She underwent left temporal lobe brain biopsy on 11/10/94: This study was inconclusive and showed evidence of atypical mononuclear cells and lymphocytes in the perivascular and subarachnoid spaces. Despite cytologic atypia the cells were felt to be reactive in nature, since immunohistochemical stains failed to disclose lymphoid clonality or non-leukocytic phenomena. Little sign of vasculopathy or tumor was found. Bacterial, fungal 