皮层电刺激功能定位与后发放阈值测定的初步研究

Primary study on electrical cortical stimulation mapping and threshold for afterdischarges

目的通过皮层电刺激进行皮层功能定位,比较大脑皮层不同部位后发放(ADs)的阈值及其对致痫区定位的意义。方法对7例难治性癫痫患者,综合分析其长程头皮视频脑电图(VEEG)、MRI及SPECT和PET资料,放置硬膜下条状或栅状电极,通过恒流电刺激对大脑皮层进行功能定位,并测定大脑皮层不同部位ADs的阈值,探讨ADs阈值与致痫区之间的关系。结果致痫区位于额叶者3例,颞叶者2例,顶叶者1例,枕叶者1例;在额叶、顶枕叶和颞叶内,相邻电极之间功能变化的阈值之差分别为11、4.5和3 mA,不同功能区之间的阈值无统计学差异(P=0.685);颞叶ADs的阈值显著低于额及顶枕叶(P=0.015);刺激致痫区时,ADs主要出现在致痫区周围2～3 cm的范围内,且节律性强,波幅高;而刺激非致痫区时,ADs出现的部位较为弥散,节律性差,波幅低;当致痫区位于或靠近皮层功能区时,选择性点状切除阈值较低的区域,不会造成明显的或永久性的神经功能障碍,疗效较好。结论皮层电刺激测定大脑皮层不同部位的ADs阈值,并进行大脑皮层功能定位,有助于致痫区定位,提高手术疗效,减少致残率。

Objective To test the safety and validity of propofol used in Wada test for the purpose of assaying language,motor and memory function in intractable epilepsy patients who could not accomplish fMRI.Methods After digital substraction angiography（DSA）,a certain dose of propofol was bolusly injected through the catheter into intracarotid artery（ICA） and produced contralateral hemiplegia.When the contralateral upper limb strength was lower than grade 3,language and memory functions were evaluated.30 minutes later,the other side of carotid catheterization was executed as well as neuropsychological test.Video-electroencephalography（V-EEG） was recorded through the whole procedure.Results There were 9 male and 3 female patients with the age range of 4-24 years-old and average age of 15 years-old.2 of 12 were epileptic encephalopathy,10 focal symptomatic epilepsy.Except for one case with posterior communicating artery openness in DSA,the other 11 cases were accomplished Wada test.Among these 11 patients,7 showed transient side effects without serious complication after injection narcotic,and 10 were operated for epilepsy.None of the operated patients developed obvious neurological deficit at postsurgical following.Conclusion It is safe and valid to apply bolus injection of propofol into intracarotid artery in Wada test to evaluate the language,motor and memory function of the cerebrum.