Patients included had to satisfy the following criteria: (1) be confirmed with drug-resistant epilepsy, following correctly prescribed and adherently taken two AEDs; (2) seizures, depicted by either scalp or invasive electro-encephalogram (EEG), the latter employing either subdural or invasive electrodes; (3) have had brain MRI imaging; (4) histologically confirmed FCD type I; and (5) postoperative follow-up ≥6 months.