Neuropsychological outcomes in adults commencing highly active anti-retroviral treatment in South Africa: a prospective study

Cognitive impairment in people living with HIV: mechanisms, controversies, and future perspectives

Despite the dramatic decrease in HIV-associated neurocognitive impairment (NCI) in the combined antiretroviral treatment (cART) era, subtler neuropsychological complications remain prevalent. In this review, we discuss the changing pathophysiology of HIV-associated NCI, considering recent evidence of HIV neuropathogenesis, and the pivotal role of cART. Furthermore, we address the multifactorial nature of NCI in people living with HIV, including legacy and ongoing insults to the brain, as well as host-specific factors. We also summarize the ongoing debate about the refinement of diagnostic criteria, exploring the strengths and limitations of these recent approaches. Finally, we present current research in NCI management in people living with HIV and highlight the need for using both pharmacological and nonpharmacological pathways toward a holistic approach.

Blood and cerebrospinal fluid biomarker changes in patients with HIV-associated neurocognitive impairment treated with lithium: analysis from a randomised placebo-controlled trial

HIV-associated neurocognitive disorders (HAND) persist in the era of antiretroviral therapy (ART). Thus, ART does not completely halt or reverse the pathological processes behind HAND. Adjuvant mitigating treatments are, therefore, prudent. Lithium treatment is known to promote neuronal brain-derived neurotrophic factors (BDNF). Lithium is also an inhibitor of glycogen synthase kinase-3 beta (GSK-3-β). We analyzed biomarkers obtained from participants in a randomized placebo-controlled trial of lithium in ART-treated individuals with moderate or severe HAND. We assayed markers at baseline and 24 weeks across several pathways hypothesized to be affected by HIV, inflammation, or degeneration. Investigated biomarkers included dopamine, BDNF, neurofilament light chain, and CD8 + lymphocyte activation (CD38 + HLADR +). Alzheimer's Disease (AD) biomarkers included soluble amyloid precursor protein alpha and beta (sAPPα/β), Aβ38, 40, 42, and ten other biomarkers validated as predictors of mild cognitive impairment and progression in previous studies. These include apolipoprotein C3, pre-albumin, α1-acid glycoprotein, α1-antitrypsin, PEDF, CC4, ICAM-1, RANTES, clusterin, and cystatin c. We recruited 61 participants (placebo = 31; lithium = 30). The age baseline mean was 40 (± 8.35) years and the median CD4 + T-cell count was 498 (IQR: 389-651) cells/μL. Biomarker concentrations between groups did not differ at baseline. However, both groups' blood dopamine levels decreased significantly after 24 weeks (adj. p < 002). No other marker was significantly different between groups, and we concluded that lithium did not confer neuroprotection following 24 weeks of treatment. However, the study was limited in duration and sample size.

Screening for HIV-associated neurocognitive impairment: Development and validation of an abbreviated neuropsychological test battery for use in South African clinical settings

BACKGROUND

The HIV Neurobehavioral Research Center International Neurobehavioral Battery is a culturally valid battery sensitive to the neurocognitive (NC) effects of HIV-infection. However, its lengthy administration time makes the battery impractical in resource-limited settings, like South Africa, which are often faced with an overwhelming disease burden, a lack of neurological and neuropsychological (NP) expertise, and staff shortages. The present study therefore sought to develop an abbreviated version of the HNRC Battery and validate this battery in a sample of people with HIV (PWH) in South Africa.

OBJECTIVE

The present study therefore sought to develop an abbreviated version of the HNRC battery and validate this battery in a sample of people with HIV (PWH) in South Africa.

METHOD

Six measures were selected based on the NC test performances of 103 HIV-positive and 135 HIV-negative South African adults. For the validation, a subgroup of 103 PWH completed the full version of the battery, while the other subgroup of 52 PWH completed only the abbreviated version. Deficit scores of each participant were calculated. These scores were used as the gold standard against which the abbreviated battery was compared.

RESULTS

There was a reduction of 81% in administration time when compared to the full version of the battery. The abbreviated battery demonstrated good sensitivity (75.0%) and excellent specificity (94.9%) when compared with the full version. The abbreviated battery showed good diagnostic accuracy in identifying NC impairment in an HIV-positive South African sample with a significant reduction in administration time, making it a more practical option in busy South African clinic settings.

CONCLUSION

The results of this study may facilitate the growth of neuroAIDS research and aid initial identification of HIV-related NC impairment in resource-constrained settings. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Functioning Problems Associated with Health Conditions with Greatest Disease Burden in South Africa: A Scoping Review

A notable rise in health-related disability for which evidence-based rehabilitation is beneficial is evident in low-to-middle income countries. This scoping review aimed to systematically identify and map the most common functioning problems associated with health conditions that contribute most to disability in South Africa using the International Classification of Functioning, Disability and Health (ICF) framework. Peer-reviewed evidence published from January 2006 to December 2021 was systematically searched from five databases. Some 268 studies reporting on functioning problems (impairments, activity limitations, and participation restrictions) in South African adults (>18 years) related to 10 health conditions were included. A total of 130 different functioning problems were mapped to the ICF. The most prevalent problems (top 20) were related to mobility, pain, and mental health but spanned across several ICF domains and were mostly in patients at primary care. The high prevalence and wide range of functioning problems may be particularly burdensome on an already strained primary health care (PHC) system. This points towards targeted planning of innovative strategies towards strengthening rehabilitation service delivery at primary care to address these complexities where there is an inadequate rehabilitation workforce.

Quantifying the burden of the post-ICU syndrome in South Africa: A scoping review of evidence from the public health sector

BACKGROUND

The post-ICU syndrome (PICS) comprises unexpected impairments in physical, cognitive, and mental health after intensive care unit (ICU) discharge, and is associated with a diminished health-related quality of life (HRQOL). A Cochrane review recommended more research in this field from low- and middle-income countries.

OBJECTIVES

This review aims to examine the extent and nature of publications in the field of PICS in the South African (SA) public health sector. Findings of available local research are contextualised through comparison with international data.

METHODS

A comprehensive literature search strategy was employed. Inclusion criteria comprised publications enrolling adult patients following admission to SA public hospital ICUs, with the aim to study the main elements of PICS (ICU-acquired neuromuscular weakness, neurocognitive impairment, psychopathology and HRQOL).

RESULTS

Three studies investigated physical impairment, 1 study psychopathology, and 2 studies HRQOL. Recommended assessment tools were utilised. High rates of attrition were reported. Neuromuscular weakness in shorter-stay patients had recovered at 3 months. Patients who were ventilated for ≥5 days were more likely to be impaired at 6 months. The study on psychopathology reported high morbidity. The HRQOL of survivors was diminished, particularly in patients ventilated for ≥5 days.

CONCLUSION

This review found a paucity of literature evaluating PICS in the SA public health sector. The findings mirror those from international studies. Knowledge gaps pertaining to PICS in medical, surgical and HIV-positive patients in SA are evident. No publications on neurocognitive impairment or the co-occurrence of PICS elements were identified. There is considerable scope for further research in this field in SA.

CONTRIBUTIONS OF THE STUDY

This review identified the available publications investigating the post ICU syndrome (PICS) in the South African public healthcare setting. A small number of ground-breaking studies were found. Knowledge gaps in this field were identified.

