Correlation between clinical-apparative and neuropathological findings in patients with cerebral manifestations of AIDS

During the course of HIV infection, the majority of patients develops opportunistic cerebral manifestations which can result in difficulties of the diagnostic work up. Since conventional diagnostic tools such as serological analysis of cerebrospinal fluid and blood and neuroimaging are not always sufficient to establish the correct diagnosis, a stereotactic biopsy is often necessary.

In order to evaluate the correctness of the clinical diagnosis of cerebral neuromanifestations in HIV infected patients, we compared the results of cerebral biopsy or autopsy with the previous clinical diagnosis. Nineteen biopsies and 49 autopsies could be analysed. A clinical diagnosis based on the neurological examination, the serological, neuroimaging, and neurophysiolgoical results was esatblished. The sensitivity, specifity, and predictive values of this diagnosis was calculated taking the neuropathological results of the biopsy or autopsy as the final diagnosis.

Except for HIV associated encephalopathy, we detected a very high conformity between the clinical and the neuropathological diagnosis. We obtained the best sensitivity for the Progressive Multifocal Leukencephalopathy (PML), whereas for cerebral toxoplasmosis the worst sensitivity and specifity was identified. When comparing the neuropathological diagnoses before and after 1993, we observed a significant decrease in the prevalence of cerebral toxoplasmosis, all other diagnoses did not change significantly. Age and sex of the patients, except for a significantly higher prevalence of PML in women, did not show any influence on the prevalence of the different neuromanifestations.

We conclude that the diagnosis of PML can be made on clinical ground alone whereas the diagnosis of cerebral toxoplasmosis, lymphoma, and more rare neuromanifestations often requires a biopsy which should be performed early in the infection.