Objective: We aimed to determine the likelihood of remission and its clinical predictors in adult patients meeting a strict definition of refractory epilepsy. We also wanted to investigate the influence of treatment regimen on remission.
Methods: A total of 246 patients with treatment refractory epilepsy (having at least 1 seizure per month and having not responded positively to at least 2 antiepileptic drugs) were identified in 2000 and followed for 3 years. We used Kaplan-Meier methods to estimate the rate of achieving a 6-month terminal seizure remission and Cox regression analysis to evaluate clinical predictors for seizure remission.
Results: The estimated 6-month terminal seizure remission rate was 19% (95% confidence interval, 14-26%) for all cases and 14% (95% confidence interval, 10-21%) when limited to those treated only with medication. Negative predictors for remission included a history of status epilepticus, younger age at intractability, number of failed drug therapies, and presence of mental retardation. No specific drug was significantly associated with remission, and frequently, no clear intervention led to terminal remission.
Interpretation: Fifteen percent (approximately 5% per year) of a drug refractory epilepsy population obtained a 6-month terminal seizure remission. Our results signify that no matter how many antiepileptic drug therapies have failed, there is always hope of a meaningful seizure remission in this population. Furthermore, we have elucidated four clinical predictors that can aid the epileptologist in prognostication.