Neuropsychological functioning and cognitive reserve in newly HIV diagnosed antiretroviral-naïve South African adults from peri-urban and informal settlements

Despite lower incidences of HIV-associated dementia due to antiretroviral therapy, neuropsychological impairment (NPI) remains a persistent challenge in sub-Saharan Africa. Improving cognitive reserve (CR) can mitigate NPI, but there are few investigations on neuropsychological (NP) performance, and its association with CR in newly diagnosed ART-naïve HIV-positive individuals to inform early treatment strategies. A comprehensive battery of tests were administered to assess various NP domains (International HIV Dementia Scale [for memory, motor speed, psychomotor speed], Digit Span Test [for attention], Action Fluency Test [for language] and Clock Drawing Test [for executive/visuospatial function]), and CR (using Cognitive Reserve Index Questionnaire) among 211 newly diagnosed ART-naïve HIV-positive participants from two clinics that serve peri-urban and informal settlement communities in KwaZulu-Natal, South Africa. Regression models were fitted to assess the association between NP performance and CR controlling for socioeconomic and clinical factors. Test results revealed high levels of impairment across NP domains: language (96.7%), memory and psychomotor speed (82.5%), concentration (17.5%), executive function (15.2%) and visuo-spatial function (3.3%). Low CR and educational attainment were the only factors consistently associated with poor NP performance based on regression. High levels of impairment were found in certain NP domains in a relatively young group of newly diagnosed ART-naïve HIV-positive individuals. Residents of peri-urban and informal settlements face multitude of complex challenges in South Africa. An early multilevel intervention targeting clinical- (e.g. CR) and structural-level challenges (e.g. access to education) is needed for mitigating HIV-associated NPI and promoting long-term healthy living.

A Meta-Analytic Review of the Effect of Antiretroviral Therapy on Neurocognitive Outcomes in Adults Living with HIV-1 in Low-and Middle-Income Countries

HIV-associated neurocognitive impairment remains a challenge even in the era of antiretroviral therapy (ART). Over 90% of people living with HIV are in low- and middle-income countries. Hence, it is not surprising that such countries bear a considerable burden of comorbidities like HIV-associated neurocognitive impairment despite an overall increase in life expectancy. The literature suggests differences in patient characteristics, clinical profile, prevalent HIV subtypes, treatment choices, pharmacogenetics, and socioeconomic factors between low- and middle-income countries compared with high-income countries. Therefore, we aimed to evaluate the effect of ART on neurocognitive outcomes in low- and middle-income countries. A comprehensive search of five databases (PubMed, CINAHL, CENTRAL, PsychInfo, Google scholar) for studies published between 1996 to 2020 was performed to identify studies that reported neurocognitive outcomes in ART-treated and ART naïve HIV positive individuals. Two independent reviewers conducted study screening, data extraction, and evaluation of the risk of bias. Pooled effect size estimates (Hedges' g) and 95% CI were computed using random-effects models. Sensitivity analysis, subgroup analysis, meta-regression, and evaluation of publication bias were also conducted. Forty studies (24 cross-sectional, 13 longitudinal studies, and two randomized controlled trials) contributed to a series of meta-analyses. We found significant small to moderate effects of antiretroviral therapy for global cognition (Hedges' g observed = 0.30; 95% CI: 0.15, 0.44; k = 25; p = 0.0003; I² = 92.1%; tau = 0.32; Q = 305.1), executive function (Hedges' g = 0.24, 95%CI: 0.02,0.46; p-0.04; k = 8; I² = 37.5%; tau = 0.23; Q = 11.2), and speed of information processing (Hedges' g = 0.25, 95% CI: 0.05, 0.45; k = 9; p = 0.02; I² = 86.4%; tau = 0.21; Q = 58.9). We found no significant ART effect on attention-working memory, learning and memory, motor function, and verbal fluency. No significant effect was seen with the duration of therapy, efavirenz use, and Central Penetrating Effectiveness (CPE) of antiretroviral therapy. Subgroup analyses identified study design (between-group and within-group; cross-sectional and longitudinal) and normative scores as significant sources of heterogeneity. Meta-regression analysis indicated that nadir CD4 modified the magnitude of ART's effect on cognitive outcomes. Age, gender, and country income-group were not significant moderators. Our findings provide systematic evidence that antiretroviral therapy improves neurocognitive outcomes in the domains of global cognition, executive function and speed of information processing, of people living with HIV in low- and middle-income countries, especially those with advanced immunosuppression. However, these findings are not definitive as they are limited by the probability of publication bias, high heterogeneity, and exclusion of significant confounders. Prospero registration number: CRD42020203791.

Strength exercise for balance and gait in HIV-associated distal symmetrical polyneuropathy: A randomised controlled trial

BACKGROUND

HIV-associated peripheral neuropathy (PN) is a common neurological complication associated with HIV infection. Distal symmetrical polyneuropathy (DSPN) is the most commonly occurring type, which is associated with symptoms such as numbness, unsteady gait and, in some cases, muscle atrophy and weakness when myelinated nerve fibres are affected. If unmyelinated nerve fibres are affected, a painful neuropathy and autonomic symptoms may occur.

OBJECTIVES

This research study assessed the effects of a strength exercise intervention on balance impairment and gait disturbance amongst individuals living with HIV-associated DSPN.

METHOD

The study was a single-blinded, randomised controlled trial (RCT) with participants sourced from four HIV centres in Kano metropolis, Nigeria. The intervention was supervised and included progressive resistance exercise (PRE) (three 40-min sessions per week for 12 weeks) using a quadriceps bench (n = 44). The control group (CG) included the non-exercise group (n = 47). The two groups continued to receive routine care. Data were summarised and analysed using inferential statistics (SPSS version 20 program) with the alpha level set at < 0.05.

RESULTS

At 12 weeks, the results revealed significant improvement with regard to balance performance (p = 0.001) and walking ability (p = 0.001) in the training group. In contrast, no significant differences in balance (P = 0.677) or gait (P = 0.578) were observed in the CG.

CONCLUSION

The findings suggest that PRE is beneficial for balance impairment and gait disturbance caused by neuropathy in persons living with HIV and receiving antiretroviral drugs.

Improvement of HIV-associated neurocognitive disorders after antiretroviral therapy intensification: the Neuro+3 study

OBJECTIVES

Despite the effectiveness of antiretroviral (ARV) therapy to control HIV infection, HIV-associated neurocognitive disorders (HAND) remain frequent. The Neuro+3 study assessed the cognitive improvement associated with ARV intensification based on increased CNS penetration effectiveness (CPE) scoring ≥+3 and total CPE score ≥9.

METHODS

Thirty-one patients, aged 18-65 years, with confirmed diagnosis of HAND and effective ARV therapy were included. The cognitive improvement was measured using Frascati three-stage classification and global deficit score (GDS) after 48 and 96 weeks of ARV intensification. Ultrasensitive HIV-RNA, neopterin, soluble CD14, CCL2, CXCL10, IL6, IL8 and NF-L were measured in plasma and cerebrospinal fluid at Day 0 (baseline), Week 48 (W48) and W96.

RESULTS

The intensified ARV was associated with a median (IQR) CPE score increase from 6 (4-7) at baseline to 10 (9-11). From baseline to W96, the median (IQR) GDS decreased from 1.4 (0.8-2.2) to 1.0 (0.6-2.0) (P = 0.009); HAND classification improved from 2 to 1 HIV-associated dementia, 22 to 8 mild neurocognitive disorders, 7 to 17 asymptomatic neurocognitive impairment and 0 to 5 patients without any neurocognitive alterations (P = 0.001). In multivariable linear regression analysis, GDS improvement at W96 was significantly associated with CPE score ≥9 after intensification (P = 0.014), CD4 lymphocyte increase at W48 (P < 0.001) and plasma CXCL10 decrease at W96 (P = 0.001).

CONCLUSIONS

In patients with HAND, a significant cognitive improvement was observed after the ARV intensification strategy, with a higher CPE score. Cognitive improvement was more often observed in the case of a switch of two drug classes, arguing for better control of CNS HIV immune activation.

Role of Brain Arterial Remodeling in HIV-Associated Cerebrovascular Outcomes

As the life expectancy of people living with HIV (PLWH) on combination antiretroviral therapy (cART) increases, so does morbidity from cerebrovascular disease and neurocognitive disorders. Brain arterial remodeling stands out as a novel investigational target to understand the role of HIV in cerebrovascular and neurocognitive outcomes. We therefore conducted a review of publications in PubMed, EMBASE, Web of Science and Wiley Online Library, from inception to April 2021. We included search terms such as HIV, cART, brain, neuroimmunity, arterial remodeling, cerebrovascular disease, and neurocognitive disorders. The literature shows that, in the post-cART era, PLWH continue to experience an increased risk of stroke and neurocognitive disorders (albeit milder forms) compared to uninfected populations. PLWH who are immunosuppressed have a higher proportion of hemorrhagic strokes and strokes caused by opportunistic infection and HIV vasculopathy, while PLWH on long-term cART have higher rates of ischemic strokes, compared to HIV-seronegative controls. Brain large artery atherosclerosis in PLWH is associated with lower CD4 nadir and higher CD4 count during the stroke event. HIV vasculopathy, a form of non-atherosclerotic outward remodeling, on the other hand, is associated with protracted immunosuppression. HIV vasculopathy was also linked to a thinner media layer and increased adventitial macrophages, suggestive of non-atherosclerotic degeneration of the brain arterial wall in the setting of chronic central nervous system inflammation. Cerebrovascular architecture seems to be differentially affected by HIV infection in successfully treated versus immunosuppressed PLWH. Brain large artery atherosclerosis is prevalent even with long-term immune reconstitution post-cART. HIV-associated changes in brain arterial walls may also relate to higher rates of HIV-associated neurocognitive disorders, although milder forms are more prevalent in the post-cART era. The underlying mechanisms of HIV-associated pathological arterial remodeling remain poorly understood, but a role has been proposed for chronic HIV-associated inflammation with increased burden on the vasculature. Neuroimaging may come to play a role in assessing brain arterial remodeling and stratifying cerebrovascular risk, but the data remains inconclusive. An improved understanding of the different phenotypes of brain arterial remodeling associated with HIV may reveal opportunities to reduce rates of cerebrovascular disease in the aging population of PLWH on cART.

Cognitive Reserve and Its Determinants in Newly HIV Diagnosed Antiretroviral-Naive Adults From Periurban and Informal Settlements: Evidence From an HIV Hyperendemic South African Setting

BACKGROUND

Cognitive reserve (CR), the brain's capacity to resist pathology, plays an essential role in preserving the cognitive health of people living with HIV. Cognitive health differs by the HIV clinical stage, but there are few studies on CR in newly diagnosed antiretroviral treatment (ART)-naive HIV-positive adults to inform early intervention in sub-Saharan Africa.

METHOD

We investigated the CR profile and its determinants among 211 newly diagnosed ART-naive HIV-positive participants from 2 clinics that serve periurban and informal settlement communities in KwaZulu-Natal, South Africa. CR domains in education, work, and leisure were assessed using the Cognitive Reserve Index questionnaire (CRIq). The CR determinants included major depression, substance use, CD4 count, history of head injury/medical comorbidity, in addition to sociodemographic status. Regression models were fitted to investigate relationships between the total/domain scores and their determinants.

RESULTS

CRIq-Total scores were concentrated in the low-medium/medium functioning range with no individual in the extreme low or high CR functioning group. The determinants of CRIq-Total and CRIq-Education were older age, higher education attainment, and being employed. For the CRIq-Work domain, we found older age associated with lower CR. Major depression was only associated with lower CRIq-Leisure.

CONCLUSION

ART scale-up will undoubtedly improve the longevity of individuals living with HIV, but we found high degree of suboptimal CR in a relatively young group of newly diagnosed ART-naive HIV-positive individuals from periurban and informal settlement communities. Early intervention focusing on increasing CR especially in socioeconomically vulnerable populations is needed to mitigate HIV-associated neurocognitive impairment and promote long-term healthy independent living.

Neurocognitive Effects of Antiretroviral Initiation Among People Living With HIV in Rural Uganda

BACKGROUND

HIV-associated neurocognitive disorders remain prevalent despite effective antiretroviral therapy (ART), but there are limited longitudinal data on people living with HIV (PLWH) in sub-Saharan Africa. We examined neuropsychological (NP) performance in PLWH in a longitudinal study in Uganda.

METHODS

Participants enrolled through the Rakai Community Cohort Study (400 ART-naive PLWH and 400 matched HIV-negative persons) were administered NP assessments. In 2017, PLWH who had initiated ART underwent a 2-year follow-up assessment. Demographically adjusted Z-scores for each NP test were established using data from the HIV- controls. Multivariable linear and logistic regressions were conducted to examine group differences in NP performance. Mixed-effects regressions were conducted to examine ART-related changes in NP outcomes.

RESULTS

Of 333 PLWH who returned for their 2-year follow-up visit, 312 (94%) had initiated ART. Those on ART had a mean age of 35.6 years (SD ± 8.5 years) and mean education of 5.4 years (SD ± 3.3 years); 49% were women. ART-associated NP improvements occurred in verbal learning and memory (P's < 0.05), motor (P's < 0.01), and some measures of processing speed (P = 0.002), whereas there were declines in attention/working memory (P's < 0.001) and semantic fluency (P < 0.001). Pre-ART CD4 count and efavirenz use were associated with a more impaired change in NP performance.

CONCLUSIONS

PLWH in this resource-limited setting showed improved neurocognitive performance on most NP tests after ART initiation. However, the declines in attention/working memory and fluency performance, as well as relationship to efavirenz, warrant further study.

The Impact of Antiretroviral Therapy on Neurocognitive Outcomes Among People Living with HIV in Low- and Middle-Income Countries (LMICs): A Systematic Review

Low and middle-income countries (LMICs) are the epicenter of the HIV epidemic. The scale-up of antiretroviral therapy (ART) has reduced mortality, but HIV-associated neurocognitive impairment (HANI) remains prevalent, which impacts functional performance, medication adherence, and quality of life. We aimed to evaluate the effect of ART on neurocognitive outcomes among people living with HIV/AIDS in LMICs and to identify determinants of these outcomes. We searched electronic databases and reference lists for studies published between 1996 and 2019. Two reviewers screened the primary studies for inclusion and performed the critical appraisal. Results were synthesized using the 'Synthesis without meta-analysis' approach through simple vote counting. We identified 31 studies conducted across four regions (Africa, Asia, South America, and Eastern Europe). Nine studies were cross-sectional, 15 were prospective, and seven were randomized controlled trials. The majority of the articles showed improved neurocognitive performance with ART use but found no association with treatment duration, regimen, central penetrating effectiveness, and conventional biomarkers. Despite the lack of appropriate norms and not accounting for practice effect in most studies, the evidence suggests ART is useful in the treatment of HIV-associated neurocognitive impairment (HANI) but limited in addressing legacy effects, and peripheral, and central viral reservoirs. Improved early ART treatment programs, viral reservoir eradication strategies, and identification of novel biomarkers will be critical in efforts to minimize HIV-associated neurocognitive impairment. PROSPERO registration: CRD42020152908.

Taking the Test: A Qualitative Analysis of Cultural and Contextual Factors Impacting Neuropsychological Assessment of Xhosa-Speaking South Africans

Objective

There is an urgent need to make neuropsychological (NP) testing more acceptable, accessible, and culturally salient, particularly for culturally, educationally, and linguistically diverse individuals from countries who may have little-to-no experience with NP testing. In settings with limited resources such as South Africa, unique cultural and contextual factors (e.g., structural inequality, poverty) may impact the experience of NP evaluation. Research in this area is limited and requires further exploration. This qualitative study explores the role of cultural and contextual factors that may impact the experience of NP evaluation in a sample of Xhosa-speaking South African adults. Participant interviews explored the context from which individuals arrived at the NP assessment (e.g., quality of education, understanding of cognitive disorders), and their experience of completing NP tests.

Method

This qualitative study used data from semistructured interviews to conduct a thematic analysis exploring contextual factors and the experience of completing NP tests for the first time among Xhosa-speaking South African adults (N = 22). Results: Although no participants had prior experience with NP testing, most found testing procedures acceptable. Most participants, however, reported a limited understanding of the purpose of NP testing and cognitive problems. Additionally, some participants reported perceptions and attitudes that could affect test performance, such as misinterpreting standard testing procedures (e.g., no feedback from the examiner, being stopped mid-task) as indicative of poor performance.

Conclusions

This study provided much needed exploration into unique cultural factors that may impact the experience of NP assessment in South Africa, which could bias test performance and interpretation, and may aid the field of cross-cultural NP in better serving culturally and linguistically diverse populations. In these countries, neuropsychologists may need to actively evaluate participants’ understanding of NP testing to help foster optimal assessment conditions. They may also need to educate participants on possible causes of cognitive disorders.

HIV-associated neurocognitive impairment in stable people living with HIV on ART in rural Tanzania

OBJECTIVES

Few studies have assessed cognitive impairment among healthy people living with HIV (PLWH) who are stable on antiretroviral treatment (ART) in sub-Saharan Africa.

METHODS

We conducted a cross-sectional study among a random sample of stable adult PLWH from rural Tanzania on ART for more than 1 year and without immunological failure or pre-existing neurological disease. We evaluated the prevalence and risk factors for neurocognitive impairment (NCI), assessed through neuropsychological tests, functional and depression questionnaires and defined as a mean Z-score ≤ -1 in two or more cognitive domains.

RESULTS

Among 243 participants [median age = 44.3 years (interquartile range: 36-52] and 71% female] we found a rate of NCI of 19.3% (95% confidence interval: 14.8-24.8%). Memory and psychomotor domains demonstrated the highest impairment. Independent predictors of NCI were age and self-reported alcohol use. Other classical risk factors were not associated with HIV-associated NCI.

CONCLUSION

Despite effective ART roll-out, NCI remained a prevalent condition in this healthy rural Tanzanian population of PLWH on ART. Age and alcohol use were key risk factors.

Antiretroviral therapy improves neurocognitive impairment in people living with HIV? A meta-analysis

Objectives

Although effective antiretroviral therapy (ART) has been used for more than two decades, HIV-associated neurocognitive disorder remains prevalent. Thus, whether ART can improve neurocognitive impairment is controversial. This review aims to explore the effects of ART on cognitive impairment in people living with HIV (PLWH).

Methods

A systematic literature search was conducted in eight databases (PubMed, Embase, Web of Science, Cochrane Library, CNKI, VIP, China Biology Medicine disc, and WanFang) to identify studies that compare cognitive function between study groups who are administered and not administered ART. We searched for articles published up to April 2019. Article evaluation and data extraction were independently conducted by two reviewers.

Results

Sixteen articles (6,694 participants)—14 cross-sectional studies and 2 cohort studies—were included in this meta-analysis. The cross-sectional studies demonstrated that ART group did not perform better than the non-ART group (OR = 1.16; 95% CI, 1.03–1.30). However, the cohort studies reported a significant improvement in cognitive function at three months (OR = 4.01; 95% CI, 2.35–6.85) and six months (OR = 9.24; 95% CI, 1.71–49.96) after ART initiation compared with the baseline data. No significant cognitive improvement was found in participants younger than 55 years old, but the two cross-sectional studies showed that ART may improve cognitive function in PLWH under 65 years old with poor physical condition and immune status.

Conclusions

ART could improve cognitive function in PLWH with poor physical condition and immune status, but it does not considerably improve cognition in the entire PLWH population.

Neurologic Complications of Human Immunodeficiency Virus Infection

PURPOSE OF REVIEW

Widespread use of antiretroviral therapy (ART) has led to near-normal life expectancy in people with human immunodeficiency virus (HIV) infection. However, neurologic complications of HIV remain common; can affect any part of the neuraxis; and are due to direct effects of the virus, immunosuppression because of untreated HIV infection, aberrant immune responses in the setting of ART initiation, and ART toxicities.

RECENT FINDINGS

HIV-associated neurocognitive disorder (HAND) remains one of the most common neurologic complications of HIV encountered today, but milder forms predominate in people on ART. No specific treatments for HAND exist, but small trials and epidemiologic evidence suggest paroxetine, intranasal insulin, and maraviroc may have utility in its treatment; further trials of these agents are ongoing. Widespread ART use has decreased the incidence of central nervous system opportunistic infections, but prognosis often remains poor in those who develop opportunistic infections. High-titer positive serum cryptococcal antigen is strongly predictive of cryptococcal meningitis and provides a tool to enhance diagnosis in areas with limited resources. HIV is an independent risk factor for stroke, and accelerated aging associated with HIV infection results in neurologic diseases of older age occurring at much younger ages in individuals infected with HIV. Ongoing HIV replication in the CSF despite peripheral virologic suppression may contribute to the development of HAND and may not improve despite adjusting the ART regimen to increase central nervous system penetrance.

SUMMARY

Neurologists are likely to encounter patients infected with HIV in clinical practice. This article reviews the presentation, diagnosis, and management of the most common neurologic conditions associated with HIV infection and ART.

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).

Neurological disorders in HIV in Africa: a review

BACKGROUND

Neurological disorders in HIV infection are a common cause of morbidity and mortality. The aim of this paper is to provide a narrative overview of up to date information concerning neurological disorders affecting HIV infected persons in Africa.

METHODS

Seminal research concerning neurological disorders among HIV-infected adults in sub-Saharan Africa from prior to 2000 was combined with an in-depth search of PubMed to identify literature published from 2000 to 2017. The following Mesh terms were used. "Nervous System Diseases" "HIV Infections" and "Africa South of the Sahara" and "Seizures" or "Spinal Cord Diseases" or "Peripheral Nervous System Diseases" or "AIDS Dementia Complex" or "Opportunistic Infections" or "Immune Reconstitution Inflammatory Syndrome" or "Stroke". Only those articles written in English were used. A total of 352 articles were identified, selected and reviewed and 180 were included in the study. These included case series, observational studies, interventional studies, guidelines and reviews with metanalyses. The author also included 15 publications on the subject covering the earlier phase of the HIV epidemic in Africa from 1987 to 1999 making a total of 195 references in the study. This was combined with extensive personal experience diagnosing and treating these neurological disorders.

RESULTS

Neurological disorders were common, typically occurring in WHO stages III/IV. These were in three main categories: those arising from opportunistic processes mostly infections, direct HIV infection and autoimmunity. The most common were those arising from direct HIV infection occurring in >50%. These included HIV-associated neurocognitive dysfunction (HAND), neuropathy and myelopathy. Opportunistic infections occurred in >20% and frequently had a 6-9-month mortality rate of 60-70%. The main causes were cryptococcus, tuberculosis, toxoplasmosis and acute bacterial meningitis. Concurrent systemic tuberculosis occurred in almost 50%.

CONCLUSION

Neurological disorders are common in HIV in Africa and the main CNS opportunistic infections result in high mortality rates. Strategies aimed at reducing their high burden, morbidity and mortality include early HIV diagnosis and anti-retroviral therapy (ART), screening and chemoprophylaxis of main opportunistic infections, improved clinical diagnosis and management and programme strengthening.

Assessment of neurocognitive deficits in people living with HIV in Sub Saharan Africa: A systematic review

Objective: People living with HIV (PLWH) are at risk for HIV-Associated Neurocognitive Disorders (HAND)/Neurocognitive Impairment (NCI). HIV prevalence in Sub-Saharan Africa (SSA) is high, but neuropsychological screening and testing for NCI among HIV-infected individuals is not done frequently. This systematic review aims to establish how NCI among HIV-infected individuals is being assessed in SSA, if and how the tests are adapted, if norms exist and identify personnel who administer them.Method: We searched PubMed, Medline, EBSCO, PsycINFO, and Web of Science. Two reviewers screened the articles for inclusion and risk of bias. We included studies from SSA with a comprehensive neuropsychological assessment battery.Results: We retrieved 212 articles and 23 articles met inclusion criteria. The most commonly used tests were the Color Trails Test 1, Color Trails Test 2, and the WAIS III Digit Symbol Test. Some tests were translated into French (Cameroon), Luganda (Uganda), Chichewa (Malawi), isiXhosa (South Africa), and Afrikaans (South Africa). Some verbal learning tests were adapted to reflect culturally appropriate language. Test administrators were either non-specialized personnel supervised by clinical neuropsychologists or clinical psychologists.Conclusion: Overall, the tests used are similar to the tests being used globally to assess NCI among HIV-infected individuals and there is a general consistency across countries. However, there is generally a lack of norms for the tests and the process of adaptation is not always well described. Future research should establish whether these tests measure neuropsychological constructs as successfully as they do in western populations where the tests were developed.

