title: Hippocampal internal architecture and postoperative seizure outcome in temporal lobe epilepsy due to hippocampal sclerosis.
abstract: OBJECTIVE
  Semi-quantitative analysis of hippocampal internal architecture (HIA) on MRI has been shown to be a reliable predictor of the side of seizure onset in patients with temporal lobe epilepsy (TLE). In the present study, we investigated the relationship between postoperative seizure outcome and preoperative semi-quantitative measures of HIA.
  
  
  METHODS
  We determined HIA on high in-plane resolution preoperative T2 short tau inversion recovery MR images in 79 patients with presumed unilateral mesial TLE (mTLE) due to hippocampal sclerosis (HS) who underwent amygdalohippocampectomy and postoperative follow up. HIA was investigated with respect to postoperative seizure freedom, neuronal density determined from resected hippocampal specimens, and conventionally acquired hippocampal volume.
  
  
  RESULTS
  HIA ratings were significantly related to some neuropathological features of the resected hippocampus (e.g. neuronal density of selective CA regions, Wyler grades), and bilaterally with preoperative hippocampal volume. However, there were no significant differences in HIA ratings of the to-be-resected or contralateral hippocampus between patients rendered seizure free (ILAE 1) compared to those continuing to experience seizures (ILAE 2-5).
  
  
  CONCLUSIONS
  This work indicates that semi-quantitative assessment of HIA on high-resolution MRI provides a surrogate marker of underlying histopathology, but cannot prospectively distinguish between patients who will continue to experience postoperative seizures and those who will be rendered seizure free. The predictive power of HIA for postoperative seizure outcome in non-lesional patients with TLE should be explored.
authors.affiliation: Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, UK.
authors.forename: Samia
authors.initials: S
authors.lastname: Elkommos
authors.affiliation: Department of Epileptology, University of Bonn, Germany; Department of Neurocognition/Imaging, Life&Brain Research Centre, Bonn, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Weber
authors.affiliation: Department of Neuropathology, University of Bonn, Germany; Department of Neuropathology, Oslo University Hospital, Norway.
authors.forename: Pitt
authors.initials: P
authors.lastname: Niehusmann
authors.affiliation: Department of Neuropathology, University of Bonn, Germany.
authors.forename: Elisa
authors.initials: E
authors.lastname: Volmering
authors.affiliation: Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Richardson
authors.affiliation: Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, UK.
authors.forename: Yen Y
authors.initials: YY
authors.lastname: Goh
authors.affiliation: Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, UK.
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Marson
authors.affiliation: Department of Epileptology, University of Bonn, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Elger
authors.affiliation: Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, UK; Department of Neuroradiology, The Walton Centre NHS Foundation Trust, Liverpool, UK; Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK. Electronic address: simon.keller@liverpool.ac.uk.
authors.forename: Simon S
authors.initials: SS
authors.lastname: Keller
mesh_terms: D000704:Analysis of Variance; D038481:Anterior Temporal Lobectomy / Q000379:methods*; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000150:complications / Q000601:surgery*; D005260:Female; D007839:Functional Laterality; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000473:pathology*; D011184:Postoperative Period; D012189:Retrospective Studies; D012598:Sclerosis / Q000150:complications / Q000473:pathology / Q000601:surgery; D016896:Treatment Outcome
keywords: Epilepsy surgery; Hippocampus; Histopathology; Outcome; Prognosis