Effects of information processing speed on learning, memory, and executive functioning in people living with HIV/AIDS

A 2-Year Longitudinal Randomized Control Trial of Speed of Processing Cognitive Training in Aging Adults with HIV-Associated Neurocognitive Disorder: Results of the Think Fast Study

Nearly 40% of people with HIV (PWH) experience HIV-associated Neurocognitive Disorder (HAND). In this 3-group efficacy study, 216 PWH 40 + years with HAND or borderline HAND were randomized to either: (1) 10 h of SOP training (n = 70); (2) 20 h of SOP training (n = 73), or (3) 10 h of Internet navigation training (n = 73; contact control group). Participants were administered a measure of SOP [i.e., the Useful Field of View Test (UFOV®)] at baseline, at posttest immediately after training, and at year 1 and year 2 follow up. Intent-to-treat linear mixed-effect models with subject-specific intercept and slope were fitted to estimate between-group mean differences at the follow-up time-points. At the post-intervention time-point, small beneficial SOP training effects were observed for the 10-h group in UFOV® total (d = 0.28, p = 0.002). Effects were of larger magnitude for the 20-h group in these same outcomes [UFOV® total (d = 0.43, p < 0.001)]. These results indicated better benefit with more training. No intervention effect was observed at year 1. At year 2, beneficial effects of small magnitude were observed again in the 10-h group [UFOV® total (d = 0.22, p = 0.253)] with larger small-to-moderate magnitude in the 20-h group [UFOV® total (d = 0.32, p = 0.104)]. This study suggests that SOP training can improve a key indicator of this cognitive performance and that treatment gains are small-to-moderate over a two-year period. Prior literature suggests slower SOP is predictive of impairment in everyday functioning in older PWH; such an approach could potentially improve everyday functioning in PWH.

A 2-year longitudinal randomized controlled trial examining the transfer of speed of processing training to secondary cognitive domains in middle-aged and older adults with HIV-associated neurocognitive disorder: Results of the think fast study

OBJECTIVE

As people with HIV (PWH) age, they are at-risk of developing cognitive impairments compared to their seronegative counterparts. Although speed of processing (SOP) training may help improve this cognitive ability, less work has examined transfer to other cognitive domains. This study examined the effect of SOP training has on secondary cognitive domains in PWH aged 40+ years.

METHOD

In this 3-group 2-year longitudinal study, 216 PWH with HIV-associated neurocognitive disorder (HAND) or borderline HAND were randomized to either: (1) 10 h of SOP training (n = 70); (2) 20 h of SOP training (n = 73); or (3) 10 h of an active control training (n = 73). Participants completed a comprehensive cognitive battery at baseline, immediately after training, and at 1 and 2 years. This battery yielded global and domain specific T-scores as well as a cognitive impairment variable. Generalized linear mixed-effect models were fitted to estimate between-group mean differences at the follow-up time-points adjusted for baseline.

RESULTS

No clinically or statistically significant improvements in any of the cognitive outcomes were observed. A sensitivity analysis was conducted; conclusions replicated those of the main analysis, with two exceptions: Global Function T and Psychomotor Speed T showed relevant training improvements among the intervention groups over the control group at the immediate post time point.

CONCLUSIONS

Although SOP training has been shown to improve cognitive abilities that correspond to driving and mobility, such training has limited therapeutic utility in improving cognition in other domains in PWH with HAND.

Two-year clinical trial examining the effects of speed of processing training on everyday functioning in adults with human immunodeficiency virus-associated neurocognitive disorder (HAND) and borderline HAND in the U.S. Deep South: Findings of the Think Fast Study

Many people living with human immunodeficiency virus (HIV) (PLWH) experience cognitive decline that impairs everyday functioning. Cognitive training approaches, such as speed of processing (SOP) training, may reduce the impact of HIV-Associated Neurocognitive Disorder (HAND) on everyday functioning. In this experimental design study called the Think Fast Study, 216 participants age 40 and older with HAND or borderline HAND were randomized to one of three groups: (1) 10 h of SOP training (n = 70); (2) 20 h of SOP training (n = 73); or (3) 10 h of Internet Navigation Control Training (a contact control group; n = 73). Participants completed several everyday functioning measures at baseline, posttest, and year 1 and year 2 follow ups, which included: (a) Modified Lawton and Brody Activities of Daily Living (ADL) Questionnaire; (b) Timed Instrumental Activities of Daily Living (TIADL) Test; (c) Patient's Assessment of Own Functioning (PAOFI); (d) Medication Adherence Questionnaire (MAQ); and (e) Medication Adherence Visual Analog Scale (VAS). Linear mixed-effect models and generalized estimating equation models were fitted to estimate between group differences at all follow-up time points. At follow-up timepoints, those in the 10-h and 20-h training groups had better scores on medication adherence measures (MAQ and VAS) than those in the control group, with effects (Cohen's d) ranging 0.13-0.41 for MAQ and 0.02-0.43 for VAS. In conclusion, SOP training improved some indicators of everyday functioning, specifically medication adherence; however, the therapeutic effects diminished over time. Implications for practice and research are posited.

Can individualized-targeted computerized cognitive training improve everyday functioning in adults with HIV-associated neurocognitive disorder?

Half of people with human immunodeficiency virus (HIV) have HIV-associated neurocognitive disorder (HAND). Fortunately, cognitive training programs can improve function across cognitive domains, which may translate to everyday functioning. The Training on Purpose (TOPS) Study was designed to reverse HAND by targeting cognitive training to specific cognitive impairments that contributed to the diagnosis. A secondary aim of TOPS was to determine whether such cognitive training improved subjective and objective everyday functioning. In this two-group pre-post experimental design study, 109 adults with HAND were randomized to either: (1) a no-contact control group (no training) or (2) the Individualized-Targeted Cognitive Training group. Each participant received approximately 10 hours of cognitive training in two selected cognitive domains based on her/his individual baseline cognitive performance. Thus, 20 hours of individualized training on these two cognitive domains occurred over a course of 12 weeks in 1-2 hour sessions. Specific to the secondary aim of TOPS, measures of everyday functioning were administered before and after cognitive training to examine transfer effects. The analyses revealed that in general, speed of processing training produced benefits in everyday functioning as measured by the medication adherence visual analogue scale and the Timed Instrumental Activities of Daily Living test. Inconsistent findings were found for the other seven cognitive training protocols in either improving everyday functioning or reducing perceived everyday functioning; however, there may be other contributing factors that obscured such effects needing further research. This study demonstrated that some training protocols vary in efficacy in altering both objective and subjective everyday functioning ability.

