Brain Magnetic Resonance Imaging Findings Associated With Cognitive Impairment in Children and Adolescents With Human Immunodeficiency Virus in Zambia

Brain Imaging in New-Onset Seizure of Children Living With Human Immunodeficiency Virus in Zambia

BACKGROUND

There are an estimated 1.5 million children living with human immunodeficiency virus (CLHIV), most residing in sub-Saharan Africa. A common hospital presentation of CLHIV is new-onset seizure, for which imaging is helpful but not routinely performed due to scarce resources. We present imaging findings and their association with clinical risk factors and outcomes in a cohort of Zambian CLHIV presenting with new-onset seizure.

METHODS

In this prospective cohort study, participants were recruited at the University Teaching Hospital in Lusaka, Zambia. Various clinical and demographic characteristics were obtained. Computed tomography (CT), magnetic resonance imaging (MRI), or both were obtained during admission or shortly after discharge. If both studies were available, MRI data was used. Two neuroradiologists interpreted images using REDCap-based NeuroInterp, a tool that quantifies brain imaging findings. Age-dependent neuropsychologic assessments were administered.

RESULTS

Nineteen of 39 (49%) children had a brain MRI, 16 of 39 (41%) had CT, and four of 39 (10%) had both. Mean age was 6.8 years (S.D. = 4.8). Children with advanced HIV disease had higher odds of atrophy (odds ration [OR] 7.2, 95% confidence interval [CI] 1.1 to 48.3). Focal abnormalities were less likely in children receiving antiretroviral therapy (ART) (OR 0.22, 95% CI 0.05 to 1.0). Children with neurocognitive impairment were more likely to have atrophy (OR 8.4, 95% CI 1.3 to 55.4) and less likely to have focal abnormalities (OR 0.2, 95% CI 0.03 to 0.9).

CONCLUSIONS

Focal brain abnormalities on MRI were less likely in CLHIV on ART. Brain atrophy was the most common imaging abnormality, which was linked to severe neurocognitive impairment.

Adherence, Adverse Events and Viral Control among Children and Adolescents with HIV in Zambia Switched to an Integrase Inhibitor Regimen

Background

Based on recent World Health Organization recommendations, there has been a large-scale transition in Sub-Saharan Africa to integrase inhibitor (II)-based antiretroviral therapy (ART) regimens.

Setting

This study was conducted at an urban referral center in Lusaka, Zambia.

Methods

This study included 297 children and adolescents with HIV (CAWH) on ART for one year prior to enrollment and followed for 1-4 years after enrollment. ART adherence, ART regimen, and viral load were assessed periodically. Structured interviews were conducted with a subset of 95 children to assess adherence barriers and side effects.

Results

Children on protease inhibitor (PI)-based regimens were more likely to report adherence problems than children taking II- or Efavirenz-based regimens (10% vs. 28%, p=0.03) and noted more days with missed doses (median 1 vs. 0, p=0.02). In interviews, the most common reasons given for poor adherence included bad medication taste, not being home when medications were due, and perceived side effects. The PI group was more likely to report that taste was a problem affecting adherence (22% vs. 4%, p=0.05) and headache as an ART side effect (17% vs. 4%, p=0.05). Switching from a PI- to an II-based regimen was associated with improved adherence (72% vs. 92%, p=0.01) and an undetectable viral load (67% vs. 78%).

Conclusions

Switching CAWH from PI-based to II-based regimens has many advantages including superior side effect profiles, adherence, and viral suppression. PI taste aversion may be a significant contributor to pediatric adherence issues. Palatability should be considered in pediatric HIV drug development.

Executive Function and Adherence in Children and Adolescents Living with HIV: Evidence from the HIV-associated Neurocognitive Disorders in Zambia (HANDZ) Study

Introduction

Executive function (EF) may be impaired in people with human immunodeficiency virus (HIV) infection, and poor EF may affect medication adherence. However, there is little data on EF in children with HIV in sub-Saharan Africa.

Methods

208 children/adolescents with perinatally acquired HIV and 208 HIV-exposed uninfected controls were recruited in Zambia for this prospective cohort study. EF was measured using performance-based, self-report, and parental report measures. Adherence over one year of follow-up was assessed through questionnaires and viral load measurement.

