title: Noninvasive localization of epileptogenic zones with ictal high-frequency neuromagnetic signals.
abstract: OBJECTIVE
  Recent reports suggest that high-frequency epileptic activity is highly localized to epileptogenic zones. The goal of the present study was to investigate the potential usefulness of noninvasive localization of high-frequency epileptic activity for epilepsy surgery.
  
  
  METHODS
  Data obtained in 4 patients, who had seizures during routine magnetoencephalography (MEG) tests, were retrospectively studied. The MEG data were digitized at 4000 Hz, and 3D MR images were obtained. The magnetic sources were volumetrically localized with wavelet-based beamformer. The MEG results were subsequently compared with clinical data.
  
  
  RESULTS
  The 4 patients had 1-4 high-frequency neuromagnetic components (110-910 Hz) in ictal and interictal activities. The loci of high-frequency activities were concordant with intracranial recordings therein 3 patients, who underwent presurgical evaluation. The loci of high-frequency ictal activities were in line with semiology and neuroimaging in all 4 of the patients. High-frequency epileptic activity was highly localized to the epileptogenic zones.
  
  
  CONCLUSIONS
  High-frequency epileptic activity can be volumetrically localized with MEG. Source analysis of high-frequency neuromagnetic signals has the potential to determine epileptogenic zones noninvasively and preoperatively for epilepsy surgery.
authors.affiliation: MEG Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45220, USA. Jing.xiang@cchmc.org
authors.forename: Jing
authors.initials: J
authors.lastname: Xiang
authors.forename: Yingying
authors.initials: Y
authors.lastname: Wang
authors.forename: Yangmei
authors.initials: Y
authors.lastname: Chen
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Rupesh
authors.initials: R
authors.lastname: Kotecha
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Huo
authors.forename: Douglas F
authors.initials: DF
authors.lastname: Rose
authors.forename: Hisako
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Nat
authors.initials: N
authors.lastname: Hemasilpin
authors.forename: Ki
authors.initials: K
authors.lastname: Lee
authors.forename: Francesco T
authors.initials: FT
authors.lastname: Mangano
authors.forename: Blaise
authors.initials: B
authors.lastname: Jones
authors.forename: Ton
authors.initials: T
authors.lastname: DeGrauw
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping / Q000379:methods; D002648:Child; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000175:diagnosis / Q000601:surgery*; D017029:Epilepsy, Complex Partial / Q000175:diagnosis / Q000601:surgery*; D017034:Epilepsy, Frontal Lobe / Q000175:diagnosis / Q000601:surgery*; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000601:surgery*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D012189:Retrospective Studies; D012815:Signal Processing, Computer-Assisted; D014741:Video Recording