not.

CONCLUSION

ANI is associated with a two-fold increased risk of progression to symptomatic HAND in a cohort with universal healthcare access. This represents the largest replication of comparable US results. Reproducibility of these findings indicate that routine monitoring of persons with ANI and exploration of clinical interventions to prevent or delay progression to symptomatic HAND are imperative.

SEARCH TERMS

HIV, HAND, HIV-associated dementia, cohort study, replicability, reproducibility.

Distinguishing Amnestic Mild Cognitive Impairment From HIV-Associated Neurocognitive Disorders

BACKGROUND

Memory impairment occurs in human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) and amnestic mild cognitive impairment (aMCI), the precursor to Alzheimer disease (AD). Methods are needed to distinguish aMCI-associated from HAND-associated impairment in people with HIV (PWH). We developed a neuropsychological method of identifying aMCI in PWH and tested this by relating AD neuropathology (β-amyloid, phospho-Tau) to aMCI versus HAND classification.

METHODS

Seventy-four HIV-positive cases (aged 50-68 years) from the National NeuroAIDS Tissue Consortium had neurocognitive data within 1 year of death and data on β-amyloid and phospho-Tau pathology in frontal brain tissue. High aMCI risk was defined as impairment (<1.0 SD below normative mean) on 2 of 4 delayed recall or recognition outcomes from a verbal and nonverbal memory test (at least 1 recognition impairment required). Differences in β-amyloid and phospho-Tau by aMCI and HAND classification were examined.

RESULTS

High aMCI risk was more common in HAND (69.0%) versus no HAND (37.5%) group. β-amyloid pathology was 4.75 times more likely in high versus low aMCI risk group. Phospho-Tau pathology did not differ between aMCI groups. Neither neuropathological feature differed by HAND status.

CONCLUSIONS

Amnestic mild cognitive impairment criteria that include recognition impairment may help to detect AD-like cognitive/biomarker profiles among PWH.

Smartphone-Based Measurement of Executive Function in Older Adults with and without HIV

OBJECTIVE

To examine feasibility, convergent validity and biases associated with a mobile color-word interference test (mCWIT) among older persons living with HIV (PLHIV).

METHOD

Over a 14-day period, 58 PLHIV and 32 HIV-uninfected individuals (aged 50-74) completed the mCWIT on smartphones once per day in real-world settings. Participants also completed a comprehensive laboratory-based neuropsychological evaluation.

RESULTS

A high rate of compliance was observed (86%) in the repeated administration of the mCWIT. A practice effect was observed in the overall sample concerning mCWIT subscores, and these learning effects were greater for PLHIV. Stabilization of performance was observed after 6 (HIV+) and 7 days (HIV-) for completion time and after 2 (HIV-) and 3 days (HIV+) for mCWIT errors. A minor fatigue effect was observed in the overall sample which was unassociated with group status. Moderate to strong correlations were found between mCWIT completion time and mCWIT errors with global neurocognition and with all of the individual neurocognitive domains. The strongest associations were with mCWIT completion time and laboratory-based global neurocognition, executive function, and working memory scores.

CONCLUSIONS

Cognitive testing administered within the context of a person's daily life provides qualitatively different data than neuropsychological testing completed in clinical settings, and it may constitute a more ecologically valid indicator of cognitive performance than traditional methods. Mobile cognitive testing has potential to help characterize real-time cognitive performance and serve as a complementary assessment tool to traditional methods.

Factors Predicting Detrimental Change in Declarative Memory Among Women With HIV: A Study of Heterogeneity in Cognition

Objective

Statistical techniques used to study cognitive function in HIV typically yield normative estimates and can mask the heterogeneity in cognitive trajectories over time. We applied a novel statistical approach to identify clusters of individuals with distinct patterns of change in declarative memory in HIV-seropositive (HIV+) and HIV-seronegative (HIV−) women.

Methods

1731 women from the Women’s Interagency HIV Study, a multi-center, prospective cohort study, completed the Hopkins Verbal Learning Test-Revised (HLVT-R) at >2 visits. To derive subgroups with similar patterns of decline by HIV-serostatus, we used a mixed-effects framework that modeled the trajectory of multiple declarative memory outcomes over time, while simultaneously clustering individuals.

Results

Of the 1731 participants, 1149 were HIV+ (70% Black/African American [AA]; 30% White/Other [W/O]) and 582 were HIV− (68% AA; 32% W/O). Race stratification was necessary to optimize clustering. Among HIV+AA’s, four subgroups emerged: a subgroup with minimal decline, two with accelerated decline, and one with stable but low performance. In HIV− AA, three subgroups emerged: one with minimal decline and two with accelerated decline. In multivariable-adjusted models among HIV+, individuals with accelerated decline were less educated (P < 0.001) and more likely to have a history of depression (P < 0.001) versus those with minimal decline. Similar subgroups were identified in W/O HIV+ and W/O HIV− participants.

Conclusion

We identified clinically meaningful subgroups of women with distinct phenotypes of declarative memory decline, which depend on race and HIV-serostatus using a data driven approach. Identification of underlying mechanisms and risk factors contributing to the observed differences are warranted. More broadly our modeling approach could be other populations to identify risk factors for accelerated cognitive decline and to personalize interventions.

An examination of reliable change methods for measuring cognitive change with the Cogstate Computerized Battery: Research and clinical implications

Objective

To compare the performance of four reliable change (RC) methods with respect to measuring cognitive change on the Cogstate Computerized Battery (CCB).

Method

We assessed cognitive change in 57 healthy, urban, well-educated males on the CCB at baseline and 6 months (Median age = 50, 65% university-educated). The study CCB version comprised seven measures covering attention, processing speed, verbal learning, and memory. Raw scores were z-score transformed using age-corrected Cogstate norms (CN) or the sample mean and standard deviation (internal standardization [IS]), and then averaged to create composite z-scores. Composite scores were entered into four RC formulae. RC was defined based on a 90% two-tailed confidence interval. Change scores were compared as continuous (z-scores) and ordinal variables (RC outcomes).

Results

CCB composite score reliability (rXY = .78–.79) was replicated in an age- and sex-matched Cogstate database sample of similar size. There was good overall agreement between the four RC methods (Bland–Altman Mdiff = .00; 95% limits of agreement with the mean—CN: z = ± .90; IS: z = ± .93), with each model adhering closely to the 10% rate of RC expected by chance alone (largest χ2 = .86, p = .99). Initial norming strategy (CN or IS) did not affect these outcomes.

Conclusions

Norming strategy and RC method choice did not significantly impact cognitive change predictions on CCB composite scores. A series of example case data are provided to practically demonstrate the steps involved in applying the longitudinal norms generated in this study. Research in more diverse normative samples is warranted.

Late cognitive outcomes among allogeneic stem cell transplant survivors: follow-up data from a 6-year longitudinal study

CONTEXT

Survivors of allogeneic hematopoietic stem cell transplantation (alloHCT) may experience cognitive impairment over time post-treatment, but early identification of these individuals is limited.

OBJECTIVES

We previously reported a prospective evaluation of cognitive functioning over the first 6 months of alloHCT. Here, we report an extension of this study, with specific aims to (1) evaluate the trajectory of cognitive outcomes over the first 6 years post-alloHCT, and (2) determine the extent to which late cognitive impairment is predicted by earlier impairment.

METHODS

Participants completed objective and subjective cognitive measures before alloHCT, and at 100 days, 6 months, and 6 years post-alloHCT. Outcome trajectories were determined using linear mixed effects models. Relationships between early and late cognitive impairment were assessed using logistic regression and receiver operator curves.

RESULTS

This analysis is based on longitudinal data from 59 participants, of whom 20 provided data at 6-year follow-up. Longitudinal models revealed an overall stability of cognitive outcomes over time, except for psychomotor efficiency/processing speed performance, which significantly improved (p = .049). However, poor learning/memory and cognitive complaints were persistently observed. At 6 years, 40% of relapse-free survivors met the impairment criteria. Impairment at 100 days was associated with impairment 6 years (OR = 20.00, p = .028) and demonstrated good accuracy in classifying those who were impaired and not impaired at 6 years (AUC = .79; 95% CI = .56-1.00).

CONCLUSION

Poor cognitive outcomes among long-term alloHCT survivors are associated with cognitive functioning during the early post-treatment period. Early identification of survivors likely to experience poor cognitive outcomes may be possible, enabling timely intervention to mitigate long-term negative impacts.

Daily Activities Related to Mobile Cognitive Performance in Middle-Aged and Older Adults: An Ecological Momentary Cognitive Assessment Study

Background

Daily activities have been associated with neurocognitive performance. However, much of this research has used in-person neuropsychological testing that requires participants to travel to a laboratory or clinic, which may not always be feasible and does not allow for the examination of real-time relationships between cognition and behavior. Thus, there is a need to understand the real-time relationship between activities in the real world and neurocognitive functioning to improve tracking of symptoms or disease states and aid in the early identification of neurocognitive deficits among at-risk individuals.

Objective

We used a smartphone-based ecological momentary cognitive assessment (EMCA) platform to examine real-time relationships between daily activities and neurocognitive performance (executive functioning and verbal learning) in the everyday environment of middle-aged and older adults with and without HIV.

Methods

A total of 103 adults aged 50-74 years (67 persons with HIV; mean age 59 years, SD 6.4) were recruited from the University of California, San Diego HIV Neurobehavioral Research Program and the San Diego community. Participants completed our EMCA protocol for 14 days. Participants reported their current daily activities 4 times per day; following 2 of the 4 daily ecological momentary assessment (EMA) surveys, participants were administered the mobile Color-Word Interference Test (mCWIT) and mobile Verbal Learning Test (mVLT), each once per day. Activities were categorized into cognitively stimulating activities, passive leisure activities, and instrumental activities of daily living (IADLs). We used multilevel modeling to examine the same-survey and lagged within-person and between-person effects of each activity type on mobile cognitive performance.

Results

On average, participants completed 91% of the EMA surveys, 85% of the mCWIT trials, and 80% of the mVLT trials, and they reported engaging in cognitively stimulating activities on 17% of surveys, passive leisure activities on 33% of surveys, and IADLs on 20% of surveys. Adherence and activity percentages did not differ by HIV status. Within-persons, engagement in cognitively stimulating activities was associated with better mCWIT performance (β=−1.12; P=.007), whereas engagement in passive leisure activities was associated with worse mCWIT performance (β=.94; P=.005). There were no lagged associations. At the aggregate between-person level, a greater percentage of time spent in cognitively stimulating activities was associated with better mean mVLT performance (β=.07; P=.02), whereas a greater percentage of time spent in passive leisure activities was associated with worse mean mVLT performance (β=−.07; P=.01). IADLs were not associated with mCWIT or mVLT performance.

Conclusions

Smartphones present unique opportunities for assessing neurocognitive performance and behavior in middle-aged and older adults’ own environment. Measurement of cognition and daily functioning outside of clinical settings may generate novel insights on the dynamic association of daily behaviors and neurocognitive performance and may add new dimensions to understanding the complexity of human behavior.

Emotional health outcomes are influenced by sexual minority identity and HIV serostatus

For people living with HIV (PLWH) and sexual minorities (SM), the intersection of identities can compound experiences like stigma and discrimination resulting in poor emotional health. We investigated the separate and interactive associations of HIV serostatus and sexual identity with emotional health. Our dataset included 371 participants. Emotional health was assessed by the NIH Toolbox emotion battery which yields negative affect, social satisfaction, and psychological well-being. Regressions were conducted for each composite, with HIV serostatus, sexual identity, and their interaction as independent variables along with covariates. The HIV serostatus x SM identity interaction was statistically significant in the regression of Negative Affect (p = .01): heterosexuals living with HIV had worse Negative Affect compared to heterosexual HIV-persons (p = .01). The interaction terms were for social satisfaction and psychological well-being were not significant. However, among PLWH, sexual minorities reported better Social Satisfaction (p = .03) and marginally better psychological well-being (p = .07) compared to heterosexuals.

HIV influences microtubule associated protein-2: potential marker of HIV-associated neurocognitive disorders

OBJECTIVE

Postmortem brains of patients diagnosed with HIV-1-associated neurocognitive disorders (HAND) exhibit loss of dendrites. However, the mechanisms by which synapses are damaged are not fully understood.

DESIGN

Dendrite length and remodeling occurs via microtubules, the dynamics of which are regulated by microtubule-binding proteins, including microtubule-associated protein 2 (MAP2). The HIV protein gp120 is neurotoxic and interferes with neuronal microtubules. We measured MAP2 concentrations in human cerebrospinal fluid (CSF) and MAP2 immunoreactivity in rat cortical neurons exposed to HIV and gp120.

METHODS

First, we examined whether HIV affects MAP2 levels by analyzing the CSF of 27 persons living with HIV (PLH) whose neurocognitive performance had been characterized. We then used rat cortical neurons to study the mechanisms of HIV-mediated dendritic loss.

RESULTS

PLH who had HAND had greater MAP2 concentrations within the CSF than cognitive normal PLH. In cortical neurons, the deleterious effect of HIV on MAP2-positive dendrites occurred through a gp120-mediated mechanism. The neurotoxic effect of HIV was blocked by a CCR5 antagonist and prevented by Helix-A, a peptide that displaces gp120 from binding to microtubules, conjugated to a nanolipoprotein particle delivery platform.

CONCLUSION

Our findings support that HIV at least partially effects its neurotoxicity via neuronal cytoskeleton modifications and provide evidence of a new therapeutic compound that could be used to prevent the HIV-associated neuropathology.

Distinct cellular immune properties in cerebrospinal fluid are associated with cognition in HIV-infected individuals initiating antiretroviral therapy

We examined the relationship between CSF immune cells and neurocognition and neuronal damage in HIV+ individuals before and after initiating antiretroviral therapy. Multivariate analysis at baseline indicated that greater CD4+ T cell abundance was associated with better cognition (p = .017), while higher CSF HIV RNA was associated with increased neuronal damage (p = .014). Following 24 weeks of antiretroviral therapy, CD8+ T cells, HLA-DR expressing CD4+ and CD8+ T cells, B cells, NK cells, and non-classical monocyte percentage decreased in CSF. Female gender was negatively associated with cognitive performance over time, as was higher percentage of HLA-DR expressing CD8+ T cells at baseline.

Cultural Neuropsychology Considerations in the Diagnosis of HIV-Associated Neurocognitive Disorders

Human Immunodeficiency Virus Type-I (HIV) is a health disparities issue that affects culturally and linguistically diverse (CALD) and underrepresented minority populations to a greater degree than non-Hispanic white populations. Neurologically speaking, CALD populations experience worse HIV-related health outcomes, which are exacerbated by inadequate neurocognitive measures, poor normative samples, and the complex interplay of sociocultural factors that may affect test interpretation. Although cross-cultural neuropsychologists are working diligently to correct this gap in the literature, currently, studies examining neurocognitive outcomes among CALD populations are sparse. The most well-studied CALD groups are of African American/Black and Latinx adults in the US, and the chapter therefore focuses on these studies. There is more limited work among other populations in the US, such as Asians, Native Hawaiians, Pacific Islanders, and American Indians/Alaskan Natives, and even fewer studies for many CALD populations outside of the US. For example, HIV neuropsychology data is rare or nonexistent in the First Peoples of Australia and Indigenous People of Canada. It is often not adequately reported in Europe for the migrant populations within those countries or other world regions that have historically large multicultural populations (e.g., South America, Caribbean countries, Asia, and Africa). Therefore, this chapter reviews HIV-related health disparities faced by CALD populations with focus on North American research where it has been specifically studied, with particular attention given to disparities in HIV-Associated Neurocognitive Disorders (HAND). International data was also included for research with focus on First Peoples of Australia and Indigenous People of Canada. The chapter also examines other sociocultural and health factors, including global and regional (e.g., rural versus urban) considerations, migration, and gender. Further, guidelines for incorporating sociocultural consideration into assessment and interpretation of neurocognitive data and HAND diagnosis when working with HIV-positive CALD populations that would be relevant internationally are provided.

Peripheral Blood Mitochondrial DNA Copy Number Obtained From Genome-Wide Genotype Data Is Associated With Neurocognitive Impairment in Persons With Chronic HIV Infection

BACKGROUND

Mitochondrial DNA (mtDNA) copy number varies by cell type and energy demands. Blood mtDNA copy number has been associated with neurocognitive function in persons without HIV. Low mtDNA copy number may indicate disordered mtDNA replication; high copy number may reflect a response to mitochondrial dysfunction. We hypothesized that blood mtDNA copy number estimated from genome-wide genotyping data is related to neurocognitive impairment (NCI) in persons with HIV.

METHODS

In the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) study, peripheral blood mtDNA copy number was obtained from genome-wide genotyping data as a ratio of mtDNA single-nucleotide polymorphism probe intensities relative to nuclear DNA single-nucleotide polymorphisms. In a multivariable regression model, associations between mtDNA copy number and demographics, blood cell counts, and HIV disease and treatment characteristics were tested. Associations of mtDNA copy number with the global deficit score (GDS), GDS-defined NCI (GDS ≥ 0.5), and HIV-associated neurocognitive disorder (HAND) diagnosis were tested by logistic regression, adjusting for potential confounders.

RESULTS

Among 1010 CHARTER participants, lower mtDNA copy number was associated with longer antiretroviral therapy duration (P < 0.001), but not with d-drug exposure (P = 0.85). mtDNA copy number was also associated with GDS (P = 0.007), GDS-defined NCI (P < 0.001), and HAND (P = 0.002). In all analyses, higher mtDNA copy number was associated with poorer cognitive performance.

CONCLUSIONS

Higher mtDNA copy number estimated from peripheral blood genotyping was associated with worse neurocognitive performance in adults with HIV. These results suggest a connection between peripheral blood mtDNA and NCI, and may represent increased mtDNA replication in response to mitochondrial dysfunction.

Better executive function is independently associated with full HIV suppression during combination therapy

OBJECTIVE

HIV-associated neurocognitive impairment continues to be prevalent and clinically relevant. We examined the relationship between neurocognition and full plasma HIV RNA suppression among study participants over a 15-year period at a large research program.

DESIGN/METHODS

We analyzed the combined prospective studies of the HIV Neurobehavioral Research Program at the University of California at San Diego. Participants were eligible for analysis if on three drug combination antiretroviral therapy with comprehensive neuropsychological testing results. Participants who reported recent nonadherence were excluded. The primary outcome was plasma HIV RNA of 50 copies/ml or less. Generalized estimating equation was used to assess for associations with full virologic suppression taking into account longitudinal visits.

RESULTS

There were 1943 participants at baseline, of whom 69.4% had plasma HIV RNA of 50 copies/ml or less. Participants with full suppression were slightly older, less likely to abuse cocaine, and had significantly better executive function. Multivariate analysis with incorporation of longitudinal visits (total = 5555) confirmed current cocaine abuse to be strongly associated with lack of virologic suppression (odds ratio = 0.45, 95% confidence interval = 0.31-0.63). In contrast, increasing age, increasing years of HIV infection, and increasing executive function (odds ratio = 1.18 for T score change of 10, 95% confidence interval = 1.07-1.30) were associated with full virologic suppression. Lack of virologic suppression at baseline was associated with a significant subsequent decline in executive function.

CONCLUSION

In a 15-year research cohort of almost 2000 HIV-infected individuals on combination antiretroviral therapy, better executive function was associated with full virologic suppression, possibly as a result rather than a cause.

Measurement of Human Immunodeficiency Virus p24 Antigen in Human Cerebrospinal Fluid With Digital Enzyme-Linked Immunosorbent Assay and Association With Decreased Neuropsychological Performance

New tools are needed to understand human immunodeficiency virus central nervous system involvement. Testing 15 cerebrospinal fluid (CSF) samples for p24 antigen, using a high-sensitivity assay, we found a strong correlation trend between CSF p24 concentration and worse neuropsychological performance.

Linked CSF reduction of phosphorylated tau and IL-8 in HIV associated neurocognitive disorder

HIV-associated neurocognitive disorder (HAND) is a common condition in both developed and developing nations, but its cause is largely unknown. Previous research has inconsistently linked Alzheimer’s disease (AD), viral burden, and inflammation to the onset of HAND in HIV-infected individuals. Here we simultaneously measured cerebrospinal fluid (CSF) levels of established amyloid and tau biomarkers for AD, viral copy numbers, and six key cytokines in 41 HIV-infected individuals off combination anti-retroviral therapy (14 with HAND) who underwent detailed clinical and neuropsychological characterization, and compared their CSF patterns with those from young healthy subjects, older healthy subjects with normal cognition, and older people with AD. HAND was associated with the lowest CSF levels of phosphorylated tau (p-Tau₁₈₁) after accounting for age and race. We also found very high CSF levels of the pro-inflammatory interferon gamma-induced protein 10 (IP-10/CXCL10) in HIV regardless of cognition, but elevated CSF interleukin 8 (IL-8/CXCL8) only in HIV-NC but not HAND. Eleven HIV-infected subjects underwent repeat CSF collection six months later and showed strongly correlated longitudinal changes in p-Tau₁₈₁ and IL-8 levels (R = 0.841). These data suggest reduced IL-8 relative to IP-10 and reduced p-Tau₁₈₁ to characterize HAND.

Heterogeneity in neurocognitive change trajectories among people with HIV starting antiretroviral therapy in Rakai, Uganda

Considerable heterogeneity exists in patterns of neurocognitive change in people with HIV (PWH). We examined heterogeneity in neurocognitive change trajectories from HIV diagnosis to 1-2 years post-antiretroviral therapy (ART). In an observational cohort study in Rakai, Uganda, 312 PWH completed a neuropsychological (NP) test battery at two-time points (ART-naïve, 1-2 years post-ART initiation). All NP outcomes were used in a latent profile analysis to identify subgroups of PWH with similar ART-related neurocognitive change profiles. In a subset, we examined subgroup differences pre-ART on cytokine and neurodegenerative biomarkers CSF levels. We identified four ART-related change subgroups: (1) decline-only (learning, memory, fluency, processing speed, and attention measures), (2) mixed (improvements in learning and memory but declines in attention and executive function measures), (3) no-change, or (4) improvement-only (learning, memory, and attention measures). ART-related NP outcomes that are most likely to change included learning, memory, and attention. Motor function measures were unchanged. Subgroups differed on eight of 34 pre-ART biomarker levels including interleukin (IL)-1β, IL-6, IL-13, interferon-γ, macrophage inflammatory protein-1β, matrix metalloproteinase (MMP)-3, MMP-10, and platelet-derived growth factor-AA. The improvement-only and mixed subgroups showed lower levels on these markers versus the no-change subgroup. These findings provide support for the need to disentangle heterogeneity in ART-related neurocognitive changes, to focus on higher-order cognitive processes (learning, memory, attention) as they were most malleable to change, and to better understand why motor function remained unchanged despite ART treatment. Group differences in pre-ART CSF levels provide preliminary evidence of biological plausibility of neurocognitive phenotyping.

Metabolic Syndrome and Neurocognitive Deficits in HIV Infection

BACKGROUND

The adverse consequences of HIV and related comorbidities on the central nervous system remain prevalent in the era of combination antiretroviral therapy. Metabolic syndrome (MetS) is a common comorbidity in HIV and has been linked to increased neurocognitive impairment in the general population. We investigated the association between MetS and neurocognition among persons living with HIV (PLHIV).

METHODS

Participants included 109 PLHIV and 92 HIV-uninfected adults (HIV-) from the Multi-dimensional Successful Aging cohort study at the University of California San Diego (age: M = 50.8, SD = 8.0). Participants completed neuromedical, psychiatric, and neurocognitive assessments. Based on a comprehensive neurocognitive battery, we examined global neurocognitive deficits (based on the entire battery) and neurocognitive deficits in 7 domains (verbal fluency, learning, recall, executive function, working memory, speed of information processing, and fine motor skills). MetS was determined via the standard criteria by the National Cholesterol Education Program's Adult Treatment Panel-III. Covariates examined included demographics and psychiatric comorbidities (and HIV disease characteristics among PLHIV).

RESULTS

MetS had an independent significant effect on global neurocognitive deficits among PLHIV (P = 0.03) but not among their HIV- counterparts (P = 0.93). Among PLHIV, MetS was most strongly associated with the neurocognitive domains of learning, fine motor skills, and executive function. Diabetes and elevated triglycerides were the MetS components most strongly linked with increased global neurocognitive deficits in PLHIV.

CONCLUSIONS

The present findings underscore the need for early identification of PLHIV at risk for MetS and the implementation of preventive and treatment approaches to lessen the development of MetS and neurocognitive impairment among PLHIV.

Properties of a brief assessment tool for longitudinal measurement of cognition in people living with HIV

Background

Mild cognitive impairment is common in chronic HIV infection and there is concern that it may worsen with age. Distinguishing static impairment from on-going decline is clinically important, but the field lacks well-validated cognitive measures sensitive to decline and feasible for routine clinical use. Measures capable of detecting improvement are also needed to assess interventions. The objective of this study is to estimate the extent of change on repeat administration of three different forms of a brief computerized cognitive assessment battery (B-CAM) developed for assessing cognitive ability in the mildly-impaired to normal range in people living with HIV. We hypothesized no change over a six-month period in people on effective antiretroviral therapy.

Methods

102 HIV+ individuals completed a set of computerized cognitive tasks on three occasions over a six-month period. Rasch analysis was used to determine if change over time (i.e. improvement due to practice) was uniform across tasks and to refine scoring in order to produce three forms of the B-CAM of equivalent level of difficulty. Group-based trajectory analysis (GBTA) was then applied to determine if performance at baseline influenced the magnitude of practice-related improvement on the battery as a whole over the course of follow-up.

Results

Two cognitive tasks (fluency and word recall) had different levels of difficulty across test sessions, related to the different forms of the tasks. These two items were split by testing session. For all other items, the level of difficulty remained constant across all three time points. GBTA showed that the sample was composed of three distinct groups of people with unique trajectories, defined mainly by level of cognitive ability at baseline. Only the highest group showed an apparent improvement over time, but this change fell within measurement error.

Conclusions

Rasch analysis provides mathematical confirmation that these three forms of the B-CAM are of equivalent difficulty. GBTA demonstrates that no adjustment of the total score is required to correct for practice effects. Application of these modern statistical methods paves the way towards rapid and robust quantification of change in cognition.

Cerebrospinal fluid viral escape in aviremic HIV-infected patients receiving antiretroviral therapy: prevalence, risk factors and neurocognitive effects

BACKGROUND

During antiretroviral therapy, HIV RNA can be detected in cerebrospinal fluid (CSF) when it is undetectable in plasma, a condition termed 'CSF viral escape'. The aim of the current study was to determine the prevalence and risk factors for CSF viral escape in two large cohorts in the USA.

METHODS

A total of 1264 HIV-infected volunteers enrolled in two US cohorts at their most recent visit between 2003 and 2011 were included in this cross-sectional analysis if their HIV RNA level in plasma was less than 50 copies/ml while receiving stable antiretroviral therapy (ART) (>6 months) and if they had HIV RNA measured in CSF at their most recent visit between 2003 and 2011. Potential risk factors were identified using univariable and multivariable regression.

RESULTS

CSF viral escape was detected in 55 adults (4.4%; 95% CI: 3.4-5.6), who had a median CSF HIV RNA of 155 copies/ml [interquartile range (IQR: 80-283)]. Patients with or without CSF viral escape had similar rates of neurocognitive impairment (38.2 vs. 37.7%; P = 0.91). CSF viral escape was independently associated with the use of ritonavir-boosted protease inhibitors [odds ratio (OR): 2.0; 95% CI: 1.1-3.8] or unboosted atazanavir (OR: 5.1; 95% CI: 1.3-16.1), CSF pleocytosis (OR: 7.6; 95% CI: 4.2-13.7) and abnormal CSF total protein (OR: 2.1; 95% CI: 1.1-3.7).

CONCLUSIONS

In this large study of aviremic patients receiving ART, CSF viral escape was uncommon and was linked to evidence of central nervous system inflammation and the use of protease inhibitors, but not with worse neurocognitive performance.

Impaired insulin sensitivity is associated with worsening cognition in HIV-infected patients

OBJECTIVE

To determine the association of insulin sensitivity and metabolic status with declining cognition in HIV-infected individuals.

METHODS

We conducted targeted clinical and metabolic measures in longitudinal plasma samples obtained from HIV-infected patients enrolled in the Central Nervous System HIV Anti-Retroviral Therapy Effects Research Study (CHARTER). Findings were validated with plasma samples from the Multicenter AIDS Cohort Study (MACS). Patients were grouped according to longitudinally and serially assessed cognitive performance as having stably normal or declining cognition.

RESULTS

Patients with declining cognition exhibited baseline hyperinsulinemia and elevated plasma c-peptide levels with normal c-peptide/insulin ratios, suggesting that insulin production was increased, but insulin clearance was normal. The association of hyperinsulinemia with worsening cognition was further supported by low high-density lipoprotein (HDL), high low-density lipoprotein/HDL ratio, and elevated cholesterol/HDL ratio compared to patients with stably normal cognition.

CONCLUSIONS

These findings suggest that hyperinsulinemia and impaired insulin sensitivity are associated with cognitive decline in antiretroviral therapy-treated HIV-infected patients.

Regression-based formulas for predicting change in memory test scores in healthy older adults: Comparing use of raw versus standardized scores

INTRODUCTION

Standardized regression based (SRB) methods can be used to determine whether meaningful changes in performance on cognitive assessments occur over time. Both raw and standardized scores have been used in SRB models but it is unclear which score metric is most appropriate for predicting follow-up performance. The aim of the present study was to examine differences in SRB prediction formulas using raw versus standard scores on two memory tests commonly used in assessment of older adults.

METHOD

The sample consisted of 135 healthy older adults who underwent baseline and 1-year follow-up neuropsychological assessment including the Hopkins Verbal Learning Test-Revised and Brief Visuospatial Memory Test-Revised. Regression models were fit to predict Time 2 scores from Time 1 scores and demographic variables. Separate models were fit using raw scores and standardized scores. Akaike's information criterion (AIC) was used to determine whether models using raw or standardized scores resulted in best fit. Pearson correlation and intraclass correlation coefficients were calculated between observed and predicted scores. Mean differences between observed and predicted scores were examined using pairwise t tests. To investigate whether a similar pattern of results would be evident using prediction formulas for nonmemory tests, all analyses were also conducted for nonmemory tests.

RESULTS

All regression models were significant, and R² values for memory test raw score models were larger than those generated by standardized score models. Memory test raw score models were also a better fit based on smaller AIC values. For nonmemory tests, raw score models did not consistently outperform standardized score models. All correlations between observed and predicted Time 2 scores were significant, and none of the predicted scores significantly differed from their respective observed score.

CONCLUSION

For each memory measure, raw score models outperformed standardized score models. For nonmemory tests, neither score metric model consistently outperformed the other.

Retest effects in working memory capacity tests: A meta-analysis

The repeated administration of working memory capacity tests is common in clinical and research settings. For cognitive ability tests and different neuropsychological tests, meta-analyses have shown that they are prone to retest effects, which have to be accounted for when interpreting retest scores. Using a multilevel approach, this meta-analysis aims at showing the reproducibility of retest effects in working memory capacity tests for up to seven test administrations, and examines the impact of the length of the test-retest interval, test modality, equivalence of test forms and participant age on the size of retest effects. Furthermore, it is assessed whether the size of retest effects depends on the test paradigm. An extensive literature search revealed 234 effect sizes from 95 samples and 68 studies, in which healthy participants between 12 and 70 years repeatedly performed a working memory capacity test. Results yield a weighted average of g = 0.28 for retest effects from the first to the second test administration, and a significant increase in effect sizes was observed up to the fourth test administration. The length of the test-retest interval and publication year were found to moderate the size of retest effects. Retest effects differed between the paradigms of working memory capacity tests. These findings call for the development and use of appropriate experimental or statistical methods to address retest effects in working memory capacity tests.

Measuring and monitoring cognition in the postoperative period

It is common for patients of all ages to experience some degree of cognitive disturbance following surgery. In most cases, impairment appears mild and is restricted to the acute post-operative period, resolving steadily and speedily. In a small number of cases, however, deficits may be more pronounced and/or endure for longer periods, significantly delaying recovery and increasing the risk of serious clinical complications. The ability to accurately measure postoperative cognition, and track recovery of function, is an important clinical task. This review explores practical and methodological issues that may confound this process, examining how best to obtain reliable and meaningful measures of cognition before and after surgery. It considers neuropsychological test selection, administration, analysis and interpretation and offers evidence-based practice points for clinicians and researchers.

Inflammation Relates to Poorer Complex Motor Performance Among Adults Living With HIV on Suppressive Antiretroviral Therapy

BACKGROUND

Inflammatory processes have been suggested to underlie early neurologic abnormalities among persons living with HIV (HIV-positive), such as deficits in complex motor function, that are purported to remit with effective antiretroviral therapy (ART). We hypothesized that HIV will have negative direct and indirect effects through inflammation on complex motor performance.

METHODS

The sample consisted of 90 ART-treated virally suppressed HIV-positive and 94 HIV-negative adults, aged 36-65 years, with balanced recruiting in each age decade (36-45, 46-55, and 56-65). Biomarkers of inflammation (d-dimer, IL-6, MCP-1/CCL2, sCD14, and TNF-α) were measured, and a composite inflammation burden score was calculated. Complex motor performance was evaluated using the Grooved Pegboard Test.

RESULTS

The HIV-positive group had worse complex motor performance (P = 0.001; Hedges g = -0.49) and a higher average inflammation burden composite score (P < 0.001; Hedges g = 0.78) than the HIV-negative group. Path analyses indicated that the indirect effect of HIV disease on complex motor performance through inflammation burden was statistically significant, accounting for 15.1% of the effect of HIV on complex motor performance.

CONCLUSIONS

Although neurologic findings (eg, deficits in motor speed/dexterity) commonly associated with HIV infection typically remit with ART, our analysis indicates that inflammation plays an important role in worse complex motor skills among HIV-positive adults. Future studies of strategies for managing chronic inflammation in HIV should consider using an inflammation burden composite and examining its effect on complex motor performance.

Neurofilament light chain in blood is negatively associated with neuropsychological performance in HIV-infected adults and declines with initiation of antiretroviral therapy

HIV-associated neurocognitive disorder (HAND) persists in the combination antiretroviral therapy (cART) era and is associated with diminished quality of life. The disorder remains challenging to diagnose given the requirement for comprehensive neuropsychological testing. Blood biomarkers are needed to facilitate the diagnosis of HAND and to gauge neurological response to antiretroviral therapy. We performed a study of plasma neurofilament light chain (NFL) that included 37 HIV-infected and 54 HIV-negative adults. In the univariate mixed-effect model involving HIV-infected participants, there was a statistically significant linear relationship between composite neuropsychological score (NPT-11) and plasma NFL (slope = - 9.9, standard error = 3.0 with 95% confidence interval - 3.2 to - 16.6 and p = 0.008 when testing slope = 0). Similarly, in the multivariate mixed-effect model, higher plasma NFL was significantly associated with worse NPT-11 (slope = - 11.5, standard error = 3.3 with 95% confidence interval - 3.7 to - 19.0 and p = 0.01 when testing slope = 0). The association between NPT-11 and NFL appeared to be driven by the group of individuals off cART. In a subset of participants who had visits before and after 24 weeks on cART (n = 11), plasma NFL declined over time (median = 22.7 versus 13.4 pg/ml, p = 0.02). In contrast, plasma NFL tended to increase over time among HIV-negative participants (median 10.3 versus 12.6 pg/ml, p = 0.065, n = 54). Plasma NFL therefore shows promise as a marker of neuropsychological performance during HIV. Larger studies are needed to determine if NFL could serve as a diagnostic tool for HAND during suppressive cART.

Sex differences in HIV-associated cognitive impairment

OBJECTIVE

We determined whether there are sex differences in the prevalence and profile of HIV-associated neurocognitive impairment, and whether sex moderates the effect of HIV-serostatus on neurocognitive impairment among HIV-positive and HIV-negative individuals. Secondarily, we assessed whether differences were explained by greater biopsychosocial risk factors in HIV-positive women.

DESIGN

An observational cohort study.

METHODS

Analyses included 1361 HIV-positive (204 women) and 702 HIV-negative (214 women) (ages = 18-79 years) participants from the UCSD HIV Neurobehavioral Research Program. Demographically corrected standardized T-scores from 15 neuropsychological tests were used to calculate domain-specific and global deficit scores (GDS). GDS at least 0.5 defined neurocognitive impairment. Biopsychosocial risk factors included low education, low reading level (education quality), lifetime substance use disorders, depressed mood (clinically significant depressive symptoms and/or current major depressive disorder) and a cumulative syndemic count (sum of biopsychosocial risk factors, range = 0-4). Race-stratified analyses were conducted. Analyses were adjusted for relevant demographic and clinical factors.

