Shiraishi Hideaki
Department of Pediatrics, Hokkaido University, Graduate School of Medicine, Hokkaido, Japan.
Brain Dev. 2011 Mar;33(3):276-81. doi: 10.1016/j.braindev.2010.10.019. Epub 2010 Nov 13.
Magnetoencephalography (MEG) is useful to localize epileptic foci in epilepsy as MEG has higher spatio-temporal resolution than conventional diagnostic imaging studies; positron emission computed tomography, single photon emission computed tomography and magnetic resonance imaging (MRI).
We use 204-channel helmet-shaped MEG with a sampling rate of 600 Hz. A single dipole method calculates equivalent current dipoles to localize epileptic sources. The equivalent current dipoles are superimposed onto MRI as magnetic source imaging (MSI). Ictal MEG data are analyzed using time-frequency analysis. The power spectrum density is calculated using short-time Fourier transform and superimposed onto MRI results.
Clustered equivalent current dipoles represent epileptogenic zones in patients with localization-related epilepsy. The surgical plan is reliably developed from source localizations of dipoles and power spectrum of interictal spike discharges, and ictal frequency.
MEG is indispensable in diagnosis and surgical resection for epilepsy to accurately localize the epileptogenic zone.
脑磁图（MEG）在癫痫中有助于定位癫痫病灶，因为MEG具有比传统诊断成像研究（正电子发射计算机断层扫描、单光子发射计算机断层扫描和磁共振成像（MRI））更高的时空分辨率。
我们使用采样率为600Hz的204通道头盔式MEG。采用单偶极子方法计算等效电流偶极子以定位癫痫源。等效电流偶极子作为磁源成像（MSI）叠加到MRI上。发作期MEG数据使用时频分析进行分析。使用短时傅里叶变换计算功率谱密度并叠加到MRI结果上。
聚集的等效电流偶极子代表定位相关癫痫患者的致痫区。手术方案可根据偶极子的源定位、发作间期棘波放电的功率谱和发作期频率可靠地制定。
MEG在癫痫的诊断和手术切除中对于准确定位致痫区不可或缺。
