Presurgical evaluation for patients with drug-resistant epilepsy requires the definition of various zones that have a variable spatial relationship with the epileptogenic zone. All the available methods to directly measure the actual seizure-onset zone and to define "the minimum amount of cortical tissue that must be resected to produce seizure-freedom" have significant limitations. We report on the case of a patient with dual pathology (hippocampal sclerosis and a post-traumatic scar) and discuss the contribution of the various presurgical investigations that led to surgery and seizure-freedom.