RESULTS

HIV-associated neurocognitive impairment was more prevalent in women versus men; however, the difference was eliminated after adjustment for reading level. In sex-stratified logistic regressions, the association between HIV-seropositivity and higher likelihood of neurocognitive impairment was stronger in women versus men; however, the association was attenuated in women, but not men, after adjusting for reading level. These results in the overall sample were specific to blacks. Sex differences in the profile of HIV-associated neurocognitive impairment varied by race.

CONCLUSION

Women, particularly black women, were most at-risk for HIV-associated neurocognitive impairment. Higher rates of HIV-associated neurocognitive impairment in women versus men may reflect differences in educational quality.

Effects of trauma, economic hardship, and stress on neurocognition and everyday function in HIV

OBJECTIVE

The causes of neurocognitive and everyday functioning impairment among aging people living with HIV (PLWH) are multifactorial. Exposure to stress and trauma can result in neurocognitive deficits via activation of neurological and other biological mechanisms.

METHOD

PLWH (n = 122) and persons without HIV (n = 95), 35-65 years of age, completed four questionnaires that were used to generate a trauma, economic hardship (food insecurity and low socioeconomic status), and stress composite variable (TES). Participants also completed a comprehensive neuropsychological battery and standardized self-reports of activities of daily living (ADLs). We examined the independent and interactive effects of TES and HIV status on neurocognitive performance and ADL declines.

RESULTS

PLWH had more traumatic events, more food insecurity, lower socioeconomic status, and higher perceived stress compared with HIV- individuals (all ps < .0001). Among PLWH, a higher composite TES score was associated with worse executive functioning (p = .02), worse learning (p = .02), worse working memory (p = .02), and more ADL declines (p < .0001), even after controlling for relevant demographic, psychiatric, substance use, and HIV disease covariates. On their own, individual TES components did not predict these outcomes. Conversely, no significant relationships were observed between TES and cognitive domains nor ADL declines among HIV- individuals.

CONCLUSIONS

A composite score of trauma, economic hardship, and stress was significantly associated with worse neurocognitive performance and functional declines among PLWH. These adverse experiences may contribute to neurocognitive and daily functioning difficulties commonly observed among PLWH. Longitudinal studies are needed to elucidate the relationships between economic/psychosocial adversities and cognitive/functional outcomes over time, and examine potential mediators, such as inflammatory biomarkers. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Multivariate Pattern Analysis of Volumetric Neuroimaging Data and Its Relationship With Cognitive Function in Treated HIV Disease

BACKGROUND

Accurate prediction of longitudinal changes in cognitive function would potentially allow for targeted intervention in those at greatest risk of cognitive decline. We sought to build a multivariate model using volumetric neuroimaging data alone to accurately predict cognitive function.

METHODS

Volumetric T1-weighted neuroimaging data from virally suppressed HIV-positive individuals from the CHARTER cohort (n = 139) were segmented into gray and white matter and spatially normalized before entering into machine learning models. Prediction of cognitive function at baseline and longitudinally was determined using leave-one-out cross-validation. In addition, a multivariate model of brain aging was used to measure the deviation of apparent brain age from chronological age and assess its relationship with cognitive function.

RESULTS

Cognitive impairment, defined using the global deficit score, was present in 37.4%. However, it was generally mild and occurred more commonly in those with confounding comorbidities (P < 0.001). Although multivariate prediction of cognitive impairment as a dichotomous variable at baseline was poor (area under the receiver operator curve 0.59), prediction of the global T-score was better than a comparable linear model (adjusted R = 0.08, P < 0.01 vs. adjusted R = 0.01, P = 0.14). Accurate prediction of longitudinal changes in cognitive function was not possible (P = 0.82). Brain-predicted age exceeded chronological age by mean (95% confidence interval) 1.17 (-0.14 to 2.53) years but was greatest in those with confounding comorbidities [5.87 (1.74 to 9.99) years] and prior AIDS [3.03 (0.00 to 6.06) years].

CONCLUSION

Accurate prediction of cognitive impairment using multivariate models using only T1-weighted data was not achievable, which may reflect the small sample size, heterogeneity of the data, or that impairment was usually mild.

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.

No neurocognitive advantage for immediate antiretroviral treatment in adults with greater than 500 CD4+ T-cell counts

OBJECTIVE

To compare the effect of immediate versus deferred antiretroviral treatment (ART) on neuropsychological test performance in treatment-naive HIV-positive adults with more than 500 CD4 cells/μl.

DESIGN

Randomized trial.

METHODS

The START parent study randomized participants to commence immediate versus deferred ART until CD4 less than 350 cells/μl. The START Neurology substudy used eight neuropsychological tests, at baseline, months 4, 8, 12 and annually, to compare groups for changes in test performance. Test results were internally standardized to z-scores. The primary outcome was the average of the eight test z-scores (QNPZ-8). Mean changes in QNPZ-8 from baseline were compared by intent-to-treat using longitudinal mixed models. Changes from baseline to specific time points were compared using ANCOVA models.

RESULTS

The 592 participants had a median age of 34 years; median baseline CD4 count was 629 cells/μl; the mean follow-up was 3.4 years. ART was used for 94 and 32% of accrued person-years in the immediate and deferred groups, respectively. There was no difference between the immediate and deferred ART groups in QNPZ-8 change through follow-up [-0.018 (95% CI -0.062 to 0.027, P = 0.44)], or at any visit. However, QNPZ-8 scores increased in both arms during the first year, by 0.22 and 0.24, respectively (P < 0.001 for increase from baseline).

CONCLUSION

We observed substantial improvement in neurocognitive test performance during the first year in both study arms, underlining the importance of using a control group in studies assessing neurocognitive performance over time. Immediate ART neither benefitted nor harmed neurocognitive performance in individuals with CD4 cell counts above 500 cells/μl.

A Longitudinal Analysis of the Impact of Physical Activity on Neurocognitive Functioning Among HIV-Infected Adults

Higher levels of physical activity (PA) have been linked to better neurocognitive functioning in many populations. The current study examines the longitudinal association between PA and neurocognitive functioning among HIV-infected and HIV-uninfected persons. Community-dwelling adults (N = 291) self-reported level of PA and completed a comprehensive neuropsychological battery at two to four study visits (Mean follow-up time = 2.6 years). Participants were divided into three PA groups: "No PA" (no PA at any visit), "consistent PA" (PA at ≥50% of visits), and "inconsistent PA" (PA < 50% of visits). A mixed effect model, adjusting for significant covariates showed that all PA groups had statistically significant, yet modest, neurocognitive decline over time; and, the consistent PA group began with, and maintained, significantly better neurocognitive function compared to the other two PA groups. This effect was evident among both HIV-uninfected and HIV-infected persons, despite the fact that HIV-infected persons showed lower baseline neurocognitive function. PA is a modifiable lifestyle behavior that may help to protect against neurocognitive impairment regardless of HIV status, however, given the proportion of HIV-infected individuals who evidence neurocognitive difficulties, a focus on increasing PA seems warranted.

