Psychiatric symptom burden in older people living with HIV with and without cognitive impairment: the UCSF HIV over 60 cohort study.

Psychiatric comorbidities are common in people living with HIV (PLWH) and adversely affect life satisfaction, treatment adherence and disease progression. There are few data to inform the burden of psychiatric symptoms in older PLWH, a rapidly growing demographic in the U.S. We performed a cross-sectional analysis to understand the degree to which symptom burden was associated with cognitive disorders in PLWH over age 60. Participants completed a standardized neuropsychological battery and were assigned cognitive diagnoses using Frascati criteria. We captured psychiatric symptom burden using the Geriatric Depression Scale (GDS) and proxy-informed Neuropsychiatric Inventory-Questionnaire (NPI-Q). Those diagnosed with HIV-associated neurocognitive disorders (HAND, n = 39) were similar to those without HAND (n = 35) by age (median = 67 years for each group, p = 0.696), education (mean = 16 years vs. 17 years, p = 0.096), CD4+ T-lymphocyte counts (mean = 520 vs. 579, p = 0.240), duration of HIV (median = 21 years for each group, p = 0.911) and sex (92% male in HAND vs. 97% in non-HAND, p = 0.617). Our findings showed similarities in HAND and non-HAND groups on both NPI-Q (items and clusters) and GDS scores. However, there was a greater overall symptom burden in HIV compared to healthy elder controls (n = 236, p < 0.05), with more frequent agitation, depression, anxiety, apathy, irritability and nighttime behavior disturbances (p < 0.05). Our findings demonstrate no differences in psychiatric comorbidity by HAND status in older HIV participants; but confirm a substantial neurobehavioral burden in this older HIV-infected population.

ApoE ε4 Is Associated With Cognition, Brain Integrity, and Atrophy in HIV Over Age 60.

BACKGROUND: There are contradicting reports on the associations between Apolipoprotein E4 (ApoE ε4) and brain outcomes in HIV with some evidence that relationships may be greatest in older age groups. METHODS: We assessed cognition in 76 clinically stable HIV-infected participants over age 60 and genotyped ApoE. Sixty-one of these subjects underwent structural brain magnetic resonance imaging and diffusion tensor imaging. RESULTS: The median age of the participants was 64 years (range: 60-84) and the median estimated duration of HIV infection was 22 years. Apo ε4 carriers (n = 19) were similar to noncarriers (n = 57) in sex (95% vs. 96% male), and education (16.0 vs. 16.2 years) ApoE ε4 carriers demonstrated greater deficits in cognitive performance in the executive domain (P = 0.045) and had reduced fractional anisotropy and increased mean diffusivity throughout large white matter tracts within the brain compared with noncarriers. Tensor-based morphometry analyses revealed ventricular expansion and atrophy in the posterior corpus callosum, thalamus, and brainstem among HIV-infected ApoE ε4 carriers compared with ε4 noncarriers. CONCLUSIONS: In this sample of older HIV-infected individuals, having at least 1 ApoE ε4 allele was associated with decreased cognitive performance in the executive functioning domain, reduced brain white matter integrity, and brain atrophy. Brain atrophy was most prominent in the posterior corpus callosum, thalamus, and brainstem. This pattern of cognitive deficit, atrophy, and damage to white matter integrity was similar to that described in HIV, suggesting an exacerbation of HIV-related pathology; although emergence of other age-associated neurodegenerative disorders cannot be excluded.

Intrinsic network connectivity abnormalities in HIV-infected individuals over age 60.

