Prefrontal cortical volume loss is associated with stress-related deficits in verbal learning and memory in HIV-infected women

Abstract

Deficits in verbal learning and memory are a prominent feature of neurocognitive function in HIV-infected women, and are associated with high levels of perceived stress. To understand the neurobiological factors contributing to this stress-related memory impairment, we examined the association between stress, verbal memory, and brain volumes in HIV-infected women. Participants included 38 HIV-infected women (Mean age=43.9years) from the Chicago Consortium of the Women's Interagency HIV Study (WIHS). Participants underwent structural magnetic resonance imaging (MRI) and completed standardized measures of verbal learning and memory and stress (Perceived Stress Scale-10; PSS-10). Brain volumes were evaluated in a priori regions of interest, including the medial temporal lobe (MTL) and prefrontal cortex (PFC). Compared to HIV-infected women with lower stress (PSS-10 scores in lower two tertiles), HIV-infected women with higher stress (scores in the top tertile), performed worse on measures of verbal learning and memory and showed smaller volumes bilaterally in the parahippocampal gyrus, superior frontal gyrus, middle frontal gyrus, and inferior frontal gyrus (p's<0.05). Reduced volumes in the inferior frontal gyrus, middle frontal gyrus, and superior frontal gyrus (all right hemisphere) were negatively associated with verbal learning and memory performance. Prefrontal cortical atrophy is associated with stress-related deficits in verbal learning and memory in HIV-infected women. The time course of these volume losses in relation to memory deficits has yet to be elucidated, but the magnitude of the volumetric differences between women with higher versus lower stress suggests a prolonged vulnerability due to chronic stress and/or early life trauma.

Keywords: Brain volume; HIV; Memory; Stress; Women.

Figure 1

Partial plot from the multivariable linear regression analysis examining the association between: (A) inferior frontal gyrus (BA44) right hemisphere volume and the verbal memory composite z-score after controlling for age and (B) Middle frontal gyrus volume and semantic clustering composite z-score. Note. The same pattern of associations was seen between inferior frontal gyrus (BA44) in the right hemisphere and percent retention (p=0.01) and delayed free recall (p=0.05) as well as the retrieval index (p=0.02). The same pattern of associations were seen between the middle frontal gyrus in the right hemisphere and all clustering scores (p’s<0.05)