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

Magnetoencephalography in Pediatric Lesional Epilepsy Surgery

• Kim H
• Lim BC
• Jeong W
• Kim JS
• Chae JH
• Kim KJ
• Chung CK
• Hwang YS
• Hwang H

• KMID: 1421620
• DOI: http://doi.org/10.3346/jkms.2012.27.6.668

Abstract

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.

Keyword

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

MeSH Terms

Adolescent
Brain/radionuclide imaging
Brain Diseases/pathology
Child
Child, Preschool
Epilepsies, Partial/pathology/*surgery
Female
Ganglioglioma/pathology
Humans
Infant
Magnetic Resonance Imaging
*Magnetoencephalography
Male
Malformations of Cortical Development/pathology
Neoplasms, Neuroepithelial/pathology
Positron-Emission Tomography
Retrospective Studies
Seizures/diagnosis

Figure

• 

  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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