Individuals infected with HIV are living longer due to effective treatment with combination antiretroviral therapy (cART). Despite these advances, HIV-associated neurocognitive disorders (HAND) remain prevalent. In this study, we analyzed resting state functional connectivity (rs-fc) data from HIV-infected and matched HIV-uninfected adults aged 60 years and older to determine associations between HIV status, neuropsychological performance, and clinical variables. HIV-infected participants with detectable plasma HIV RNA exhibited decreased rs-fc within the salience (SAL) network compared to HIV-infected participants with suppressed plasma HIV RNA. We did not identify differences in rs-fc within HIV-infected individuals by HAND status. Our analysis identifies focal deficits in the SAL network that may be mitigated with suppression of plasma virus. However, these findings suggest that rs-fc may not be sensitive as a marker of HAND among individuals with suppressed plasma viral loads.

Practice effect and normative data of an HIV-specific neuropsychological testing battery among healthy Thais.

OBJECTIVE: A longitudinal cohort study was conducted in Bangkok, Thailand between 2008 and 2013 in order to determine the practice effect of serial neuropsychological testing and establish normative data among normal (HIV-uninfected) Thai volunteers. MATERIAL AND METHOD: The authors enrolled 511 cognitively healthy individuals (HIV-uninfected, no drug abuse or other previous/current neurological or psychological conditions) to assess baseline performance on a HIV-specific neuropsychological testing battery. Ninety-nine subjects were re-assessed at 6 and 12 months to evaluate practice effects. RESULTS: The mean age of the 99 subjects completing longitudinal visits was 49.2 years and 53 were male. The authors identified improved mean raw scores on most neuropsychological tests with repeated measurements; however only change in WHO Auditory Verbal Learning Test (AVLT) scores (learning, attention, immediate and delayed recall tasks) met statistical significance, with larger differences seen between baseline and 6-month compared to 6 and 12 months follow-up. Older age correlated with poorer baseline raw score, and was a predictor of worse performance at 6 months and 12 months on several tasks. Level of education was associated with practice effects on several tests. No similar effects were observed with gender. CONCLUSION: The authors identified improved performance after repeated measurements revealing a significant practice effect on an HIV-specific neuropsychological testing battery employed in Bangkok, Thailand. Main predictors were age and educational attainment.

The Montreal cognitive assessment to screen for cognitive impairment in HIV patients older than 60 years.

Progress in HIV treatments has led to HIV-infected patients living into their 60s and older. Because HIV-associated neurocognitive disorder (HAND) in older age is associated with more executive dysfunction, cognitive screening instruments tapping this domain may be optimal. We examined the Montreal Cognitive Assessment to identify HAND in 67 HIV-infected patients older than 60 years, of which 40% were diagnosed with HAND. Receiver operating characteristic curve identified an optimal cutpoint of ≤ 25 for HAND with a sensitivity of 72% and specificity of 67%. We conclude that the Montreal Cognitive Assessment has only moderate performance characteristics for cognitive screening of HIV-infected elders.

Mapping white matter integrity in elderly people with HIV.

People with HIV are living longer as combination antiretroviral therapy (cART) becomes more widely available. However, even when plasma viral load is reduced to untraceable levels, chronic HIV infection is associated with neurological deficits and brain atrophy beyond that of normal aging. HIV is often marked by cortical and subcortical atrophy, but the integrity of the brain's white matter (WM) pathways also progressively declines. Few studies focus on older cohorts where normal aging may be compounded with HIV infection to influence deficit patterns. In this relatively large diffusion tensor imaging (DTI) study, we investigated abnormalities in WM fiber integrity in 56 HIV+ adults with access to cART (mean age: 63.9 ± 3.7 years), compared to 31 matched healthy controls (65.4 ± 2.2 years). Statistical 3D maps revealed the independent effects of HIV diagnosis and age on fractional anisotropy (FA) and diffusivity, but we did not find any evidence for an age by diagnosis interaction in our current sample. Compared to healthy controls, HIV patients showed pervasive FA decreases and diffusivity increases throughout WM. We also assessed neuropsychological (NP) summary z-score associations. In both patients and controls, fiber integrity measures were associated with NP summary scores. The greatest differences were detected in the corpus callosum and in the projection fibers of the corona radiata. These deficits are consistent with published NP deficits and cortical atrophy patterns in elderly people with HIV.

