title: Electro- and magneto-encephalographic spike source localization of small focal cortical dysplasia in the dorsal peri-rolandic region.
abstract: OBJECTIVE
  Small focal cortical dysplasia (FCD) may be ambiguous or overlooked on magnetic resonance (MR) imaging. Source localization of EEG and magnetoencephalography (MEG) spikes was evaluated to confirm the diagnosis of small FCD.
  
  
  METHODS
  This study included 6 epilepsy patients with a single small lesion on MR imaging suggesting FCD within a single gyrus among 181 consecutive epilepsy patients admitted to our epilepsy monitoring unit over 27 months. Stereotypical interictal spikes were detected on simultaneous EEG and MEG recordings and the onset-related source of averaged spikes was estimated.
  
  
  RESULTS
  All 6 patients had unique clinical characteristics as follows: leg sensori-motor seizures in 5 patients and eye version in 1 patient; a small MR imaging lesion suggesting FCD in the dorsal peri-rolandic region, which had been overlooked until our evaluation; and both EEG and MEG dipoles were estimated adjacent to the MR imaging lesion.
  
  
  CONCLUSIONS
  Source localization of EEG and MEG spikes can confirm the diagnosis of FCD based on a single small MR imaging lesion, which was overlooked by previous examination of MR images.
  
  
  CONCLUSIONS
  Examination of MR images should be based on spike source localization as well as seizure semiology to identify subtle MR imaging abnormalities.
authors.affiliation: Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan; Department of Pediatrics, Dokkyo Medical University Koshigaya Hospital, Koshigaya, Saitama, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Itabashi
authors.affiliation: Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan. Electronic address: jink@med.tohoku.ac.jp.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Jin
authors.affiliation: Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Iwasaki
authors.affiliation: Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Okumura
authors.affiliation: Department of Functional Brain Imaging, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Miyagi, Japan.
authors.forename: Akitake
authors.initials: A
authors.lastname: Kanno
authors.affiliation: Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kato
authors.affiliation: Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Teiji
authors.initials: T
authors.lastname: Tominaga
authors.affiliation: Department of Functional Brain Imaging, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Miyagi, Japan.
authors.forename: Ryuta
authors.initials: R
authors.lastname: Kawashima
authors.affiliation: Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Nobukazu
authors.initials: N
authors.lastname: Nakasato
mesh_terms: D000200:Action Potentials; D000293:Adolescent; D000328:Adult; D004569:Electroencephalography / Q000379:methods; D004827:Epilepsy / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods; D008297:Male; D054220:Malformations of Cortical Development / Q000175:diagnosis / Q000503:physiopathology*; D009044:Motor Cortex / Q000002:abnormalities / Q000503:physiopathology*; D055815:Young Adult
keywords: EEG; Focal cortical dysplasia; Magnetic resonance imaging; Magnetoencephalography; Sensori-motor seizure; Source localization