Publication Abstract Display
Type: Published Abstract
Title: Additive effects of aging and HIV infection on semantic verbal fluency: An analysis of clustering and switching.
Authors: Iudicello JE, Woods SP, Deutsch R, Grant I and the HNRC Group
Year: 2011
Publication: International Neuropsychological Society 39th Annual Meeting, Boston, Mass
Volume: Issue: Pages:
Abstract:Objective: Although both aging and HIV infection are independently associated with semantic fluency impairment, the possible additive effects of these risk factors are unknown. This study examined the component cognitive processes of semantic fluency in older HIV-infected adults and their associations with everyday functioning. Participants and Methods: Participants included 257 patients across 4 demographically matched groups: Younger (i.e., ≤40 years) Healthy (n=93), Younger HIV-infected (n=50), Older (i.e., >50 years) Healthy (n=51), and Older HIV-infected (n=63) individuals. Participants were administered a standard semantic fluency protocol scored according to established clustering and switching guidelines (Troyer et al., 1997) as part of a comprehensive neuropsychological evaluation. Results: Jonckheere-Terpstra tests revealed a significant stepwise additive effect between the groups for overall semantic fluency output (p = 0.004) and a trend for declining switching performance (p = 0.056), but not cluster size (p = 0.826), with greatest deficits evident in the Older HIV-infected participants. Results were not better explained by confounding psychiatric, medical, or HIV disease characteristics. Within the older HIV-infected adults, poorer switching was associated with deficits in learning and executive functioning and self-reported declines in everyday functioning. Conclusions: Results suggest that HIV infection and aging may confer adverse additive effects on the executive components of semantic fluency (i.e., switching), which was associated with poorer everyday functioning outcomes and may be driven by the combined frontostriatal neuropathological burden of these two conditions. Prospective neuroimaging and biomarker studies are needed to further delineate the neural substrates of switching impairment in older HIV-infected individuals.

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