title: Gradient magnetic-field topography for dynamic changes of epileptic discharges.
abstract: We developed gradient magnetic-field topography (GMFT) for magnetoencephalography (MEG). We plotted the Euclidean norms of gradient magnetic fields occurring at the centers of 102 sensors onto 49-point grids and projected these norms onto the MRI brain surface of a 12-year-old boy who presented with neocortical epilepsy secondary to a left temporal tumor. The peak gradient magnetic field located posterior to the tumor and correlated to MEG dipoles. The gradient magnetic field propagated to the temporo-parietal region and corresponded with spike locations on electrocorticography. GMFT revealed the location and distribution of spikes while avoiding the inverse problem.
authors.affiliation: Department of Neurosurgery, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Hiroshima, 734-8551, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Hashizume
authors.forename: Koji
authors.initials: K
authors.lastname: Iida
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shirozu
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Hanaya
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kiura
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kurisu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Otsubo
mesh_terms: D001931:Brain Mapping; D002648:Child; D004833:Epilepsy, Temporal Lobe / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D015225:Magnetoencephalography; D008297:Male; D017711:Nonlinear Dynamics