title: Hippocampal atrophy in temporal lobe epilepsy: the 'generator' and 'receiver'.
abstract: OBJECTIVE
  Some patients with unilateral medial temporal lobe epilepsy (MTLE) display bilateral hippocampal atrophy on MRI, even though seizures originate in only one hippocampus. The correct identification of the epileptogenic hippocampus (the 'generator') vs the non-epileptogenic (the 'receiver') may lead to better surgical planning and results.
  
  
  METHODS
  We studied 14 patients with MTLE (eight left and six right) who became seizure free after unilateral hippocampal resection, with hippocampal sclerosis confirmed by histology. Hippocampal tridimensional morphometry was performed comparing patients and healthy controls employing a voxel-wise Wilcoxon test. Results were corrected for multiple comparisons with the application of a False Discovery Rate (FDR)-corrected threshold for q < 0.05.
  
  
  RESULTS
  Patients with MTLE showed atrophy involving the ipsilateral hippocampus and the contralateral hippocampus, more pronouncedly within the ipsilateral hippocampus in the anterior-inferior aspect of the hippocampal head (left MTLE, left hippocampus x = -28, y = -16, z = -24, Z = 3.6; right MTLE, right hippocampus x = 22, y = -11, z = -27, Z = 2.9). On the contralateral hippocampus, the atrophy was more noticeable in the posterior head and body areas.
  
  
  CONCLUSIONS
  The epileptogenic hippocampal atrophy has an anatomically distinct pattern compared with the contralateral hippocampus. This information may help guide the presurgical assessment of MTLE.
authors.affiliation: Division of Neurology, Department of Neurosciences, Medical University of South Carolina, Charleston, 29425, USA. bonilha@musc.edu
authors.forename: L
authors.initials: L
authors.lastname: Bonilha
authors.forename: J J
authors.initials: JJ
authors.lastname: Halford
authors.forename: P S
authors.initials: PS
authors.lastname: Morgan
authors.forename: J C
authors.initials: JC
authors.lastname: Edwards
mesh_terms: D000328:Adult; D001284:Atrophy / Q000473:pathology; D004833:Epilepsy, Temporal Lobe / Q000473:pathology*; D005260:Female; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged