A prospective, long-term population-based study was conducted to determine the evolution of drug resistance and remission in 144 patients with childhood-onset epilepsy followed at University of Turku, Finland, and Epilepsy Research Group, Berlin, Germany. At the end of 37-year follow-up (range 11-42 years) since their first seizure before age 16 years, 67% were in terminal remission, on or off antiepileptic drugs. Remission was early, within the first year of treatment in 31% of patients; it was late, with a mean delay of 9 years in 50%. The course was remitting-relapsing before achieving terminal remission in 19%. Twenty seven (19%) patients were drug resistant from onset and never entered 5-year remission during follow-up. The etiology of the epilepsy syndrome was important in outcome. Symptomatic, localization-related and generalized epilepsies were more often drug resistant than idiopathic epilepsies, either generalized or focal. 
COMMENT. The study finds that initial success or failure to achieve remission is not a reliable indicator of long-term outcome of childhood-onset epilepsy. Remission, defined as a seizure-free period of 5 or more consecutive years, is achieved by the end of a long followup period in 50% of patients without relapse, and in 20% after relapse. One-third has a poor outcome, with persistent seizures after a remission or without any remission period.