White matter fiber bundle lengths are shorter in cART naive HIV: an analysis of quantitative diffusion tractography in South Africa

This study examines white matter microstructure using quantitative tractography diffusion magnetic resonance imaging (qtdMRI) in HIV+ individuals from South Africa who were naïve or early in the initiation of antiretroviral therapy. Fiber bundle length (FBL) metrics, generated from qtdMRI, for whole brain and six white matter tracts of interest (TOI) were assessed for 135 HIV+ and 21 HIV- individuals. The association between FBL metrics, measures of disease burden, and neuropsychological performance were also investigated. Results indicate significantly reduced sum of whole brain fiber bundle lengths (FBL, p < 0.001), but not average whole brain FBL in the HIV+ group compared to the HIV- controls. The HIV+ group exhibited significantly shorter sum of FBL in all six TOIs examined: the anterior thalamic radiation, cingulum bundle, inferior and superior longitudinal fasciculi, inferior frontal occipital fasciculus, and the uncinate fasciculus. Additionally, average FBLs were significantly shorter select TOIs including the inferior longitudinal fasciculus, cingulum bundle, and the anterior thalamic radiation. Shorter whole brain FBL sum metrics were associated with poorer neuropsychological performance, but were not associated with markers of disease burden. Taken together these findings suggest HIV affects white matter architecture primarily through reductions in white matter fiber numbers and, to a lesser degree, the shortening of fibers along a bundle path.

Effects of HIV on executive function and verbal fluency in Cameroon

HIV-associated neurocognitive disorders (HAND) are frequently associated with impaired executive function and verbal fluency. Given limited knowledge concerning HAND in Sub-Saharan-Africa and lack of Cameroonian adult neuropsychological (NP) test norms, we administered four executive function [Halstead Category Test (HCT), Wisconsin Card Sorting Test (WCST), Color Trails-II (CTT2), and Stroop Color-Word-Interference (SCWT)] and three verbal fluency (Category, Action, and Letter Fluency) tests to 742 adult Cameroonians (395 HIV-, 347 HIV+). We developed demographically-corrected NP test norms and examined the effects of HIV and related variables on subjects' executive function and verbal fluency. HIV+ subjects had significantly lower T-scores on CTT2 (P = 0.005), HCT (P = 0.032), WCST (P < 0.001); lower executive function composite (P = 0.002) and Action Fluency (P = 0.03) T-scores. ART, viremia, and CD4 counts did not affect T-scores. Compared to cases harboring other viral subtypes, subjects harboring HIV-1 CRF02_AG had marginally higher CTT2 T-scores, significantly higher SCWT (P = 0.015) and executive function (P = 0.018) T-scores. Thus, HIV-1 infection in Cameroon is associated with impaired executive function and some aspects of verbal fluency, and viral genotype influenced executive function. We report the first normative data for assessing executive function and verbal fluency in adult Cameroonians and provide regression-based formulas for computing demographically-adjusted T-scores. These norms will be useful for investigating HIV/AIDS and other diseases affecting cognitive functioning in Cameroon.

Home-versus acquired-language test performance on the Hopkins Verbal Learning Test-Revised among multilingual South Africans

The Hopkins Verbal Learning Test-Revised (HVLT-R) has been adapted for use in many different languages and in low- and middle-income countries. However, few adaptations have evaluated performance differences between home- and acquired-language administrations. The present study examined performance on an adapted HVLT-R between multilingual South Africans who chose to be tested in a home or acquired language. The HVLT-R was administered to 112 multilingual, isiXhosa as home language, Black South African adults (49% men) with no major medical, neurological, or psychiatric problems. Sixty-one preferred to take the test in isiXhosa and 51 preferred English. We examined between-language differences in word equivalency, primary scores, learning indices, and serial position effects. We also examined language, age, education, and gender on test performance. English-examinees were significantly younger and more educated than isiXhosa-examinees (p's < .05). Although isiXhosa words had more letters and syllables than English words (p's <.001), there were no significant differences between groups on HVLT-R performance or serial recall (p's > .05). More education and being a woman predicted better Total and Delayed Recall (p's<.05). Performance on this modified HVLT-R appears similar between English and isiXhosa administrations among South African isiXhosa first language speakers, which makes comparisons between preferred language administrations appropriate.

Effect of age and level of education on neurocognitive impairment in HIV positive Zambian adults

OBJECTIVE

Older age and lower education levels are known to be associated with worse neurocognitive (NC) performance in healthy adults, and individuals with HIV infection may experience accelerated brain/cognition aging. However, higher education may possibly protect against HIV-associated neurocognitive disorders (HAND). The aim of the current cross-sectional study was to assess the effect of age and education in an HIV-1 clade C infected adult population in urban Zambia.

METHOD

Demographically corrected Zambian norms on a neuropsychological (NP) test battery were used to correct for normal age and education effects. The study assessed 286 HIV positive (+) males (37.1%) and females (62.9%) with a mean age of 41.35 (SD = 8.56) and mean years of education = 10.16 (SD = 2.18). A comprehensive NP test battery was used to assess cognitive domains frequently affected by HIV: attention/working memory, learning/and delayed recall, executive function, verbal fluency, processing speed, verbal and visual episodic memory, and fine motor skills.

RESULTS

In younger HIV+ Zambians, higher education evidenced protective effects against NC impairments overall, and for the specific domains of executive functions, learning and speed of information processing. Impairment scores did not support accelerated overall brain aging although the restricted age range and relative youth of our total sample may have precluded detection of such tendencies.

CONCLUSIONS

The present study raises the need to investigate factors that could be implicated in the poor neurocognitive performance among the younger, less educated HIV+ individuals in Zambia. (PsycINFO Database Record

Aged Chinese-origin rhesus macaques infected with SIV develop marked viremia in absence of clinical disease, inflammation or cognitive impairment

BACKGROUND

Damage to the central nervous system during HIV infection can lead to variable neurobehavioral dysfunction termed HIV-associated neurocognitive disorders (HAND). There is no clear consensus regarding the neuropathological or cellular basis of HAND. We sought to study the potential contribution of aging to the pathogenesis of HAND. Aged (range = 14.7-24.8 year) rhesus macaques of Chinese origin (RM-Ch) (n = 23) were trained to perform cognitive tasks. Macaques were then divided into four groups to assess the impact of SIVmac251 infection (n = 12) and combined antiretroviral therapy (CART) (5 infected; 5 mock-infected) on the execution of these tasks.

RESULTS

Aged SIV-infected RM-Ch demonstrated significant plasma viremia and modest CSF viral loads but showed few clinical signs, no elevations of systemic temperature, and no changes in activity levels, platelet counts or weight. Concentrations of biomarkers of acute and chronic inflammation such as soluble CD14, CXCL10, IL-6 and TNF-α are known to be elevated following SIV infection of young adult macaques of several species, but concentrations of these biomarkers did not shift after SIV infection in aged RM-Ch and remained similar to mock-infected macaques. Neither acute nor chronic SIV infection or CART had a significant impact on accuracy, speed or percent completion in a sensorimotor test.

CONCLUSIONS

Viremia in the absence of a chronic elevated inflammatory response seen in some aged RM-Ch is reminiscent of SIV infection in natural disease resistant hosts. The absence of cognitive impairment during SIV infection in aged RM-Ch might be in part attributed to diminishment of some facets of the immunological response. Additional study encompassing species and age differences is necessary to substantiate this hypothesis.

