Neuropediatric Department, Christian-Albrechts-University, Kiel, Germany.
Epilepsia. 2012 Sep;53(9):1597-606. doi: 10.1111/j.1528-1167.2012.03587.x. Epub 2012 Jul 10.
In the presurgical evaluation of children and juvenile patients with refractory focal epilepsy, the main challenge is to localize the point of seizure onset as precisely as possible. We compared results of the conventional electroencephalography-functional magnetic resonance imaging (EEG-fMRI) analysis with those obtained with a newly developed method using voltage maps of average interictal epileptiform discharges (IEDs) recorded during clinical long-term monitoring and with the results of the electric source imaging (ESI).
Simultaneous EEG-fMRI was recorded in nine patients (ages 1.5-17.5 years) undergoing presurgical evaluation. The postoperative outcome and resected area were compared with the following: the localizations of blood oxygen-level dependent (BOLD) signal changes associated with IEDs, which were identified by visual inspection changes using SPM5 software (Analysis I); BOLD signal changes related to IED topography, which was characterized using spike-specific voltage maps of average IED recorded outside the MR scanner during clinical long-term monitoring (Analysis II); as well as results of EEG source analysis based on the distributed linear local autoregressive average (LAURA) algorithm using the Cartool software by Denis Brunet (Analysis III).
All nine patients had postoperative outcome Engel class I-IIb (postoperative time 6-26 months). The analysis I revealed an IED-related area of activation within the resection area in 3 (33%) of 9 patients, analysis II was able to reliably localize the source of epileptic activity in 4 (44%) of 9 patients, and analysis III rendered results concordant with the postoperative resection site in all nine patients.
The localization of seizure onset based on EEG-fMRI may be a useful adjunct in the preoperative evaluation but also has some deficits that impair the reliability of results. In contrast, EEG source analysis is clearly a more credible method for epileptic focus localization in children with refractory epilepsies. It seems likely that the analysis based on IED topography (Analysis II) may increase sensitivity and reliability of EEG-fMRI in some patients. However, the benefit from this innovative method in children is rather limited compared with adults.
在儿童和青少年难治性局灶性癫痫患者的术前评估中，主要的挑战是尽可能精确地定位癫痫发作起始点。我们比较了常规脑电图-功能磁共振成像（EEG-fMRI）分析的结果与使用记录于临床长期监测期间的间歇性癫痫样放电（IED）平均电压图的新开发方法的结果以及电源成像（ESI）的结果。
对 9 名（年龄 1.5-17.5 岁）接受术前评估的患者进行同步 EEG-fMRI 记录。将术后结果和切除区域与以下内容进行比较：与 IED 相关的血氧水平依赖（BOLD）信号变化的定位，这些变化通过 SPM5 软件（分析 I）的视觉检查变化来识别；与 IED 拓扑相关的 BOLD 信号变化，这些变化使用在 MR 扫描仪外部记录的 IED 平均尖峰特异性电压图进行特征描述（分析 II）；以及基于 Denis Brunet 的 Cartool 软件的分布式线性局部自回归平均（LAURA）算法的 EEG 源分析结果（分析 III）。
所有 9 例患者术后结果均为 Engel Ⅰ-Ⅱ b 级（术后时间 6-26 个月）。分析 I 在 9 例患者中的 3 例（33%）中发现与 IED 相关的激活区域在切除区域内，分析 II 能够可靠地定位 9 例患者中的 4 例（44%）的癫痫活动源，分析 III 在所有 9 例患者中均得出与术后切除部位一致的结果。
基于 EEG-fMRI 的癫痫发作起始点定位可能是术前评估的有用辅助手段，但也存在一些缺陷，会降低结果的可靠性。相比之下，EEG 源分析显然是儿童难治性癫痫患者癫痫灶定位更可信的方法。基于 IED 拓扑的分析（分析 II）似乎可以提高某些患者 EEG-fMRI 的敏感性和可靠性。然而，与成年人相比，这种创新方法对儿童的益处相当有限。
