title: Diffusion tensor imaging assessment of the epileptogenic zone in children with localization-related epilepsy.
abstract: OBJECTIVE
  Patients with MR imaging-negative epilepsy could have subtle FCD. Our aim was to determine if structural changes could be identified by using DTI in children with intractable epilepsy, from MR imaging-visible FCD and MR imaging-negative localization-related epilepsy, that were concordant with the epileptogenic zone as defined by using the MEG dipole cluster.
  
  
  METHODS
  Eight children with MR imaging-visible FCD and 16 with MR imaging-negative epilepsy underwent DTI and MEG. Twenty-six age-matched healthy children underwent DTI. Analysis was performed on controls across individual patients. Agreement between the location of DTI abnormalities and FCD and MEG dipole clusters was assessed.
  
  
  RESULTS
  In patients with MR imaging-visible FCD, abnormal FA, MD, λ(1), λ(2), and λ(3) were lobar concordant with the MEG dipole cluster in 4/8 (50.0%), 5/8 (62.5%), 3/8 (37.5%), 6/8 (75.0%), and 5/8 (62.5%), respectively. In patients with MR imaging-visible FCD, abnormal FA, MD, λ(1), λ(2), and λ(3) overlapped the x-, y-, and z-axes of the MEG dipole cluster in 1/8 (12.5%), 4/8 (50%), 4/8 (50%), 6/8 (75%), and 4/8 (50%), respectively, and with FCD in 1/8 (12.5%), 3/8 (37.5%), 0/8 (0%), 3/8 (37.5%), and 1/8 (12.5%), respectively. In patients with MR imaging-negative epilepsy, abnormal FA, MD, λ(1), λ(2), and λ(3) were lobar-concordant with the MEG dipole cluster in 11/16 (68.8%), 11/16 (68.8%), 8/16 (50.0%), 10/16 (62.5%), and 10/16 (62.5%), respectively, and overlapped the x-, y-, and z-axes of the MEG dipole cluster in 9/16 (56.3%), 10/16 (62.5%), 8/16 (50%), 8/16 (50%), and 8/16 (50%), respectively. There was no significant difference between abnormal DTI lobar concordance with the MEG dipole cluster in patients with MR imaging-visible FCD and MR imaging-negative epilepsy.
  
  
  CONCLUSIONS
  White matter changes can be detected with DTI in children with MR imaging-visible FCD and MR imaging-negative epilepsy, which were concordant with the epileptogenic zone in more than half of the patients.
authors: Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada. Elysa.Widjaja@sickkids.ca
authors: E
authors: E
authors: Widjaja
authors: S
authors: S
authors: Geibprasert
authors: H
authors: H
authors: Otsubo
authors: O C
authors: OC
authors: Snead
authors: S Z
authors: SZ
authors: Mahmoodabadi
mesh_terms: D000293:Adolescent; D001921:Brain / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004828:Epilepsies, Partial / Q000473:pathology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity