The impact of environmental risk factors on HIV-associated cognitive decline in children

The adolescent HIV executive function and drumming (AHEAD) study, a feasibility trial of a group drumming intervention amongst adolescents with HIV

AHEAD feasibility trial assessed the feasibility and acceptability of an 8-session group drumming programme aiming to improve executive function, depression and anxiety symptoms, and perceived social support in adolescents living with HIV in a rural low-income South African setting. Sixty-eight 12- to 19-year-old adolescents participated. They were individually randomised. The intervention arm (n = 34) received weekly hour-long group drumming sessions. Controls (n = 34) received no intervention. Feasibility and acceptability were assessed using rates of: enrolment; retention; attendance; logistical problems; adolescent-reported acceptability. Secondary measures included: five Oxford Cognitive Screen-Executive Function (OCS-EF) tasks; two Rapid Assessment of Cognitive and Emotional Regulation (RACER) tasks; the Self-Reporting Questionnaire-20 (SRQ-20) measuring depression and anxiety symptoms; the Multidimensional Scale of Perceived Social Support (MSPSS). All feasibility criteria were within green progression limits. Enrolment, retention, and acceptability were high. There was a positive effect on adolescent depressed mood with signal for a working memory effect. There were no significant effects on executive function or socio-emotional scales. Qualitative findings suggested socio-emotional benefits including: group belonging; decreased internalised stigma; improved mood; decreased anxiety. Group drumming is a feasible and acceptable intervention amongst adolescents living with HIV in rural South Africa. A full-scale trial is recommended.

State of the Mind: Growing up with HIV

Human immunodeficiency virus (HIV) is a neurotropic virus that has a detrimental impact on the developing central nervous system (CNS) of children growing up with perinatal HIV (PHIV) due to a combination of pathophysiological processes related to direct viral cytopathic effects and immune activation. This leads to a spectrum of neurocognitive impairment ranging from severe encephalopathy to subtle domain-specific cognitive impairments, as well as psychological disorders that are compounded by HIV-related stigma and sociodemographic factors that disproportionately affect PHIV children. Early commencement and consistent use of combination antiretroviral therapy (cART) has resulted in a dramatic improvement in neuropsychological outcomes for PHIV children; however, they remain vulnerable to cognitive impairment and psychological disorders, as evidenced by imaging findings, randomised clinical trials and observational studies. An optimal neuroprotective cART regimen remains elusive in children, but systemic viral suppression, regular neurocognitive and psychological screening and ready access to neuropsychological management strategies are key components for optimising neuropsychological outcomes. However, a lack of standardised and validated screening tools, particularly in resource-limited settings, hinders a precise understanding of the nature, prevalence and associations between neuropsychological symptomatology and HIV health. This article reviews the natural history, cellular pathophysiology and structural and functional imaging findings for children growing up with HIV, as well as summarising management strategies related to antiretroviral therapy, screening tools and specific interventions for neurocognitive impairments and psychological disorders.

Machine-learning classification of neurocognitive performance in children with perinatal HIV initiating de novo antiretroviral therapy

OBJECTIVE

To develop a predictive model of neurocognitive trajectories in children with perinatal HIV (pHIV).

DESIGN

Machine learning analysis of baseline and longitudinal predictors derived from clinical measures utilized in pediatric HIV.

METHODS

Two hundred and eighty-five children (ages 2-14 years at baseline; Mage = 6.4 years) with pHIV in Southeast Asia underwent neurocognitive assessment at study enrollment and twice annually thereafter for an average of 5.4 years. Neurocognitive slopes were modeled to establish two subgroups [above (n = 145) and below average (n = 140) trajectories). Gradient-boosted multivariate regressions (GBM) with five-fold cross validation were conducted to examine baseline (pre-ART) and longitudinal predictive features derived from demographic, HIV disease, immune, mental health, and physical health indices (i.e. complete blood count [CBC]).

RESULTS

The baseline GBM established a classifier of neurocognitive group designation with an average AUC of 79% built from HIV disease severity and immune markers. GBM analysis of longitudinal predictors with and without interactions improved the average AUC to 87 and 90%, respectively. Mental health problems and hematocrit levels also emerged as salient features in the longitudinal models, with novel interactions between mental health problems and both CD4 cell count and hematocrit levels. Average AUCs derived from each GBM model were higher than results obtained using logistic regression.

CONCLUSION

Our findings support the feasibility of machine learning to identify children with pHIV at risk for suboptimal neurocognitive development. Results also suggest that interactions between HIV disease and mental health problems are early antecedents to neurocognitive difficulties in later childhood among youth with pHIV.

The effect of HIV infection and exposure on cognitive development in the first two years of life in Malawi

OBJECTIVES

To assess longitudinal patterns and determinants of cognitive development in infants living with HIV, infants exposed to maternal HIV infection, and HIV-unexposed infants.

METHODS

Prospective, community-based cohort study of 555 Malawian infants aged 8 weeks to 24 months, using multivariable linear mixed-effects regression models with random intercepts to analyze repeated measures of cognitive function.

RESULTS

At 3 months of age, cognitive scores on the Bayley Scales of Infant Development (BSID 3rd edition) were lower in the 96 HIV-infected infants (mean = 14.1 (SD:4.8)) compared to the 289 HIV-exposed (mean = 16.5 (SD:3.7)) and the 170 unexposed infants (mean = 17.5 (SD:3.3)). Over the first two years of life, the small deficit in cognitive development of infants living with HIV who survived and remained in care did not increase (mean score 52.9 among HIV-infected vs 55.6 among HIV unexposed). In multivariable analysis, malnutrition and a more advanced clinical infant HIV stage had a negative impact on cognition at age 3, while financial security, care by the biological mother, and ART for mother and child were associated with better cognitive status at this young age. The positive influence of maternal ART reversed with age.

CONCLUSIONS

Malawian infants exposed to HIV had a cognitive development that was similar to their unexposed peers in the first two years of life, while that of HIV infected infants lagged behind from the start. Early initiation of effective ART in all HIV infected mothers and infants, and prevention of infant malnutrition are important to safeguard cognitive development of children affected by HIV.

Trajectory Analysis of Cognitive Outcomes in Children With Perinatal HIV

BACKGROUND

Children with perinatal HIV (pHIV) may display distinct long-term cognitive phenotypes. We used group-based trajectory modeling to identify clusters of children with pHIV after similar developmental trajectories and predictors of belonging to select cognitive trajectory groups.

METHODS

Participants included children, 4-17 years of age, with pHIV in Thailand and Cambodia. Cognitive measures included translated versions of Intelligence Quotient tests, Color Trails Tests and Beery-Buktenica Developmental Test of Visual-Motor Integration conducted semiannually over 3-6 years. The best fit of trajectory groups was determined using maximum likelihood estimation. Multivariate logistic regression identified baseline factors associated with belonging to the lowest scoring trajectory group.

RESULTS

Group-based trajectory analyses revealed a 3-cluster classification for each cognitive test, labeled as high, medium and low scoring groups. Most trajectory group scores remained stable across age. Verbal IQ declined in all 3 trajectory groups and the high scoring group for Children's Color Trails Test 1 and 2 showed an increase in scores across age. Children in the lowest scoring trajectory group were more likely to present at an older age and report lower household income.

CONCLUSIONS

Group-based trajectory modeling succinctly classifies cohort heterogeneity in cognitive outcomes in pHIV. Most trajectories remained stable across age suggesting that cognitive potential is likely determined at an early age with the exception of a small subgroup of children who displayed developmental gains in select cognitive domains and may represent those with better cognitive reserve. Poverty and longer duration of untreated HIV may predispose children with pHIV to suboptimal cognitive development.

Global HIV neurology: a comprehensive review

: Neurological conditions associated with HIV remain major contributors to morbidity and mortality and are increasingly recognized in the aging population on long-standing combination antiretroviral therapy (cART). Importantly, growing evidence shows that the central nervous system (CNS) may serve as a reservoir for viral replication, which has major implications for HIV eradication strategies. Although there has been major progress in the last decade in our understanding of the pathogenesis, burden, and impact of neurological conditions associated with HIV infection, significant scientific gaps remain. In many resource-limited settings, antiretrovirals considered second or third line in the United States, which carry substantial neurotoxicity, remain mainstays of treatment, and patients continue to present with severe immunosuppression and CNS opportunistic infections. Despite this, increased global access to cART has coincided with an aging HIV-positive population with cognitive sequelae, cerebrovascular disease, and peripheral neuropathy. Further neurological research in low-income and middle-income countries (LMICs) is needed to address the burden of neurological complications in HIV-positive patients, particularly regarding CNS viral reservoirs and their effects on eradication.

Impact of Perinatally Acquired HIV Disease Upon Longitudinal Changes in Memory and Executive Functioning

BACKGROUND

Little is known regarding effects of perinatally acquired HIV infection (PHIV) on longitudinal change in memory and executive functioning (EF) during adolescence despite the importance of these skills for independence in adulthood.

