title: Is the type and extent of hippocampal sclerosis measurable on high-resolution MRI?
abstract: BACKGROUND
  The purpose of this study is to relate hippocampal volume and FLAIR signal intensity to Wyler grading of hippocampal sclerosis (HS).
  
  
  METHODS
  Of 100 consecutive patients with temporal lobe epilepsy and HS as histopathological diagnosis, 32 had high-resolution 3 Tesla MRI and anatomically well-preserved hippocampi following amygdalo-hippocampectomy. Hippocampal volume on 3D T1-weighted gradient echo and signal intensity on coronal FLAIR sequences were determined using FreeSurfer and SPM tools and related to Wyler grading. Seizure outcome was determined after 1 year.
  
  
  RESULTS
  Histopathology showed four Wyler II, 19 Wyler III, and 9 Wyler IV HS. Hippocampal volumes were 3.08 ml for Wyler II (Wyler II/contralateral side: p > 0.05), 2.19 ml for Wyler III (p < 0.01), 2.62 ml for Wyler IV (p = 0.01), and 3.08 ml for the contralateral side. Normalized FLAIR signals were 1,354 (p = 0.0004), 1,408 (p < 0.0001), 1,371 (p < 0.04), and 1,296, respectively. Wyler II hippocampi were visually normal. Two of four (50%) Wyler II, 16/19 (84%) Wyler III, and 6/9 (66%) Wyler IV patients achieved Engel I outcome.
  
  
  CONCLUSIONS
  Combined volumetry and quantitative FLAIR signal analysis clearly identifies Wyler III and IV HS. Quantitative FLAIR signal analysis may be helpful to identify Wyler II HS.
authors: Dept. of Neuroradiology, Medical Center University of Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany, horst.urbach@uniklinik-freiburg.de.
authors: H
authors: H
authors: Urbach
authors: H J
authors: HJ
authors: Huppertz
authors: R
authors: R
authors: Schwarzwald
authors: A J
authors: AJ
authors: Becker
authors: J
authors: J
authors: Wagner
authors: M Delsous
authors: MD
authors: Bahri
authors: H J
authors: HJ
authors: Tschampa
mesh_terms: D004827:Epilepsy / Q000473:pathology*; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D009929:Organ Size; D012189:Retrospective Studies; D012598:Sclerosis