Reliable change and minimum clinically important difference (MCID) of the Repeatable Battery for the Assessment of Neuropsychology Status (RBANS) in a heterogeneous dementia sample: Support for reliable change methods but not the MCID

We compare reliable change scores and recently published anchor-based cutoffs for minimum clinically important difference (MCID) for the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) in a sample of patients diagnosed with various forms of dementia. For memory clinic patients with dementia evaluated twice over a one-year interval (N = 53), observed retest RBANS index scores were compared with predicted retest index scores based on regression formulae developed from cognitively healthy older adults. Patient RBANS change scores were also compared to suggested MCID anchors. Patients with dementia demonstrated a reliable decline on most RBANS indices, with evidence that the Visuospatial/Constructional and Language Indices might be less sensitive to decline over time. Although there was consistency between MCID and reliable changes in this sample, there was a substantial proportion where the MCID was exceeded, with no reliable change. We attempted to create MCIDs from the Clinical Dementia Rating Sum of Box scores for RBANS reliable change scores, but failed to find significant associations. Overall, the findings support use of the regression based reliable change approach, but we caution use of the MCID approach for the RBANS.

Covertly active and progressing neurochemical abnormalities in suppressed HIV infection

Objective

To assess whether HIV-related brain injury is progressive in persons with suppressed HIV infection.

Methods

Seventy-three HIV+ virally suppressed men and 35 HIV- men, screened for psychiatric and alcohol/drug use disorders, underwent neuropsychological evaluation and proton magnetic resonance spectroscopy (¹H-MRS) at baseline and after and 23 ± 5 months. ¹H-MRS included brain regions known to be vulnerable to HIV and aging: frontal white matter (FWM), posterior cingulate cortex (PCC), and caudate area (CA). Major brain metabolites such as creatine (Cr: marker of cellular energy), N-acetyl aspartate (NAA: marker of neuronal integrity), choline (marker of cellular membrane turnover), glutamate/glutamine (excitatory/inhibitory neurotransmitter), and myo-Inositol (mI: marker of neuroinflammation) were calculated with reference to water signal. Neurocognitive decline was corrected for practice effect and baseline HIV-associated neurocognitive disorder (HAND) status.

Results

Across the study period, 44% had intact cognition, 42% stable HAND (including the single case that improved), 10% progressing HAND, and 4% incident HAND. When analyzing the neurochemical data per neurocognitive trajectories, we found decreasing PCC Cr in all subgroups compared with controls (p < 0.002). In addition, relative to the HIV- group, stable HAND showed decreasing FWM Cr, incident HAND showed steep FWM Cr reduction, whereas progressing HAND had a sharply decreasing PCC NAA and reduced but stable CA NAA. When analyzing the neurochemical data at the group level (HIV+ vs HIV- groups), we found stable abnormal metabolite concentrations over the study period: decreased FWM and PCC Cr (both p < 0.001), decreased PCC NAA and CA NAA (both p < 0.05) and PCC mI increase (p < 0.05). HIV duration and historical HAND had modest effects on metabolite changes.

Conclusions

Our study reveals covertly active or progressing HIV-related brain injury in the majority of this virally suppressed cohort, reflecting ongoing neuropathogenic processes that are only partially worsened by historical HAND and HIV duration. Longer-term studies will be important for determining the prognosis of these slowly evolving neurochemical abnormalities.

Neuropsychological function is improved among opioid dependent adults who adhere to opiate agonist treatment with buprenorphine-naloxone: a preliminary study

BACKGROUND

Among persons with opioid use disorder (OUD), neuropsychological dysfunction is associated with depression, and better neuropsychological function is associated with opioid abstinence. However, it is unknown whether depressive symptomatology or adherence to opiate agonist treatment are associated with neuropsychological change over time.

METHODS

We recruited 20 buprenorphine/naloxone-treated adults with OUD (M Age = 45.2 years [SD = 8.1]; 25% female) to complete baseline and 6 month visits containing a neuropsychological test battery and self-reported measures of depressive symptomatology and medication adherence.

RESULTS

Depressive symptomatology was not significantly related to neuropsychological change (p's > .05). Greater adherence to buprenorphine/naloxone was associated with improvements in learning, memory, and global functioning (r's = .52-60; p's < .05).

CONCLUSIONS

Among OUD patients, greater adherence to buprenorphine/naloxone is associated with improved neuropsychological functioning over time. In contrast, depressive symptomatology is not associated with neuropsychological functioning over time. Supporting adherence to buprenorphine/naloxone may improve and/or preserve learning and memory functioning in individuals treated for OUD.

TRIAL REGISTRATION

NCT01108679 . Registered 21 April 2010.

Monitoring HIV-Associated Neurocognitive Disorder Using Screenings: a Critical Review Including Guidelines for Clinical and Research Use

Screening tools to identify HIV-associated neurocognitive disorder (HAND) are primarily devised to detect cognitive impairment on a single occasion. With the chronicity of HIV infection and the risk of HAND developing or progressing despite viral control, it may be pertinent to repeat HAND screening at more than one time point. Despite this, there are limited data on longitudinal use of such screening tools, particularly with regard to the role of practice effects. Additionally, no guidelines currently exist on the timeframe between testing intervals, or recommendation of the magnitude of baseline impairment that warrants follow-up testing. The aim of the current paper was to review existing evidence for longitudinal validity of HAND screening tools. Only those HAND screening tools previously found to have high cross-sectional criterion validity were included. Preliminary recommendations for clinical use and future research are proposed including in international settings.

Neuropsychological Assessment: Past and Future

Neuropsychological assessment tools are the staple of our field. The development of standardized metrics sensitive to brain-behavior relationships has shaped the neuropsychological questions we can ask, our understanding of discrete brain functions, and has informed the detection and treatment of neurological disorders. We identify key turning points and innovations in neuropsychological assessment over the past 40-50 years that highlight how the tools used in common practice today came to be. Also selected for emphasis are several exciting lines of research and novel approaches that are underway to further probe and characterize brain functions to enhance diagnostic and treatment outcomes. We provide a brief historical review of different clinical neuropsychological assessment approaches (Lurian, Flexible and Fixed Batteries, Boston Process Approach) and critical developments that have influenced their interpretation (normative standards, cultural considerations, longitudinal change, common metric batteries, and translational assessment constructs). Lastly, we discuss growing trends in assessment including technological advances, efforts to integrate neuropsychology across disciplines (e.g., primary care), and changes in neuropsychological assessment infrastructure. Neuropsychological assessment has undergone massive growth in the past several decades. Nonetheless, there remain many unanswered questions and future challenges to better support measurement tools and translate assessment findings into meaningful recommendations and treatments. As technology and our understanding of brain function advance, efforts to support infrastructure for both traditional and novel assessment approaches and integration of complementary brain assessment tools from other disciplines will be integral to inform brain health treatments and promote the growth of our field. (JINS, 2017, 23, 778-790).

Soluble membrane attack complex in the blood and cerebrospinal fluid of HIV-infected individuals, relationship to HIV RNA, and comparison with HIV negatives

The soluble membrane attack complex (sMAC) represents the terminal product of the complement cascade. We enrolled 47 HIV+ adults (12 of whom underwent a second visit at least 24weeks after starting therapy) as well as 11 HIV negative controls. At baseline, cerebrospinal fluid (CSF) sMAC was detectable in 27.7% of HIV+ individuals. CSF sMAC correlated with CSF HIV RNA levels and was more likely to be detectable in HIV+ individuals on cART compared to HIV negative controls. In HIV+ participants, there were negative association trends between sMAC and neurocognitive performance but these did not reach statistical significance.

Modifications in acute phase and complement systems predict shifts in cognitive status of HIV-infected patients

BACKGROUND

The prevalence of HIV-associated neurocognitive disorders (HAND) has not changed considerably in the last two decades. Potent antiretroviral therapy has shifted the severity of HAND to milder phenotypes, but excess morbidity and mortality continue to be associated with HAND. Changes in numerous markers of immune function, inflammation, and cellular stress have been repeatedly associated with HAND, but the underlying systems that drive these changes have not been identified.

