Prospective analysis of seizures occurring in human immunodeficiency virus type-1 infection.

A prospective, case-control study was undertaken to characterise seizures occurring in the context of human immunodeficiency type-1 (HIV-1) infection. Fifty consecutive patients with a documented seizure were enrolled along with fifty control patients. Among cases the median CD4 cell count was 8/mm3 and 84% had a prior AIDS defining illness; 14/mm3 and 80% among the control group. Generalised seizures were seen in 84%, partial with secondary generalisation in 10% and partial in 6%. Associated conditions included cerebral toxoplasmosis (22%), cryptococcal meningitis (8%), progressive multifocal leukoencephalopathy (6%), cytomegalovirus encephalitis (6%), central nervous system (CNS) lymphoma (2%), and other causes (14%) including pre-HIV epilepsy. No associated condition was identified in 42% of patients of whom 18% were receiving foscarnet therapy at the time of seizure, compared with 4% of control patients (p < 0.001). Concentrations of cerebrospinal fluid â2-microglobulin and neopterin, markers that have been associated with HIV-1 involvement of the CNS, were elevated in 12/12 and 13/13 patients, respectively, of the group with no identifiable cause for their seizure. We conclude that seizures occur principally in patients with advanced HIV-1 disease, with opportunistic infections of the CNS the predominant underlying condition. In the group with no identifiable cause foscarnet therapy and subclinical HIV-1 involvement of the CNS may be factors responsible for seizure activity.