J Korean Med Sci.  2012 Jun;27(6):668-673. 10.3346/jkms.2012.27.6.668.

Magnetoencephalography in Pediatric Lesional Epilepsy Surgery

  • 1Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea. neuroandy@snubh.org
  • 2Department of Pediatrics, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul, Korea.
  • 3Pediatric Clinical Neuroscience Center, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul, Korea.
  • 4MEG Center, Seoul National University Hospital, Seoul, Korea.
  • 5Department of Neurosurgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.


This study was performed to assess the usefulness of magnetoencephalography (MEG) as a presurgical evaluation modality in Korean pediatric patients with lesional localization-related epilepsy. The medical records and MEG findings of 13 pediatric patients (6 boys and 7 girls) with localization-related epilepsy, who underwent epilepsy surgery at Seoul National University Children's Hospital, were retrospectively reviewed. The hemispheric concordance rate was 100% (13/13 patients). The lobar or regional concordance rate was 77% (10/13 patients). In most cases, the MEG spike sources were clustered in the proximity of the lesion, either at one side of the margin (nine patients) or around the lesion (one patient); clustered spike sources were distant from the lesion in one patient. Among the patients with clustered spike sources near the lesion, further extensions (three patients) and distal scatters (three patients) were also observed. MEG spike sources were well lateralized and localized even in two patients without focal epileptiform discharges in the interictal scalp electroencephalography. Ten patients (77%) achieved Engel class I postsurgical seizure outcome. It is suggested that MEG is a safe and useful presurgical evaluation modality in pediatric patients with lesion localization-related epilepsy.


Magnetoencephalography; Epilepsy Surgery; Localization; Spike Source; Magnetic Source Imaging

MeSH Terms

Brain/radionuclide imaging
Brain Diseases/pathology
Child, Preschool
Epilepsies, Partial/pathology/*surgery
Magnetic Resonance Imaging
Malformations of Cortical Development/pathology
Neoplasms, Neuroepithelial/pathology
Positron-Emission Tomography
Retrospective Studies


  • Fig. 1 Distribution and location of clustered MEG spike sources. (A) T1-weighted axial brain magnetic resonance imaging (MRI) shows MEG spike sources clustered around the margin of the lesion. Because the spike sources are overlaid in a single axial image, spike sources that are inside the lesion are located superior or inferior to the lesion (patient 2). (B) T2-weighted axial brain MRI shows MEG spike sources clustered on the margin of the lesion (overlaid image of patient 7). (C) T1-weighted axial brain MRI shows MEG spike sources clustered at the margin lateral to the lesion (overlaid image of patient 12). Epileptogenic lesion (arrow) is visible in brain MRI. R, right; L, left; A, anterior; P, posterior.

  • Fig. 2 MEG spike sources clustered around the lesion and scattered in patient 12. (A-C) Axial, sagittal, and coronal contrast-enhanced T1-weighted brain magnetic resonance imaging (MRI) show clusters and distant scatters (overlaid on a single brain MRI image). (D) MEG spike sources presented in an imaginary three-dimensional plane show the distribution of MEG spike sources of clusters and scatters. R, right; L, left; H, head; F, foot; AL, anterior left; PR, posterior right; A, anterior; P, posterior.


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