A Mobile App to Screen for Neurocognitive Impairment: Preliminary Validation of NeuroScreen Among HIV-Infected South African Adults

Background

Neurocognitive impairment (NCI) is one of the most common complications of HIV infection, and has serious medical and functional consequences. South Africa has 7 million people living with HIV (PLHIV) with up to three-quarters of antiretroviral therapy (ART)-naïve individuals having NCI. South Africa’s health system struggles to meet the care needs of its millions of PLHIV; screening for NCI is typically neglected due to limited clinical staff trained to administer, score, and interpret neuropsychological tests, as well as long test batteries and limited screening tools for South African populations. Without accurate, clinically useful, and relatively brief NCI screening tests that can be administered by all levels of clinical staff, critical opportunities to provide psychoeducation, behavioral planning, additional ART adherence support, and adjuvant therapies for NCI (when they become available) are missed. To address these challenges and gap in care, we developed an mHealth app screening tool, NeuroScreen, to detect NCI that can be administered by all levels of clinical staff, including lay health workers.

Objective

The purpose of this study was to examine sensitivity and specificity of an adapted version of NeuroScreen to detect NCI (as determined by a gold standard neuropsychological test battery administered by a trained research psychometrist) among HIV-infected South Africans when administered by a lay health worker.

Methods

A total of 102 HIV-infected black South African adults who had initiated ART at least 12 months prior were administered NeuroScreen and a gold standard neuropsychological test battery in the participants’ choice of language (ie, English or isiXhosa). Three composite z scores were calculated for NeuroScreen: (1) sum of all individual test scores, (2) sum of all individual test scores and error scores from four tests, and (3) sum of four tests (abbreviated version). Global deficit scores were calculated for the gold standard battery where a score of 0.5 or greater indicated the presence of NCI.

Results

The mean age of participants was 33.31 (SD 7.46) years, most (59.8%, 61/102) had at least 12 years of education, and 81.4% (83/102) of the sample was female. Gold standard test battery results indicated that 26.5% (27/102) of the sample had NCI. Sensitivity and specificity of age-, education-, and sex-adjusted NeuroScreen scores were 81.48% and 74.67% for composite score 1, 81.48% and 81.33% for composite score 2, and 92.59% and 70.67% for composite score 3, respectively.

Conclusions

NeuroScreen, a highly automated, easy-to-use, tablet-based screening test to detect NCI among English- and isiXhosa-speaking South African HIV patients demonstrated robust sensitivity and specificity to detect NCI when administered by lay health workers. NeuroScreen could help make screening for NCI more feasible. However, additional research is needed with larger samples and normative test performance data are needed.

HIV-Associated Neurocognitive Disorder

In the last two decades, several advancement studies have increased the care of HIV-infected individuals. Specifically, the development for preparation of combination antiretroviral therapy has resulted in a dramatic decline in the rate of deaths from AIDS. The term “HIV-associated neurocognitive disorder” (HAND) has been used to distinguish the spectrum of neurocognitive dysfunction associated with HIV infection. HIV can pass to the CNS during the early stages of infection and last in the CNS. CNS inflammation and infection lead to the development of HAND. The brain can serve as a sanctuary for ongoing HIV replication, even when the systemic viral suppression has been achieved. HAND can remain in patients treated with combination antiretroviral therapy, and its effect on survival, quality of life, and everyday functioning make it a significant unresolved problem. This chapter discusses details of the computational modeling studies on mechanisms and structures of human dopamine transporter (hDAT) and its interaction with HIV-1 trans activator of transcription (Tat).

HIV-Associated Neurocognitive Disorders: A Global Perspective

The present review on HIV-associated neurocognitive disorders (HAND) provides a worldwide overview of studies that have investigated the rate and neuropsychological (NP) profile of HAND research since the inception of the 2007 HAND diagnostic nomenclature. In the first part, the review highlights some of the current controversies around HAND prevalence rates. In the second part, the review critically assesses some solutions to move the field forward. In the third part, we present the cross-sectional NP profile in non-Western HIV+ cohorts and in relation to Western cohorts' findings. The adopted global perspective highlights the successful expansion of NP studies in HIV infection to culturally diverse low- to medium-income countries with high HIV burden. These studies have produced interestingly similar rates of HAND whether patients were naïve or treated and/or virally suppressed compared to the rich income countries where the NP research in NeuroHIV has originated. The perspective also demonstrates that globally, the group which is the most representative of the HIV epidemic, and thus at risk for HAND are persons with chronic HIV infection and survivors of past immunosuppression, while in relative terms, those who have been treated early with long-term viral suppression represent a minority. In the last part, we present a review of the naturalistic longitudinal NP global studies in HIV+cohorts, discuss the role of longitudinal design in solving issues around the question of asymptomatic neurocognitive impairment, and the question of biomarker discovery. Finally, we conclude by calling for greater methods and data harmonization at a global level. (JINS, 2017, 23, 860-869).

Objective impairments of gait and balance in adults living with HIV-1 infection: a systematic review and meta-analysis of observational studies

BACKGROUND

Gait and balance deficits are reported in adults with HIV infection and are associated with reduced quality of life. Current research suggests an increased fall-incidence in this population, with fall rates among middle-aged adults with HIV approximating that in seronegative elderly populations. Gait and postural balance rely on a complex interaction of the motor system, sensory control, and cognitive function. However, due to disease progression and complications related to ongoing inflammation, these systems may be compromised in people with HIV. Consequently, locomotor impairments may result that can contribute to higher-than-expected fall rates. The aim of this review was to synthesize the evidence regarding objective gait and balance impairments in adults with HIV, and to emphasize those which could contribute to increased fall risk.

METHODS

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. An electronic search of published observational studies was conducted in March 2016. Methodological quality was assessed using the NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Narrative synthesis of gait and balance outcomes was performed, and meta-analyses where possible.

RESULTS

Seventeen studies were included, with fair to low methodological quality. All studies used clinical tests for gait-assessment. Gait outcomes assessed were speed, initiation-time and cadence. No studies assessed kinetics or kinematics. Balance was assessed using both instrumented and clinical tests. Outcomes were mainly related to center of pressure, postural reflex latencies, and timed clinical tests. There is some agreement that adults with HIV walk slower and have increased center of pressure excursions and -long loop postural reflex latencies, particularly under challenging conditions.

CONCLUSIONS

Gait and balance impairments exist in people with HIV, resembling fall-associated parameters in the elderly. Impairments are more pronounced during challenging conditions, might be associated with disease severity, are not influenced by antiretroviral therapy, and might not be associated with peripheral neuropathy. Results should be interpreted cautiously due to overall poor methodological quality and heterogeneity. Locomotor impairments in adults with HIV are currently insufficiently quantified. Future research involving more methodological uniformity is warranted to better understand such impairments and to inform clinical decision-making, including fall-prevention strategies, in this population.

Adding a brief self-report cognitive tool to the IHDS improves effectiveness of identifying patients with HIV-associated dementia in South Africa

We compared the diagnostic accuracy of two brief screening tools (the International HIV Dementia Scale (IHDS), and the IHDS combined with a novel self-report instrument, the HIV Cognitive Symptom Questionnaire (HCSQ)) with that of three brief neuropsychological screening batteries (a 2-, a 3-, and a 4-test battery, each consisting of standardized cognitive tests) in discriminating individuals with HIV-associated dementia (HAD) from those with milder forms of cognitive impairment. We analyzed data from 94 isiXhosa-speaking South African HIV-infected participants who were screened as part of a clinical trial evaluating adjunctive treatment in patients with moderate to severe HIV-associated cognitive impairment. A comprehensive neuropsychological battery diagnosed 53% (50/94) of the participants with HAD. We evaluated the sensitivity and specificity for the screening tools and screening batteries. The brief screening tool performed better compared to the brief neuropsychology battery. The IHDS-HCSQ combination delivered 94% sensitivity and 63% specificity for HAD compared to the IHDS (74 and 70% at a cutoff of ≤8) which offers a viable and quick way to screen for HAD in people living with HIV. It is easy to administer, is time- and cost-efficient, and it appears to be a better option, for these purposes, than brief neuropsychology batteries. It is viable for use in clinical, research, and workplace settings when identification of HIV-infected people with severe cognitive impairment is required.

