Abstracts

Rationale: Patients with juvenile myoclonic epilepsy (JME) generally have a good response to appropriate antiepileptic drugs (AEDs). However, some patients with JME show drug resistance associated with factors such as coexistence of absence seizures, atypical seizure semiology, and lack of insight into the disease. A few small group studies have indicated that focal EEG abnormalities (FEAs) are also associated with drug resistance in JME, but this association has not been established. The present study investigated the relationship between drug resistance and interictal and ictal FEAs recorded by long-term video EEG monitoring (VEEG) in patients with JME.Methods: A total of 562 patients underwent 4-day VEEG in our epilepsy monitoring unit from September 2010 to November 2014. Thirteen patients (5 men and 8 women, aged 14-35 years) received outpatient antiepileptic medication under diagnoses of JME for at least 1 year after VEEG. VEEG data were retrospectively reviewed to evaluate the presence of FEAs defined as a single regional spike or regional spikes preceding a generalized spike and wave complex. The number of AEDs at the final visit was used to evaluate the drug resistance of patients with JME.Results: Twelve of the 13 patients showed interictal generalized epileptiform abnormalities, and 11 of these 12 patients also showed ictal events. Eight of these 12 patients had interictal FEAs, and 3 of these 8 patients also had ictal FEAs. The number of AEDs prescribed at the final visit in the 8 patients with interictal FEAs was 3 AEDs in 5 patients, 2 AEDs in 2 patients, and 1 AED in1 patient. The number of AEDs in the 3 patients with ictal FEAs was 3 AEDs in 2 patients and 2 AEDs in 1 patient. All 4 patients without interictal or ictal FEAs were taking 1 or 2 AEDs at the final visit. The number of AEDs during VEEG had no correlation with FEAs, which indicates that administration of the AEDs did not cause FEAs.Conclusions: Patients with JME who had FEAs needed more AEDs for seizure control than patients without FEAs. Ictal as well as interictal FEAs recorded by VEEG might be useful to predict drug resistance in patients with JME.