- Subjects currently on felbamate or having been on felbamate within less than 18 months prior to Visit 1- Subjects currently treated with phenytoin or having been on phenytoin in the last month prior to Visit 1- Subjects currently on vigabatrine. Subjects having been on vigabatrine if no visual fields examination report available including standard static (Humphrey or Octopus) or cinetic perimetry (Goldman)- Subject taking any drug with possible central nervous system (CNS) effects- Subjects taking any drug that may significantly influence the metabolism of BRV (CYP2C or CYP3A potent inducers/inhibitors)- Known clinically significant acute or chronic illness or illness which may impair reliable participation in the trial, necessitate the use of medication not allowed by protocol or represent a safety risk in the Investigator's opinion- Subjects with history of severe adverse hematological reaction to any drug- Impaired hepatic function: ALAT/SGPT, ASAT/SGOT, alkaline phosphatase, GGT value of more than three times the upper limit of the reference range- History of suicide attempt during the last 5 years- Subject with suicidal ideations within the last year or at risk of suicide attempt unless cleared by written confirmation from a psychiatrist and approved by the UCB physician- Ongoing psychiatric disorder other than mild controlled disorder