Results

Children with HIV performed significantly worse on all three measures of EF. Lower parental rating of EF was associated with poorer antiretroviral therapy adherence (OR: 1.5, 95% CI = 1.02 - 2.2, p = 0.04).

Conclusion

Children with HIV have EF impairments which may lead to consequences like poor medication adherence and treatment failure. Interventions to improve EF or compensate for impaired EF may be necessary in this population.

Brain Differences in Adolescents Living With Perinatally Acquired HIV Compared With Adoption Status Matched Controls: A Cross-sectional Study

BACKGROUND AND OBJECTIVES

Despite effective combination antiretroviral therapy (cART), adolescents with perinatally acquired HIV (PHIV) exhibit cognitive impairment, of which structural changes could be the underlying pathophysiologic mechanism. Prior MRI studies found lower brain volumes, higher white matter (WM) hyperintensity (WMH) volume, lower WM integrity, and differences in cerebral blood flow (CBF). However, these findings may be confounded by adoption status, as a large portion of adolescents with PHIV have been adopted. Adoption has been associated with malnutrition and neglect, which, in turn, may have affected brain development. We investigated the long-term effects of PHIV on the brain, while minimizing the confounding effect of adoption status.

METHODS

We determined whole-brain gray matter (GM) and WM volume with 3D T1-weighted scans; total WMH volume with fluid-attenuated inversion recovery; CBF in the following regions of interest (ROIs): WM, GM, and subcortical GM with arterial spin labeling; and whole-brain WM microstructural markers: fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) with diffusion tensor imaging in cART-treated adolescents with PHIV visiting our outpatient clinic in Amsterdam and controls matched for age, sex, ethnic origin, socioeconomic status, and adoption status. We assessed differences in neuroimaging parameters between adolescents with PHIV and controls using linear regression models adjusted for age and sex and applied multiple comparison correction.

RESULTS

Thirty-five adolescents with PHIV and 38 controls were included with a median age of 14.9 (interquartile range [IQR]: 10.7-18.5) and 15.6 (IQR: 11.1-17.6) years, respectively, with a similar rate of adoption. We found a lower overall FA (beta = -0.012; p < 0.014, -2.4%), a higher MD (beta = 0.014, p = 0.014, 1.3%), and a higher RD (beta = 0.02, p = 0.014, 3.3%) in adolescents with PHIV vs adoption-matched controls, but no differences in AD. We found comparable GM, WM, and WMH volume and CBF in ROIs between adolescents with PHIV and controls. We did not find an association between cognitive profiles and WM microstructural markers in adolescents with PHIV.

DISCUSSION

Irrespective of adoption status, adolescents with PHIV exhibited subtle lower WM integrity. Our findings may point toward early-acquired WM microstructural alterations associated with HIV.

Longitudinal Cognitive Outcomes in Children With HIV in Zambia: 2-Year Outcomes From the HIV-Associated Neurocognitive Disorders in Zambia (HANDZ) Study

OBJECTIVE

To describe longitudinal outcomes and predictors of cognitive outcomes in children with HIV in Zambia.

BACKGROUND

Multiple studies have shown that children with HIV are at risk for impaired cognition. However, there are limited data on longitudinal cognitive outcomes in children with HIV.

METHODS

We conducted a prospective cohort study of 208 perinatally infected children with HIV ages 8-17 years, all treated with antiretroviral therapy, and 208 HIV-exposed uninfected controls. Participants were followed for 2 years. Cognition was assessed with a custom NIH Toolbox Cognition Battery, and tests were combined to generate a Summary Cognition Score (SCS). The contribution of potential risk factors to outcomes was explored using regression models and group-based trajectory modeling.

RESULTS

HIV was strongly associated with lower SCS at baseline [β-14, 95% confidence interval (CI): -20 to -7, P < 0.001]. Change scores over time were similar between groups, but poorer average performance in children with HIV persisted at the 2-year follow-up visit (adjusted β = -11, 95% CI: -22 to -0.3, P = 0.04). Other than HIV, the strongest predictors of baseline SCS included socioeconomic status index (β =3, 95% CI: 1, 5, P = 0.004), history of growth stunting (β=-14, 95% CI: -23 to -6, P = 0.001), history of CD4 count below 200 (β = -19, 95% CI: -35 to -2, P = 0.02), and history of World Health Organization stage 4 disease (β = -10, 95% CI: -19 to -0.2, P = 0.04). In the group-based trajectory model, HIV+ status predicted membership in the lowest performing trajectory group (odds ratio 2.5, 95% CI: 1.2 to 5.1, P = 0.01).

CONCLUSIONS

Children with HIV are at risk of poor cognitive outcomes, despite chronic treatment with antiretroviral therapy.

Validation of the National Institute of Health Toolbox Cognition Battery (NIHTB-CB) in Children and Adolescents with and without HIV Infection in Lusaka, Zambia

The objective of this study was to validate the NIH Toolbox Cognition Battery (NIHTB-CB) in Zambian children with and without HIV-infection. Children living with HIV and HIV-exposed, uninfected (HEU) children completed traditional neuropsychological and NIHTB-CB tasks. Using pairwise correlation and a linear regression model we measured associations between traditional measure composite scores and parental ratings of children's abilities, and NIHTB-CB scores. A Receiver Operating Characteristic (ROC) curve was developed to identify participants with impairment. 389 children, 8-17 years old participated. NIHTB-CB and traditional measures converged well as a whole and when comparing analogous individual tests across the two batteries. The NIHTB-CB composite score discriminated between the groups and was positively associated with external criteria for cognitive function: parental ratings of intelligence and school performance. Some English vocabulary and/or an unfamiliar cultural context presented challenges. NIHTB-CB was associated with children's everyday cognitive abilities, though future use may require linguistic and cultural adaptation.

Central Nervous System Impact of Perinatally Acquired HIV in Adolescents and Adults: an Update

Purpose of Review

Perinatally acquired HIV infection (PHIV) can confer neurodevelopmental risk. As children with PHIV increasingly survive through adolescence and into adulthood, understanding its long-term central nervous system (CNS) impacts is critical for maximizing adult outcomes and quality of life.

Recent Findings

Recently published neurocognitive and neuroimaging findings show impacts on the CNS associated with early HIV disease progression that endure into adolescence and young adulthood. Although developmental trajectories in adolescence largely appear stable, further research on maturational processes is indicated.

Summary

Although early antiretroviral therapy in infancy appears to be protective, it is not universally available and current youth largely developed without its benefit. The neurocognitive effects of HIV and the multiple other risks to neurodevelopment experienced by youth with PHIV call for further longitudinal research and a multifaceted approach to prevention and intervention.

Socioeconomic Status and Cognitive Function in Children With HIV: Evidence From the HIV-Associated Neurocognitive Disorders in Zambia (HANDZ) Study

BACKGROUND

Multiple previous studies have identified a detrimental effect of pediatric HIV on cognitive function. Socioeconomic status (SES) is one of the strongest predictors of cognitive performance and may affect the relationship between HIV and cognition.

METHODS

As part of the ongoing HIV-Associated Neurocognitive Disorders in Zambia (HANDZ) study, a prospective cohort study, we recruited 208 participants with HIV and 208 HIV-exposed uninfected controls, all aged 8-17 years. A standardized questionnaire was administered to assess SES, and all participants had comprehensive neuropsychological testing. An NPZ8 score was derived as a summary measure of cognitive function. Logistic regression and linear regression were used to model the relationship between SES and cognitive function, and mediation analysis was used to identify specific pathways by which SES may affect cognition.

RESULTS

Children with HIV performed significantly worse on a composite measure of cognitive function (NPZ8 score -0.19 vs. 0.22, P < 0.001) and were more likely to have cognitive impairment (33% vs. 19%, P = 0.001). Higher SES was associated with reduced risk of cognitive impairment (odds ratio 0.8, 95% confidence interval: 0.75-0.92, P < 0.001) in both groups, with similar effects in children with HIV and HIV-exposed uninfected groups. SES was more strongly correlated with NPZ8 score in children with HIV than in uninfected controls (Pearson's R 0.39 vs. 0.28), but predicted NPZ8 in both groups. Mediation analysis suggested that the effect of SES on cognition was most strongly mediated through malnutrition.

CONCLUSIONS

Cognitive function is strongly correlated with SES in children with HIV, suggesting a synergistic effect of HIV and poverty on cognitive function.

