功能磁共振与皮层电刺激定位感觉运动区的比较

目的 通过功能磁共振(fMRI)与皮层电刺激做点对点的比较,以判断fMRI对感觉运动区定位的精确性,从而评价其在功能定位中的意义及其临床应用价值.方法 对14例EEG示异常放电部位位于感觉运动区的难治性癫痫患者,术前采用双手握拳-伸缩运动任务进行血氧依赖水平(BOLD)扫描,运用BOLD技术的fMRI定位皮质感觉运动区.皮层电极植入术后给予头颅连续无间断CT扫描获取电极与颅骨的对应关系,通过神经导航仪将CT、fMRI影像与导航序列MRI图像融合后,得出含有皮层激活区和电极的融合图像建立三维立体图像,与皮层电刺激.结果进行比较,以评价fMRI定位皮质感觉运动区的准确性.结果 14例fMRI可见激活部位主要分布于对侧中央区、辅助运动区和小脑.其中11例成功完成皮层电刺激,结果显示fMRI与电刺激的吻合率为91.7%.结论 BOLD技术具有较高的敏感性和精确率,对感觉运动区定位有重要的临床应用价值.

fMRI in preoperative assessment of sensorimotor areas: correlation with direct cortical stimulation

Objective To study the accuracy of functional magnetic resonance imaging (fMRI) by comparing the relationship between the preoperative fMRI with blood oxygen level dependent (BOLD) technique and cortical stimulation for cortical mapping of sensorimotor areas in patients with epilepsy.And to estimate the significance of fMRI in localizing the functional areas as well as its clinical application value.Methods A flexion and extension of fingers tasks were used for 14 refractory epilepsy patients,whose EEG demonstrated that the abnormal discharge part was located in sensorimotor areas.A standard 3.0T MR images system was utilized to localize the sensorimotor areas,using the BOLD contrast technique.The BOLD images were integrated with the routine navigational MR images (T1-weighted three-dimensional fast spoiled gradient recalled sequence).All the patients accepted operation twice.In the first operation we implanted cortical electrodes to the abnormal discharge areas.Postoperative continuous CT scan was performed to make sure the relationship between electrodes and skull.The second operation was lesion resection.The CT images were integrated with merged images above by navigation form 3D images,which consisted of activated functional area and electrodes.After the first operation the cortical electrostimulation was also performed,the overlapping was used to adjust the relationship between areas activated by flexion and extension of fingers tasks in BOLD-fMRI and site inducing sensorimotor interruption in postoperative cortical electrostimulatior.Results The activation sites of 14 patients were mainly localized in contralateral precentral gyrus,contralateral postcentral gyrus,supplementary motor area and cerebellum.The cortical electrostimulation results of 11 patients demonstrated that the concordance between fMRI and electrostimulation was found to be 91.7%.Conclusion BOLD-fMRI is a highly sensitive and accuracy technique to locate sensorimotor areas and has a significant clinical application value.