Intersectionality of Socioecological Factors Associated With Cognitive Function Among Older Women With HIV in the United States: A Structural Equation Model Analysis Using Data From the Women's Interagency HIV Study

ABSTRACT

Increased life expectancy of people with HIV has health implications including the intersection of the long-term use of antiretroviral treatment, inflammatory events, and age-related immunosenescence. In a cross-sectional study utilizing using the Socio-Eecological Model, we identified pathways of cognitive function (CF) among 448 women with HIV, 50 years and older. A structural equation model showed the direct effects of mood (β = -0.25, p < .01), comorbidities (β = --0.13, p < .05), race (β = --0.13, p < .05), and abuse (β = 0.27, p < .001) on the latent variable CF. Substance and alcohol use, depressive symptoms, cigarette smoking, and the number of comorbidities are important considerations when designing interventions utilizing using a multi-level and intersectional lens to maximize positive CF outcomes.

Processing speed impairment in chronic inflammatory demyelinating polyneuropathy patients: a cross-sectional study

BACKGROUND

There is a lack of evidence of cognitive involvement in chronic inflammatory demyelinating polyneuropathy (CIDP) and, the reports about the involvement of the brain and central nervous system (CNS) are few and controversial. The Five Digit Test (FDT) evaluates processing speed (PS) and executive functions orally.

OBJECTIVE

To evaluate the performance on the FDT of CIDP patients with and without CNS (brain/cerebellum) alterations observed on brain Magnetic Resonance Imaging (MRI) scans.

METHODS

The Hospital Anxiety and Depression Scale (HADS, to assess neuropsychiatry symptoms), the Rasch-built Overall Disability Scale (R-ODS; to assess disability), and the FDT (to assess cognition) were applied to 14 CIDP patients and 24 age-matched healthy control subjects. The patients were submitted to routine brain MRI and, according to the results, they were divided into two groups: those with abnormalities on the MRI (CIDPabnl) and those with normal parameters on the MRI (CIDPnl). The FDT data of five CIDPnl patients and nine CIDPabnl subjects were analyzed. Comparisons between the groups were performed for each task of the FDT.

RESULTS

We found statistical differences for both groups of CIDP patients in terms of PS, for the patients spent more time performing the PS tasks than the controls. The PS measures were negatively associated with disability scores (reading: r = -0.47; p = 0.003; counting: r = -0.53; p = 0.001).

CONCLUSIONS

Our data suggested the presence of PS impairment in CIDP patients. Disability was associated with slow PS.

Cognitive Intra-individual Variability in HIV: an Integrative Review

Nearly 30-50% of people living with HIV experience HIV-Associated Neurocognitive Disorder (HAND). HAND indicates performance at least one standard deviation below the normative mean on any two cognitive domains. This method for diagnosing or classifying cognitive impairment has utility, however, cognitive intraindividual variability provides a different way to understand cognitive impairment. Cognitive intraindividual variability refers to the scatter in cognitive performance within repeated measures of the same cognitive test (i.e., inconsistency) or across different cognitive tests (i.e., dispersion). Cognitive intraindividual variability is associated with cognitive impairment and cognitive decline in various clinical populations. This integrative review of 13 articles examined two types of cognitive intraindividual variability in people living with HIV, inconsistency and dispersion. Cognitive intraindividual variability appears to be a promising approach to detect subtle cognitive impairments that are not captured by traditional mean-based neuropsychological testing. Greater intraindividual variability in people living with HIV has been associated with: 1) poorer cognitive performance and cognitive decline, 2) cortical atrophy, both gray and white matter volume, 3) poorer everyday functioning (i.e., driving simulation performance), specifically medication adherence, and 4) even mortality. This inspires future directions for research. First, greater cognitive intraindividual variability may reflect a greater task demand on executive control to harness and regulate cognitive control over time. By improving executive functioning through cognitive training, it may reduce cognitive intraindividual variability which could slow down cognitive decline. Second, cognitive intraindividual variability may be reconsidered in prior cognitive intervention studies in which only mean-based cognitive outcomes were used. It is possible that such cognitive interventions may actually improve cognitive intraindividual variability, which could have clinical relevance.

Southwestern Assessment of Processing Speed (SWAPS): A new brief test with demographically-corrected norms in an ethnically and educationally diverse population

Objective. Neuropsychological measures of processing speed have long been used as sensitive indices of cognitive functioning. Most of these commonly used tests are proprietary, and there is a need for brief, freely available tools that can be used in diverse clinical and research settings. The Southwestern Assessment of Processing Speed (SWAPS) is a 60-second digit-symbol transcription task developed as a brief alternative to commercially available coding tests. Demographically-corrected normative data are presented along with reliability and sensitivity/specificity values in older adults with and without cognitive impairment.Method. SWAPS data from 915 healthy aging individuals (NC) and 858 subjects with clinical diagnoses of mild cognitive impairment (MCI; n = 430) and Alzheimer's disease clinical syndrome (ADCS; n = 428) were obtained from the Texas Alzheimer's Research and Care Consortium (TARCC). TARCC participants represent ethnically and educationally diverse community-dwelling individuals age 50+.Results. SWAPS scores showed the expected associations with age, sex, and education, and the interaction between age and education were significant predictors of SWAPS scores. Test-retest reliability in NC was good, and the SWAPS distinguished impaired and non-impaired groups with adequate to excellent sensitivity and specificity for the primary analyses, with optimal cut-off points provided. Raw score- to uncorrected normalized T-scores and demographically-corrected SWAPS T-scores using regression-based norms are presented along with scoring programs for the calculation of each.Conclusions. The SWAPS is a brief, free, easily administered test with demographically-corrected regression-based norms and promising utility for detection of cognitive impairment and efficient assessment of processing speed.

Anterior Insula Activation During Cardiac Interoception Relates to Depressive Symptom Severity in HIV-Positive and HIV-Negative Postmenopausal Women

OBJECTIVE

This study aimed to determine whether subclinical symptoms of depression in postmenopausal women are associated with blood oxygen level-dependent (BOLD) activity within the anterior insula during cardiac interoceptive awareness and whether this association differs for persons living with the human immunodeficiency virus (PWH).

METHOD

Twenty-three postmenopausal (mean [standard deviation] age = 56.5 [4.8] years) and 27 HIV-negative women (mean [standard deviation] age = 56.4 [8.0]) underwent functional magnetic resonance imaging while performing a heartbeat detection task. BOLD activation within the bilateral anterior insula based on the contrast of a heartbeat detection condition with and without a distracting tone was entered along with age, HIV status, and psychological stress into two multivariate regression models with self-reported depressive symptom severity as the outcome.

RESULTS

Depressive symptoms did not vary by HIV status, nor was there a main effect or interaction for PWH on insula BOLD activation. Depressive symptoms were positively associated with psychological stress for the left ( β = 0.310, t (49) = 2.352, p = .023) and right brain models ( β = 0.296, t (49) = 2.265, p = .028) as well as the magnitude of BOLD activation in the left insula ( β = 0.290, t (49) = 2.218, p = .032) and right insula ( β = 0.318, t (49) = 2.453, p = .018), respectively. Exploratory analyses revealed that greater magnitude of BOLD activation attributed to exteroceptive noise (tone) was also correlated with self-reported distrust and preoccupation with interoceptive sensations.

CONCLUSIONS

Results support an active interference model for interoceptive awareness wherein greater BOLD signal in the anterior insula in the presence of distracting exteroceptive stimuli may reflect greater prediction error, a feature of depression.

