3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item Executive function performance in HIV positive adolescents of anti-retroviral treatment in Johannesburg, South Africa.(2014-02-26) Maganlal, UrvashiExecutive Function is conceptualized in this study as the ability to form (the planning functionality obtained through initiation and working memory), maintain (response selection and the ability to self-regulate and inhibit) and switch (cognitive flexibility, mental tracking, organization and sequencing) mental processes in order to effect a positive outcome. The present research is a quasi-experimental study embedded in the Positivist tradition that sets out to empirically evaluate the Executive Function profile of seropositive adolescents (n = 29) emerging from a low socio-economic background and currently on a managed ART programme when compared to a healthy contrast group (based on age, socio-demographic and educational system). As a quantitative study, Executive Function was operationalized through the use of multiple tests of Executive Function such as the Delis-Kaplan Executive Function Colour Word Interference Test (D-KEFS CWIT), the Wisconsin Card Sorting Test (WCST) and the Trail Making Test Part B (TMT-B). As the study formed part of a larger study that included additional neurocognitive tests, including the WISC-R, selected subtests from the WISC-R were used to validate specific arguments relating to the study. The results showed that HIV positive adolescents were inclined to have poorer Executive Function performance especially under situations of higher cognitive load when compared to the unaffected group. The implications of these results are discussed in this research.Item Verbal fluency and vocabulary in English in bi/multilingual adolescents living with HIV-1 in South Africa.(2014-02-26) Van Wyk, CindySouth Africa has the most prominent percentage of individuals living with the Human Immunodeficiency Virus (HIV) in the world, with the most prominent form of transmission of HIV in South Africa being vertical mother-to-child transmission. From 1997 until 2004, South Africa had limited access to ARV treatment at and after birth due to the government legislation. As a consequence, treatment of HIV may only have been initiated after clinical presentation of immune deficiency. A paucity of information therefore exists regarding this population in addition to the specific age demographic of adolescents. Adolescents may be negatively influenced by the cortical thinning associated with HIV, and this study therefore aims to investigate the verbal fluency and vocabulary (in English) of 30 bi- or multilingual seropositive adolescents that are currently on a managed anti-retroviral programme in comparison to an HIV-negative contrast group of 70 bi- or multilingual adolescents in South Africa (matched for age, education, and socioeconomic status). The study found that there were no significant results between the HIV-positive and HIV-negative groups on the measures of vocabulary, semantic naming, or phonemic naming in ‘F’ as determined by their performance on the neuropsychological assessments. Significant results were noted between the HIV-positive and HIV-negative groups on the phonemic naming categories of ‘A’ and ‘S’ however, and negative correlations between performance in these categories and current viral load, and viral load at Highly Active Antiretroviral Therapy (HAART) initiation were also noted. This research formed part of a broader study examining the overall neurocognitive effects of HIV-1 infection in adolescents in South Africa.Item Attention and concentration functions in HIV-positive adolescents who are on anti-retroviral treatment.(2014-02-26) Rice, Jessica DawnApproximately 11.5 million Human Immunodeficiency Virus (HIV)-positive individuals were living in South Africa in 2007, many of whom were infected via mother-to-child transmission. The current study aimed to compare the attentional and concentration functioning of 30 seropositive adolescents on managed anti-retroviral (ARV) programmes, with a comparable group of 71 seronegative adolescents. The results showed that the uncorrected errors on trial 1; self-corrected errors on trial 2; time taken, uncorrected and self-corrected errors on trial 3 of the Stroop Colour-Word Interference Test; and the errors on the Trail Making Test Part B were significantly poorer in the seropositive sample. The results also indicated that the clinical variations in the HIV-positive sample, including the age at which ARVs were commenced; duration of ARV treatment; World Health Organisation (WHO) stage at diagnosis; starting and current CD4+ counts; and starting viral load, but with the exception of the current viral load, impacted significantly on test performance.Item Memory functioning in HIV positive adolescents receiving anti-retroviral treatment.(2014-02-26) Fraser, ShonaIn 2007 it was reported that an estimated 33 million people worldwide were living with the Human Immunodeficiency Virus (HIV). Of this, 35% (approximately 11.5 million) live in South Africa, most of whom were infected with HIV by mother to child transmission. Due to government legislation, until 2004, South Africans had limited access to Antiretroviral (ARV) treatment at and after birth. As a consequence, treatment of HIV was, at this time, only in government facilities, initiated after the clinical presentation of immune deficiency. This study compared the memory functioning of low socio-economic seropositive adolescents that were on a managed anti-retroviral programme to that of a contrast group that were HIV negative. The groups were matched for age, gender, demographics and educational level. The relative impact of variables such as duration of ARV treatment, drug regimen, WHO stage at diagnosis and CD4+ count were all considered. Performance on a comprehensive neuropsychological battery was compared between the HIV positive group and their typically developing counterparts both in terms of memory functions as well as other cognitive processes that may have an effect on memory. The HIV positive group performed significantly below their HIV negative peers in processing speed, holistic processing, and spatial processing as well as specific visual functions such as visual constructional skills, visual recall ability, disruptions in both storage and retrieval of visuospatial information, and visual spatial working memory. No significant differences were found between the groups on tasks measuring verbal memory and verbal learning ability indicating that the neurocognitive profile of clade C HIV has a different presentation from the other clades. The findings suggest that the preferential effect HIV has on the frontostriatal circuits in the brain impacts memory processes due to the destructive impact of the virus on the myelination of these circuits. As a result of the higher degree of white matter tracts in the right hemisphere, holistic and integrative processing is impaired and visuospatial functions are affected whereas verbal processes are largely spared. The resulting neurocognitive profile is similar to that of nonverbal learning disorders and may benefit from similarly constructed interventions such as placing more emphasis on verbal learning strategies and limiting dependence on visual information for HIV positive pupils.Item Psychomotor functioning of HIV positive adolescents on antiretroviral treatment in Johannesburg, South Africa.