Prospective study of new-onset seizures in patients with human immunodeficiency virus infection: etiologic and clinical aspects.

OBJECTIVE: To determine the frequency and etiologic and clinical aspects of new-onset seizures in patients with human immunodeficiency virus (HIV) infection. DESIGN: A prospective survey of an HIV-infected patient cohort. SETTING: Outpatients and inpatients in a university hospital in Barcelona, Spain. PATIENTS: Five hundred fifty HIV-infected patients recruited over 1 year. MAIN OUTCOME MEASURE: Analysis of new-onset seizures, with detailed medical history and appropriate workup. RESULTS: Seventeen HIV-infected patients (3%) had a new-onset seizure during the study period. Fourteen (82%) of 17 patients had acquired immunodeficiency syndrome diagnosed according to the 1993 CDC Expanded AIDS Definition. Mean latency (+/-SD) between diagnosis of HIV infection and the first seizure was 60.7+/-37.6 months. Seizure cause was drug toxicity in 8 patients (47%) and intracranial lesion in 6 patients (35.3%). Two patients had seizures related to metabolic derangements. No cause was found in 1 case. The first seizure was generalized in 12 patients (70.6%), simple partial motor seizure in 2 (11.8%), and simple partial seizure evolving to generalized seizure in 3 (17.6%). We found partial seizures in 66.6% of patients who had intracranial lesions. Most patients were treated with phenytoin, which was well tolerated and effective in controlling seizures. CONCLUSIONS: New-onset seizures are infrequent in patients with HIV. In most cases a definite or probable cause is identified, which is usually related to toxic and/or metabolic factors. Most seizures are generalized, and partial seizures suggest a focal cerebral lesion.