Deficits in self-awareness impact the diagnosis of asymptomatic neurocognitive impairment in HIV.

A recent national survey of HIV(+) adults noted that nearly three-quarters of cognitively impaired individuals are categorized as having asymptomatic neurocognitive impairment (ANI), lacking documented compromise of everyday function. The clinical impact and long-term consequences of ANI are unknown and the importance of this asymptomatic diagnosis has raised concerns in clinical care settings where competing priorities often exist. In this study, we conducted structured tests of everyday functioning in a sample of HIV(+) subjects over 60 years of age and asked subjects to rate their performance relative to peers. We demonstrate that individuals with neuropsychological testing impairment often lack self-awareness of functional performance deficits. Specifically, ANI subjects rated functional performance similar to that of HIV-negative control subjects, despite noted deficits in objective measures of function. These findings have important implications for use of self-report of function in the diagnosis of HIV-associated neurocognitive disorders (HAND), likely underestimating symptomatic impairment.

Impact of HIV and aging on neuropsychological function.

Cognitive efficiency decreases with age, and advancing age is the leading risk factor for most neurodegenerative disorders that result in dementia. In HIV infection, risk for cognitive impairment is consistently linked to advancing chronological age. As the HIV epidemic enters its fourth decade in the USA, extended life expectancy will likely result in an increased prevalence of cognitive disorders by virtue of these factors. However, it is less clear if HIV potentiates or accelerates the risk for cognitive impairment given that most reports are mixed or demonstrate only a small interaction effect. More critically, it is unclear if HIV will modulate the neuropathology associated with non-HIV cognitive disorders in a manner that will increase risk for diseases such as cerebrovascular and Alzheimer's disease. In the coming years, with increasing numbers of HIV+ patients entering their 60s and 70s, background risk for neurodegenerative disorders will be sufficiently high as to inform this issue on clinical grounds. This review summarizes knowledge of cognition in HIV as it relates to age and presents some emerging controversies.

Screening for cognitive impairment in human immunodeficiency virus.

Recent publications estimate the prevalence of human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) exceeds 50%, and this rate is likely higher among older patients. Cognitive impairment may impact medication adherence, and symptomatic impairment has been linked to all-cause mortality providing some impetus for early detection. There are currently insufficient data to inform solid recommendations on screening methods. Most HIV-specific tools have poor performance characteristics for all but the most severe form of impairment, which accounts for <5% of cases. Reliance on symptoms is likely to miss a substantial proportion of individuals with HAND due to poor insight, confounding mood disturbances, and lack of well-informed proxies. In the aging HIV-positive population, broader screening tools may be required to allow sensitivity for both HIV and neurodegenerative disorders. We describe the clinical presentation of HAND, review existing data related to screening tools, and provide preliminary and practical recommendations in the absence of more definitive studies.

Hippocampal formation lesions impair performance in an odor-odor association task independently of spatial context.

The rodent hippocampal system is known to play an important role in memory. Evidence that this role is not limited to spatial memory has come from studies using a variety of non-spatial memory tasks. One example is the social transmission of food preference paradigm, a task in which rats learn an odor-odor association with no explicit spatial memory component. However, because training and testing in this task typically take place in the same environment, it is possible that memory for the spatial context in which odors are experienced during training is critical to subsequent retention performance. If this is the case, it might be expected that lesions of the hippocampal system would impair memory performance by disrupting the establishment of a representation of the training environment. We addressed this issue by training rats in one spatial context and then testing them either in the same or a different spatial context. Normal control rats performed equally well when tested in an environment that was the same or different from that used during training, and the retention impairment exhibited by rats with hippocampus plus subiculum lesions was equivalent in the two test environments. These results support the view that the hippocampal system is necessary for the flexible expression of nonspatial memories even when the spatial context in which the memory is acquired is not critical to retrieval.