Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA 02129, USA.
Neuroimage. 2010 Mar;50(1):217-22. doi: 10.1016/j.neuroimage.2009.12.033. Epub 2009 Dec 16.
The purpose of this study is to assess the accuracy of spatiotemporal source analysis of magnetoencephalography (MEG) and scalp electroencephalography (EEG) for representing the propagation of frontotemporal spikes in patients with partial epilepsy. This study focuses on frontotemporal spikes, which are typically characterized by a preceding anterior temporal peak followed by an ipsilateral inferior frontal peak. Ten patients with frontotemporal spikes on MEG/EEG were studied. We analyzed the propagation of temporal to frontal epileptic spikes on both MEG and EEG independently by using a cortically constrained minimum norm estimate (MNE). Spatiotemporal source distribution of each spike was obtained on the cortical surface derived from the patient's MRI. All patients underwent an extraoperative intracranial EEG (IEEG) recording covering temporal and frontal lobes after presurgical evaluation. We extracted source waveforms of MEG and EEG from the source distribution of interictal spikes at the sites corresponding to the location of intracranial electrodes. The time differences of the ipsilateral temporal and frontal peaks as obtained by MEG, EEG and IEEG were statistically compared in each patient. In all patients, MEG and IEEG showed similar time differences between temporal and frontal peaks. The time differences of EEG spikes were significantly smaller than those of IEEG in nine of ten patients. Spatiotemporal analysis of MEG spikes models the time course of frontotemporal spikes as observed on IEEG more adequately than EEG in our patients. Spatiotemporal source analysis may be useful for planning epilepsy surgery, by predicting the pattern of IEEG spikes.
本研究旨在评估脑磁图（MEG）和头皮脑电图（EEG）时空源分析在代表部分癫痫患者额颞部棘波传播中的准确性。本研究集中于额颞部棘波，其特征通常为先前颞部峰值，随后是同侧额下部峰值。对 10 例 MEG/EEG 有额颞部棘波的患者进行了研究。我们通过使用皮层约束最小范数估计（MNE）分别独立分析 MEG 和 EEG 上颞部到额部癫痫棘波的传播。通过从患者 MRI 得出的皮质表面，获得了每个棘波的时空源分布。所有患者均在术前评估后接受了额外的颞叶和额叶颅内脑电图（IEEG）记录。我们从对应颅内电极位置的棘波源分布中提取了 MEG 和 EEG 的源波形。在每个患者中，对 MEG、EEG 和 IEEG 获得的同侧颞部和额部峰值的时间差异进行了统计学比较。在所有患者中，MEG 和 IEEG 显示出颞部和额部峰值之间的相似时间差异。在 10 例患者中的 9 例中，EEG 棘波的时间差异明显小于 IEEG。在我们的患者中，MEG 棘波的时空分析比 EEG 更能充分模拟 IEEG 上观察到的额颞部棘波的时程。时空源分析可能有助于通过预测 IEEG 棘波的模式来规划癫痫手术。
