[Clinical and paraclinical diagnosis of AIDS neurologic lesions].

Seventy to eighty percent of HIV-infected patients exhibit neurological disorders at an advanced stage of the disease. In almost 90% of cases anatomical examination of brains shows histological lesions. Even when often reversible neurological disorders occur during the HIV primary infection, most of the manifestations of central nervous system (CNS) damage remains the prerogative of severe immunodepression. The principal CNS lesions associated with HIV infection are presented here with the clinical and biological elements that lead to the diagnosis. Cerebral toxoplasmosis holds a privileged place in these manifestations since it responds to an efficient curative and prophylactic treatment with a well-codified medical care based on the test treatment. Biological data, therefore, only have a contributing value. HIV encephalopathy is frequent, but the dementia syndrome is less frequent than the finding of associated imaging and pathological anatomy: atrophy and lesions of the white matter. Thus, the dementia complex is an elimination diagnosis. Cryptococcosis must be systematically considered, not only in patients with meningeal symptoms and headaches, but also with those with isolated fever. The demonstration of cryptococcus and cryptococcic antigen in the CSF has an almost absolute diagnostic value; imaging plays a very small diagnostic role, looking for an exceptional cryptococcoma. Multifocal progressive leukoencephalopathy benefits from the accuracy of MRI, and the diagnosis is usually based on clinical data, MRI and evidence of the virus in the CSF by PCR, even though the only mean of obtaining full proof is, in theory, stereotaxic biopsy. Primary cerebral lymphoma is the diagnostic alternative to toxoplasmosis.(ABSTRACT TRUNCATED AT 250 WORDS)