Purpose: To investigate the probability of achieving remission of seizures after a newly diagnosed unprovoked epileptic seizure in an adult population-based cohort.
Methods: 107 patients aged 17 years or older with a newly diagnosed unprovoked epileptic seizure (index seizure) in 1985 through 1987 were followed up until the date of death or to the end of 1996. The proportion of cases during follow-up that attained a 1-year, 3-year, 5-year remission was calculated by actuarial analyses. Variables for stratification were age at diagnosis, seizure type, etiology, EEG, and the occurrence of seizures within 1 year of initiation of antiepileptic drug (AED) therapy.
Results: Cumulative 1-, 3- and 5-year remission rates were 68, 64, and 58%. There was no statistically significant difference regarding time points of achieving a 1-year remission after epilepsy diagnosis and the subsequent probability during follow-up of attaining a 5-year remission. Having seizures within 1 year after beginning with an AED was a statistically significant predictor of never achieving 1-year remission of seizures during follow-up (refractory seizures). Other stratified variables were not statistically significant predictors.
Conclusions: Seizure prognosis for the majority of patients with newly diagnosed epilepsy is good. The time required after epilepsy diagnosis to achieve a 1-year remission of seizures does not affect the probability of additionally achieving a 5-year remission. Patients with refractory seizures can be identified within a few years from diagnosis of epilepsy. These patients must be targeted early for optimization of pharmacologic treatment, possible surgery, and psychosocial intervention.