New onset seizures in HIV--seizure semiology, CD4 counts, and viral loads.

Thirty-seven HIV-positive patients with new-onset seizures (NOS) were prospectively identified during a 1-year study period. The patients were categorized according to the different mechanisms causing NOS in HIV, namely focal brain lesion (FBL) in 21 patients (57%), meningitis in 6 patients (16%), metabolic derangement (no patient), and no identified cause (NIC) other than HIV itself (10 patients, 27%). Seizure semiology, CD4 counts, and blood and cerebral spinal fluid (CSF) viral loads were studied to identify any special characteristics of the different categories. With respect to seizure semiology, all NIC patients had generalized seizures. Two-thirds of the meningitis patients had generalized seizures with one-third having focal seizures. Half of the patients with FBL had generalized seizures and one-third had focal seizures. Status epilepticus was strongly associated with FBL. No significant difference could be detected between the subgroups with respect to CD4 counts and serum and CSF viral loads. The median CD4 count in all patients was 108 cells/ml, indicating advanced immunosuppression. In the FBL group this was 104 cells/ml. In the meningitis group the median CD4 count was 298 cells/ml, and in the NIC group this was 213 cells/ml. Similarly, no differences were noted in the NOS categories with respect to serum and CSF viral loads. Seizures in HIV are a nonspecific manifestation of the seizure mechanism.