title: Surgical pathologic features of cerebral cortical lesions taken from 600 patients with intractable epilepsy.
abstract: OBJECTIVE
  To determine the scope of histopathological variation in lesions responsible for epileptogenesis, I retrospectively reviewed the features of surgical specimens taken consecutively from 600 patients with intractable epilepsy.
  
  
  METHODS
  The patients were divided into three groups on the basis of age at seizure onset: 94 patients with infantile onset (before 1year of age), 307 patients with juvenile onset (between 1 and 12years of age), and 199 patients with adolescent/adult onset (at 13years of age or beyond). Histological and immunohistochemical evaluations of the surgical specimens were performed.
  
  
  RESULTS
  In the infant group, seizure duration was significantly shorter than in the other groups, and malformations caused by abnormalities of cortical development, including focal cortical dysplasia (FCD) type IIa/b, tuberous sclerosis, hemimegalencephaly, and polymicrogyria were predominant, whereas in the juvenile and adolescent/adult groups, other lesions such as hippocampal sclerosis (HS), tumors, FCD type I, and vascular lesions were frequently observed. For patients with HS, seizure duration in the juvenile group was significantly longer than in the adolescent/adult group. FCD type IIIa was noted in nearly half of patient with HS in both juvenile and adolescent/adult groups. The causative tumors included dysembryoplastic neuroepithelial tumors, gangliogliomas, astrocytomas, and other glioneuronal and glial tumors.
  
  
  CONCLUSIONS
  Various histopathological entities and types, showing clear predominance depending on the age at seizure onset, were observed in patients with epilepsy. These features appear to provide information on the pathomechanisms of the lesions and their clinical relevance in affected patients.
authors.affiliation: Department of Pathology, Brain Research Institute, University of Niigata, Niigata, Japan. kakita@bri.niigata-u.ac.jp
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Kakita
mesh_terms: D017668:Age of Onset; D002540:Cerebral Cortex / Q000473:pathology* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography / Q000379:methods; D004827:Epilepsy / Q000473:pathology* / Q000601:surgery; D005260:Female; D006624:Hippocampus / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D012008:Recurrence; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: Children; Epilepsy; Focal cortical dysplasia; Infants; Malformations of cortical development; Pathology