Moderate to severe HIV-associated neurocognitive impairment: A randomized placebo-controlled trial of lithium

BACKGROUND

HIV-associated neurocognitive disorder (HAND) remains highly prevalent despite effective anti-retroviral therapy (ART). A number of adjunctive pharmacotherapies for HAND have been studied with disappointing results, but preliminary data suggest that lithium may provide clinical benefit. In addition, the low cost of lithium would facilitate access in low- and middle-income countries which carry the greatest burden of HIV.

METHODS

Our objective was to evaluate the 24-week efficacy and safety of lithium in patients with moderate to severe HAND. Our primary efficacy endpoint was the change in Global Deficit Score (GDS) from baseline to 24 weeks, whereas our secondary endpoint was the change in proton magnetic resonance spectroscopy (H-MRS) brain metabolite concentrations. We conducted a 24-week randomized placebo-controlled trial of lithium as adjunctive pharmacotherapy. We enrolled participants with moderate to severe HAND, on ART for at least 6 months, with suppressed viral loads and attending public sector primary care clinics in Cape Town, South Africa. We randomized 66 participants to lithium (n = 32) or placebo (n = 34). Lithium or placebo was dosed 12-hourly and titrated to achieve the maintenance target plasma concentration of 0.6 to 1.0 mmol/L. Sham lithium concentrations were generated for participants receiving placebo.

RESULTS

Totally 61 participants completed the study (lithium arm = 30; placebo arm = 31). Participants at enrolment had a mean age of 40 years and a median CD4+ T-cell count of 500 cells/μL. The median change in GDS between baseline and week 24 for the lithium and placebo arms were -0.57 (95% confidence interval [CI] -0.77, -0.32) and -0.56 (-0.69, -0.34) respectively, with a mean difference of -0.054 (95% CI -0.26, 0.15); P = 0.716. The improvement remained similar when analyzed according to age, severity of impairment, CD4+ count, time on ART, and ART regimen. Standard H-MRS metabolite concentrations were similar between the treatment arms. The study drug was well tolerated in both study arms. Six serious adverse events occurred, but none were considered related to the study drug.

CONCLUSION

Adjunctive lithium pharmacotherapy in patients on ART with HAND was well tolerated but had no additional benefit on neurocognitive impairment.

HIV-associated neurocognitive disorder--pathogenesis and prospects for treatment

In the past two decades, several advancements have improved the care of HIV-infected individuals. Most importantly, the development and deployment of combination antiretroviral therapy (CART) has resulted in a dramatic decline in the rate of deaths from AIDS, so that people living with HIV today have nearly normal life expectancies if treated with CART. The term HIV-associated neurocognitive disorder (HAND) has been used to describe the spectrum of neurocognitive dysfunction associated with HIV infection. HIV can enter the CNS during early stages of infection, and persistent CNS HIV infection and inflammation probably contribute to the development of HAND. The brain can subsequently serve as a sanctuary for ongoing HIV replication, even when systemic viral suppression has been achieved. HAND can remain in patients treated with CART, and its effects on survival, quality of life and everyday functioning make it an important unresolved issue. In this Review, we describe the epidemiology of HAND, the evolving concepts of its neuropathogenesis, novel insights from animal models, and new approaches to treatment. We also discuss how inflammation is sustained in chronic HIV infection. Moreover, we suggest that adjunctive therapies--treatments targeting CNS inflammation and other metabolic processes, including glutamate homeostasis, lipid and energy metabolism--are needed to reverse or improve HAND-related neurological dysfunction.

Executive Dyscontrol of Learning and Memory: Findings from a Clade C HIV-positive South African Sample

OBJECTIVE

Although pre-clinical work suggests there might be differences in neurovirulence across HIV-1 clades, few studies investigate neuropsychological deficits in the globally predominant clade C infection. The purpose of this study was to investigate verbal learning and memory performance in HIV-positive individuals in Cape Town, South Africa, where clade C is the most prevalent subtype of the virus.

METHOD

Using a case-control design, we recruited 53 isiXhosa-speaking, cART-naïve HIV-positive adults and 53 demographically matched HIV-negative controls. Participants were administered a comprehensive neuropsychological test battery. The test of interest was the Hopkins Verbal Learning Test-Revised (HVLT-R); previous studies have used that instrument to identify executive dyscontrol of verbal learning and memory processes in clade B HIV-positive participants.

RESULTS

HIV-positive participants showed only partial impairment on the HVLT-R's learning/memory components (e.g., they recalled significantly fewer words across learning trials, but displayed relatively intact performance on delayed recall trials). They also displayed little executive dyscontrol over encoding and retrieval processes (e.g., there were no significant between-group differences on measures of semantic or serial clustering).

CONCLUSIONS

Post-cART era studies suggest that verbal learning and memory performance is impaired in clade B samples, at least partially due to executive dyscontrol over encoding and retrieval processes. We found few such impairments in the current clade C sample. These preliminary findings suggest different CNS vulnerability across clades that would have implications for delineating clade-specific neuropathological and neurocognitive clinical features.

Contemporary issues on the epidemiology and antiretroviral adherence of HIV-infected adolescents in sub-Saharan Africa: a narrative review

Introduction

Adolescents are a unique and sometimes neglected group in the planning of healthcare services. This is the case in many parts of sub-Saharan Africa, where more than eight out of ten of the world's HIV-infected adolescents live. Although the last decade has seen a reduction in AIDS-related mortality worldwide, largely due to improved access to effective antiretroviral therapy (ART), AIDS remains a significant contributor to adolescent mortality in sub-Saharan Africa. Although inadequate access to ART in parts of the subcontinent may be implicated, research among youth with HIV elsewhere in the world suggests that suboptimal adherence to ART may play a significant role. In this article, we summarize the epidemiology of HIV among sub-Saharan African adolescents and review their adherence to ART, emphasizing the unique challenges and factors associated with adherence behaviour.

Methods

We conducted a comprehensive search of online databases for articles, relevant abstracts, and conference reports from meetings held between 2010 and 2014. Our search terms included “adherence,” “compliance,” “antiretroviral use” and “antiretroviral adherence,” in combination with “adolescents,” “youth,” “HIV,” “Africa,” “interventions” and the MeSH term “Africa South of the Sahara.” Of 19,537 articles and abstracts identified, 215 met inclusion criteria, and 148 were reviewed.

Discussion

Adolescents comprise a substantial portion of the population in many sub-Saharan African countries. They are at particular risk of HIV and may experience worse outcomes. Although demonstrated to have unique challenges, there is a dearth of comprehensive health services for adolescents, especially for those with HIV in sub-Saharan Africa. ART adherence is poorer among older adolescents than other age groups, and psychosocial, socio-economic, individual, and treatment-related factors influence adherence behaviour among adolescents in this region. With the exception of a few examples based on affective, cognitive, and behavioural strategies, most adherence interventions have been targeted at adults with HIV.

Conclusions

Although higher levels of ART adherence have been reported in sub-Saharan Africa than in other well-resourced settings, adolescents in the region may have poorer adherence patterns. There is substantial need for interventions to improve adherence in this unique population.

Poor organisational strategy differentiates cognitively impaired and unimpaired HIV-positive adults

Many HIV-positive individuals manifest symptoms indicative of central nervous system injury. Frequently, those symptoms include cognitive impairment in domains supported by cortical and/or subcortical processing (e.g., executive functioning). The present study investigated one aspect of executive functioning, namely, organisational strategy (i.e., the strategy a person uses when attempting to complete a complex task efficiently). The Rey Complex Figure Test was administered to a group of HIV-positive individuals ( n = 63) and a matched group of HIV-negative individuals ( n = 63). Organisational strategy in completing the task was measured using the Rey Complex Figure Organizational Strategy Score system, which is a quantitative capture of the quality of the approach taken to the task. There were no significant between-group differences in Rey Complex Figure Organizational Strategy Scores, but within the HIV-positive group, increased level of overall cognitive impairment was associated with increasingly poor organisational strategy. These findings suggest that assessment of organisational strategy (and, more generally, assessment of executive functioning) in completing complex tasks may be a valuable component of neuropsychological batteries that attempt to describe the degree of cognitive impairment (and, by implication, the extent of functional impairment) experienced by people living with HIV.

