An emerging severe leukoencephalopathy: is it due to HIV disease or highly active antiretroviral therapy?

We report an individual who had HIV-associated dementia, but a good clinical response to antiretroviral therapy, with a rising CD4 count and undetectable viral load. A severe leukoencephalopathy was noted at postmortem; however, no HIV immunopositive cells were found in the brain, suggesting that this new severe leukoencephalopathy is associated with immune reconstitution.