METHODS

PHIV (n = 144) and perinatally HIV-exposed uninfected youth (PHEU, n = 79), ages 12-17, completed standardized tests of memory and EF at baseline and 2 years later. Changes from baseline for each memory and EF outcome were compared between PHEU and PHIV youth with (PHIV/C, n = 39) and without (PHIV/non-C, n = 105) history of CDC class C (AIDS-defining) diagnoses. Among PHIV youth, associations of baseline and past disease severity with memory and EF performance at follow-up were evaluated using adjusted linear regression models.

RESULTS

Participants were primarily black (79%); 16% were Hispanic; 55% were female. Mean memory and EF scores at follow-up generally fell in the low-average to average range. Pairwise comparison of adjusted mean change from baseline to follow-up revealed significantly greater change for PHIV/non-C compared with PHEU youth in only one verbal recognition task, with a difference in mean changes for PHIV/non-C versus PHEU of -0.99 (95% CI: -1.80 to -0.19; P = 0.02). Among youth with PHIV, better immunologic status at baseline was positively associated with follow-up measures of verbal recall and recognition and cognitive inhibition/flexibility. Past AIDS-defining diagnoses and higher peak viral load were associated with lower performance across multiple EF tasks at follow-up.

CONCLUSIONS

Youth with PHIV demonstrated stable memory and EF during a 2-year period of adolescence, allowing cautious optimism regarding long-term outcomes.

Contributions of Disease Severity, Psychosocial Factors, and Cognition to Behavioral Functioning in US Youth Perinatally Exposed to HIV

Among perinatally HIV-infected (PHIV) and perinatally HIV-exposed, uninfected (PHEU) youth, we evaluated the contributions of home environment, psychosocial, and demographic factors and, among PHIV only, HIV disease severity and antiretroviral treatment (ART), to cognitive functioning (CF) and behavioral functioning (BF). A structural equation modeling (SEM) approach was utilized. Exploratory factor analysis was used to reduce predictor variables to major latent factors. SEMs were developed to measure associations between the latent factors and CF and BF outcomes. Participants included 231 PHIV and 151 PHEU youth (mean age = 10.9 years) enrolled in the PHACS adolescent master protocol. Youth and caregivers completed assessments of CF, BF, psychosocial factors and HIV health. Medical data were also collected. Clusters of predictors were identified, establishing four parsimonious SEMs: child-assessed and caregiver-assessed BF in PHIV and PHEU youth. Among both groups, higher caregiver-child stress predicted worse BF. Caregiver resources and two disease severity variables, late presenter and better past HIV health, were significant predictors of CF in PHIV youth. Higher youth CF was associated with better caregiver-reported BF in both groups. Caregiver resources predicted caregiver-reported BF in PHEU youth, which was mediated via youth CF. Among PHIV youth, better past HIV health and caregiver resources mediated the effects of CF on caregiver-assessed BF. Using SEMs, we found a deleterious impact of caregiver and child stress on BF in both groups and of HIV disease factors on the CF of PHIV youth, reinforcing the importance of early comprehensive intervention to reduce risks for impairment.

Community-Based Needs Assessment of Neurodevelopment, Caregiver, and Home Environment Factors in Young Children Affected by HIV in Lima, Peru

BACKGROUND

In many resource-poor settings such as Peru, children affected by HIV have a high prevalence of neurodevelopmental delays (NDDs) and remain excluded from adequate treatment.

METHODS

Community health workers (CHWs) administered NDD screening instruments to assess child development and associated caregiver and household factors in 14 HIV-affected parent-child dyads. Focus group discussion with caregivers was conducted to explore their needs and behaviors around early child stimulation and to assess their perceptions of the screening experience.

RESULTS

Over 70% of the children had abnormal classification in at least 1 (out of 5) developmental domains according to Ages and States Questionnaire-provided cutoff scores. Caregiver depression and stress were associated with abnormal development as were some parenting behavior factors. Knowledge about child development was low. Caregivers felt testing and discussing results with a CHW were very insightful. Reported caregiver behavior differed between caregivers with HIV-infected children and those with uninfected children.

CONCLUSION

Taken together, these exploratory quantitative data suggest that parenting behaviors associated with low child development scores may be modifiable and that community-based testing is well received and informative to these HIV-infected caregivers.