Reduced neuronal population in the dorsolateral prefrontal cortex in infant macaques infected with simian immunodeficiency virus (SIV)

Pediatric HIV infection remains a global health crisis with an estimated 150,000 new mother-to-child (MTCT) infections each year. Antiretroviral therapy (ART) has improved childhood survival, but only an estimated 53% of children worldwide have access to treatment. Adding to the health crisis is the neurological impact of HIV on the developing brain, in particular cognitive and executive function, which persists even when ART is available. Imaging studies suggest structural, connectivity, and functional alterations in perinatally HIV-infected youth. However, the paucity of histological data limits our ability to identify specific cortical regions that may underlie the clinical manifestations. Utilizing the pediatric simian immunodeficiency virus (SIV) infection model in infant macaques, we have previously shown that early-life SIV infection depletes the neuronal population in the hippocampus. Here, we expand on these previous studies to investigate the dorsolateral prefrontal cortex (dlPFC). A total of 11 ART-naïve infant rhesus macaques (Macaca mulatta) from previous studies were retrospectively analyzed. Infant macaques were either intravenously (IV) inoculated with highly virulent SIVmac251 at ~1 week of age and monitored for 6-10 weeks or orally challenged with SIVmac251 from week 9 of age onwards with a monitoring period of 10-23 weeks post-infection (19-34 weeks of age), and SIV-uninfected controls were euthanized at 16-17 weeks of age. Both SIV-infected groups show a significant loss of neurons along with evidence of ongoing neuronal death. Oral- and IV-infected animals showed a similar neuronal loss which was negatively correlated to chronic viremia levels as assessed by an area under the curve (AUC) analysis. The loss of dlPFC neurons may contribute to the rapid neurocognitive decline associated with pediatric HIV infection.

A Longitudinal Analysis of Cerebral Blood Flow in Perinatally HIV Infected Adolescents as Compared to Matched Healthy Controls

Despite effective combination anti-retroviral therapy (cART), perinatally HIV infected (PHIV) adolescents still experience cognitive complications. We previously reported higher cerebral blood flow (CBF) in basal ganglia and white matter (WM) in PHIV children compared to matched controls. In healthy children CBF is associated with cognitive domains. To determine longitudinal changes in CBF and its impact on cognitive complications, we measured CBF—using arterial spin labeling—in 21 PHIV adolescents and 23 controls matched for age, sex and socio-economic status twice with a mean follow-up of 4.6 years. We explored associations between CBF changes and WM micro- and macrostructural markers and cognitive domains using linear mixed models. The median age at follow-up was comparable between PHIV adolescents 17.4y (IQR:15.3–20.7) and controls 16.2y (IQR:15.6–19.1). At baseline, PHIV had higher CBF in the caudate nucleus and putamen. CBF development was comparable in gray matter (GM), WM and subcortical regions in both groups. In our cohort, we found that over time an increase of GM CBF was associated with an increase of visual motor function (p = 0.043) and executive function (p = 0.045). Increase of CBF in the caudate nucleus, putamen and thalamus was associated with an increase processing speed (p = 0.033; 0.036; 0.003 respectively) and visual motor function (p = 0.023; 0.045; 0.003 respectively). CBF development is relatively normal in PHIV adolescents on cART. CBF decline is associated with cognitive impairment, irrespective of HIV status.

Neighborhood-Based Socioeconomic Determinants of Cognitive Impairment in Zambian Children With HIV: A Quantitative Geographic Information Systems Approach

BACKGROUND

Place-based inequalities, such as exposure to violence and access to nutritious food and clean water, may contribute to human immunodeficiency virus (HIV)-associated cognitive impairment. In this study, we investigated neighborhood effects on cognition in children and adolescents with HIV in Lusaka, Zambia.

METHODS

We conducted a prospective cohort study of 208 children with perinatally acquired HIV (ages 8-17) and 208 HIV-exposed uninfected controls. Participants underwent neuropsychological testing and interviews assessing socioeconomic status. Geographic regions with clusters of participants with HIV and cognitive impairment were identified using quantitative geographic information systems (QGIS) and SaTScan. Associations between location of residence and cognitive function were evaluated in bivariable and multivariable regression models. Mediation analysis was performed to assess direct and indirect effects of location of the residence on cognitive impairment.