Retinal Thinning in People With Well-Controlled HIV Infection

BACKGROUND

Retinal measurements correlate with disease progression in patients with multiple sclerosis; however, whether they associate with neurologic disease in people with controlled HIV is unknown. Using spectral domain optical coherence tomography, we evaluated retinal differences between people with HIV and HIV-negative controls and investigated clinical correlates of retinal thinning.

METHODS

People with HIV on antiretroviral therapy for at least 1 year and HIV-negative controls recruited from the same communities underwent spectral domain optical coherence tomography, ophthalmic examination, brain MRI, and neuropsychological testing. Retinal nerve fiber layer (RNFL) and ganglion cell inner plexiform layer (GC-IPL) thicknesses were compared between groups using analysis of covariance with relevant clinical variables as covariates. Linear regression was used to explore associations of HIV history variables, cognitive domain scores, and MRI volume measurements within the HIV group.

RESULTS

The HIV group (n = 69), with long-duration HIV infection (median time from diagnosis 19 years) and outstanding viral control have thinner retinal layers than HIV-negative controls (n = 28), after adjusting for covariates (GC-IPL: P = 0.002; RNFL: P = 0.024). The effect of HIV on GC-IPL thickness was stronger in women than in men (Women: P = 0.011; Men: P = 0.126). GC-IPL thickness is associated with information processing speed in the HIV group (P = 0.007, semipartial r = 0.309). No associations were found with retinal thinning and MRI volumes or HIV factors.

CONCLUSIONS

People with HIV on antiretroviral therapy have thinning of the RNFL and GC-IPL of the retina, and women particularly are affected to a greater degree. This retinal thinning was associated with worse performance on tests of information processing speed.

Neutral sphingomyelinase 2 inhibition attenuates extracellular vesicle release and improves neurobehavioral deficits in murine HIV

People living with HIV (PLH) have significantly higher rates of cognitive impairment (CI) and major depressive disorder (MDD) versus the general population. The enzyme neutral sphingomyelinase 2 (nSMase2) is involved in the biogenesis of ceramide and extracellular vesicles (EVs), both of which are dysregulated in PLH, CI, and MDD. Here we evaluated EcoHIV-infected mice for behavioral abnormalities relevant to depression and cognition deficits, and assessed the behavioral and biochemical effects of nSMase2 inhibition. Mice were infected with EcoHIV and daily treatment with either vehicle or the nSMase2 inhibitor (R)-(1-(3-(3,4-dimethoxyphenyl)-2,6-dimethylimidazo[1,2-b]pyridazin-8-yl)pyrrolidin-3-yl)-carbamate (PDDC) began 3 weeks post-infection. After 2 weeks of treatment, mice were subjected to behavior tests. EcoHIV-infected mice exhibited behavioral abnormalities relevant to MDD and CI that were reversed by PDDC treatment. EcoHIV infection significantly increased cortical brain nSMase2 activity, resulting in trend changes in sphingomyelin and ceramide levels that were normalized by PDDC treatment. EcoHIV-infected mice also exhibited increased levels of brain-derived EVs and altered microRNA cargo, including miR-183-5p, miR-200c-3p, miR-200b-3p, and miR-429-3p, known to be associated with MDD and CI; all were normalized by PDDC. In conclusion, inhibition of nSMase2 represents a possible new therapeutic strategy for the treatment of HIV-associated CI and MDD.

HIV-1 gp120 Impairs Spatial Memory Through Cyclic AMP Response Element-Binding Protein

HIV-associated neurocognitive disorders (HAND) remain an unsolved problem that persists despite using antiretroviral therapy. We have obtained data showing that HIV-gp120 protein contributes to neurodegeneration through metabolic reprogramming. This led to decreased ATP levels, lower mitochondrial DNA copy numbers, and loss of mitochondria cristae, all-important for mitochondrial biogenesis. gp120 protein also disrupted mitochondrial movement and synaptic plasticity. Searching for the mechanisms involved, we found that gp120 alters the cyclic AMP response element-binding protein (CREB) phosphorylation on serine residue 133 necessary for its function as a transcription factor. Since CREB regulates the promoters of PGC1α and BDNF genes, we found that CREB dephosphorylation causes PGC1α and BDNF loss of functions. The data was validated in vitro and in vivo. The negative effect of gp120 was alleviated in cells and animals in the presence of rolipram, an inhibitor of phosphodiesterase protein 4 (PDE4), restoring CREB phosphorylation. We concluded that HIV-gp120 protein contributes to HAND via inhibition of CREB protein function.

Relationships between executive functioning and health-related quality of life in adult survivors of brain tumor and matched healthy controls

INTRODUCTION

Few studies have considered health-related quality of life (HRQOL) as a primary outcome measure in adult survivors of primary brain tumor (PBT), and fewer still have studied the cognitive factors that may influence it. Research suggests that executive functions (EFs) are associated with HRQOL, but there is scant evidence to support this. The present study was conducted to (1) extend prior findings about HRQOL limitations in a sample of stable, long-term adult survivors of PBT, (2) investigate the associations between objective/reported EFs and HRQOL, and (3) identify the EFs that contribute most to HRQOL.

METHOD

We recruited 40 survivors of PBT (> 2 years post-treatment) and 40 matched healthy controls. Participants completed an objective EF assessment (inhibition, working memory, shifting, and rule detection) and two self-report questionnaires probing EFs (Behavior Rating Inventory of Executive Function-Adult) and HRQOL (Medical Outcomes Study Short-Form 36). Participants' relatives completed observer-rated versions of these questionnaires.

RESULTS

Patients' objective EF performances were relatively intact. However, patients and caregivers reported significantly more problems than healthy controls and their relatives, for both EFs and HRQOL. There were only negligible links between objective EFs and HRQOL, whereas numerous associations were found between reported EFs and HRQOL components. ANCOVA models revealed that specific reported EF processes contributed to both the physical and mental components of HRQOL, regardless of group.

CONCLUSIONS

From a clinical point of view, this study demonstrates that even several years after end of treatment, adult PBT survivors experience substantial problems across different HRQOL domains. HRQOL assessment should therefore be part of the long-term follow-up of PBT survivors, and clinicians should consider EF limitations when designing appropriate survivorship care plans. These findings indicate that cognitive interventions targeting EFs could improve HRQOL.

HIV infection is linked with reduced error-related default mode network suppression and poorer medication management abilities

OBJECTIVE

Brain activity linked with error processing has rarely been examined among persons living with HIV (PLWH) despite importance for monitoring and modifying behaviors that could lead to adverse health outcomes (e.g., medication non-adherence, drug use, risky sexual practices). Given that cannabis (CB) use is prevalent among PLWH and impacts error processing, we assessed the influence of HIV serostatus and chronic CB use on error-related brain activity while also considering associated implications for everyday functioning and clinically-relevant disease management behaviors.

