STEREOLOGICAL ANALYSIS OF CEREBRAL ATROPHY IN HUMAN IMMUNODEFICIENCY VIRUS-ASSOCIATED DEMENTIA

Brain atrophy is a common finding in patients with AIDS, but the relat ionship of atrophy to HIV-associated dementia is unclear. We used unbi ased, stereological methods on postmortem brain specimens to estimate volumes of different brain regions in patients prospectively diagnosed with and without HIV-associated dementia. Thirty HIV-seropositive (9 without AIDS/without dementia, 6 with AIDS/without dementia, 15 with A IDS/with dementia) and 7 HIV-seronegative controls were studied using the technique of point counting and Cavalieri's principle of volume es timation. There was a significant reduction in the mean neocortical vo lume (15%, p=0.032) in the group with AIDS when compared to the serone gative controls, and this difference was accentuated when comparing on ly the group with HIV-associated dementia to the seronegatives (neocor tex: 18%, p=0.020). There were no significant differences between the AIDS groups with and without HIV-associated dementia, although there w as a trend for smaller volumes in the most severely demented patients. There were no differences in white matter volumes between groups. In conclusion, patients dying with AIDS, and particularly those with HIV- associated dementia, show significant neocortical atrophy when compare d to seronegative controls. The lack of a significant difference in ce rebral atrophy between HIV-seropositive patients with and without deme ntia suggests that atropy may be a more generalized phenomenon of AIDS as opposed to a specific marker for HIV-associated dementia.