RESULTS

Residence in Chawama, one of the poorest neighborhoods in Lusaka, was significantly associated with cognitive impairment in participants with HIV (odds ratio 2.9; P = .005) and remained significant in a multivariable regression model controlling for potential confounders. Mediation analysis found that 46% of the cognitive effects of residence in Chawama were explained by higher rates of malnutrition, lower school attendance, and poorer self-reported health.

CONCLUSIONS

Place-based socioeconomic inequality contributes to cognitive impairment in Zambian children and adolescents with HIV. Neighborhood effects may be mediated by concentrated poverty, malnutrition, limited access to education and health care, and other yet unknown environmental factors that may be potentially modifiable.

Cerebrovascular Disease in Children Perinatally Infected With Human Immunodeficiency Virus in Zambia

BACKGROUND

High rates of cerebrovascular disease (CVD) have previously been described in pediatric human immunodeficiency virus (HIV). However, little is known about pediatric CVD in the era of antiretroviral therapy or about the contribution of CVD to HIV-associated neurocognitive disorders.

METHODS

We completed a neuroimaging substudy of the HIV-Associated Neurocognitive Disorders in Zambia study, a prospective cohort study of neurocognitive complications of pediatric HIV. Brain magnetic resonance imaging (1.5 T) was acquired for 34 HIV+ children on antiretroviral therapy and 17 HIV-exposed uninfected children (aged eight to 17 years). Demographics, medical history, neurological examination, and neuropsychologic testing results were collected. Two neuroradiologists, unaware of HIV status and clinical course, read the scans.

RESULTS

CVD was identified in seven of 34 children with HIV (HIV+ CVD+) and no HIV-exposed uninfected children (21% vs 0%, P = 0.05). Three participants had white matter changes suggestive of small vessel disease, four had infarcts, and two had evidence of intracranial artery stenosis. Age of antiretroviral therapy initiation and exposure to protease inhibitors or efavirenz was not significantly different between children with and without CVD. HIV+ CVD+ children had significantly worse scores on a summary measure of cognition than the HIV+ CVD- group (NPZ8 score -0.57 vs 0.33, P = 0.04).

CONCLUSIONS

This study demonstrates high rates of CVD in children with HIV despite antiretroviral therapy, and worse cognitive performance in children with CVD. Longitudinal studies are necessary to determine the mechanisms and incidence of new-onset CVD in children with HIV.

Differences in location of cerebral white matter hyperintensities in children and adults living with a treated HIV infection: A retrospective cohort comparison

Cerebral white matter hyperintensities (WMH) persist in children and adults living with HIV, despite effective combination antiretroviral therapy (cART). As age and principal routes of transmission differ between children (perinatally) and adults (behaviorally), comparing the characteristics and determinants of WMH between these populations may increase our understanding of the pathophysiology of WMH. From separate cohorts of 31 children (NOVICE) and 74 adults (AGEhIV), we cross-sectionally assessed total WMH volume and number of WMH per location (periventricular vs. deep) using fluid-attenuated inversion recovery (FLAIR) MRI images. WMH were either periventricular when within 10mm of the lateral ventricles, or deep otherwise. We assessed patient- or HIV-related determinants of total WMH volume (adjusted for intracranial volume) and location of WMH using logistic regression, while stratifying on children and adults. At enrollment, median age of participants was 13.8 years (IQR 11.4-15.9) for children and 53.4 years (IQR 48.3-60.8) for adults and 27/31 children (87%) and 74/74 adults (100%) had an HIV RNA viral load <200 copies/mL. WMH were present in 16/27 (52%) children and 74/74 adults (100%). The prevalence of deep WMH was not different between groups, (16/16 [100%] in children vs. 71/74 [96%] in adults, p = 0,999), yet periventricular WMH were more prevalent in adults (74/74 [100%]) compared to children (9/16; 56%) (p<0.001). Median WMH volume was higher in adults compared to children (1182 mm3 [425-2617] vs. 109 mm3 [61.7-625], p<0.001). In children, boys were more likely to have deep WMH compared to girls. In adults, older age was associated with higher total WMH volume, and age, hypertension and lower CD4+ T-lymphocyte nadir with a higher number of periventricular WMH. Our findings suggest that the location of WMH differs between children and adults living with HIV, hinting at a different underlying pathogenesis.

