SV2A and Focal-onset seizure: BRV is a new antiepileptic drug (AED) with a high affinity for vesicle protein 2A (SV2A) and recently approved as adjunctive therapy for focal onset seizures.Methods: In this observational study of six-month duration, BRV (50-200 mg) was administered to 76 patients with drug-resistant focal epilepsy, who were ≥16-year-old and who suffered from daily, weekly, monthly and yearly recurrent seizures.