Neuropsychology in South Africa: confronting the challenges of specialist practice in a culturally diverse developing country

Ethical issues in clinical neuropsychology: International diversity perspectives

OBJECTIVE

Much of the information about the ethical practice of clinical neuropsychology has focused on North America. Additionally, of the scholarly publications on the intersection of ethical issues and cultural diversity practices in neuropsychology, most have focused on North America. The extent to which practitioners in other parts of the world are aware of, and find useful, such information is largely unknown. Similarly, the extent to which North American neuropsychologists are familiar with ethical issues and challenges encountered around the world is unknown. The purpose of this article is to advance the discussion of ethical issues in clinical neuropsychology from an international diversity perspective.

METHOD

The article presents, via a panel interview format, the thoughts and experiences of a small sample of neuropsychologists who represent all continents except North America (and Antarctica).

RESULTS

Neuropsychologists across continents share an ethical commitment to providing services that are beneficial, and not harmful, to the recipients of the services. Professional competence is at the heart of such services.

CONCLUSIONS

Through continued and expanded dialogue about ethical issues with neuropsychology colleagues around the world, the potential exists for improvement in the provision of effective and compassionate care in our own towns.

Controlling for inequality in neuropsychological assessment: using Crawford and Howell’s (1998) single-case methodology with norms from demographically homogeneous groups of South Africans

The practice of neuropsychological assessment in South Africa is complicated by the lack of norms that are representative of clients’ educational and linguistic experiences. In an attempt to address this challenge, we argue that Crawford and Howell’s Single-Case Methodology in Neuropsychology is a good option for the neuropsychological investigation of cases that are not well represented by the available norms. This research design and inferential statistical method compares the scores of one case to the performance of a carefully matched sample of modest size. In order that practitioners and researchers might use this methodology, we provide a set of norms for South Africans with specific demographic profiles on a range of well-researched and commonly used neuropsychological tests. We provide an illustrative case study to demonstrate the application of Crawford and Howell’s Single-Case Methodology, which shows how the selection of an appropriately matched norm (control) group is an effective way to reduce test biases for individuals who are not represented by the original test norms.

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.

Moving on from HAND: why we need new criteria for cognitive impairment in people with HIV and a proposed way forward

HIV-associated neurocognitive disorders (HAND) criteria are frequently used to describe cognitive impairment in people with HIV (PWH) across diverse populations globally. These criteria typically find 20-60% of PWH meet criteria for HAND, which does not tally with clinical observations in the modern era that cognitive disorders present relatively infrequently. Most with HAND have asymptomatic neurocognitive impairment (ANI), however the significance of low cognitive test performance without symptoms is uncertain. Methods underlying HAND criteria carry a false positive rate that can exceed 20%. Comorbidities, education and complex socioeconomic factors can influence cognitive test performance, further increasing the potential for misclassification. We propose a new framework to characterise cognitive impairment in PWH which requires a clinical history and acknowledges the multifactorial nature of low cognitive test performance. This framework is intended to be applicable across diverse populations globally, be more aligned with clinical observations and more closely represent HIV brain pathology.

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.

Single case-control design for the study of the neuropsychological deficits and dissociations in Huntington's disease-like 2

The Single-Case Methodology in Neuropsychology (Crawford & Howell, 1998) is a research design and robust inferential statistical method that facilitates the neuropsychological description of one case in terms of the differences between its profile and the performance of a carefully matched sample (Crawford & Garthwaite, 2012). The comparison is made by means of a t-test statistic that treats the normative sample as a sample and not as a population, with a particular effect-size associated with the size (n) of the sample. It is an ideal method for the neuropsychological investigation of rare diseases, such as Huntington’s Disease Like-2 (HDL2), especially when the cases are embedded in contexts of great diversity. This paper presents a step by step guide to the implementation of this method in a series of demographically and clinically diverse group of patients.

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The application of a Single-Case Methodology in Neuropsychology enables the characterisation of rare diseases while controlling for demographic and context-related variables.

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The implementation Single-Case Methodology in Neuropsychology provides test norms for homogenous groups that can be used by practitioners in their clinical work.