Cerebral toxoplasmosis in HIV-infected patients over 2015-2018 (a case study of Russia)

Cerebral toxoplasmosis is a leading cause of the central nervous system disorders in acquired immune deficiency syndrome. This study aimed to investigate the clinical course of cerebral toxoplasmosis in human immunodeficiency virus (HIV)-infected individuals. The study included 90 HIV-infected patients with cerebral toxoplasmosis, who underwent inpatient treatment. In case of positive enzyme immunoassay, HIV infection was confirmed with the immunoblot test. The HIV-1 ribonucleic acid level was determined using the polymerase chain reaction method. The flow cytometry was used for counting CD4 (cluster of differentiation 4 cells). Pathomorphological examination included the autopsy, gross and microscopic examination of internal organs, histological and other methods. The incidence of cerebral toxoplasmosis significantly increases at the CD4 count below 100 cells/μl, P < 0.001, and at the HIV viral load above 50 copies/ml, P < 0.05. The clinical picture of cerebral toxoplasmosis included focal symptoms, cognitive impairment, toxic syndrome, mild cerebral symptoms and a meningeal symptom. Given the absence of a specific clinical picture and the absence of abnormal laboratory and instrumental findings, the cerebral toxoplasmosis needs to be diagnosed with a number diagnostic methods combined: clinical examination, laboratory testing, immunological examination, molecular genetic testing and neuroradiological imaging.

Stroke and HIV in Botswana: A prospective study of risk factors and outcomes

OBJECTIVE

HIV is associated with an increased risk of stroke, but there are sparse data on risk factors for stroke in people living with HIV in Sub-Saharan African. The goal of this study was to identify HIV-specific stroke characteristics and risk factors among adults in Botswana.

METHODS

We conducted a prospective cohort study in Gaborone, Botswana from June 2015 to June 2017 comparing risk factors and outcomes among adults with and without HIV admitted for acute stroke. In addition, we conducted a case-control study comparing patients with HIV and stroke to outpatients with HIV and no history of stroke.

RESULTS

A total of 52 patients with imaging-confirmed acute stroke were enrolled. Stroke patients with HIV were younger than those without HIV (median age 40 vs 54, p = .005). Hypertension was the most common risk factor identified in both HIV+ and HIV- groups, but was more common in patients without HIV (81% vs. 55%, p = .04). Patients with HIV were significantly more likely to have a small-vessel lacunar syndrome compared to patients without HIV (67% vs. 29%, p = .02). In the case-control analysis, patients with HIV and stroke were more likely to have hypertension than stroke-free controls (53% vs. 16%; OR 7.2, 95% CI 1.5-33.8, p = .01), and were more likely to drink alcohol (53% vs. 21%, OR 3.7, 95% CI 1.1-12.1, p = .03).

CONCLUSIONS

Individuals with HIV present with strokes at younger ages than individuals without HIV. Among those with HIV, hypertension and alcohol use are significant risk factors for stroke.

Brain morphometric differences in youth with and without perinatally-acquired HIV: A cross-sectional study

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We performed vertex-wise analyses comparing grey matter in youth with and without perinatally-acquired HIV (PHIV).

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PHIV youth had reduced cortical thickness, surface area, and gyrification compared to control youth.

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PHIV youth did not exhibit the same pattern of inverse grey matter-age relationships that were observed in control youth.

Youth with perinatally-acquired HIV (PHIV) experience specific and global cognitive deficits at increased rates compared to typically-developing HIV-uninfected youth. In youth with PHIV, HIV infects the brain early in development. Neuroimaging studies have demonstrated altered grey matter morphometry in youth with PHIV compared to typically-developing youth. This study examined cortical thickness, surface area, and gyrification of grey matter in youth (age 11–20 years old) with PHIV (n = 40) from the Pediatric HIV/AIDS Cohort Study (PHACS) compared to typically-developing presumed HIV uninfected and unexposed youth (n = 80) from the Pediatric Imaging, Neurocognition and Genetics Study (PING) using structural magnetic resonance imaging. This study also examined the relationship between grey matter morphometry and age. Youth with PHIV had reduced cortical thickness, surface area, and gyrification compared to typically-developing youth. In addition, an inverse relationship between age and grey matter volume was found in typically-developing youth, but was not observed in youth with PHIV. Longitudinal studies are necessary to understand the neurodevelopmental trajectory of youth with PHIV.