METHODS

A sample of 109 participants, stratified into four groups by HIV and CB (HIV+/CB+, n = 32; HIV+/CB-, n = 27; HIV-/CB+, n = 28; HIV-/CB-, n = 22), underwent fMRI scanning while completing a modified Go/NoGo paradigm called the Error Awareness Task (EAT). Participants also completed a battery of well-validated instruments including a subjective report of everyday cognitive failures and an objective measure of medication management abilities.

RESULTS

Across all participants, we observed expected error-related anterior insula (aI) activation which correlated with better task performance (i.e., less errors) and, among HIV- participants, fewer self-reported cognitive failures. Regarding awareness, greater insula activation as well as greater posterior cingulate cortex (PCC) deactivation were notably linked with aware (vs. unaware) errors. Regarding group effects, unlike HIV- participants, PLWH displayed a lack of error-related deactivation in two default mode network (DMN) regions (i.e., PCC, medial prefrontal cortex [mPFC]). No CB main or interaction effects were detected. Across all participants, reduced error-related PCC deactivation correlated with reduced medication management abilities and PCC deactivation mediated the effect of HIV on such abilities. More lifetime CB use was linked with reduced error-related mPFC deactivation among HIV- participants and poorer medication management across CB users.

CONCLUSIONS

These results demonstrate that insufficient error-related DMN suppression linked with HIV infection, as well as chronic CB use among HIV- participants, has real-world consequences for medication management behaviors. We speculate that insufficient DMN suppression may reflect an inability to disengage task irrelevant mental operations, ultimately hindering error monitoring and behavior modification.

Can Individualized-Targeted Computerized Cognitive Training Benefit Adults with HIV-Associated Neurocognitive Disorder? The Training on Purpose Study (TOPS)

Half of people with HIV (PWH) have HIV-associated neurocognitive disorder (HAND). This study examined whether cognition can be improved using a framework targeting impaired individual cognitive domains in PWH with HAND. In this two-group pre-post experimental design study, 88 adults with HAND were randomized to either: (1) a no-contact control group (n = 40) or (2) the Individualized-Targeted Cognitive Training group (n = 48). Baseline cognitive performance was assessed on eight cognitive domains. A theoretical framework was used to determine the two cognitive domains selected for training. With priority on speed of processing (SOP) and attention impairments, participants received SOP and/or attention training if such impairments were detected; if not, participants were assigned to cognitive training in one/two of the least impaired cognitive domains contributing to their HAND diagnosis. Global cognitive score was slightly improved following training (p = 0.256; d = - 0.21), but it was not significant. Significant improvements were observed on SOP following training in that domain (SOP; d = - 0.88; p = 0.011). SOP training also improved functioning in other cognitive domains. This individualized cognitive intervention did not change HAND status, but it did result in improved SOP, in turn yielding improvement in other cognitive domains.

Connectome-based prediction of global cognitive performance in people with HIV

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Networks strengths predicted global cognitive performance in PWH.

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Model generalized to data from an independent PWH sample.

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Network strengths in PWH with HAND were different from either controls or PWH without HAND.

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Network strengths may serve as a potential biomarker to assist HAND diagnosis.

Global cognitive performance plays an important role in the diagnosis of HIV-associated neurocognitive disorders (HAND), yet to date, there is no simple way to measure global cognitive performance in people with HIV (PWH). Here, we performed connectome-based predictive modeling (CPM) to pursue a neural biomarker of global cognitive performance in PWH based on whole-brain resting-state functional connectivity. We built a CPM model that successfully predicted individual differences in global cognitive performance in the training set of 67 PWH by using leave-one-out cross-validation. This model generalized to both 33 novel PWH in the testing set and a subset of 39 PWH who completed a follow-up visit two years later. Furthermore, network strengths identified by the CPM model were significantly different between PWH with HAND and without HAND. Together, these results demonstrate that whole-brain functional network strengths could serve as a potential neural biomarker of global cognitive performance in PWH.

Robot-Based Assessment of HIV-Related Motor and Cognitive Impairment for Neurorehabilitation

There is a pressing need for strategies to slow or treat the progression of functional decline in people living with HIV. This paper explores a novel rehabilitation robotics approach to measuring cognitive and motor impairment in adults living with HIV, including a subset with stroke. We conducted a cross-sectional study with 21 subjects exhibiting varying levels of cognitive and motor impairment. We tested three robot-based tasks – trajectory tracking, N-back, and spatial span – to assess if metrics derived from these tasks were sensitive to differences in subjects with varying levels of executive function and upper limb motor impairments. We also examined how well these metrics could estimate clinical cognitive and motor scores. The results showed that the average sequence length on the robot-based spatial span task was the most sensitive to differences between various cognitive and motor impairment levels. We observed strong correlations between robot-based measures and clinical cognitive and motor assessments relevant to the HIV population, such as the Color Trails 1 (rho = 0.83), Color Trails 2 (rho = 0.71), Digit Symbol – Coding (rho = 0.81), Montreal Cognitive Assessment – Executive Function subscore (rho = 0.70), and Box and Block Test (rho = 0.74). Importantly, our results highlight that gross motor impairment may be overlooked in the assessment of HIV-related disability. This study shows that rehabilitation robotics can be expanded to new populations beyond stroke, namely to people living with HIV and those with cognitive impairments.

The relationship between neuropsychological dispersion, processing speed and memory after electrical injury

Introduction: Previous studies of neuropsychological performance in electrical injury (EI) patients have produced evidence of deficits in various cognitive domains, but studies have yet to investigate relationships among performance in cognitive domains post-EI. This study examined whether dispersion among neuropsychological test scores was associated with injury parameters and neuropsychological performance in EI patients. Additionally, we examined whether dispersion, processing speed and/or executive abilities explain variance in episodic verbal and visual memory performance among EI patients.Method: Data from 52 post-acute EI patients undergoing outpatient evaluation with objectively-verified valid neuropsychological test performance were examined. Tests included measures of verbal and visual memory, processing speed, and executive functioning. Dispersion was calculated from executive functioning and processing speed scores.Results: Dispersion was not related to mean performance or injury characteristics, but was significantly negatively correlated with performance on a test of processing speed, suggesting that increased dispersion is associated with reduced cognitive efficiency post-EI. Delayed visual memory was related to both dispersion scores and processing speed. Stepwise regression equations predicting delayed memory determined that processing speed most significantly predicted delayed visual memory, even after controlling for immediate visual memory. No significant relationships emerged between verbal memory and non-memory neuropsychological scores.Conclusions: This is the first study to examine neuropsychological dispersion and relationships among domains of cognitive functioning in EI. Current results suggested that neuropsychological dispersion is not a marker of general functioning or severity of injury in EI patients, but may represent more specific processing speed abilities. Processing speed predicts delayed visual memory performance in EI patients, which should be considered in interpreting test scores during evaluations.

Central Auditory Tests to Track Cognitive Function in People With HIV: Longitudinal Cohort Study

Background

The development of neurocognitive deficits in people infected with HIV is a significant public health problem. Previous cross-sectional studies have shown that performance on central auditory tests (CATs) correlates with cognitive test results in those with HIV, but no longitudinal data exist for confirmation. We have been performing longitudinal assessments of central auditory and cognitive function on a cohort of HIV-positive and HIV-negative individuals in Dar es Salaam, Tanzania to understand how the central auditory system could be used to study and track the progress of central nervous system dysfunction.

