脑磁图对颅内电极脑电图电极埋置的指导价值

Effect of magnetoencephaiography on intracranial electrode placement strategy in intractable partial epilepsy

目的通过研究脑磁图（MEG）对侵入性颅内电极脑电图（icEEG）中电极埋置策略的影响，评价MEG在癫痫外科术前评估中的应用价值。方法收集83例经临床发作症状学、电生理及影像学诊断为难治性部分性癫痫患者，根据MEG是否参与评估电极埋置策略分为两组，比较两组手术疗效的差异。手术疗效按照Engel疗效评价标准分级，EngelⅠ、Ⅱ、Ⅲ级为手术有效，EngelⅣ级为手术无效。结果两组中，MEG未参与电极埋置策略评估的共43例，术后有效23例，占54％；而MEG参与评估电极埋置策略的共40例，术后有效31例，占78％，两组手术疗效差异有统计学意义（X^2=5．256，P=0．022）。结论MEG能够指导电极埋置位置，增加发作起始区被电极覆盖的几率，提高颅内电极脑电监测的定位准确率，从而提高手术疗效。

Objective To study whether magnetoencephalography （MEG） could indicate intracranial electroencephalography（icEEG） by affecting electrode placement and localization of the seizure onset zone, and then improve the curative effect of the surgical patients of refractory partial epilepsy. Methods Of all consecutive epilepsy surgery candidates between 21309 -2010, 83 cases who meet the refractory partial epilepsy diagnostic criteria were prospectively enrolled in this research. The 83 patients were randomly divided into two groups. In one group （MEG ＋ icEEG group）, including 43 patients, the MEG results were provided to affect the initial intracranial electrodes placement decision which was based on case - history, semilogy, EEG, MRI. By contrast, for the other group（icEEG group）, including 40 patients, the MEG localization results were not provided- All patients underwent epileptogenic feei surgical resection. The follow - up was performed at least 12 months after the operatiotr The surgical outcome was evaluated by Engel curative effect grading. Engel I, 11, Ill was defined as effeetiv whereas Engel 1V was recognized as invalid. Results According to the surgical outcome of icEEG group, 23 patients （54%） obtained good postsurgical seizure outcome. While in MEG ＋ icEEG group, the rate was 78% （31/40）. There was statistically significant difference between the two groups（x2 =5.256, P =0.022）. Conclusions MEG spike localization could affect icEEG by indicating the electrodes placement, increasing the chance that the seizure onset zone is sampled and improving diagnostic yield of icEEG when patients undergo icEEG for presurgical epilepsy evaluations, finally promote the effectiveness of the surgical resection.