The association of perceived stress and verbal memory is greater in HIV-infected versus HIV-uninfected women

In contrast to findings from cohorts comprised primarily of HIV-infected men, verbal memory deficits are the largest cognitive deficit found in HIV-infected women from the Women's Interagency HIV Study (WIHS), and this deficit is not explained by depressive symptoms or substance abuse. HIV-infected women may be at greater risk for verbal memory deficits due to a higher prevalence of cognitive risk factors such as high psychosocial stress and lower socioeconomic status. Here, we investigate the association between perceived stress using the Perceived Stress Scale (PSS-10) and verbal memory performance using the Hopkins Verbal Learning Test (HVLT) in 1009 HIV-infected and 496 at-risk HIV-uninfected WIHS participants. Participants completed a comprehensive neuropsychological test battery which yielded seven cognitive domain scores, including a primary outcome of verbal memory. HIV infection was not associated with a higher prevalence of high perceived stress (i.e., PSS-10 score in the top tertile) but was associated with worse performance on verbal learning (p < 0.01) and memory (p < 0.001), as well as attention (p = 0.02). Regardless of HIV status, high stress was associated with poorer performance in those cognitive domains (p's < 0.05) as well as processing speed (p = 0.01) and executive function (p < 0.01). A significant HIV by stress interaction was found only for the verbal memory domain (p = 0.02); among HIV-infected women only, high stress was associated with lower performance (p's < 0.001). That association was driven by the delayed verbal memory measure in particular. These findings suggest that high levels of perceived stress contribute to the deficits in verbal memory observed in WIHS women.

Cognitive Deficits in HIV Infected Children

BACKGROUND AND OBJECTIVES

Children infected with HIV are at risk for significant neurological and neuropsychological problems. This study is aimed at identifying cognitive deficits in HIV-infected children and to compare them with equal number of normal controls.

MATERIALS AND METHODS

Twenty children with HIV infection who are currently on antiretroviral therapy were recruited. They were assessed for their intelligence using Malin's Intelligence Scale for Indian Children and also evaluated for their cognitive abilities with a comprehensive neuropsychological battery. They were matched with equal number of normal controls.

RESULTS

HIV-infected children have shown substantial impairments in the domains of attention, language, verbal learning and memory, visuomotor functions, fine motor performance, and executive functions.

CONCLUSION

HIV-infected children have average intelligence, but they performed poorly on several neuropsychological measures.

Neurodevelopmental outcomes in HIV-exposed-uninfected children versus those not exposed to HIV

Human immunodeficiency virus (HIV)-negative children born to HIV-infected mothers may exhibit differences in neurodevelopment (ND) compared to age- and gender-matched controls whose lives have not been affected by HIV. This could occur due to exposure to HIV and antiretroviral agents in utero and perinatally, or differences in the environment in which they grow up. This study assessed neurodevelopmental outcomes in HIV-exposed uninfected (HEU) and HIV-unexposed uninfected (HUU) children enrolled as controls in a multicenter ND study from Thailand and Cambodia. One hundred sixty HEU and 167 HUU children completed a neurodevelopmental assessment using the Beery Visual Motor Integration (VMI) test, Color Trails, Perdue Pegboard, and Child Behavior Checklist (CBCL). Thai children (n = 202) also completed the Wechsler Intelligence Scale (IQ) and Stanford-Binet II memory tests. In analyses adjusted for caregiver education, parent as caregiver, household income, age, and ethnicity, statistically significant lower scores were seen on verbal IQ (VIQ), full-scale IQ (FSIQ), and Binet Bead Memory among HEU compared to HUU. The mean (95% CI) differences were -6.13 (-10.3 to -1.96), p = 0.004; -4.57 (-8.80 to -0.35), p = 0.03; and -3.72 (-6.57 to -0.88), p = 0.01 for VIQ, FSIQ, and Binet Bead Memory, respectively. We observed no significant differences in performance IQ, other Binet memory domains, Color Trail, Perdue Pegboard, Beery VMI, or CBCL test scores. We conclude that HEU children evidence reductions in some neurodevelopmental outcomes compared to HUU; however, these differences are small and it remains unclear to what extent they have immediate and long-term clinical significance.

