Correlation of in vivo neuroimaging abnormalities with postmortem human immunodeficiency virus encephalitis and dendritic loss

Abstract

Background: In the absence of significant opportunistic infection, the most common alterations on neuroimaging in the brains of patients with AIDS include enlarged cerebrospinal fluid spaces, white-matter loss, volume loss in striatal structures, and white-matter signal abnormalities. Although previous studies have linked brain viral levels to these alterations, other neuropathological mechanisms might also contribute to them.

Objective: To examine the relationship between findings on premortem magnetic resonance images and postmortem neuropathologic evidence of human immunodeficiency virus (HIV) encephalitis and neurodegeneration.

Design: Morphometric analysis of magnetic resonance imaging in seropositive cases with matched seronegative controls, and the correlation of these volumes to neuropathological measures in autopsied seropositive cases.

Setting: University of California, San Diego, HIV Neurobehavioral Research Center.

Subjects: Twenty-one seropositive subjects studied at autopsy and 19 seronegative cases.

Main outcome measures: In vivo structural magnetic resonance imaging data analyzed by quantitative methods, with comparison of volumes from magnetic resonance imaging and neuropathological data from autopsies.

Results: The HIV-seropositive subjects demonstrated cerebrospinal fluid increases relative to seronegative controls. These increases were associated with a significant decrease in the volumes of cerebral and cerebellar white matter, caudate nucleus, hippocampus, and, to a lesser extent, cerebral cortex. The volume of cerebral white-matter tissue with elevated signal was also increased. This signal elevation in white matter predicted the autopsy diagnosis of HIV encephalitis, as well as the extent of dendritic loss as assessed by analysis of microtubule-associated protein 2 immunoreactivity.

Conclusions: White-matter and cortical damage resulting from HIV disease are closely related. In vivo magnetic resonance imaging may be a valuable adjunct in the assessment of patients at risk for developing HIV encephalitis.