Abstracts

Rationale: Research on seizure remission (SR) in patients with idiopathic generalized epilepsy (IGE) focuses mostly on children. We aimed to investigate the clinical factors associated with SR among adults with IGE. Methods: We captured data on all consecutive patients during their first encounter in a tertiary outpatient epilepsy program serving a large geographic region. We included all adults with a probable diagnosis of IGE as judged by epileptologists. SR was defined as seizure freedom during the previous year. Variables of interest included age, age of onset, family history of seizures, having ever been referred to an epilepsy-monitoring unit (EMU), number of antiepileptic drugs (AEDs) ever tried (0-2 or 3 or more), number of seizure types (1, 2, or 3 or more), having ever been exposed to carbamazepine, oxcarbazepine, or phenytoin (CBZ/OXC/PHT), and experiencing generalized tonic-clonic seizures (GTCS), myoclonic seizures (MS) and/or absence seizures (AS). Logistic regression was used to investigate the association between the variables of interest and SR, with statistical significance as p<0.05. Interactions between age of onset, number of AEDs, and number and types of seizures were explored using two models, one involving the number and the other involving the specific types of seizures. Results: Among 1588 consecutive patients, 174 (10.96%) aged >18 years were diagnosed with probable IGE. Their age (mean +/- standard deviation) was 33.6 +/- 15.0 years and age of onset was 18.94 +/- 14.4 years. Fifty-one (30.2%) patients were in SR. Sixty-nine (58.5%) patients not in SR and 28 (54.9%) in SR had ever tried CBZ/OXC/PHT and 33 (28.0%) not in SR and 10 (19.6%) in SR had tried more than two AEDs. Nineteen (16.2%) patients not in SR and 10 (19.6%) in SR had a family history of seizures and 16 (13.6%) not in SR and 4 (7.8%) in SR had been referred to the EMU. Of patients not in SR, 61 (51.7%) had one seizure type, 35 (29.7%) had two types, 18 (15.25) had three types, 98 (83.0%) had GTCS, 23 (19.5%) had MS, and 33 (28.0%) had AS. Of patients in SR, 34 (66.7%) had one seizure type, 13 (25.5%) had two types, 3 (5.9%) had three types, 42 (82.4%) had GTCS, 8 (15.7%) had MS, and 5 (9.8%) had AS. None of the interactions were significant in either model (p>0.05). Most factors were not significantly associated with SR (p>0.05). However, patients with >3 seizure types were significantly less likely to be in SR compared to those experiencing one seizure type (OR 0.27 [95%CI:0.075-0.97]). Analyses by specific seizure types showed that patients with AS were significantly less likely to be in SR (OR 0.23[95%CI:0.081-0.65]). Conclusions: The proportion of patients with IGE not achieving SR was high (69.8%) in our population, perhaps reflecting the focus on adults seen in tertiary care, or an evolving diagnosis. In this population, only the number and types of seizures were significantly associated with SR. AS are typically treatment responsive in children, their persistence into adulthood may be a marker of non-remission.