Long-term risks following first remission in childhood-onset epilepsy. A population-based study.

Although most patients with newly-treated epilepsy enter remission, the risks associated with first remission are not well-known. It is thus of great clinical interest to assess the long-term risks of poor seizure outcome and premature retirement for those in their very first remission and to determine predictive clinical features. We determined the likelihood of seizure relapse, remission following relapse, and premature retirement after entering first seizure remission of 5 years or more in a population-based cohort of 115 medically treated patients, who were followed up since their first seizure during childhood. At the end of the 42-year median follow-up from the onset of adequate medication before the age of 16 years, 115 (82%)/141 patients entered a first remission of at least 5 years. Although 69 (60%) of the 115 patients had no relapse, at least one seizure relapse was seen in 46 (40%) and 14 (12%) never re-entered five-year remission. Among the 115 patients, 33 (30%) were prematurely retired. On multivariate analysis of clinical features, cognitive impairment predicted seizure relapse for those entering their first remission of 5 years or more. Relapse, symptomatic etiology, and early onset of epilepsy were significant predictors of premature retirement. Despite entering their first remission of 5 years or more, individuals with epilepsy face clinically important risks including relapse, failure to re-enter remission following relapse, and premature retirement. Cognitive impairment predicted seizure relapse, while relapse, symptomatic etiology, and early onset of epilepsy were significant predictors of premature retirement.