After the screening visit (V1), patients will enter the baseline period. At the end of the baseline period (V2), eligible patients will be randomised in a ratio of 2:1 to receive double-blind treatment with Eslicarbazepine acetate or Placebo in addition to concomitant therapy with 1 or 2 Anti-Epileptic Drugs (AEDs). Concomitant AED therapy will be kept stable during the whole study.