Prognosis of epilepsy in newly referred patients: a multicenter prospective study of the effects of monotherapy on the long-term course of epilepsy. Collaborative Group for the Study of Epilepsy.

A cohort of 280 previously untreated epilepsy subjects (159 men and 121 women aged 2-81 years) recruited in 14 Italian centers were treated with antiepileptic drug (AED) monotherapy and followed for a median period of 48 months to investigate the rates of seizure remission (i.e., complete control), in general and with reference to various prognostic factors. The cumulative probability of achieving 1-year remission was 62% by 1 year after onset of treatment, 81% by 2 years, 92% by 3 years, and 98% by 5 years. The corresponding figures for 2- and 3-year remission at 5 years were 92 and 78%, respectively. Sixty-two patients (22.1%) had no remission period with monotherapy. Remission rates were significantly lower among patients with two or more seizure types and were inversely correlated to the number of seizures before treatment. The rate of seizure relapses during the first year of follow-up appear to correlate to the risk of developing refractory epilepsy (i.e., with no remission).