1Brain & Mind Research Center, Nagoya University, Nagoya, Aichi.
Departments of2Pediatrics.
J Neurosurg. 2020 Mar 13;134(3):1027-1036. doi: 10.3171/2020.1.JNS192567. Print 2021 Mar 1.
The authors recently reported a novel subsecond analysis method of analyzing EEG-functional MRI (fMRI) to improve the detection rate of epileptic focus. This study aims to validate the utility of this method for presurgical evaluation in pharmacoresistant focal epilepsy.
Among 13 patients with focal epilepsy undergoing presurgical examinations including simultaneous EEG-fMRI at 3T, 11 patients had interictal epileptiform discharges (IEDs) during fMRI. The authors used the sequence of topographic maps during the IEDs as a reference to obtain subsecond fMRI activation maps with the same temporal resolution as the EEG data, and constructed "spike-and-slow-wave-activation-summary" (SSWAS) maps that showed the activation frequency of voxels during IEDs. Clusters were defined by thresholding the SSWAS maps (voxel value > 10), and those containing voxels with the top 3 highest activation frequencies were considered significant. Significant hemodynamic responses using conventional event-related (ER) analysis and SSWAS maps were compared with the resection areas and surgical outcomes at 1 year after surgery.
Using ER analysis, 4 (36%) of 11 patients had significant hemodynamic responses. One of 4 patients had significant hemodynamic responses in the resection area and good surgical outcome. Using SSWAS maps, 10 (91%) of 11 patients had significant hemodynamic responses. Six of 10 patients had significant hemodynamic responses in the resection area, and 5 of the 6 patients achieved good surgical outcomes. The remaining 4 patients had significant hemodynamic responses distant from the resection area, and only 1 of the 4 patients achieved good surgical outcomes. The sensitivity, specificity, positive predictive value, and negative predictive value of SSWAS maps were 83.3%, 75.0%, 83.3%, and 75.0%, respectively.
This study demonstrated the clinical utility of SSWAS maps for presurgical evaluation of pharmacoresistant focal epilepsy. The findings indicated that subsecond EEG-fMRI analysis may help surgeons choose the resection areas that could lead to good surgical outcomes.
作者最近报道了一种新的亚秒级分析方法，用于分析脑电图-功能磁共振成像（fMRI），以提高癫痫灶的检测率。本研究旨在验证该方法在抗药性局灶性癫痫术前评估中的效用。
在 13 名接受包括 3T 同步 EEG-fMRI 检查的局灶性癫痫患者中，11 名患者在 fMRI 期间出现发作间期癫痫样放电（IEDs）。作者使用 IED 期间地形图序列作为参考，以获得与 EEG 数据具有相同时间分辨率的亚秒级 fMRI 激活图，并构建了“尖峰和慢波激活总结”（SSWAS）图，显示了 IED 期间体素的激活频率。通过阈值处理 SSWAS 图（体素值>10）定义簇，那些包含最高 3 个激活频率体素的簇被认为是显著的。使用传统的事件相关（ER）分析和 SSWAS 图比较显著的血液动力学反应与术后 1 年的切除区域和手术结果。
使用 ER 分析，11 名患者中有 4 名（36%）出现显著的血液动力学反应。其中 1 名患者在切除区域出现显著的血液动力学反应，手术效果良好。使用 SSWAS 图，11 名患者中有 10 名（91%）出现显著的血液动力学反应。10 名患者中有 6 名在切除区域出现显著的血液动力学反应，其中 5 名患者手术效果良好。其余 4 名患者在切除区域以外出现显著的血液动力学反应，其中仅 1 名患者手术效果良好。SSWAS 图的灵敏度、特异性、阳性预测值和阴性预测值分别为 83.3%、75.0%、83.3%和 75.0%。
本研究证明了 SSWAS 图在抗药性局灶性癫痫术前评估中的临床效用。研究结果表明，亚秒级 EEG-fMRI 分析可能有助于外科医生选择可能导致良好手术效果的切除区域。