Neurodevelopment in perinatally HIV-infected children: a concern for adolescence. J Int AIDS Soc. 2013;16:18603. [PMID: 23782482 PMCID: PMC3687073 DOI: 10.7448/ias.16.1.18603]

Globally, an estimated 3.4 million children are living with HIV, yet little is known about the effects of HIV and antiretroviral treatment (ART) on the developing brain, and the neurodevelopmental and behavioural outcomes of perinatally HIV-infected (PHIV+) adolescents. We reviewed the literature on neurodevelopmental outcomes in PHIV+ children and adolescents, and summarized the current evidence on behaviour, general cognition, specific domains, hearing and language, school performance and physical disabilities due to neurological problems. Evidence suggests that PHIV+ children do not perform as well as controls on general cognitive tests, processing speed and visual-spatial tasks, and are at much higher risk for psychiatric and mental health problems. Children with AIDS-defining diagnoses are particularly at risk for poorer outcomes. A striking finding is the lack of published data specific to the adolescent age group (10-25 years), particularly from resource-constrained countries, which have the highest HIV prevalence. In addition, extreme heterogeneity in terms of timing and source of infection, and antiretroviral experience limits our ability to summarize findings of studies and generalize results to other settings. Due to the complex nature of the developing adolescent brain, environmental influences and variation in access to ART, there is an urgent need for research on the longitudinal trajectory of neurodevelopment among children and adolescents perinatally infected with HIV, especially in high burden resource-constrained settings.

Impact of HIV severity on cognitive and adaptive functioning during childhood and adolescence

BACKGROUND

The influence of disease severity on cognitive and adaptive functioning in perinatally HIV-infected youth with (PHIV+/C) and without (PHIV+/NoC) a previous AIDS-defining illness (Centers for Disease Control and Prevention Class C event), compared with perinatally HIV-exposed but uninfected youth (PHEU) is not well understood.

METHODS

This was a cross-sectional analysis of cognitive and adaptive functioning in PHIV+/C (n = 88), PHIV+/NoC (n = 270) and PHEU (n = 200) youth aged 7-16 years, from a multisite prospective cohort study. Youth and caregivers completed the Wechsler Intelligence Scale for Children, Fourth Edition and the Adaptive Behavior Assessment System, Second Edition, respectively. We compared means and rates of impairment between groups, and examined associations with other psychosocial factors.

RESULTS

Overall mean scores on measures of cognitive and adaptive functioning were in the low average range for all 3 groups. After adjustment for covariates, mean full-scale intelligence quotient scores were significantly lower for the PHIV+/C group than the PHIV+/NoC and PHEU groups (mean = 77.8 versus 83.4 and 83.3, respectively), whereas no significant differences were observed between the PHEU and PHIV+/NoC groups in any domain. Lower cognitive performance for the PHIV+/C group was primarily attributable to a prior diagnosis of encephalopathy. No significant differences between groups were observed in adaptive functioning.

CONCLUSION

For long-term survivors, youth with HIV infection and a prior Centers for Disease Control and Prevention Class C event have higher risk for cognitive but not adaptive impairment regardless of current health status; this finding appears attributable to a previous diagnosis of encephalopathy. Early preventive therapy may be critical in reducing risk of later neurodevelopmental impairments.

Poor cognitive functioning of school-aged children in thailand with perinatally acquired HIV infection taking antiretroviral therapy

Neurocognitive outcome is an essential aspect of treatment for HIV-infected children. This study is aimed at assessing cognitive functioning in school-aged HIV-infected children and the change after receiving antiretroviral therapy (ART). We conducted a prospective cohort study of HIV-infected Thai children from 6-12 years of age compared with HIV-affected (children of HIV-positive mothers who were not infected with HIV), and normal control groups. Wechsler Intelligence Scale for Children-III (WISC-III) was administered at enrollment and 30 months of follow-up. Semistructured interviews of primary caregivers were performed. From April to October 2003, 121 children were enrolled; 39 HIV-infected, 40 HIV-affected, and 42 control children with a median age of 9.3 years. The HIV-infected group had a mean (standard deviation [SD]) CD4 percentage of 13.8% (5.3), 87% of whom had been receiving ART for a median of 35 weeks. At the first cognitive assessment, the mean (SD) of full-scale intelligence quotient (FSIQ) was 79 (13) and 88 (10) among HIV-infected and HIV-affected children, which was statistically lower than that of the control group at 96 (13; p < 0.01). The proportion of children with average intelligence level (FSIQ > 90) among 3 groups were 21%, 49%, and 76%, respectively (p < 0.01). At 30 months of follow-up, the HIV-infected group had a mean (SD) CD4 percentage of 25.6% (5.6); 77% had undetectable viral load. The mean (SD) FSIQ of children among three groups were 75 (12), 85 (12), and 91 (12), respectively. Compared with the baseline assessment, the verbal scale score significantly decreased in all groups, including the controls, whereas the performance scales did not change. In conclusion, school-aged HIV-infected children have lower cognitive function than HIV-affected and normal children. Cognitive function was not improved after receiving ART. Further study to address whether early ART can preserve cognitive functioning among HIV-infected children should be explored.