Department of Philosophy "P. Martinetti", Università degli Studi di Milano, Milan, Italy; Department of Biomedical and Clinical Sciences "L. Sacco", Università degli Studi di Milano, Milan, Italy; ASST GOM Niguarda, Piazza dell'Ospedale Maggiore 3, Milan, Italy.
Institute of Neuroscience, Consiglio Nazionale delle Ricerche, Parma, Italy.
J Neurosci Methods. 2024 Sep;409:110193. doi: 10.1016/j.jneumeth.2024.110193. Epub 2024 Jun 12.
Scalp EEG is one of the main tools in the clinical evaluation of epilepsy. In some cases intracranial Interictal Epileptiform Discharges (IEDs) are not visible from the scalp. Recent studies have shown the feasibility of revealing them in the EEG if their timings are extracted from simultaneous intracranial recordings, but their potential for the localization of the epileptogenic zone is not yet well defined.
We recorded simultaneous high-density EEG (HD-EEG) and stereo-electroencephalography (SEEG) during interictal periods in 8 patients affected by drug-resistant focal epilepsy. We identified IEDs in the SEEG and systematically analyzed the time-locked signals on the EEG by means of evoked potentials, topographical analysis and Electrical Source Imaging (ESI). The dataset has been standardized and is being publicly shared.
Our results showed that IEDs that were not clearly visible at single-trials could be uncovered by averaging, in line with previous reports. They also showed that their topographical voltage distributions matched the position of the SEEG electrode where IEDs had been identified, and that ESI techniques can reconstruct it with an accuracy of ∼2 cm. Finally, the present dataset provides a reference to test the accuracy of different methods and parameters.
Our study is the first to systematically compare ESI methods on simultaneously recorded IEDs, and to share a public resource with in-vivo data for their evaluation.
Simultaneous HD-EEG and SEEG recordings can unveil hidden IEDs whose origins can be reconstructed using topographical and ESI analyses, but results depend on the selected methods and parameters.
头皮脑电图是癫痫临床评估的主要工具之一。在某些情况下，颅内发作间期癫痫样放电（IEDs）无法从头皮上观察到。最近的研究表明，如果从同步的颅内记录中提取其时间，就可以在脑电图中揭示这些放电，但它们在致痫区定位方面的潜力尚未得到很好的定义。
我们在 8 例药物难治性局灶性癫痫患者的发作间期记录了高密度脑电图（HD-EEG）和立体脑电图（SEEG）。我们在 SEEG 中识别出 IEDs，并通过诱发电位、拓扑分析和电源成像（ESI）对 EEG 上的时锁信号进行系统分析。该数据集已标准化，并正在公开共享。
我们的结果表明，IEDs 在单次试验中无法清晰显示，可以通过平均来揭示，这与之前的报告一致。它们还表明，其拓扑电压分布与已经确定 IEDs 的 SEEG 电极位置相匹配，并且 ESI 技术可以以约 2cm 的精度重建它。最后，本数据集为测试不同方法和参数的准确性提供了参考。
我们的研究首次系统地比较了同时记录的 IEDs 的 ESI 方法，并共享了具有体内数据的公共资源以进行评估。
同步的 HD-EEG 和 SEEG 记录可以揭示隐藏的 IEDs，其起源可以通过拓扑和 ESI 分析进行重建，但结果取决于所选的方法和参数。
