Department of Neurological Surgery, University of Chicago, Chicago, IL, USA.
Department of Neurology, University of Chicago, Chicago, IL, USA.
Clin Neurophysiol. 2022 Dec;144:142-150. doi: 10.1016/j.clinph.2022.08.013. Epub 2022 Aug 30.
Stereo-electroencephalography (SEEG) is inherently-three-dimensional and can be modeled using source localization. This study aimed to assess the validity of ictal SEEG source localization.
The dominant frequency at ictal onset was used for source localization in the time and frequency domains using rotating dipoles and current density maps. Validity was assessed by concordance with the epileptologist-defined seizure onset zone (conventional SOZ) and the surgical treatment volume (TV) of seizure-free versus non-seizure-free patients.
Source localization was performed on 68 seizures from 27 patients. Median distance to nearest contact in the conventional SOZ was 7 (IQR 6-12) mm for time-domain dipoles. Current density predicted ictal activity with up to 86 % (60-87 %) accuracy. Distance from time-domain dipoles to the TV was smaller (P = 0.045) in seizure-free (2 [0-4] mm) versus non-seizure-free (12 [2-17] mm) patients, and predicted surgical outcome with 91 % sensitivity and 63 % specificity. Removing near-field data from contacts within the TV negated outcome prediction (P = 0.51).
Source localization of SEEG accurately mapped ictal onset compared with conventional interpretation. Proximity of dipoles to the TV predicted seizure outcome when near-field recordings were analyzed.
Ictal SEEG source localization is useful in corroborating the epileptogenic zone, assuming near-field recordings are obtained.
立体脑电图（SEEG）具有固有三维性，可以通过源定位进行建模。本研究旨在评估发作期 SEEG 源定位的有效性。
使用旋转偶极子和电流密度图，在时域和频域中，根据发作起始时的优势频率进行源定位。通过与癫痫学家定义的发作起始区（常规 SOZ）和无发作与有发作患者的手术治疗体积（TV）的一致性来评估有效性。
对 27 名患者的 68 次发作进行了源定位。时域偶极子到常规 SOZ 最近接触点的中位数距离为 7（IQR 6-12）mm。电流密度以高达 86%（60-87%）的准确度预测了发作期活动。与无发作患者（2[0-4]mm）相比，时间域偶极子到 TV 的距离在无发作患者中较小（P=0.045），并且以 91%的灵敏度和 63%的特异性预测了手术结果。从 TV 内的接触点去除近场数据会消除对结果的预测（P=0.51）。
与常规解释相比，SEEG 的源定位能更准确地定位发作起始。当分析近场记录时，偶极子与 TV 的接近程度预测了发作结果。
假设获得近场记录，发作期 SEEG 源定位在证实致痫区方面是有用的。