Objective

The goal of the project was to determine if CATs can track the trajectory of cognitive function over time in people diagnosed with HIV.

Methods

Tests of peripheral and central auditory function as well as cognitive performance were performed on 382 individuals over the course of 3.5 years. Visits were scheduled every 6 months. CATs included tests of auditory temporal processing (gap detection) and speech perception in noise (Hearing in Noise Test and Triple Digit Test). Cognitive tests included the Montreal Cognitive Assessment (MoCA), Test of Variables of Attention (TOVA), and subtests from the Cogstate battery. HIV-positive subjects were divided into groups based on their CAT results at their final visit (bottom 20%, top 20%, middle 60%). Primary analyses focused on the comparison between HIV-positive individuals that performed worse on CATs (bottom 20%) and the overall HIV-positive group (middle 60%). Data were analyzed using linear mixed-effect models with time as the main fixed effect.

Results

The group with the worst (bottom 20%) CAT performance showed a difference in trajectory for the MoCA (P=.003), TOVA (P<.048), and Cogstate (P<.046) over the course of the study period compared to the overall HIV-positive group. A battery of three CATs showed a significant difference in cognitive trajectory over a relatively short study period of 3.5 years independent of age (bottom 20% vs HIV-positive group).

Conclusions

The results of this study support the ability for CATs to track cognitive function over time, suggesting that central auditory processing can provide a window into central nervous system performance. CATs can be simple to perform, and are relatively insensitive to education and socioeconomic status because they only require repeating sentences, numbers, or detecting gaps in noise. These tests could potentially provide a time-efficient, low-cost method to screen for and monitor cognitive decline in patients with HIV, making them a useful surveillance tool for this major public health problem.

Robot-based assessment of HIV-related motor and cognitive impairment for neurorehabilitation

There is a pressing need for strategies to slow or treat the progression of functional decline in people living with HIV. This paper explores a novel rehabilitation robotics approach to measuring cognitive and motor impairment in adults living with HIV, including a subset with stroke. We conducted a cross-sectional study with 21 subjects exhibiting varying levels of cognitive and motor impairment. We developed three robot-based tasks – trajectory tracking, N-back, and spatial span – to assess if metrics derived from these tasks were sensitive to differences in subjects with varying levels of executive function and upper limb motor impairments. We also examined if these metrics could estimate clinical cognitive and motor scores. The results showed that the average sequence length on the robot-based spatial span task was the most sensitive to differences between subjects’ cognitive and motor impairment levels. We observed strong correlations between robot-based measures and clinical cognitive and motor assessments relevant to the HIV population, such as the Color Trails 1 (rho = 0.83), Color Trails 2 (rho = 0.71), Digit Symbol – Coding (rho = 0.81), Montreal Cognitive Assessment – Executive Function subscore (rho = 0.70), and Box and Block Test (rho = 0.74). Importantly, our results highlight that gross motor impairment may be overlooked in the assessment of HIV-related disability. This study shows that rehabilitation robotics can be expanded to new populations beyond stroke, namely to people living with HIV and those with cognitive impairments.

Assessing Cognitive Functioning in People Living With HIV (PLWH): Factor Analytic Results From CHARTER and NNTC Cohorts

BACKGROUND

Single summary scores, such as the Global Deficit Score, are often used to classify overall performance on neuropsychological batteries. The factor structure of test scores that underlie Global Deficit Score in studies of people living with HIV (PLWH) was assessed to determine whether individual test scores loaded onto a unitary factor to summarize performance.

SETTING

Secondary data analysis on baseline data of PLWH from National NeuroAIDS Tissue Consortium and CNS HIV Antiretroviral Therapy Effects Research (CHARTER) Study.

METHOD

Primary analyses included testing model structure and fit of neuropsychological test scores with confirmatory and exploratory factor analyses. Secondary analyses involved receiver operating characteristic curves, and associations with psychosocial and medical variables.

RESULTS

Participants with confounds were excluded, leading to 798 (National NeuroAIDS Tissue Consortium) and 1222 (CHARTER) cases. When confirmatory factor analysis models were structured to be consistent with theoretically-based cognitive domains, models did not fit adequately. Per exploratory factor analyses, tests assessing speeded information processing, working memory, and executive functions loaded onto a single factor and explained the most variance in both cohorts. This factor tended to be associated with age, estimated premorbid ability, and aspects of substance use history. Its relation to age, in context of demographically corrected neuropsychological scores, suggested accelerated aging.

CONCLUSION

Results indicate that individual neuropsychological tests did not load exactly onto expected domains, suggesting another framework for future analyses of cognitive domains. The possibility of a new index, and its use to assess cognitive impairment in PLWH, is suggested for further diagnostic and prognostic purposes.

Effects of HIV infection, antiretroviral therapy, and immune status on the speed of information processing and complex motor functions in adult Cameroonians

HIV-associated neurocognitive deficits include impaired speed-of-information processing (SIP) and motor functions. There is lack of Cameroonian adult norms for assessing SIP or motor functions. This study of 683 Cameroonians (320 HIV+, 363 HIV-) establishes demographically-adjusted norms for six SIP [Wechsler-Adult-Intelligence-Scale (WAIS)-III Digit Symbol (WAIS-IIIDS) and Symbol Search (WAIS-IIISS), Stroop Color-Naming, Stroop Word-Reading, Trail-Making Test-A (TMT-A), Color Trails-1 (CTT1)], and two motor function [Grooved Pegboard-dominant (GP-DH) and non-dominant (GP-NDH) hands] tests. We assessed viral effects on SIP and motor functions. HIV-infected persons had significantly lower (worse) T scores on GP-DH, WAIS-IIIDS, Stroop Word-Reading, TMT-A; lower motor and SIP summary T scores. Significantly higher proportion of cases (20.7%) than controls (10.3%) had impaired SIP. Male cases had better T scores than female cases on GP-NDH, WAIS-IIIDS, WAIS-IIISS, TMT-A, CTT1; better SIP summary T scores. Antiretroviral therapy (ART) was associated with significantly better T scores on GP-NDH, WAIS-IIIDS, Stroop Color-Naming; better motor and SIP summary T scores. Cases with higher CD4 had better T scores on WAIS-IIIDS, TMT-A, CTT1; better SIP summary T scores. Overall, we demonstrate that HIV infection in Cameroon is associated with deficits in SIP and motor functions; ART and higher CD4 are associated with better cognitive performance. We provide SIP and psychomotor functions normative standards, which will be useful for neurobehavioral studies in Cameroon of diseases affecting the brain.

Microalbuminuria: a sentinel of neurocognitive impairment in HIV-infected individuals?

Background

According to population-based studies, microalbuminuria is associated with subsequent cognitive decline over a 4–6-year period, because of cerebral small-vessel disease (CSVD). This prospective cross-sectional study (NCT02852772) was designed to evaluate whether a history of microalbuminuria is associated with subsequent cognitive decline in combined antiretroviral therapy (cART)-treated persons living with human immunodeficiency virus (PLHIVs).

Methods

From our computerized medical database, we identified 30 PLHIVs (median age 52 years), immunovirologically controlled on cART, who had microalbuminuria in 2008 and had undergone, between 2013 and 2015, a comprehensive neuropsychological assessment (NPA) including seven domains (cases): information-processing speed, motor skills, executive functions, attention/working memory, learning/memory, reasoning and verbal fluency. Forty-nine PLHIVs matched for age (median age 48 years; p = 0.19), sex, and year of first HIV-seropositivity without microalbuminuria in 2008 were identified and underwent the same NPA between 2013 and 2015 (controls).

Results

Cases performed less well than controls for information-processing speed (p = 0.01) and motor skills (p = 0.02), but no differences were found for the other cognitive domains and global z-scores. A multivariable linear-regression model adjusted for confounding factors confirmed the microalbuminuria effect for the information-processing-speed z score.

Conclusion

cART-treated PLHIVs with a history of microalbuminuria subsequently had worse cognitive performances for the information-processing-speed domain, possibly because of CSVD. Our observations should be considered preliminary findings of a temporal link between microalbuminuria, CSVD, and subsequent cognitive impairment.

HIV, Depression, and Cognitive Impairment in the Era of Effective Antiretroviral Therapy

PURPOSE OF REVIEW

Mental health disorders, especially depression, are prevalent among people living with HIV (PLWH) and are associated with cognitive impairment (CI) among HIV-uninfected (HIV-) individuals. We conducted a comprehensive review of the link between depression and cognition among PLWH.

RECENT FINDINGS

Studies examining depression and cognition in PLWH report high rates of current (median = 24%) and lifetime depression (42%). There is reliable evidence that depression is associated with overall CI among PLWH, and in the cognitive domains of processing speed, executive function, learning and memory, and motor function. Although few studies have examined the interaction between HIV serostatus and depression on CI, there is no evidence of a stronger association between CI and depression in PLWH compared with HIV- controls. Depression is prevalent and reliably associated with CI in PLWH, with an overall pattern of domain-specific associations similar to that of HIV- individuals.

A culturally fair test of processing speed: Construct validity, preliminary normative data, and effects of HIV infection on performance in South African adults

OBJECTIVES

Impaired processing speed (PS) is a feature of cognitive profiles associated with neurological disorders particularly prevalent in low- or middle-income countries (LMICs). However, commonly used PS tests are not validated for use in LMICs. We assessed, using a sample of healthy South African adults, the construct validity of PS tests contained within NeuroScreen (a tablet-based application and test battery designed to be culturally fair), and established preliminary normative data for those tests (Study 1). Moreover, because South Africa has the highest population prevalence of people living with HIV and PS deficits are a core feature of HIV-associated cognitive impairment, we assessed whether NeuroScreen could detect PS impairment in a sample of HIV-infected South African adults (Study 2).

METHODS

In Study 1 (N = 112 healthy adults) and Study 2 (the Study 1 sample, plus n = 102 HIV-infected adults), we administered Neuroscreen and a standardized paper-and-pencil neuropsychological test battery.

RESULTS

In Study 1, factor analyses indicated that NeuroScreen PS scores loaded onto one factor and converged with scores on paper-and-pencil PS tests. Regression modeling indicated that age significantly predicted NeuroScreen PS performance (i.e., younger participants performed better). In Study 2, HIV-infected participants performed significantly more poorly on NeuroScreen PS tests than their HIV-uninfected counterparts. Moreover, a significantly larger proportion of HIV-infected participants displayed impaired PS when judged against the regression-based norms.

CONCLUSIONS

These results suggest that NeuroScreen has cross-cultural utility in assessing adult PS performance, and that it might be useful in tracking trajectories of PS decline within HIV infection. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Longitudinal trajectories of neurocognitive test performance among individuals with perinatal HIV-infection and -exposure: adolescence through young adulthood

There are an estimated 2.1 million youth less than 15 years of age living with HIV globally (the majority perinatally HIV-infected [PHIV]) and millions more perinatally HIV-exposed uninfected (PHEU) youth who are expected to survive through adolescence and into adulthood. Transitioning from adolescence to young adulthood requires adaptation to more demanding social interactions, academic pressures, and individual responsibilities which place distinct demands on neurocognitive functions. This study examined longitudinal trajectories of neurocognitive test performance in the domains of processing speed (PS), working memory (WM), and executive functioning (EF) among PHIV and demographically similar PHEU from adolescence through young adulthood. Data for this paper come from four time points, spanning approximately 10 years, within the Child and Adolescent Self-Awareness and Health Study (CASAH). Youth age ranged from 15 to 29 years. Longitudinal linear mixed effect models were computed for each test. Few differences in performance were found on tests of EF and WM between PHIV and PHEU youth as they aged, though PHEU youth showed significantly better PS as they aged than PHIV youth. Future research is needed to understand these vulnerable youth's neurocognitive trajectories as a function of HIV infection and -exposure, biological functions and psychosocial stressors.

Novel Machine Learning Identifies Brain Patterns Distinguishing Diagnostic Membership of Human Immunodeficiency Virus, Alcoholism, and Their Comorbidity of Individuals

The incidence of alcohol use disorder (AUD) in human immunodeficiency virus (HIV) infection is twice that of the rest of the population. This study documents complex radiologically identified, neuroanatomical effects of AUD+HIV comorbidity by identifying structural brain systems that predicted diagnosis on an individual basis. Applying novel machine learning analysis to 549 participants (199 control subjects, 222 with AUD, 68 with HIV, 60 with AUD+HIV), 298 magnetic resonance imaging brain measurements were automatically reduced to small subsets per group. Significance of each diagnostic pattern was inferred from its accuracy in predicting diagnosis and performance on six cognitive measures. While all three diagnostic patterns predicted the learning and memory score, the AUD+HIV pattern was the largest and had the highest predication accuracy (78.1%). Providing a roadmap for analyzing large, multimodal datasets, the machine learning analysis revealed imaging phenotypes that predicted diagnostic membership of magnetic resonance imaging scans of individuals with AUD, HIV, and their comorbidity.

Information processing deficit in older adults with HIV infection: A comparison with Parkinson's disease

OBJECTIVE

Individuals with HIV treated with antiretroviral therapy can expect to reach average life span, making them susceptible to combined disease and aging effects on cognitive and motor functions. Slowed processing speed in HIV is a concern for cognitive and everyday functioning and is sensitive to declines in aging. We hypothesized that information processing (IP) deficits, over and above that expected with normal aging, would occur in older HIV patients similar to those observed in Parkinson's disease (PD) patients, with both conditions affecting frontostriatal pathways.

METHOD

Groups comprised 26 individuals with HIV infection, 29 with mild-to-moderate PD, and 21 healthy controls (C). Speed of IP was assessed with the oral version of the Symbol Digit Modalities Test and the color naming condition of the Golden Stroop Task.

