title: Advantageous information provided by magnetoencephalography for patients with neocortical epilepsy.
abstract: OBJECTIVE
  We evaluated whether magnetoencephalography (MEG), in addition to surgery, was valuable for the diagnosis and management of epileptic syndromes in patients with neocortical epilepsy (NE).
  
  
  METHODS
  We studied MEG in 73 patients (29 females; aged 1-26years; mean 10.3years) for the clinical diagnosis of epilepsy and for preoperative evaluation. MEG data were recorded by 204-channel whole head gradiometers with a 600Hz sampling rate. MEG spike sources were localized on magnetic resonance images (MRI) using a single dipole model to project equivalent current dipoles.
  
  
  RESULTS
  MEG localized an epileptic focus with single clustered dipoles in 24 (33%) of 73 NE patients: 16 (25%) of 64 symptomatic localization-related epilepsy (SLRE) patients and eight (89%) of nine idiopathic localization-related epilepsy (ILRE) patients. MEG provided advantageous information in 12 (50%) of 24 patients with clustered dipoles and confirmed the diagnosis in the remaining 12 (50%). Furthermore, the use of MEG resulted in changes to surgical treatments in nine (38%) patients and in medical management in eight (33%). MEG confirmed the diagnosis in eight (16%) of 49 patients with scattered dipoles. MRI identified a single lesion (28 patients, 38%), multiple lesions (5, 7%), and no lesion (40, 55%). MRI provided confirming information in 19 of 28 patients with a single lesion and 18 of them required surgical resections. MRI did not provide any supportive information in 54 (74%) patients with a single (9), multiple (5) and no lesion (40).
  
  
  CONCLUSIONS
  Our study shows that MEG provides fundamental information to aid the choice of diagnostic and therapeutic procedures including changes in medication in addition to surgical treatments for NE.
authors.affiliation: Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Tomoshiro
authors.initials: T
authors.lastname: Ito
authors.affiliation: Division of Neurology, Department of Pediatrics, The Hospital for Sick Children and The University of Toronto, Toronto, Canada. Electronic address: hiroshi.otsubo@sickkids.ca.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Otsubo
authors.affiliation: Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Shiraishi
authors.affiliation: Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Kazuyori
authors.initials: K
authors.lastname: Yagyu
authors.affiliation: Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Takahashi
authors.affiliation: Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Ueda
authors.affiliation: Faculty of Health Sciences, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Fumiya
authors.initials: F
authors.lastname: Takeuchi
authors.affiliation: Division of Magnetoencephalography, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Division of Magnetoencephalography, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Nakane
authors.affiliation: Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Shinobu
authors.initials: S
authors.lastname: Kohsaka
authors.affiliation: Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan; Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Saitoh
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D058256:Brain Waves / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004827:Epilepsy / Q000175:diagnosis* / Q000628:therapy; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D019579:Neocortex / Q000503:physiopathology*; D055815:Young Adult
keywords: Diagnosis and treatment; Equivalent current dipole; Idiopathic localization-related epilepsy; Symptomatic localization-related epilepsy; Tertiary care