(2014-02-25) MacIlwaine, StephanieIn 2009 an estimated 33 million people were living with the Human Immunodeficiency Virus (HIV). Of this global population, 35% live in South Africa. Furthermore, sub-Saharan Africa is home to 80% of the world’s population of HIV-1 positive children and adolescents. The most prominent form of transmission of HIV in children in South Africa is from mother to child. Until 2004, South Africans had limited access to ARV treatment at and after birth due to the government legislation. As a consequence, treatment of HIV in children may only have been initiated after clinical presentation of immune deficiency. Therefore, currently, HIV-1 positive adolescents born during the period of restricted ARV-access may have experienced physical and developmental symptoms associated with the virus including neurological deficits, prior to initiating treatment. This study investigated the current psychomotor functioning, such as psychomotor speed, manual dexterity, graphomotor and visual-motor coordination of a group of low socio-economic HIV-1 positive adolescents in Johannesburg, South Africa, who are now on a managed antiretroviral programme and how this compared to a HIV negative contrast group. A Mann-Whitney U Test indicated a significant difference in mean non-dominant hand performance in the Grooved Pegboard Test between the two groups (U = 738, p < .05), with the HIV positive group performing slower than the HIV negative group. An independent samples t-test indicated a significant difference between groups in the Block Design subtest of the WISC-R [t(88) = -2.93, p < .01] where the HIV positive group performed significantly worse than the HIV negative group. Additionally, a Mann-Whitney U Test revealed a significant difference in number of errors made in the WISC-R Mazes subtest between groups (U = 736.50, p < .05), where the HIV negative group made more errors. Another Mann-Whitney U Test revealed a significant difference between groups in the ROCFT Copy score (U = 534.50, p < .01) where the HIV positive group achieved a significantly lower score than the HIV negative group. Lastly, a Mann-Whitney U Test demonstrated significant differences between the groups in the Trail Making Test A time (U = 445.00, p < .01), Trail Making Test B time (U = 509.00, p < .01), the number of errors made on the Trail Making Test B (U = 729.00, p < .05) and the difference between Trail Making Test B – A time (U = 769.50, p < .05) with the HIV positive group performing slower and making more errors in Part B than the contrast group. The findings of the current study imply that HIV-1 vertically-infected adolescents in Johannesburg, South Africa, on a delayed HAART programme appear to have persisting difficulties in complex psychomotor skills where an integration of functions is required. Furthermore, these results indicate an overall poor psychomotor performance in comparison to international normative data, supporting previous findings. Developmental, remedial and therapeutic recommendations were made.Item The effects of highly active antiretroviral therapy on the cognitive-linguistic abilities of adults living with HIV and AIDS in South Africa.(2013-07-24) Mupawose, AnniahIn the context of HIV high infection rate in South Africa, an assumption can be made that there is a high prevalence of HIV-associated neurocognitive disorders or cognitive linguistic deficits. The aim of this study was to determine assess whether highly active antiretroviral therapy (HAART) affected the cognitive – linguistic abilities of individuals living with HIV and AIDS before and after HAART use; and to determine whether their functional performance in terms of engaging in activities of daily living was affected by HAART use. Adults living with HIV and AIDs were recruited through purposive convenience sampling to participate in the study. They were divided into three groups. The experimental and cross sectional group included participants who were HIV infected and initiated HAART. The comparison group included participants who elected not to start HAART. Participants in all three group were assessed using the Cognitive – Linguistic Quick Test and were also required to fill out a structured interview scale at baseline, four and eight months. For the experimental group 55 participants were tested at baseline, 55 at four months and 52 at eight months after HAART initiation. The comparison group included 21 participants who tested at baseline, ten at four months and nine at eight months. The cross sectional group included different participants who recruited at baseline (55) before HAART initiation, then again at four (44) and eight months (42) after HAART initiation. Descriptive analysis revealed that the mean scores for both the Cognitive – Linguistic Quick Test (CLQT) and the structured interview schedule (IS) in all the cognitive domains increased for all three groups from four and eight months after testing. However the severity ratings provided by the CLQT indicated that neurocognitive deficits were still prevalent among the participants after HAART intiation. The most impaired cogntive – linguistic ability was executive functions and the least impaired was language. One way ANOVA analysis on the CLQT and IS revealed that was a signiifcant difference in performance between the three groups at baseline, four and eight months. Repeated measures analysis revealed significant differences or improvements within participants across the three time periods. The greatest improvement was observed from baseline to eight months especially on the CLQT. ANCOVA analysis on the Cognitive- Linguistic Quick Test indicated that education had a major impact on cognitive – linguistic abilities followed by age and CD4 count. However, ANCOVA analysis on the structured interview scale revealed that the effect of time, participant group and to a lesser extent age influenced the participants cognitive – linguistic abilities when it came to perfroming activities of daily living. Quantitave inquiry using content analysis showed that participants in all three groups cited attention, followed by visual and language problems as hindering their abilities to perform activities of daily living. The implications from this study revealed that even though HAART improves cognitive –linguistic abilities, neurocognitive deficits were still prevalent. Therefore findings suggest that health professionals need to monitor the neurocognitive impairments of their patients so as determine levels of functional performance.