The effects of antiretroviral treatment initiation on cognition in HIV-infected individuals with advanced disease in Pune, India

There has been a reduction in the most severe cases of HIV-associated neurocognitive disorders (HAND) with advances in antiretroviral treatment (ART). But the prevalence of milder forms of HAND still remains high. Data from systematically conducted studies on the effects of ART on cognition are scanty in India, where HIV-1 clade C is prevalent. The purpose of the present study was to assess the effect of antiretroviral therapy in HIV-seropositive (HIV+) individuals (n = 92) with CD4 cell counts <200 cells/mm(3). The overall and domain-specific levels of cognitive functioning were determined using a locally recruited normative sample, and a change in neurocognitive functioning at the 1-year follow-up visit was analyzed. Results revealed cognitive impairment in 44.6 % of the HIV+ group at baseline. At the 1-year follow-up, the group showed significant improvement in the Learning domain (p < 0.05). HIV+ individuals showing improvement in the global cognitive scores had a significantly lower baseline CD4 cell count compared to others. Overall, the degree of improvement associated with the magnitude of rise in CD4 suggests the possibility that early, mild subclinical deficits may also benefit from treatment.

Impact of the HIV Tat C30C31S dicysteine substitution on neuropsychological function in patients with clade C disease

Previous animal studies have identified a C31S residue substitution in the C30C31 dicysteine motif of the Tat protein that is associated with reduced neurovirulence in clade C human immunodeficiency virus (HIV). However, clinical studies of patients infected with clade C HIV have reported significant levels of cognitive impairment. To date, no study has specifically examined cognitive function in clade C-infected patients as a function of the presence or absence of the Tat C31 substitution. The present study investigated the impact of the Tat C30C31S genetic substitution among individuals residing in South Africa infected with clade C HIV that either exhibited the C30C31 motif (n = 128) or the C31S motif (n = 46). A control group of seronegative individuals was included to examine the overall impact of HIV on cognitive performance. All individuals completed a comprehensive neuropsychological battery consisting of tests sensitive to HIV. Results revealed that clade C-infected individuals performed significantly worse across cognitive tests compared to seronegative controls. However, there were no significant differences in cognitive performances between individuals with the C31S motif versus those without the C31S substitution. Proximal CD4 cell count and plasma viral load were unrelated to cognitive performances for either group. Results confirm that the C31S dicysteine motif substitution of the Tat protein does not appreciably moderate neuropsychological outcomes in clade C. Further, these findings highlight the importance of clinical management of cognitive symptoms among individuals infected with this viral clade worldwide.

Epidemiology of neurodegenerative diseases in sub-Saharan Africa: a systematic review

BACKGROUND

Sub-Saharan African (SSA) countries are experiencing rapid transitions with increased life expectancy. As a result the burden of age-related conditions such as neurodegenerative diseases might be increasing. We conducted a systematic review of published studies on common neurodegenerative diseases, and HIV-related neurocognitive impairment in SSA, in order to identify research gaps and inform prevention and control solutions.

METHODS

We searched MEDLINE via PubMed, 'Banque de Données de Santé Publique' and the database of the 'Institut d'Epidemiologie Neurologique et de Neurologie Tropicale' from inception to February 2013 for published original studies from SSA on neurodegenerative diseases and HIV-related neurocognitive impairment. Screening and data extraction were conducted by two investigators. Bibliographies and citations of eligible studies were investigated.

RESULTS

In all 144 publications reporting on dementia (n = 49 publications, mainly Alzheimer disease), Parkinsonism (PD, n = 20), HIV-related neurocognitive impairment (n = 47), Huntington disease (HD, n = 19), amyotrophic lateral sclerosis (ALS, n = 15), cerebellar degeneration (n = 4) and Lewy body dementia (n = 1). Of these studies, largely based on prevalent cases from retrospective data on urban populations, half originated from Nigeria and South Africa. The prevalence of dementia (Alzheimer disease) varied between <1% and 10.1% (0.7% and 5.6%) in population-based studies and from <1% to 47.8% in hospital-based studies. Incidence of dementia (Alzheimer disease) ranged from 8.7 to 21.8/1000/year (9.5 to 11.1), and major risk factors were advanced age and female sex. HIV-related neurocognitive impairment's prevalence (all from hospital-based studies) ranged from <1% to 80%. Population-based prevalence of PD and ALS varied from 10 to 235/100,000, and from 5 to 15/100,000 respectively while that for Huntington disease was 3.5/100,000. Equivalent figures for hospital based studies were the following: PD (0.41 to 7.2%), ALS (0.2 to 8.0/1000), and HD (0.2/100,000 to 46.0/100,000).

CONCLUSIONS

The body of literature on neurodegenerative disorders in SSA is large with regard to dementia and HIV-related neurocognitive disorders but limited for other neurodegenerative disorders. Shortcomings include few population-based studies, heterogeneous diagnostic criteria and uneven representation of countries on the continent. There are important knowledge gaps that need urgent action, in order to prepare the sub-continent for the anticipated local surge in neurodegenerative diseases.

Prepulse inhibition in HIV-associated neurocognitive disorders

Sensorimotor inhibition, or the ability to filter out excessive or irrelevant information, theoretically supports a variety of higher-level cognitive functions. Impaired inhibition may be associated with increased impulsive and risky behavior in everyday life. Individuals infected with HIV frequently show impairment on tests of neurocognitive function, but sensorimotor inhibition in this population has not been studied and may be a contributor to the profile of HIV-associated neurocognitive disorders (HAND). Thirty-seven HIV-infected individuals (15 with HAND) and 48 non-infected comparison subjects were assessed for prepulse inhibition (PPI), an eyeblink startle paradigm measuring sensorimotor gating. Although HIV status alone was not associated with PPI deficits, HIV-positive participants meeting criteria for HAND showed impaired PPI compared to cognitively intact HIV-positive subjects. In HIV-positive subjects, PPI was correlated with working memory but was not associated with antiretroviral therapy or illness factors. In conclusion, sensorimotor disinhibition in HIV accompanies deficits in higher-order cognitive functions, although the causal direction of this relationship requires investigation. Subsequent research on the role of sensorimotor gating on decision-making and risk behaviors in HIV may be indicated.

Limitations to the identification of HIV-associated neurocognitive disorders in clinical practice

OBJECTIVES

The objective of this study was to establish the level of awareness of HAND among healthcare providers, the screening tools that are currently used in its detection and factors that limit cognitive assessments.

METHODS

We distributed a 12-item questionnaire to doctors and nurses who work in the Department of Genitourinary Medicine and Infectious Disease (GUIDE) service and also to doctors who work in the emergency department (ED) at St James Hospital.

RESULTS

35 surveys were collected, 54% (n = 19) from the GUIDE service and 46% (n = 16) from the ED. 82% (n = 29) of participants were doctors from interns to consultants. There was reasonable appreciation among participants with regards the prevalence of neurocognitive impairment (estimated at 29.1% among patients on HAART, and 39.3% among patients not on HAART). Screening tools were rarely used by GUIDE and ED clinicians (25% vs. 15% of the time). The Mini Mental State Examination (MMSE) was previously used by 37% (n = 13) of the group. Very few people had used the HIV Dementia Scale (HIVDS) 6% (n = 2). 34% of respondents felt that 'Orientation in Person, Place and Time was a sufficient screening tool for cognitive assessment'. Lack of time, exposed environment and lack of availability of screening tool were cited as limitations to cognitive screening in the ED environment.

CONCLUSIONS

This study examines awareness of HAND among healthcare providers and also reasons for inadequate assessment. There is a need for consensus on screening guidelines. A quick, easy to use and readily available screening tool may have a role in the acute setting in identifying high-risk patients.