Abstracts

Although much is known about the rate of seizure remission in adults that have undergone epilepsy surgery or children with newly diagnosed epilepsy, prognosis for adults with intractable epilepsy is not clearly defined. Population-based or community-based study would require large sample size to detect those with intractable epilepsy that subsequently experience remission. Therefore, examining patients followed at a tertiary clinic setting offers a unique opportunity to study the prognosis in intractable epilepsy patients.
Our objectives were to determine the frequency of seizure remission and to evaluate the influence of clinical factors on a 6- month seizure remission among a cohort of adults with intractable epilepsy followed at a tertiary clinic setting., This was a retrospective cohort study. We reviewed all adult patients seen in 2001 at the Columbia University Epilepsy Center. Subjects met our criteria if 1) they had failed [ge]2 AEDs at the index date in 2001, 2) if they had on average [ge]1 seizure per month for 3 consecutive months prior to the index date, and 3) enough follow-up time to experience study endpoint. Those who met our criteria of intractability were followed from their index visit in 2001 until their most recent visit to determine if they experienced a 6-month seizure free period.
Crude remission rates were determined, overall and for subgroups, and logistic regression analysis was used to establish the independent significance of the clinical variables, which included history of prior epilepsy surgery, status epilepticus, age of onset, epilepsy classification, developmental delay, and etiology. Analysis was conducted stratifying the subjects by their status of epilepsy surgery following entry into the study., Out of 1389 patients seen at the center in 2001, 191 subjects met our criteria of intractable epilepsy. Mean follow-up of these subjects was 3.5 years.
The subjects had the following epilepsy types:
Localization-related epilepsy 158 (83%)
Primary generalized epilepsy 10 (5%)
Symptomatic generalized epilepsy 20 (10%)
Both LRE and generalized epilepsy 2 (1%)
Unclassifiable 1 (1%)
Thirty four subjects had epilepsy surgery after entering the study of whom 21(61.7%) experienced a 6-month remission. Of 157 subjects that did not have epilepsy surgery, 32(20.3%) experienced a 6-month remission during the follow-up.
None of the clinical variables were significant predictors of a 6-month remission in either group., Subjects not eligible or refusing epilepsy surgery achieved a 6-month remission at a rate of 6% per year. We found no significant predictors of 6-month remission, likely related to power. We suggest a multicenter study with systematic follow-up of intractable cases to address this issue., (Supported by K12 RR017648.)