Abstract：
BACKGROUND: 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.
METHODS: 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.
RESULTS: 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.
METHODS: 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.
CONCLUSIONS: 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.
METHODS: 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.
RESULTS: 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.
METHODS: 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.
CONCLUSIONS: 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.
摘要：
背景：头皮脑电图是临床评估癫痫的主要工具之一。在某些情况下，从头皮看不到颅内发作间癫痫样放电（IED）。最近的研究表明，如果从同时的颅内记录中提取它们的时间，则在EEG中揭示它们的可行性，但是它们在癫痫发生区的定位潜力尚不明确。
方法：我们记录了8例耐药局灶性癫痫患者在发作间期同时进行的高密度脑电图（HD-EEG）和立体脑电图（SEEG）。我们在SEEG中识别了IED，并通过诱发电位系统地分析了EEG上的时间锁定信号，地形分析和电源成像（ESI）。该数据集已经标准化，并且正在公开共享。
结果：我们的结果表明，在单一试验中不清晰可见的IED可以通过平均来发现，与以前的报告一致。他们还表明，他们的地形电压分布与SEEG电极的位置相匹配，并且ESI技术可以以〜2厘米的精度重建它。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。
方法：我们的研究首次系统地比较了同时记录的IED的ESI方法，并与体内数据共享公共资源以进行评估。
结论：同时进行HD-EEG和SEEG记录可以揭示隐藏的IED，其起源可以通过地形和ESI分析进行重建，但结果取决于所选的方法和参数。
方法：我们记录了8例耐药局灶性癫痫患者在发作间期同时进行的高密度脑电图（HD-EEG）和立体脑电图（SEEG）。我们在SEEG中识别了IED，并通过诱发电位系统地分析了EEG上的时间锁定信号，地形分析和电源成像（ESI）。该数据集已经标准化，并且正在公开共享。
结果：我们的结果表明，在单一试验中不清晰可见的IED可以通过平均来发现，与以前的报告一致。他们还表明，他们的地形电压分布与SEEG电极的位置相匹配，并且ESI技术可以以〜2厘米的精度重建它。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。
方法：我们的研究首次系统地比较了同时记录的IED的ESI方法，并与体内数据共享公共资源以进行评估。
结论：同时进行HD-EEG和SEEG记录可以揭示隐藏的IED，其起源可以通过地形和ESI分析进行重建，但结果取决于所选的方法和参数。
