Browsing by Author "Joska, John Anton"

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    Neurocognitive disorders in young adults commencing highly active anti-retroviral treatment in the Western Cape
    (2010) Joska, John Anton; Flisher, Alan J; Stein, Dan J
    HIV-associated neurocognitive disorders (HAND) remain prevalent in the era of highly active anti-retroviral therapy (HAART). The aim of the study was to investigate whether HAND are as prevalent in South Africa as in other regions, and whether individuals with HAND in South Africa will respond to HAART. The literature was reviewed to elucidate potential mechanisms of the development of HIV-associated dementia (HAD), the most severe form of HAND, and to establish the effect that HAART has exerted on HAND across diverse studies. A prospective clinical cohort study was initiated in Cape Town, comprising 170 participants. The reviewed literature suggests that HAD is likely mediated by a range of HIV-related factors (including possible difference in HIV sub-type) and host-related factors.
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    Neurocognitive disorders in young adults commencing highly active antiretroviral treatment in the Western Cape
    (2010) Joska, John Anton; Flisher, Alan; Stein, Dan
    Background: HIV-associated neurocognitive disorders (HAND) remain prevalent in the era of highly active anti-retroviral therapy (HAART). It is not known whether HAND are as prevalent in South Africa as in other regions, and whether individuals with HAND in South Africa will respond to HAART. Methods: The published literature was reviewed to elucidate potential mechanisms of the development of HIV-associated dementia (HAD)- the most severe form of HAND- and to establish the effect that HAART has exerted on HAND across diverse studies. A prospective clinical cohort study was initiated in Cape Town, in which 170 participants completed baseline clinical and neuropsychological assessments. Laboratory investigations included apolipoprotein E (APOE) genotyping. The performance of the International HIV Dementia Scale (IHDS) as a brief screening tool was analysed using a receiver operating characteristic (ROC). At one-year, 105 participants were re-assessed for neuropsychological change. Results: The reviewed literature suggests that HAD is likely mediated by a range of HIV-related factors (including possible difference in HIV sub-type) and host-related factors. In addition, while neurocognitive improvements are reported in most prospective studies, these are dogged by differences in methodology and approach. In this study, 25.4% of participants met criteria for HAD at baseline and this was associated with lower levels of education and male gender. The APOE4 allelic variant was not associated with those who had developed HAD, despite this variant being common in Cape Town. The IHDS performed reasonably well on ROC analysis, detecting 86% of dementia cases using a cut-off score of ≤11. At one-year follow-up, participants had improved significantly on neuropsychological assessment, including a small sub-sample who had not initiated HAART. Significant associated factors were male gender, the use of HAART and worse baseline neuropsychological test performance. Conclusion: HAND- including HAD- are common conditions in South Africa, where HIV clade C is predominant. Further work to identify cases and delineate mechanisms of disease and treatment response is needed. This might take the form of larger prospective studies, incorporating control groups. Such studies could better elucidate disease mechanisms with a view to developing targets for therapeutic interventions.
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    The relationship between neurocognitive disorders, prospective memory impairment and white matter damage in clade C HIV-positive subjects
    (2010) Hoare, Jacqueline; Joska, John Anton; Stein, Dan J
    AIMS: To examine the relationship between prospective memory, cognitive function and Diffusion tensor imaging (DTI)/ White matter integrity of human immunodeficiency virus (HIV) positive individuals in the Western Cape. We hypothesize that: 1. Individuals infected with HIV will exhibit significantly poorer microstructural integrity of the white matter than HIV negative individuals, as determined by in vivo diffusion tensor imaging. We expect that values of fractional anisotropy (FA) - a measure of directional water diffusion- in the frontal white matter will be significantly lower among HIV patients compared to controls 2. Lower FA measured in the frontal white matter will correlate significantly with impaired performance on tests of prospective memory