Despite major advances in all fields, Focal Cortical Dysplasias remain a mystery. From the first description 50 years ago by Taylor and colleagues, nobody could suspect that they would become perhaps the most relevant aetiology of focal epilepsies in patients of all ages, particularly those with refractory seizures. Therefore, there is an urgent need to better understand the mechanisms of epileptogenicity and the natural course of these brain developmental lesions, to recognise their many faces, and to determine the best care. There are several unresolved issues, and framing these aspects in a straightforward way may help clinicians to be attentive to further advances in the field. Many questions need very focused approaches, from people producing knowledge that impacts patients around the world every day. Based on the art, reflection and personal views shaped by the solid experience of a large panel of experts who have worked in the field for the last decades, this book provides a clear focus on the most recent advances in basic research. Combining numerous carefully selected illustrations and very practical information on the best use of all available tools and on the optimal care for patients, this book is bound to become a reference book.