title: Clinicopathological associations in temporal lobe epilepsy patients utilising the current ILAE focal cortical dysplasia classification.
abstract: OBJECTIVE
  This study utilised the revised 2011 ILAE classification of focal cortical dysplasia (FCD) (Blümcke et al., 2011) to examine pathology in a cohort of children and adults who underwent temporal lobe epilepsy (TLE) surgery, and to describe the electroclinical and imaging features associated with these pathologies.
  
  
  METHODS
  The sample population were children (n=26) and adults (n=47) who underwent TLE surgery between 2002 and 2011 at our institutions. Neuropathology and MRI studies were re-reviewed by experts blinded to the original diagnosis. EEG and clinical data including current seizure outcome were determined by patient file review and/or patient contact. Pre-operative data, post-operative outcome and pathological diagnoses were compared.
  
  
  RESULTS
  The commonest pathology in the adult cohort was isolated hippocampal sclerosis (HS) (n=24, 51.1%) and in the paediatric cohort, isolated tumour (n=10, 38.5%). Overall, HS with associated FCD (FCD IIIA) was the third most common pathology (n=12, 16.4%). Temporal grey matter signal changes on MRI were associated with FCD IIIA (p=0.035). FCD IIIA had the poorest post-surgical seizure outcome compared to all other pathologies (p=0.026). A history of bilateral convulsive seizures was more common in adults (n=40, p<0.0005), and was associated with failure to achieve postoperative seizure freedom (p=0.045). Postoperatively, paediatric TLE had higher rates of seizure freedom (p=0.005) and more children had ceased medication (p<0.0005).
  
  
  CONCLUSIONS
  FCD IIIA is a comparatively common pathological subtype in TLE, with a poor post-surgical outcome. Pre-operative recognition of FCD IIIA may be feasible through grey matter signal change on MRI. Paediatric patients had a higher rate of seizure freedom than adults. Pre-operative bilateral convulsive seizures were associated with poor outcome after surgery.
authors.affiliation: Sydney Children's Hospitals Network (Randwick), High St, Randwick, Sydney, NSW 2031, Australia; University of New South Wales, NSW 2052, Australia. Electronic address: Alexandra.Johnson@sesiahs.health.nsw.gov.au.
authors.forename: Alexandra M
authors.initials: AM
authors.lastname: Johnson
authors.affiliation: South Eastern Area Laboratory Services, Barker St, Randwick, Sydney, NSW 2031, Australia; Prince of Wales Hospital, High St, Randwick, Sydney, NSW 2031, Australia. Electronic address: ella.sugo01@gmail.com.
authors.forename: Ella
authors.initials: E
authors.lastname: Sugo
authors.affiliation: Sydney Children's Hospitals Network (Randwick), High St, Randwick, Sydney, NSW 2031, Australia. Electronic address: Daniela.e.barreto@gmail.com.
authors.forename: Daniela
authors.initials: D
authors.lastname: Barreto
authors.affiliation: Sydney Children's Hospitals Network (Randwick), High St, Randwick, Sydney, NSW 2031, Australia; University of New South Wales, NSW 2052, Australia. Electronic address: a.cunningham@unsw.edu.au.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Cunningham
authors.affiliation: Prince of Wales Hospital, High St, Randwick, Sydney, NSW 2031, Australia. Electronic address: chee-chung.hiew@sesiahs.health.nsw.gov.au.
authors.forename: Chee-Chung
authors.initials: CC
authors.lastname: Hiew
authors.affiliation: Sydney Children's Hospitals Network (Randwick), High St, Randwick, Sydney, NSW 2031, Australia; University of New South Wales, NSW 2052, Australia. Electronic address: John.Lawson@health.nsw.gov.au.
authors.forename: John A
authors.initials: JA
authors.lastname: Lawson
authors.affiliation: Prince of Wales Hospital, High St, Randwick, Sydney, NSW 2031, Australia; University of New South Wales, NSW 2052, Australia. Electronic address: ernest.somerville@sesiahs.health.nsw.gov.au.
authors.forename: Ernest R
authors.initials: ER
authors.lastname: Somerville
authors.affiliation: Sydney Children's Hospitals Network (Randwick), High St, Randwick, Sydney, NSW 2031, Australia; University of New South Wales, NSW 2052, Australia. Electronic address: a.connolly@unsw.edu.au.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Connolly
authors.affiliation: Sydney Children's Hospitals Network (Randwick), High St, Randwick, Sydney, NSW 2031, Australia; University of New South Wales, NSW 2052, Australia. Electronic address: annie.bye@health.nsw.gov.au.
authors.forename: Annie M E
authors.initials: AM
authors.lastname: Bye
mesh_terms: D000328:Adult; D002648:Child; D015331:Cohort Studies; D004833:Epilepsy, Temporal Lobe / Q000145:classification* / Q000175:diagnosis* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D054220:Malformations of Cortical Development / Q000145:classification / Q000175:diagnosis / Q000601:surgery; D065704:Malformations of Cortical Development, Group III / Q000145:classification* / Q000175:diagnosis* / Q000601:surgery; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: FCD IIIA; Surgery; Temporal lobe epilepsy