Interictal magnetoencephalography and the irritative zone in the electrocorticogram
Interictal magnetoencephalography and the irritative zone in the electrocorticogram
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DOI：
10.1093/brain/awp137
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发表时间：
2009-11-01
期刊：
影响因子：
14.5
通讯作者：
Leijten, F. S. S.
中科院分区：
文献类型：
--
作者：
Agirre-Arrizubieta, Z.;Huiskamp, G. J. M.;Leijten, F. S. S.
脑磁图(MEG)被认为是一种有用的工具来计划电极放置的慢性颅内硬膜下皮质脑电图(ECoG)的候选人癫痫手术，甚至作为ECoG的替代品。脑磁图记录通常是发作间歇期的，因此充其量只能反映发作间歇期的大脑皮层脑电。要评估脑磁图的临床价值，重要的是要了解发作间期脑磁图如何很好地反映发作间期的脑电活动。从1998年到2008年，38名ECoG候选人接受了151个通道的脑磁图记录和3D磁共振成像，作为术前评估的一部分。使用多重信号分类算法对发作间期的脑磁图棘波进行识别、聚类、平均和建模，并与磁共振成像共同配准。用电极网和电极条连续记录ECOG，持续时间约1周。在一个有代表性的清醒发作间期ECoG样本中，发作间期棘波被识别并平均化。使用幅度和同步表面积测量相结合的方法来表征和量化不同的尖峰。根据这一测量方法对ECoG棘波进行排序，并在磁共振成像表面绘制。MEG和ECoG的发作间期棘波被分配到预定义的解剖脑区，并进行关联分析。所有发作间期脑磁图波峰均与发作间期脑电波峰相关联。总体而言，所有发作间期ECoG峰中有56%与发作间期脑磁图对应。两者之间的关联度在大脑半球间和额部眼眶区域为90%，在额上、中央和外侧区域为75%，但在内侧颞区仅为25%。脑磁图是发作间期ECoG棘波存在的可靠指标，可用于计划颅内电极的放置。然而，大量发作间期的ECoG峰不能被MEG检测到，因此MEG不能被认为是ECoG的替代品。
Magnetoencephalography (MEG) is considered a useful tool for planning electrode placement for chronic intracranial subdural electrocorticography (ECoG) in candidates for epilepsy surgery or even as a substitute for ECoG. MEG recordings are usually interictal and therefore, at best, reflect the interictal ECoG. To estimate the clinical value of MEG, it is important to know how well interictal MEG reflects interictal activity in the ECoG. From 1998 to 2008, 38 candidates for ECoG underwent a 151-channel MEG recording and 3D magnetic resonance imaging as a part of their presurgical evaluation. Interictal MEG spikes were identified, clustered, averaged and modelled using the multiple signal classification algorithm and co-registered to magnetic resonance imaging. ECoG was continuously recorded with electrode grids and strips for similar to 1 week. In a representative sample of awake interictal ECoG, interictal spikes were identified and averaged. The different spikes were characterized and quantified using a combined amplitude and synchronous surface-area measure. The ECoG spikes were ranked according to this measure and plotted on the magnetic resonance imaging surface rendering. Interictal spikes in MEG and ECoG were allocated to a predefined anatomical brain region and an association analysis was performed. All interictal MEG spikes were associated with an interictal ECoG spike. Overall, 56% of all interictal ECoG spikes had an interictal MEG counterpart. The association between the two was >= 90% in the interhemispheric and frontal orbital region, similar to 75% in the superior frontal, central and lateral temporal regions, but only similar to 25% in the mesial temporal region. MEG is a reliable indicator of the presence of interictal ECoG spikes and can be used to plan intracranial electrode placements. However, a substantial number of interictal ECoG spikes are not detected by MEG, and therefore MEG cannot be considered a substitute for ECoG.