title: Interhemispheric and intrahemispheric language reorganization in complex partial epilepsy.
abstract: OBJECTIVE
  To investigate interhemispheric and intrahemispheric reorganization in patients with localization-related epilepsy.
  
  
  METHODS
  We studied 50 patients with a left hemispheric focus and 20 normal right-handed controls with a 3T echoplanar imaging blood oxygen level dependent functional MRI auditory-based word definition decision task. Data were analyzed using SPM 2. Using region of interest for Broca and Wernicke areas and an asymmetry index (AI), patients were categorized as left language (LL; AI > or = 0.20) or atypical language (AL; AI <0.20) for region. The point maxima activation for normal controls (p <0.05 corrected FDR) was identified in Broca and midtemporal regions and then used as a point of reference for individual point maxima identified at p < 0.001, uncorrected.
  
  
  RESULTS
  Patient groups showed increased frequency of having activation in right homologues. Activation in AL groups occurred in homologous right regions; distances for point maxima activation in homologous regions were the same as point maxima distances in normal control activation in left regions. Distances for LL patient in left regions showed a trend for differences for midtemporal gyrus (6 mm posterior, 3 mm superior) but variability around mean difference distance was significant. There was no effect of age at epilepsy onset, duration, or pathology on activation maxima.
  
  
  CONCLUSIONS
  Right hemisphere language regions in patients with left hemispheric focus are homologues of left hemisphere Broca and broadly defined Wernicke areas. We found little evidence for intrahemispheric reorganization in patients with left hemisphere epilepsy who remain left language dominant by these methods.
authors.affiliation: Department of Neuroscience, Children's National Medical Center, 111 Michigan Ave. NW, Washington, DC 20010, USA.
authors.forename: L R
authors.initials: LR
authors.lastname: Rosenberger
authors.forename: J
authors.initials: J
authors.lastname: Zeck
authors.forename: M M
authors.initials: MM
authors.lastname: Berl
authors.forename: E N
authors.initials: EN
authors.lastname: Moore
authors.forename: E K
authors.initials: EK
authors.lastname: Ritzl
authors.forename: S
authors.initials: S
authors.lastname: Shamim
authors.forename: S L
authors.initials: SL
authors.lastname: Weinstein
authors.forename: J A
authors.initials: JA
authors.lastname: Conry
authors.forename: P L
authors.initials: PL
authors.lastname: Pearl
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: L G
authors.initials: LG
authors.lastname: Vezina
authors.forename: W H
authors.initials: WH
authors.lastname: Theodore
authors.forename: W D
authors.initials: WD
authors.lastname: Gaillard
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001931:Brain Mapping; D002648:Child; D002675:Child, Preschool; D017029:Epilepsy, Complex Partial / Q000503:physiopathology*; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D007839:Functional Laterality; D006801:Humans; D007223:Infant; D007802:Language; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D009473:Neuronal Plasticity; D013702:Temporal Lobe / Q000503:physiopathology*; D055815:Young Adult