颅内电极在感觉运动区皮质发育不良癫痫手术中的应用

目的:探讨长程颅内电极监测及电刺激方法,在感觉运动区皮质发育不良的难治性癫痫外科手术评估中的意义。方法:筛选MRI提示的皮质发育不良区域与重要功能区-感觉运动区位置关系密切的11例难治性癫痫患者,且头皮长程视频脑电监测及PET检查也初步提示癫痫发作与皮质发育不良所在脑区有关,在可疑脑区放置颅内电极,然后进行颅内电极长程视频脑电监测及电刺激检测,对癫痫起源位置及功能区定位,明确癫痫发作起源区域与感觉运动功能区的解剖学关系,在定位结果指导下进行切除术。结果:11例中3例位于左侧半球,8例位于右侧半球,11例感觉运动功能区皮质分布均存在不同程度变异,7例癫痫发作起源区域与感觉运动功能区一定范围重叠,其中5例与感觉区重叠,该5例切除了起源区域与发作有关的部分感觉区,2例部分致痫灶与运动区重叠,该2例仅切除了除与发作有关的运动区以外的癫痫起源区域,4例癫痫发作起源区域与感觉运动功能区相对独立,该4例完全切除癫痫发作起源区域;手术后6例患者发作消失,2例患者发作频率减少90%以上,1例癫痫发作控制无效,2例患者发生部分感觉缺失,但对生活无明显影响。结论:在皮质发育不良的癫痫患者中,有较高比例的病人伴有功能区皮层分布的变异,长程颅内电极监测及电刺激能够实现癫痫起源区域及功能区精确定位,明确功能区变异情况,对于指导病灶切除,避免损伤功能区皮质,减少术后并发症具有重要意义。

The Application of Intracranial Electrode and cortex electrical stimulation in epilepsy patients with focal cortical dysplasia located in primary motor/sensory area

Objective: To evaluate the role of identification of eloquent cortex and seizure onset zone by intracranial electrode and cortex electrical stimulation in intractable epilepsy patients with focal cortical dysplasia located in primary motor/ sensory area of the brain. Methods: There were 11 intractable epilepsy patients with focal cortical dysplasia. Cortical dysplasia area located closely to the primary motor/sensory area and showed a close relationship with seizure onset zone by presurgical evaluation with scalp EEG, MRI or PET. Subdural electrodes were implanted on cortical surface by craniotomy. Intracranial EEG monitoring and cortical stimulation was performed after the operation. The epileptogenic zone was resected according to the results of intracranial EEG monitoring and cortical stimulation. Results: The cortical dysplasia areas were located on the left cerebral hemisphere in 3 patients and were located on the right cerebral hemisphere in 8 patients. All of the 11 patients had eloquent cortex variations in different degrees. In 7 patients whose seizure onset zone were overlapping with the primary motor/sensory area, 5 patients whose seizure onset zone overlapped with the primary sensory area accepted complete resections of the seizure onset zone including a part of the sensory area overlapped with seizure onset zone, and 2 patients whose seizure onset zone overlapped with the primary motor area accepted partial resections of the seizure onset zone besides the overlapping area. The other 4 patients whose seizure onset zones were isolated from the functional cortex accepted complete resection of the seizure onset zone. After the surgery, 6 patients were seizure free, 2 patients had a 90 % reduction of seizure onset frequency. In 1 patient, the surgery had no seizure control effect. Only 2 patients had partially loss of sensation, but their daily lives were not significantly affected. Conclusion: In intractable epilepsy patients with focal cortical dysplasia closely related to the eloquent cortex, the variations of eloquent cortex were common. The application of intracranial electrical monitoring and cortical electrical stimulation can precisely identify the variations and identify the relationship between eloquent area and seizure onset zone, so it can be an useful tool in directing the resection and avoiding damagement of the eloquent cortex.