Abstracts

Rationale: IGEs are genetically-medicated disorders that are relatively easily controlled with standard antiepileptic drugs (AEDs). Only a minority of patients with IGEs continue to have seizures despite appropriate treatment. Various factors are suggested to contribute to AED resistance in IGEs but detailed examinations of the contributing factors in large samples of patients with IGEs are scarce. The objective of this study was to determine what factors are associated with seizure-freedom in patients with idiopathic generalized epilepsy (IGE) and a subset of patients with juvenile myoclonic epilepsy (JME). Methods: In this retrospective chart review of 709 patients with ICD-9 diagnostic codes 345.10/345.11, we collected information on seizure freedom (dependent variable), EEG and MRI characteristics, medication use, demographic information and seizure history (predictors). Fisher’s Exact tests or Student’s t-tests were used to compare predictors between those seizure-free and not seizure-free in two groups: IGE patients (excluding JME) and JME. Logistic regression was used to estimate odds ratios for seizure freedom for significant predictors. Analyses were performed using SPSS V.15.0. Results: At the time of this analysis, there were 198 cases with complete data available for inclusion (JME N=54). JME patients were more likely to be seizure-free compared to other IGEs types (83.3% of JME vs. 67.3 % of other IGEs; p=0.026). The presence of focal abnormalities on the EEG (as defined by the presence of any focal slowing or unilateral epileptiform discharges was not associated with continuing seizures (OR=1.11; 95% CI 0.57-2.19). In patients with JME (but not other IGEs), later age of onset was associated with higher chance of seizure-freedom (p=0.034). Failure to become seizure-free with valproate was predicitve of failure to become seizure-free with other treatments (OR=5.65; 95% CI 2.63-12.12). Conclusions: This study indicates that the diagnosis of IGE other than JME, lack of response to valproate, and younger age of epilepsy onset (JME only) may be associated with worse outcomes in patients with IGEs. Whether the intractable IGE patients have a different subtype of IGE or focal (possibly frontal) epilepsy that mimic IGE requires further investigation.