Dementia in AIDS patients in Oslo; the role of HIV encephalitis and CMV encephalitis

In a well-defined population of adult AIDS patients from Oslo, we studied t he correlation between clinical dementia and autopsy results. The study inc luded 91% of all adult AIDS patients from Oslo who died between 1983 and 19 96. The autopsy rate was 73% (167/229). Twenty-three percent of patients ha d definite dementia and 24% possible dementia. In more than half of the pat ients with definite dementia multinucleated giant cells were present in the brain tissue, suggesting that the dementia was due to HIV encephalitis. Di ffuse damage of white matter also showed a significant association with cli nical dementia. When found alone it tended to occur in symptomatic patients with a short survival time from onset of dementia until death. This indica tes that diffuse damage of white matter may be an early stage of HIV enceph alitis. CMV encephalitis was found in 28 cases (17%). Of these, 20 were cla ssified as definitely or possibly demented. In 14 of these 20 cases we dete cted no multinucleated giant cells, suggesting that CMV caused or contribut ed to the dementia. Multiple logistic regression supported an association b etween CMV and conditions clinically classified as HIV dementia. We conclud e that HIV encephalitis is the major cause of dementia in AIDS patients, bu t that CMV encephalitis as a cause of dementia has been underestimated.