RESULTS

The HIV group was impaired on speed of IP tasks compared with both the C and PD groups. Even after controlling for normal aging effects, older age in the HIV group correlated with IP slowing. Slower IP speed was associated with poorer general cognitive ability and more extrapyramidal motor signs in older HIV-infected individuals.

CONCLUSIONS

The notable effects of impaired IP speed, over and above neurotypical age-related declines, indicate that older HIV-infected individuals may have an enhanced vulnerability for developing nonmotor and motor symptoms despite antiretroviral therapy. Assessing for oral IP speed may provide the unique opportunity to identify early signs of progressive clinical declines in HIV. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Targeting HIV-Related Neurocognitive Impairments with Cognitive Training Strategies: Insights from the Cognitive Aging Literature

Approximately 50% of older adults with HIV meet the Frascati diagnostic criteria of HIV-associated neurocognitive disorders (HAND) which can interfere with everyday function such as medication adherence, employment, and driving ability, thus reducing quality of life. As the number of older adults with HIV continues to grow, many will become vulnerable to cognitive frailty, especially as they experience multimorbidities, polypharmacy, and geriatric syndromes. Healthcare professionals need strategies to prevent, remediate, and compensate for cognitive losses observed in memory, language, executive functioning, and speed of processing. Sadly, there are no standard protocols or accepted treatment/intervention guidelines to address HAND at this time. Fortunately, evidence from the cognitive aging literature indicates that cognitive training can protect and improve cognition in normal older adults and may even reduce the incidence of dementia/MCI. This article provides the scientific context in which computerized cognitive training approaches have been successfully used in older adults and provides examples of how these approaches have been translated to adults with HIV. Evidence from ongoing clinical trials are also presented that suggest that reversing a diagnosis of HAND may be possible. Recommendations for clinical practice and research are provided.

Computerized Cognitive Training for the Neurocognitive Complications of HIV Infection: A Systematic Review

The synergistic effects of HIV and aging on the brain may compromise cognitive reserve, resulting in HIV-associated neurocognitive disorder. The neuroscience literature suggests that computerized cognitive training programs represent a practical strategy to protect or remediate cognitive functioning in older adults. Such cognitive training programs may hold similar therapeutic benefits for adults living with HIV. This systematic review evaluated the effects of cognitive training interventions in adults living with HIV. This systematic review includes 13 studies that have been conducted or are being conducted. Results suggest that cognitive training may improve the cognitive domain that is the target of training. One case study even demonstrated a reversal of HIV-associated neurocognitive disorder after cognitive training. Although greater evidence is needed to establish treatment guidelines, current evidence suggests that cognitive training improves cognitive function, which translates to more optimal everyday functioning (i.e., driving), improved mood, greater locus of control, and enhanced quality of life.

Relationship between visuospatial episodic memory, processing speed and executive function: are they stable over a lifespan?

The present study evaluated the association between episodic memory, executive function and processing speed in a sample with different age ranges. We tested the hypothesis that processing speed, executive function and memory are more strongly associated during childhood and old age. We evaluated 571 participants, aged six to 92 years, divided into four age groups: children/adolescents, young adults, middle-aged adults and older adults. Correlation analyses suggested that the shared variance between the processing speed and memory is strong in childhood but weak across other age ranges. Executive function, however, had a stronger association both in childhood and in old age, when compared with the intermediate stages. We conclude that the effects of processing speed and executive function on memory are not stable across human development. These functions may be compensatory mechanisms for memory functioning in childhood and old age.

Diffusion Kurtosis Imaging Shows Similar Cerebral Axonal Damage in Patients with HIV Infection and Multiple Sclerosis

BACKGROUND AND PURPOSE

In this pilot study, we sought to investigate the pathological changes in the white matter (WM) of medically complex, combination antiretroviral therapy (cART)-treated patients with human immunodeficiency virus (HIV), comparing them to patients with long-standing, secondary progressive multiple sclerosis (SPMS).

METHODS

Using diffusion kurtosis imaging (DKI)-derived WM tract integrity (WMTI) metrics, 15 HIV and 15 age- and sex-matched SPMS patients with similar disease duration underwent magnetic resonance imaging analysis. Maps of WMTI metrics were created. Tract-based spatial statistics analysis of the whole brain and regions of interest analysis of the corpus callosum (CC) and the anterior thalamic radiations (ATRs) were performed and the derived WMTI metrics were compared between the groups of patients.

RESULTS

Axonal water fraction, an index of chronic axonal loss, showed similarities between HIV and the chronic MS patients in all regions; in contrast, tortuosity, a measure more sensitive to myelin loss, was regionally variable. In addition, in HIV patients, WMTI metrics of the CC and left ATR were associated with cognitive test scores, suggesting clinical relevance for these measures of WM damage.

CONCLUSIONS

We conclude that DKI-derived WMTI metrics may be a valuable tool in assessing the WM changes of medically complex HIV-infected individuals. While not powered to examine potential etiologies of WM changes in this pilot sample, regional variations in WMTI metrics were seen. When contrasted with changes consequent to chronic MS of similar duration, HIV and its comorbidities appear to result in similar degrees of axonal damage, but regionally variable amounts of myelin loss and extraxonal abnormality.

Can computerized cognitive training reverse the diagnosis of HIV-associated neurocognitive disorder? A research protocol

Nearly 50% of adults with HIV have some form of HIV-associated neurocognitive disorder (HAND), ranging from subtle to symptoms that interfere with everyday functioning and quality of life. HAND is diagnosed when a person performs more than 1 standard deviation below his or her normative mean on standardized measures in two or more cognitive domains (e.g., attention, speed of processing, verbal memory, executive functioning). As adults age with HIV, they are more likely to develop comorbidities such as cardiovascular disease, hypertension, and insulin resistance that may further contribute to poorer cognitive functioning and HAND. Certain computerized cognitive training programs may be able to improve specific cognitive domains in those with HIV. Such programs may be effective in changing the diagnosis of HAND in cognitively vulnerable adults. In this article, we describe the design and methods of TOPS-the Training On Purpose Study. In this on-going experimental study, 146 older adults (50+) with HAND are randomized to either: (i) an Individualized-Targeted Cognitive Training group, or (ii) a no-contact control group. This study targets those cognitive domains in which participants experience a deficit and trains participants with the corresponding computerized cognitive training program for that domain. An Individualized Targeted Cognitive Training approach using cognitive-domain-specific cognitive training programs may offer symptom relief to those individuals diagnosed with HAND, which may actually reverse this diagnosis. Given that these cognitive training programs are commercially available, this approach represents a potential paradigm shift in how HAND is considered and treated.

Testing a Computerized Cognitive Training Protocol in Adults Aging With HIV-Associated Neurocognitive Disorders: Randomized Controlled Trial Rationale and Protocol

Background

HIV-associated neurocognitive disorders occur in nearly 50% of adults with HIV. Such disorders can interfere with everyday functioning such as driving and medication adherence. Therefore, cognitive interventions are needed to address such neurocognitive disorders as well as improve everyday functioning, especially as people age with HIV.