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The method was customised for the South African population by controlling variables of specific relevance, such as linguistic diversity and quality of education.

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).

Comparison of the Huntington's Disease like 2 and Huntington's Disease Clinical Phenotypes

Background

Huntington's disease like 2 (HDL2) is the most common Huntington's disease (HD) phenocopy in many countries and described as the phenocopy with the greatest resemblance to HD. The current clinical description of HDL2 is based on retrospective data. It is unknown whether HDL2 has clinical features that distinguish it from HD.

Objective

To describe the HDL2 phenotype and compare it to HD systematically.

Methods

A blinded cross-sectional design was used to compare the HDL2 (n = 15) and HD (n = 13) phenotypes. African ancestry participants underwent assessments, including the Unified Huntington's Disease Rating Scale (UHDRS). The UHDRS motor component was video recorded and evaluated by blinded experts and the inter-rater reliability calculated.

Results

Both groups were homogeneous in terms of demographics and disease characteristics. However, HDL2 patients presented three years earlier with more prominent dysarthria and dystonia. Raters could not distinguish between the two diseases with a high level of agreement. No significant differences in the TMS between HDL2 and HD were found. In both disorders, disease duration correlated with motor scores, with the exception of chorea. Psychiatric and cognitive scores were not significantly different between the groups.

Conclusions

The HDL2 phenotype is similar to HD and is initially characterized by dementia, chorea, and oculomotor abnormalities, progressing to a rigid and bradykinetic state, suggesting the UHDRS is useful to monitor disease progression in HDL2. Although HDL2 patients scored higher on some UHDRS domains, this did not differentiate between the two diseases; it may however be emerging evidence of HDL2 having a more severe clinical phenotype.

Generalizability of demographically corrected Zambian neuropsychological norms to South African women

Objective: Demographically corrected norms typically account for the effects of age, education, and in some cases, sex and other factors (e.g. race/ethnicity). However, generalizability of normative standards to different countries and ethnic groups is not universal. This study sought to determine whether demographically specific Zambian neuropsychological norms would generalize to a group of South African women.Method: 212 English-Xhosa bilingual, South African (SA) women were administered a comprehensive neuropsychological (NP) test battery in either English or Xhosa. We examined rates of "impairment" using Global Deficit Scores (GDS) based upon published, demographically corrected norms from a nearby African country (Zambia). Using multiple regression, we examined the extent to which Zambian norms "corrected" for the effects of age and education in this SA sample.Results: Compared to the normative standards from Zambia, the South African women performed somewhat worse than expected on a few test measures and better than expected on others, but their GDS and associated "impairment" rates were close to what was seen in Zambia. Demographically corrected Zambian norms adequately adjusted for the effects of age and years of education in this sample of SA women, with the exception that Zambian norms appeared to "under correct" for the positive effects of years of education on tests of information processing speed.Conclusions: Demographically corrected norms developed for Zambia may adequately adjust for the effects of age in SA women. Further research is needed to determine whether additional corrections for education are needed in SA, especially for tests of information processing speed.

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.

International perspectives on education, training, and practice in clinical neuropsychology: comparison across 14 countries around the world

OBJECTIVE

To review and summarize data provided by special issue authors regarding the education, training, and practice of neuropsychologists from 14 surveyed countries.

METHOD

A table was constructed to present an overview of variables of interest.

RESULTS

There is considerable diversity among surveyed countries regarding the education and training required to enter practice as a clinical neuropsychologist. Clinical neuropsychologists are typically well compensated, at least in comparison to what constitutes an average salary in each country.

CONCLUSIONS

Despite substantial variations in education and training pathways, and availability of neuropsychologists from country to country, two common areas for future development are suggested. First, identification, development, and measurement of core competencies for neuropsychological education and practice are needed that can serve as a unifying element for the world's clinical neuropsychologists. Second, greater emphasis on recognizing and addressing the need for assessment and treatment of diverse populations is needed if the world's citizens can hope to benefit from the expertise of practitioners in our field.