[Diagnostic and prognostic implications of the first epileptic seizure in adulthood]

Actual epidemiological studies show a prevalence rate for active epilepsy in 0.5-1%, whereas single seizures occur in up to 5% of the general population. Assessment of the significance of first epileptic reaction requires precise definition and classification of the episode, a careful analysis of the entire context including thorough case history, and indirect anamnesis. The value of EEG-techniques for this issue is part of a controversial discussion. By means of cranial computerized tomography (cCT), brain tumours were detected as structural correlate in 5 to 16% of first-seizure-patients. In recent studies, estimated risk of seizure recurrence after first unprovoked seizure ranged from 27% to 78%: most of the relapses were observed in the first 6 months after the first event. The wide range of relapse rates is due to the divergent methodological designs (retro- versus prospective design, selection of patients, length of time before study entry) in the different studies. There are conflicting results concerning risk factors and predictive value of the following variables: pathology in the neurostatus, focal seizure type or Todd's paresis, history of febrile seizures, symptomatic genesis, and specific epileptic potentials and time of day of seizure event. In an actual metaanalysis of recent studies, seizure etiology and EEG were the strongest predictors of recurrence. The preliminary results of our prospective study with a strict protocol and first-seizure-design are presented: we observed a seizure relapse in 26.7% of 78 adult patients (age range: 17-84 years) after a mean latency of 4.4 months. Until now, there is no evidence for potential predictors of seizure recurrence.(ABSTRACT TRUNCATED AT 250 WORDS)