title: Magnetoencephalography in patients with tuberous sclerosis and localization-related epilepsy.
abstract: OBJECTIVE
  To clarify the usefulness of magnetoencephalography (MEG) for diagnosis of the spatial relations between spike foci and suspicious epileptogenic tubers on MRI in patients with tuberous sclerosis (TS) and to compare MEG spike foci with single-photon emission computed tomography (SPECT) findings.
  
  
  METHODS
  We analyzed magnetic fields of epileptic spike discharges in 15 patients with TS and localization-related epilepsy (LRE) by using MEG (a whole-head 204-channel magnetometer system). We investigated the spatial relation between the equivalent current dipoles (ECDs) of interictal spike discharges and visible cortical tubers on MRI. We also compared results of MEG and MRI with SPECT findings.
  
  
  RESULTS
  MEG detected a cluster of ECDs around one cortical tuber in six of 15 patients and clusters of ECDs around two cortical tubers in five patients. Interictal SPECT was disappointing in detection of epileptic foci in TS. However, MEG spike foci showed spatial consistency with ictal hyperperfusion areas in two patients. Three patients with single ECD clusters underwent surgical treatment: two have been seizure free, and one has obtained seizure reduction of >90%.
  
  
  CONCLUSIONS
  ECDs were located around visible tuber nodules. MEG enabled precise localization of the epileptic foci and provided crucial information for surgical treatment in patients with TS and partial epilepsy. TS patients showing a single ECD cluster on MEG may be appropriate candidates for surgical treatment.
authors.affiliation: Department of Homeostatic Regulation and Development, Niigata Graduate School of Medical and Dental Sciences, and Department of Pediatric Neurology, Epilepsy Center, Nishi-Niigata Chuo National Hospital, Niigata, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Kamimura
authors.forename: Jun
authors.initials: J
authors.lastname: Tohyama
authors.forename: Makoto
authors.initials: M
authors.lastname: Oishi
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Akasaka
authors.forename: Osamu
authors.initials: O
authors.lastname: Kanazawa
authors.forename: Mutsuo
authors.initials: M
authors.lastname: Sasagawa
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Kato
authors.forename: Kousaku
authors.initials: K
authors.lastname: Ohno
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Masuda
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kameyama
authors.forename: Makoto
authors.initials: M
authors.lastname: Uchiyama
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D004828:Epilepsies, Partial / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data; D015225:Magnetoencephalography / Q000706:statistics & numerical data*; D008297:Male; D013702:Temporal Lobe / Q000503:physiopathology / Q000601:surgery; D015899:Tomography, Emission-Computed, Single-Photon / Q000706:statistics & numerical data; D014402:Tuberous Sclerosis / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery