To ensure non-interventional status, the neurologist's decision that it is in the patient's best interest to be prescribed with adjunctive ESL has to be made before and independently of his/her decision to include the patient in the study. At all circumstances during the study the patients will be treated and followed according to routine clinical practice. ESL and concomitant medication should be managed by the neurologist according to the respective Summary of Product Characteristics (SPC).In order to reflect real-life practice and to ensure the observational nature of this study, no fixed time-points for study assessment were defined. Intermediate follow-up data will be collected whenever a patient attends to the study's neurologist consultation.