METHOD

In this study, we used systems informatics to interrogate the cerebrospinal fluid proteomic content of longitudinal samples obtained from HIV-infected adults with stably unimpaired, stably impaired, worsening, or improving neurocognitive performance.

RESULTS AND CONCLUSION

The patterns of change in cerebrospinal fluid protein content implicated the induction of acute phase and complement systems as important regulators of neurocognitive status. Worsening neurocognitive performance was preceded by induction of acute phase and complement systems, whereas improving neurocognitive performance was preceded by a downregulation of these systems.

Greater decline in memory and global neurocognitive function in HIV/hepatitis C co-infected than in hepatitis C mono-infected patients treated with pegylated interferon and ribavirin

The human immunodeficiency virus (HIV), hepatitis C virus (HCV), and the treatment of HCV with pegylated interferon and ribavirin (IFN/RBV) have been associated with neurocognitive and psychiatric abnormalities. The goal of this research was to prospectively evaluate neurocognitive functioning among a group of HCV mono-infected and HIV/HCV co-infected patients during the first 24 weeks of IFN/RBV treatment while accounting for practice effects, normal variations in change over time, and variations in IFN/RBV treatment exposure. Forty-four HCV mono-infected and 30 HIV/HCV co-infected patients were enrolled in a prospective study of patients beginning on IFN/RBV for chronic HCV infection. Patients were administered a depression inventory, a measure of fatigue, a structured psychiatric interview, and a neurocognitive battery at baseline and 24 weeks after initiation of treatment. Analyses were conducted to explore possible associations between neurocognitive functioning and the following: HIV/HCV co-infection vs. HCV mono-infection, IFN and RBV treatment exposure, psychiatric status, liver disease stage, and other medical characteristics. At baseline, there were no significant differences between the two groups' neuropsychiatric or neurocognitive function other than the mono-infected group had significantly higher reports of fatigue (p = 0.033). Over the course of 24 weeks of treatment after controlling for practice effects, the HIV/HCV co-infected patients experienced significantly greater declines in memory (t(56) = 2.14, p = 0.037) and global neurocognitive functioning (t(53) = 2.28, p = 0.027). In a well-characterized sample of mono-infected and co-infected patients, it appears that persons with HIV/HCV co-infection are potentially more vulnerable to neurocognitive sequalae during HCV treatment.

Cognitive change trajectories in virally suppressed HIV-infected individuals indicate high prevalence of disease activity

BACKGROUND

The longitudinal rate and profile of cognitive decline in persons with stable, treated, and virally suppressed HIV infection is not established. To address this question, the current study quantifies the rate of cognitive decline in a cohort of virally suppressed HIV+ persons using clinically relevant definitions of decline, and determine cognitive trajectories taking into account historical and baseline HAND status.

METHODS

Ninety-six HIV+ (clinically stable and virally undetectable) and 44 demographically comparable HIV- participants underwent standard neuropsychological testing at baseline and 18-months follow-up. We described clinically relevant cognitive trajectories based on standard definitions of historical and baseline HAND status and cognitive decline. Historical, moderate to severe HAND was formally diagnosed at the start of the cART era in 15/96 participants based on clinical neurological and neuropsychological assessment. The same standard of care has been applied to all participants at St. Vincent's Hospital Infectious Disease Department for the duration of their HIV infection (median of 20 years).

RESULTS

Relative to HIV- controls (4.5%), 14% of HIV+ participants declined (p = .11), they also scored significantly lower on the global change score (p = .03), processing speed (p = .02), and mental flexibility/inhibition (p = .02) domains. Having HAND at baseline significantly predicted cognitive decline at follow up (p = .005). We determined seven clinically relevant cognitive trajectories taking into account whether participant has a history of HAND prior to study entry (yes/no); their results on the baseline assessment (baseline impairment: yes/no) and their results on the 18-month follow up (decline or stable) which in order of prevalence were: 1) No HAND history, no baseline impairment, 18-month follow-up stable (39%), 2) No HAND history, baseline impairment, 18-month follow-up stable (35%), 3) History of HAND; baseline impairment, 18-month follow-up stable (9%) 4) No history of HAND, baseline impairment, 18-month follow-up decline (7%), 5) History of HAND, no baseline impairment, 18-month follow-up stable (3%), 6) No HAND history, no baseline impairment, 18-month follow-up decline (3%) 7) History of HAND, baseline impairment, 18-month follow-up decline (3%). There was no relationship between cognitive decline (taking into account historical and baseline HAND) and traditional HIV disease biomarkers.

CONCLUSIONS

Despite long-term viral suppression, we found mostly subclinical levels of decline in psychomotor speed and executive functioning (mental flexibility and cognitive inhibition); well-established markers of HAND progression. Moreover, 57% of our cohort is undergoing slow evolution of their disease, challenging the notion of prevalent neurocognitive stability in virally suppressed HIV infection.

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.

Changes in cognitive function in women with HIV infection and early life stress

INTRODUCTION

HIV is frequently associated with deficits in brain function, including memory, psychomotor speed, executive function and attention. Early life stress (ELS) has also been shown to have a direct influence on neurocognitive performance. However, little is known about the combined impact of ELS and HIV on neurocognitive function over time. The aim of the present study was to follow a cohort of affected women, allowing us to assess the effects of HIV and childhood trauma on cognition and the change in cognition over time.

METHOD

A battery of neurocognitive tests was administered to 117 women at baseline and then a year later. The sample included a total of 67 HIV+ and 50 HIV- women, 71 with ELS and 46 without ELS. Controlling for age, education and antiretroviral therapy (ART) at baseline and 12-month follow-up, raw scores were compared across groups using a repeated-measures analysis of covariance.

RESULTS

More women were on ART at follow-up compared to baseline. Results revealed a significant combined HIV and childhood trauma effect over time on the Wisconsin Card Sorting Test (p = .003) and Category Fluency Test (p = .006). A significant individual HIV effect over time was evident on the WAIS-III Digit Symbol Test (p = .03) and the Controlled Oral Word Association Test (p = .003).

CONCLUSION

Findings suggest better performance in abstract reasoning, speed of information processing and verbal fluency over time. While all groups showed improvements that may correspond to practice effects, effects of HIV and childhood trauma remained evident at 12-month follow-up despite greater ART uptake and improved HIV disease status. This is the first study to assess the combined impact of HIV and trauma on neurocognitive function over time in an all-female cohort with more advanced disease.

HIV and aging

With the wider availability of antiretrovirals, the world's HIV population is aging. More than 10% of the 34.5 million HIV-positive individuals worldwide are over the age of 50 years and the average age continues to increase. In the USA more than 50% of the 1.3 million people with HIV are over 50 years old and by the year 2030 it is estimated that 70% will be over the age of 50 years. Although the life expectancy of HIV-positive people has increased dramatically, it still lags behind that of HIV-negative individuals. There is controversy about whether HIV itself accelerates the aging process. Elevated rates of inflammation seen in people with HIV, even if their viral loads are suppressed and their CD4 counts are preserved, are associated with greater rates of cardiovascular, renal, neurocognitive, oncological, and osteoporotic disease. These conditions increase exponentially in the elderly and will represent a major challenge for HIV patients. In addition, conditions such as geriatric syndromes including frailty are also seen at higher rates. Management of the aging HIV patient includes an emphasis on early diagnosis and treatment, preventative measures for co-morbidities, and avoiding polypharmacy. Finally, the issue of quality of life, prioritization of medical issues, and end of life care become increasingly important as the patient grows older.