Objective

This article reports and discusses the overall rationale and development of speed of processing training, a computerized Internet cognitive training program, to improve this specific neurocognitive ability as well as everyday functioning and quality of life in adults aging with HIV. Although this protocol has been shown to improve speed of processing, everyday functioning, and quality of life in healthy, community-dwelling older adults in the advanced cognitive training in vital elderly (ACTIVE) study, its efficacy in adults aging with HIV has not been established. Nevertheless, such a cognitive intervention is particularly germane as 52%-59% of adults with HIV experience HIV-associated neurocognitive disorders (HAND), and both the frequency and severity of such disorders may increase with advancing age.

Methods

The description of this longitudinal randomized controlled trial covers the following: (1) rationale for speed of processing training in this clinical population, (2) overview of overall study design, (3) eligibility criteria and HAND, (4) intervention dosage, (5) assessment battery, and (6) examination of biomarkers.

Results

The project was funded in April 2016 and enrolment is on-going. The first results are expected to be submitted for publication in 2020.

Conclusions

Similar novel cognitive intervention approaches are suggested as they may be of value to those with HAND and may utilize similar features of this current randomized controlled trial (RCT) protocol to examine their therapeutic efficacy.

Trial Registration

ClinicalTrials.gov NCT02758093; https://clinicaltrials.gov/ct2/show/NCT02758093 (Archived by Webcite at http://www.webcitation.org/6p8C5fBCX)

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.

HIV-1 Vpr disrupts mitochondria axonal transport and accelerates neuronal aging

Disruption of mitochondria axonal transport, essential for the maintenance of synaptic and neuronal integrity and function, has been identified in neurodegenerative diseases. Whether HIV-1 viral proteins affect mitochondria axonal transport is unknown, albeit HIV-associated neurocognitive disorders occur in around half of the patients living with HIV. Therefore, we sought to examine the effect of HIV-1 viral protein R (Vpr) on mitochondria axonal transport. Using mice primary neuronal cultures, we demonstrated that 4-day Vpr treatment reduced the ratio of moving mitochondria associated with (i) less energy (ATP) supply, (ii) reduction in Miro-1 and (iii) increase of α-synuclein which led to loss of microtubule stability as demonstrated by inconsecutive distribution of acetylated α-tubulin along the axons. Interestingly, the effect of Vpr on mitochondria axonal transport was partially restored in the presence of bongkrekic acid, a compound that negatively affected the Vpr-adenine nucleotide translocator (ANT) interaction and totally restored the ATP level in neurons. This indicated Vpr impaired mitochondria axonal transport partially related to its interaction with ANT. The above effect of Vpr was similar to the data obtained from hippocampal tissues isolated from 18-month-old aging mice compared to 5-month-old mice. In accord with previous clinical findings that HIV infection prematurely ages the brain and increases the susceptibility to HAND, we found that Vpr induced aging markers in neurons. Thus, we concluded that instead of causing cell death, low concentration of HIV-1 Vpr altered neuronal function related with inhibition of mitochondria axonal transport which might contribute to the accelerated neuronal aging.

Multicomponent analysis of a digital Trail Making Test

OBJECTIVE

The purpose of the current study was to use a newly developed digital tablet-based variant of the TMT to isolate component cognitive processes underlying TMT performance.

METHOD

Similar to the paper-based trail making test, this digital variant consists of two conditions, Part A and Part B. However, this digital version automatically collects additional data to create component subtest scores to isolate cognitive abilities. Specifically, in addition to the total time to completion and number of errors, the digital Trail Making Test (dTMT) records several unique components including the number of pauses, pause duration, lifts, lift duration, time inside each circle, and time between circles. Participants were community-dwelling older adults who completed a neuropsychological evaluation including measures of processing speed, inhibitory control, visual working memory/sequencing, and set-switching. The abilities underlying TMT performance were assessed through regression analyses of component scores from the dTMT with traditional neuropsychological measures.

RESULTS

Results revealed significant correlations between paper and digital variants of Part A (r_s = .541, p < .001) and paper and digital versions of Part B (r_s = .799, p < .001). Regression analyses with traditional neuropsychological measures revealed that Part A components were best predicted by speeded processing, while inhibitory control and visual/spatial sequencing were predictors of specific components of Part B. Exploratory analyses revealed that specific dTMT-B components were associated with a performance-based medication management task.

CONCLUSIONS

Taken together, these results elucidate specific cognitive abilities underlying TMT performance, as well as the utility of isolating digital components.

Neuropsychological profiles of adults and older adults with HIV

The wider availability of highly active antiretroviral therapy has resulted in a concomitant increase in adults aging with HIV and the persistence of milder forms of neuropsychological impairment in this cohort. This study investigated the differences in neuropsychological functioning between a group of HIV+ adults and older adults and an HIV− matched control group. Participants from a semi-urban community clinic volunteered to participate in the study. The performance of 50 participants (33 HIV+ and 17 HIV−) who met the inclusion criteria were compared on the following measures: Dementia Rating Scale-2, the Stroop Color and Word Test, the Symbol Digits Modalities Test, and the Delis–Kaplan Executive Function System Trail Making Test. The results indicated that the HIV+ in comparison with the HIV− negative group had poorer performance profiles in global cognitive functioning, memory, executive functioning, visuoconstruction ability, psychomotor functioning, and processing speed. The findings suggest that further research in South Africa will contribute to a better understanding of the neuropsychological profiles of adults aging with HIV and inform intervention strategies specific to addressing the mental healthcare needs of this subgroup.

Cognitive impairment in HIV and HCV co-infected patients: a systematic review and meta-analysis

Cognitive impairment has been well documented in HIV and hepatitis C virus (HCV) mono-infections. However, in the context of HIV/HCV co-infection the research is more limited. The aim of this systematic review was to describe the characteristics of cognitive impairment in HIV/HCV co-infection and to examine the differences in cognitive performance between HIV/HCV and HIV and HCV mono-infected patients. Of the 437 records initially screened, 24 papers met the inclusion criteria and were included in the systematic review. Four studies were included in the meta-analysis. Most studies indicated that HIV/HCV co-infected patients had a higher level of cognitive impairment than HIV mono-infected patients. Meta-analysis indicated, however, that HIV mono-infected patients had a significantly higher global deficit score than co-infected patients. The results also indicated that co-infected patients were more likely to be impaired in information processing speed than HIV mono-infected patients. These findings can be challenged by biasing factors such as the small number of studies, heterogeneity of the samples, and a large diversity of methodological procedures. Future research with consistent and comprehensive neuropsychological batteries and covering a greater diversity of risk factors is needed, in order to clarify the effects of both viruses on cognitive function and the mechanisms that underlie these effects. Because cognitive impairments may pose significant challenges to medication adherence, quality of life and overall functioning, such knowledge may have important implications to the planning and implementation of effective interventions aimed at optimising the clinical management of these infections.