Ictal MEG in two children with partial seizures.
We report on the successful identification of epileptic foci in two children with partial epilepsy using ictal magnetoencephalography (MEG). Case 1 is a 12-year-old male suffering with simple partial seizures with leftwards nystagmus. Ictal SPECT revealed a hyperperfusion area in the right lateral occipital area, and MRI revealed cortical dysplasia in the same area. Interictal EEG dipoles were concentrated in the right mesial occipital lobe. Both interictal and ictal MEG dipoles were concentrated in the right mesial occipital lobe, which corresponded well with neuroimaging data and his clinical features. Case 2 is a 5-year-old female suffering with simple partial seizures with left-side facial twitching. Interictal EEG dipoles were located in her left motor area, the pre-sylvian fissure, close to the location of the interictal MEG-estimated dipoles. Ictal EEGs showed no remarkable changes associated with her clinical manifestations. However, ictal MEG showed high-voltage slow waves over her left hemisphere, and ictal MEG iso-contour maps revealed a clear dipolar pattern, which suggested that the MEG dipole was located in the area of the sylvian fissure. Ictal SPECT revealed hyperperfusion areas around the left sylvian fissure.


CONCLUSIONS
Ictal MEG is useful for determining the precise location of epileptic focus in patients with motionless seizures, including children.
Department of Child Neurology, Okayama University Medical School, Shikatacho 2-5-1, Okayama 700-8558, Japan. magenta@md.okayama-u.ac.jp
Harumi
H
Yoshinaga
Yoko
Y
Ohtsuka
Yoshiaki
Y
Watanabe
Miki
M
Inutsuka
Yoshihiro
Y
Kitamura
Kazushi
K
Kinugasa
Eiji
E
Oka
D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D009421:Nervous System Malformations / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D009778:Occipital Lobe / Q000473:pathology / Q000503:physiopathology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013702:Temporal Lobe / Q000473:pathology / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon