title: Investigation of widespread neocortical pathology associated with hippocampal sclerosis in epilepsy: a postmortem study.
abstract: OBJECTIVE
  One possible cause for surgical failure following temporal lobectomy for the treatment of epilepsy due to classical hippocampal sclerosis (CHS) is the presence of more widespread cortical changes. Neocortical changes in CHS shown by quantitative neuroimaging studies may involve hippocampal projection pathways. Our aim was to quantitate neocortical pathology using a postmortem series of brains from patients with epilepsy and CHS.
  
  
  METHODS
  Sections from 13 cortical regions from both left and right hemispheres, including hippocampal projection pathways, were examined from nine epilepsy patients with unilateral CHS (4), bilateral CHS (2), non-CHS (3), and non-epilepsy controls (4). Using GFAP, CD68, and NPY immunohistochemistry as markers of acquired neocortical pathology, quantitative analysis of the staining fractions in the cortex and white matter was carried out.
  
  
  RESULTS
  Higher staining fractions were observed for all markers in both cortex and white matter in CHS patients, which was significantly different for CD68 and NPY compared to controls (p < 0.05) but not to non-CHS epilepsy cases. There was no significant difference between staining fractions in left and right hemispheres for unilateral CHS cases. Regional analysis showed preferential gliosis and microgliosis of temporal poles, frontal poles, and orbitofrontal cortex in epilepsy cases.
  
  
  CONCLUSIONS
  This study supports acquired neocortical pathology in epilepsy patients both with and without CHS. Cortical pathology does not show lateralization to the side of CHS. Preferential involvement of the temporal and frontal poles may relate to other factors, such as cortical injury associated with seizures, rather than involvement through hippocampal pathways.
authors.affiliation: Department of Clinical and Experimental Epilepsy, Divisions of Neuropathology Neurology, UCL, Institute of Neurology, London, UK.
authors.forename: Francine
authors.initials: F
authors.lastname: Blanc
authors.forename: Lillian
authors.initials: L
authors.lastname: Martinian
authors.forename: Ioannis
authors.initials: I
authors.lastname: Liagkouras
authors.forename: Claudia
authors.initials: C
authors.lastname: Catarino
authors.forename: Sanjay M
authors.initials: SM
authors.lastname: Sisodiya
authors.forename: Maria
authors.initials: M
authors.lastname: Thom
mesh_terms: D000328:Adult; D000368:Aged; D004827:Epilepsy / Q000150:complications / Q000473:pathology*; D005260:Female; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019579:Neocortex / Q000473:pathology*; D012598:Sclerosis