title: The clinicopathologic spectrum of focal cortical dysplasias: a consensus classification proposed by an ad hoc Task Force of the ILAE Diagnostic Methods Commission.
abstract: OBJECTIVE
  Focal cortical dysplasias (FCD) are localized regions of malformed cerebral cortex and are very frequently associated with epilepsy in both children and adults. A broad spectrum of histopathology has been included in the diagnosis of FCD. An ILAE task force proposes an international consensus classification system to better characterize specific clinicopathological FCD entities.
  
  
  METHODS
  Thirty-two Task Force members have reevaluated available data on electroclinical presentation, imaging, neuropathological examination of surgical specimens as well as postsurgical outcome.
  
  
  RESULTS
  The ILAE Task Force proposes a three-tiered classification system. FCD Type I refers to isolated lesions, which present either as radial (FCD Type Ia) or tangential (FCD Type Ib) dyslamination of the neocortex, microscopically identified in one or multiple lobes. FCD Type II is an isolated lesion characterized by cortical dyslamination and dysmorphic neurons without (Type IIa) or with balloon cells (Type IIb). Hence, the major change since a prior classification represents the introduction of FCD Type III, which occurs in combination with hippocampal sclerosis (FCD Type IIIa), or with epilepsy-associated tumors (FCD Type IIIb). FCD Type IIIc is found adjacent to vascular malformations, whereas FCD Type IIId can be diagnosed in association with epileptogenic lesions acquired in early life (i.e., traumatic injury, ischemic injury or encephalitis).
  
  
  CONCLUSIONS
  This three-tiered classification system will be an important basis to evaluate imaging, electroclinical features, and postsurgical seizure control as well as to explore underlying molecular pathomechanisms in FCD.
authors.affiliation: Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany. ingmar.bluemcke@uk-erlangen.de
authors.forename: Ingmar
authors.initials: I
authors.lastname: Blümcke
authors.forename: Maria
authors.initials: M
authors.lastname: Thom
authors.forename: Eleonora
authors.initials: E
authors.lastname: Aronica
authors.forename: Dawna D
authors.initials: DD
authors.lastname: Armstrong
authors.forename: Harry V
authors.initials: HV
authors.lastname: Vinters
authors.forename: Andre
authors.initials: A
authors.lastname: Palmini
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Jacques
authors.forename: Giuliano
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authors.lastname: Avanzini
authors.forename: A James
authors.initials: AJ
authors.lastname: Barkovich
authors.forename: Giorgio
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authors.lastname: Battaglia
authors.forename: Albert
authors.initials: A
authors.lastname: Becker
authors.forename: Carlos
authors.initials: C
authors.lastname: Cepeda
authors.forename: Fernando
authors.initials: F
authors.lastname: Cendes
authors.forename: Nadia
authors.initials: N
authors.lastname: Colombo
authors.forename: Peter
authors.initials: P
authors.lastname: Crino
authors.forename: J Helen
authors.initials: JH
authors.lastname: Cross
authors.forename: Olivier
authors.initials: O
authors.lastname: Delalande
authors.forename: François
authors.initials: F
authors.lastname: Dubeau
authors.forename: John
authors.initials: J
authors.lastname: Duncan
authors.forename: Renzo
authors.initials: R
authors.lastname: Guerrini
authors.forename: Philippe
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authors.lastname: Kahane
authors.forename: Gary
authors.initials: G
authors.lastname: Mathern
authors.forename: Imad
authors.initials: I
authors.lastname: Najm
authors.forename: Ciğdem
authors.initials: C
authors.lastname: Ozkara
authors.forename: Charles
authors.initials: C
authors.lastname: Raybaud
authors.forename: Alfonso
authors.initials: A
authors.lastname: Represa
authors.forename: Steven N
authors.initials: SN
authors.lastname: Roper
authors.forename: Noriko
authors.initials: N
authors.lastname: Salamon
authors.forename: Andreas
authors.initials: A
authors.lastname: Schulze-Bonhage
authors.forename: Laura
authors.initials: L
authors.lastname: Tassi
authors.forename: Annamaria
authors.initials: A
authors.lastname: Vezzani
authors.forename: Roberto
authors.initials: R
authors.lastname: Spreafico
mesh_terms: D026683:Advisory Committees / Q000592:standards; D002540:Cerebral Cortex / Q000002:abnormalities* / Q000473:pathology*; D014943:Global Health; D006801:Humans; D054220:Malformations of Cortical Development / Q000145:classification* / Q000175:diagnosis* / Q000473:pathology; D012955:Societies, Medical / Q000592:standards