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

Semantic memory navigation in HIV: Conceptual associations and word selection patterns

Objective: This proof-of-concept study aimed to characterize semantic memory profiles in individuals with human immunodeficiency virus (HIV) and mild neurocognitive impairment. Method: Using a semantic relatedness task, we explored conceptual association and word selection patterns in people living with HIV (PLWH; n = 50) relative to people living without HIV (n = 46). We also studied whether word selection patterns in the PLWH group were associated with working memory capacity, cognitive flexibility and inhibitory control. Results: While accuracy did not differ between groups, PLWH produced significantly longer responses than controls (r = .32), with fewer hypernyms (d = .47), more troponyms (r = .37), and words that were more frequent (r = .39) and had more phonological neighbors (r = .22). These patterns survived covariation with participants' cognitive status. None of these patterns correlated with measures of working memory, cognitive flexibility, inhibitory control or viral load (all correlation coefficients < .36). Conclusions: Together, these results suggest that PLWH might use alternative word finding strategies during semantic memory navigation, irrespective of the severity of other cognitive symptoms. Such findings contribute to the characterization of cognitive deficits in HIV and to the search for novel markers of the condition.

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.

HIV-1C and HIV-1B Tat protein polymorphism in Southern Brazil

The transactivator of transcription (Tat) is a key HIV regulatory protein. We aimed to identify the frequency of key polymorphisms in HIV-1C compared with HIV-1B Tat protein, chiefly in the cysteine-, arginine-, and glutamine-rich domains and identify novel point mutations in HIV-1B and C sequences from Southern Brazil. This study was the first to investigate the genetic diversity and point mutations within HIV-1 Tat C in a Brazilian cohort. This was an observational, cross-sectional study, which included sequences of HIV-1B (n = 20) and HIV-1C (n = 21) from Southern Brazil. Additionally, 344 HIV-1C sequences were obtained from the Los Alamos database: 29 from Brazil and 315 from Africa, Asia, and Europe. The frequency of C31S substitution on HIV-1 Tat C in Brazil was 82% vs. 10% in the HIV-1B group (p < 0.0001). The frequency of the R57S substitution among the HIV-1C sequences from Brazil was 74% vs. 20% in HIV-1B (p = 0.004), and that of substitution Q63E in HIV-1C was 80% and 20% in HIV-1B (p < 0.0001). The mutation P60Q was more frequent in HIV-1B than in HIV-1C (55% and 6.12%, respectively, p < 0.0001)). Novel point mutations in the HIV-1C and B Tat functional domains were described. The frequency of C31S and other key point mutations in HIV-1 Tat C in Brazil were similar to those described in Africa, although lower than those in India. The Tat-B and C sequences found in Southern Brazil are consistent with biological differences and have potential implications for HIV-1 subtype pathogenesis.

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).

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.

Cross-cultural assessment of HIV-associated cognitive impairment using the Kaufman assessment battery for children: a systematic review

INTRODUCTION

Despite improved efficacy of, and access to, combination antiretroviral therapy (cART), HIV-associated cognitive impairments remain prevalent in both children and adults. Neuropsychological tests that detect such impairment can help clinicians formulate effective treatment plans. The Kaufman Assessment Battery for Children (KABC), although developed and standardized in the United States, is used frequently in many different countries and cultural contexts to assess paediatric performance across various cognitive domains. This systematic review investigated the cross-cultural utility of the original KABC, and its 2nd edition (KABC-II), in detecting HIV-associated cognitive impairment in children and adolescents.

METHODS

We entered relevant keywords and MeSH terms into the PubMed, PsycInfo, EBSCOHost, ProQuest, and Scopus databases, with search limits set from 1983-2017. Two independent reviewers evaluated the retrieved abstracts and manuscripts. Studies eligible for inclusion in the review were those that (a) used the KABC/KABC-II to assess cognitive function in children/adolescents aged 2-18 years, (b) featured a definition of cognitive impairment (e.g. >2 SD below the mean) or compared the performance of HIV-infected and uninfected control groups, and (c) used a sample excluded from population on which the instruments were normed.

RESULTS AND DISCUSSION

We identified nine studies (eight conducted in African countries, and one in the United Kingdom) to comprise the review's sample. All studies detected cognitive impairment in HIV-infected children, including those who were cART-naïve or who were cART treated and clinically stable. KABC/KABC-II subtests assessing simultaneous processing appeared most sensitive. Evaluation of the methodological quality of the selected studies by two independent reviews suggested that shortcomings included reporting and selection biases.

CONCLUSIONS

This systematic review provides evidence for the cross-cultural utility of the KABC/KABC-II, particularly the simultaneous processing subtests, in detecting cognitive impairment in HIV-infected children (including those who are clinically stable). Although the current results suggest there is justification for using the KABC/KABC-II primarily in East Africa, further investigation is required to explore the instrument's utility in other HIV-prevalent regions of the globe.