Abstracts

Rationale: Seizures have been reported to occur at a rate between 3-17% in patients with human immunodeficiency virus (HIV) infection. Such a high percentage, as compared to a normal population, is not surprising. Neurological complications occur in over 50% of patients with acquired immune deficiency syndrome (AIDS). We conducted our research to confirm that the majority of HIV-infected patients with new onset seizures have seizures due to identifiable CNS pathology. Methods: We retrospectively analyzed The Ohio State University Medical Center (OSUMC) Information Warehouse, an archive of existing medical records and billing data for inpatients and outpatients, over a 3-year period (1/1/2006-12/31/2008). We searched for HIV-infected adults (age greater than 18 years) with new onset seizures using ICD-9 codes for HIV and seizures, epilepsy, or convulsions. We collected demographic information including age at enrollment in the study, gender, the latency between HIV diagnosis and seizure onset, seizure recurrence during the study, presence of HIV antiviral medications at the time of seizure onset, results of investigations for the seizures including electroencephalogram (EEG), neuroimaging, serum laboratories, cerebrospinal fluid (CSF), CD4 cell counts, and HIV RNA viral loads. We divided the study population by etiology of new onset seizure into those related to HIV-related CNS pathology, CNS pathology unrelated to HIV, and other non-CNS etiologies. Results: Thirty-four HIV-infected adults with new onset seizures were identified. The population included 82% males with a mean age of 41 7.6 years. There was no known etiology for seizure in 14 patients (41.18%). CNS pathology related to HIV was the cause for seizure in 14 patients (41.18%). Seizure due to acute CNS pathology unrelated to HIV was determined in 2 patients (5.88%), and systemic etiology occurred in 4 patients (11.76%). No significant differences between groups were detected regarding CD4 counts and viral loads. The majority of patients had advanced HIV infection with 81.3% with a CD4 count <200 cells/mm³ preceding seizure and 65.6% with a CD4 count <50 cells/mm³ preceding seizure. Recurrent seizures occurred in 3 of 30 patients (27.3%) with HIV-related CNS pathology and 13 of 30 patients (68.4%) with other cause for seizure (p=0.029). Recurrent seizures occurred in 4 of 30 patients (30.8%) with all CNS pathology versus 12 of 30 patients (70.6%) with other cause for seizure (p=0.030). Conclusions: In the majority of patients, seizure was not related to HIV pathology. A lower percentage of patients with HIV-related CNS pathology had recurrent seizures compared to those with other causes for new onset seizure. This suggests there may be a possible underlying mechanism of the human immunodeficiency virus itself, rather than CNS pathology, provoking seizures.