title: Group-specific regional white matter abnormality revealed in diffusion tensor imaging of medial temporal lobe epilepsy without hippocampal sclerosis.
abstract: OBJECTIVE
  In comparison to temporal lobe epilepsy (TLE) patients with hippocampal sclerosis (TLE-HS), TLE patients without HS (TLE-NH) have a similar clinical course but may result in worse surgical outcome. We investigated whether the clinical features related to the lack of HS in TLE patients (TLE-NH) can be explained by water diffusion abnormalities throughout diffusion tensor imaging (DTI) by voxel-based analysis.
  
  
  METHODS
  Nineteen patients with TLE-HS (left/right TLE 12:7), 18 patients with TLE-NH (left/right TLE 10:8), and 20 controls were included in the study. By statistical parametric mapping (SPM2), the diffusion properties specific to disease characteristics (TLE-HS vs. TLE-NH) were analyzed.
  
  
  RESULTS
  In TLE-HS, we found the areas of increased mean diffusivity (MD) in their ipsilateral temporal and extratemporal areas including the hippocampus, parahippocampal, and frontoparietal regions. Left TLE-HS showed a characteristic MD increase in the ipsilateral posterior cingulum, isthmus of corpus callosum, and contralateral occipital and temporal regions, which was not observed in right TLE-HS group. In left TLE-NH, two regions of increased MD were observed in the ipsilateral posterior fornix (within fusiform gyrus) and posterior cingulum. Right TLE-NH did not show any increased MD.
  
  
  CONCLUSIONS
  In left TLE-NH, we could find the water diffusion change along the posterior cingulum, which was quite different from the extensive abnormality from TLE-HS. In addition, there was a lesion-side-specific distribution (left predominant) of pathology in mesial TLE. This provides a possibility that TLE-NH is a heterogeneous or entity different from TLE-HS.
authors.affiliation: Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Young-Min
authors.initials: YM
authors.lastname: Shon
authors.forename: Yeong-In
authors.initials: YI
authors.lastname: Kim
authors.forename: Bang-Bon
authors.initials: BB
authors.lastname: Koo
authors.forename: Jong-Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Hye J
authors.initials: HJ
authors.lastname: Kim
authors.forename: Woo J
authors.initials: WJ
authors.lastname: Kim
authors.forename: Kook J
authors.initials: KJ
authors.lastname: Ahn
authors.forename: Dong W
authors.initials: DW
authors.lastname: Yang
mesh_terms: D000293:Adolescent; D000328:Adult; D038481:Anterior Temporal Lobectomy; D001284:Atrophy; D001921:Brain / Q000473:pathology / Q000503:physiopathology; D001931:Brain Mapping / Q000379:methods; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D056324:Diffusion Tensor Imaging / Q000379:methods; D004292:Dominance, Cerebral / Q000502:physiology; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006624:Hippocampus / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012598:Sclerosis; D012984:Software; D013702:Temporal Lobe / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D055815:Young Adult