Neuroimaging of AIDS. I. Viral infections.

Viral infections of the brain and spinal cord cause significant morbidity and mortality in patients afflicted with AIDS. Debate continues over the specific mechanisms and pathways of how HIV-1 manifests itself in the brain and spinal cord. Attempts to predict which seropositive patients develop neurocognitive deficits caused by HIV-1 and how soon these deficits will occur in the course of disease have had limited success. The neuropathologic changes of HIV-1 must be distinguished from other viral infections, such as cytomegalovirus, JC papovavirus (progressive multifocal leukoencephalopathy), herpes simplex virus type 1, and varicella-zoster virus. In addition to cerebral spinal fluid sampling and serum testing, some specific features are seen with contrast-enhanced CT, MR imaging, proton MR spectroscopy, SPECT, and PET.