Aix Marseille Université, INSERM, INS, Institut de Neurosciences des Systèmes, Marseille, France.
Physiol Meas. 2017 Sep 21;38(10):N118-N127. doi: 10.1088/1361-6579/aa7655.
The simultaneous recording of intracerebral EEG (stereotaxic EEG, SEEG) and magnetoencephalography (MEG) is a promising strategy that provides both local and global views on brain pathological activity. Yet, acquiring simultaneous signals poses difficult technical issues that hamper their use in clinical routine. Our objective was thus to develop a set of solutions for recording a high number of SEEG channels while preserving signal quality.
We recorded data in a patient with drug resistant epilepsy during presurgical evaluation. We used dedicated insertion screws and optically insulated amplifiers. We recorded 137 SEEG contacts on 10 depth electrodes (5-15 contacts each) and 248 MEG channels (magnetometers). Signal quality was assessed by comparing the distribution of RMS values in different frequency bands to a reference set of MEG acquisitions.
The quality of signals was excellent for both MEG and SEEG; for MEG, it was comparable to that of MEG signals without concurrent SEEG. Discharges involving several structures on SEEG were visible on MEG, whereas discharges limited in space were not seen at the surface.
SEEG can now be recorded simultaneously with whole-head MEG in routine. This opens new avenues, both methodologically for understanding signals and improving signal processing methods, and clinically for future combined analyses.
同时记录脑内脑电图（立体脑电图，SEEG）和脑磁图（MEG）是一种很有前途的策略，它提供了大脑病理活动的局部和全局视图。然而，获取同步信号带来了困难的技术问题，阻碍了它们在临床常规中的应用。因此，我们的目标是开发一套解决方案，以在保持信号质量的同时记录大量 SEEG 通道。
我们在一名药物难治性癫痫患者的术前评估中记录数据。我们使用了专用的插入螺钉和光隔离放大器。我们在 10 个深部电极（每个电极 5-15 个接触点）上记录了 137 个 SEEG 接触点和 248 个 MEG 通道（磁强计）。通过将不同频带的 RMS 值分布与一组参考 MEG 采集进行比较，评估信号质量。
MEG 和 SEEG 的信号质量都非常好；对于 MEG，其质量与没有同时进行 SEEG 的 MEG 信号相当。SEEG 上涉及多个结构的放电在 MEG 上可见，而在表面上则看不到空间受限的放电。
现在可以在常规情况下同时记录 SEEG 和全头 MEG。这为理解信号和改进信号处理方法开辟了新的途径，也为未来的联合分析提供了临床依据。
