Synthetic aperture magnetometry (SAM) compared with electro-corticography (ECoG) in children with focal cortical dysplasia

摘要

[Objective] MEG can accurately localize the epileptic region contributing to the magnetic field to within a few millimeters in epilepsy patients. The purpose of this study was to compare the localization of certain frequencies in the interictal discharges detected by spatially filtered MEG with the location of ictal rhythmic discharges identified by electrocorticography (ECoG) in children with intractable partial seizures secondary to focal cortical dysplasia. [Methods] We obtained 30 min of MEG recordings during interictal resting states in 3 children with intractable partial seizures with focal cortical dysplasia. Data were analyzed by synthetic aperture magnetometry (SAM). ECoG was recorded with split screen video monitoring to localize the seizure onset zone and eloquent cortex. [Results] The ECoG revealed the epileptogenic zone where various frequencies appeared and accumulated at the time of seizure onset. The interictal epileptic spike discharges demonstrated activity in a wide spectral range. The anatomical location of the interictal discharges determined by SAM corresponded to the seizure onset zone delineated by ECoG. [Conclusion] MEG and SAM are useful tools to localize the epileptogenic zone in children with focal cortical dysplasia.