During the non-invasive evaluation phase for refractory epilepsy, the localization of the epileptogenic zone (EZ) is essential for the surgical protocols. Confirmation of laterality is required when the preoperative evaluation limits the EZ into bilateral anterior temporal lobes or bilateral frontal lobes. High frequency oscillations (HFOs) are considered to be promising biological markers for the EZ. However, a large number of studies on HFOs stem from intracranial researches. There were few quantitative measures for scalp-HFOs, so we proposed a new method to quantify and analyze scalp-HFOs. This method was called 'scalp-HFO index' (HI) and calculated in both the EZ and non-EZ. The calculation was based on the numbers and spectral power of scalp-HFOs automatically detected. We labeled the brain lobes involved in the EZ as regions of interest (ROI). The HIs based on the ripple numbers (n-HI) and spectral power (s-HI) were significantly higher in the ROI than in the contra-ROI (P=0.012, P=0.003), indicating that HIs contributed to the lateralization of EZ. The sensitivity and specificity of n-HI for the localization of the EZ were 90% and 79.58%, respectively, suggesting that n-HI was valuable in localizing the EZ. HI may contribute to the implantation strategy of invasive electrodes. However, few scalp HFOs were recorded when the EZ was located in the medial cortex region.

中文翻译：

---

Scalp-HFO 指数是术前评估中致痫区偏侧化和定位的生物标志物

在难治性癫痫的非侵入性评估阶段，致癫痫区 (EZ) 的定位对于手术方案至关重要。当术前评估将 EZ 限制在双侧前颞叶或双侧额叶时，需要确认偏侧性。高频振荡 (HFO) 被认为是 EZ 的有前途的生物标志物。然而，大量关于 HFO 的研究源于颅内研究。头皮 HFO 的定量测量方法很少，因此我们提出了一种量化和分析头皮 HFO 的新方法。这种方法被称为“头皮 HFO 指数”（HI），并在 EZ 和非 EZ 中计算。该计算基于自动检测到的头皮 HFO 的数量和光谱功率。我们将 EZ 中涉及的脑叶标记为感兴趣区域 (ROI)。基于波纹数 (n-HI) 和光谱功率 (s-HI) 的 HI 在 ROI 中显着高于对侧 ROI (P=0.012, P=0.003)，表明 HI 有助于易。n-HI 对 EZ 定位的敏感性和特异性分别为 90% 和 79.58%，表明 n-HI 在定位 EZ 中很有价值。HI 可能有助于侵入性电极的植入策略。然而，当 EZ 位于内侧皮质区域时，很少记录头皮 HFO。n-HI 对 EZ 定位的敏感性和特异性分别为 90% 和 79.58%，表明 n-HI 在定位 EZ 中很有价值。HI 可能有助于侵入性电极的植入策略。然而，当 EZ 位于内侧皮质区域时，很少记录头皮 HFO。n-HI 对 EZ 定位的敏感性和特异性分别为 90% 和 79.58%，表明 n-HI 在定位 EZ 中很有价值。HI 可能有助于侵入性电极的植入策略。然而，当 EZ 位于内侧皮质区域时，很少记录头皮 HFO。