Seizure remission and relapse in adults with intractable epilepsy: a cohort study.

Purpose: To investigate the cumulative probabilities of >or=12 month seizure remission and seizure relapse following remission, and to test the associations of clinical characteristics with these two study end points in a prevalence cohort of intractable adult epilepsy patients during medical management.

Methods: A retrospective cohort study of intractable epilepsy patients seen in 2001 at a single center was conducted. Kaplan-Meier analysis was used to estimate the cumulative probabilities of seizure remission and subsequent seizure relapse. Cox proportional hazards models were used to estimate the association (1) between clinical factors and >or=12 month seizure remission and (2) between clinical factors and seizure relapse following remission.

Results: One hundred eighty-seven subjects met the eligibility criteria for intractable epilepsy. The estimate of probability of remission was about 4% per year. Seizure remission was temporary for some individuals, as 5 out of 20 subjects with remission ultimately relapsed. No clinical factors predicted the likelihood of achieving >or=12 month seizure remission or subsequent seizure relapse.

Discussion: Some people with intractable epilepsy achieve >or=12 month seizure remission during medical treatment. Remission, however, is only temporary for some individuals. We were unable to identify clear predictors for remission.