Generalized polyspike train: an EEG biomarker of drug-resistant idiopathic generalized epilepsy

Objective: To identify clinical and EEG biomarkers of drug resistance in adults with idiopathic generalized epilepsy.
Methods: We conducted a case-control study consisting of a discovery cohort and a replication cohort independently assessed at two different centres. In each centre patients with idiopathic generalized epilepsy phenotype and generalized spike-wave discharges on EEG were classified as drug-resistant or drug-responsive. EEG changes were classified into pre-defined patterns and compared between the two groups in the discovery cohort. Factors associated with drug resistance in multivariable analysis were tested in the replication cohort.
Results: The discovery cohort included 85 patients (29% drug-resistant and 71% drug-responsive). Their median age at assessment was 32 years and 50.6% were female. Multivariable analysis showed that having higher number of seizure types (3 vs. 1: odds ratio [OR]= 31.1, 95% confidence interval [CI] 4.5-214, p<0.001; 3 vs. 2: OR=14.6, 9...