title: Type I focal cortical dysplasia: surgical outcome is related to histopathology.
abstract: Pre-surgical and post-surgical data were examined and compared from 215 consecutive patients undergoing surgery for intractable epilepsy. Patients were selected on the basis of a proven histopathological diagnosis of type I focal cortical dysplasia (FCD I), alone or associated with other lesions. The patients were divided into five sub-groups: i) 66 with isolated FCD I, ii) 76 with FCD I and hippocampal sclerosis, iii) 49 with FCD I and tumours, iv) 16 with FCD I and other malformations of cortical development and v) eight with FCD I and anoxic-ischaemic or inflammatory diseases. The duration of epilepsy was greatest in patients with FCD I associated with hippocampal sclerosis, and those with isolated FCD I showed the highest seizure frequency at the time of surgery. Hippocampal sclerosis and tumours were the most frequent pathological lesions associated with FCD I in temporal lobe epilepsy. Febrile seizures significantly correlated with the presence of hippocampal sclerosis and FCD I. Isolated FCD I was observed in 31% of the patients, characterized by frequent seizures, negative magnetic resonance imaging, and frequent frontal or multilobar involvement. In comparison to patients with FCD I associated with hippocampal sclerosis, MCD or tumours, the patients with isolated FCD I had a worse post-surgical outcome (46% in class I). Our findings indicate that there is a high incidence of FCD I associated with other apparently distinct pathologies, particularly those affecting the temporal lobe, and highlight the need for a comprehensive clinicopathological approach for the classification of FCD I.
authors.affiliation: Division of Epilepsy Clinic and Experimental Neurophysiology, C. Besta Neurological Institute IRCCS Foundation, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Tassi
authors.forename: Rita
authors.initials: R
authors.lastname: Garbelli
authors.forename: Nadia
authors.initials: N
authors.lastname: Colombo
authors.forename: Manuela
authors.initials: M
authors.lastname: Bramerio
authors.forename: Giorgio
authors.initials: G
authors.lastname: Lo Russo
authors.forename: Francesco
authors.initials: F
authors.lastname: Deleo
authors.forename: Gloria
authors.initials: G
authors.lastname: Milesi
authors.forename: Roberto
authors.initials: R
authors.lastname: Spreafico
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D001921:Brain / Q000473:pathology; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004827:Epilepsy / Q000473:pathology / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D054220:Malformations of Cortical Development / Q000145:classification / Q000473:pathology* / Q000601:surgery*; D009474:Neurons / Q000473:pathology; D012016:Reference Values; D016896:Treatment Outcome