Background Although various monitoring techniques have been used routinely in the treatment of the lesions in the skull base, iatrogenic facial paresis or paralysis remains a significant clinical problem. The aim of this study was to investigate the effect of intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation on preservation of facial nerve function. Method From January to November 2005, 19 patients with large acoustic neuroma were treated using intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation （TCEMEP） for preservation of facial nerve function. The relationship between the decrease of MEP amplitude after tumor removal and the postoperative function of the facial nerve was analyzed. Results MEP amplitude decreased more than 75% in 11 patients, of which 6 presented significant facial paralysis （H-B grade 3）, and 5 had mild facial paralysis （H-B grade 2）. In the other 8 patients, whose MEP amplitude decreased less than 75%, 1 experienced significant facial paralysis, 5 had mild facial paralysis, and 2 were normal. Conclusions Intraoperative TCEMEP can be used to predict postoperative function of the facial nerve. The decreased MEP amplitude above 75 % is an alarm point for possible severe facial paralysis.
LIU Bai-yunTIAN Yong-jiLIU WenLIU Shu-lingQIAO HuiZHANG Jun-tingJim Gui-jun
目的采用脑磁图(magnetoencephalography,MEG)的等价电流偶极子定位法(Equivalent current dipole,ECD)和合成孔径磁场定位法(SAM Synthetic Aperture Magnetometry,SAM)定位母语为汉语的健康自愿者的语言中枢,探讨汉字的语言处理过程。方法对10例母语为汉语的健康受试者给予默读真词、假词的语言任务刺激,记录刺激后产生的诱发磁场,将采集的数据与MRI叠加获得磁源性影像(MSI Magnetic source imaging)语言功能区定位。用同样的方法对4例胶质瘤患者进行术前语言功能区定位,术中皮层电刺激所定位语言功能区,明确是否产生言语障碍。结果所有受试者真词、假词均在双侧大脑半球诱发出明显的晚期磁反应波,左侧大脑半球磁反应波分化较右侧大脑半球好,Broca区位于额下同后部,Wernicke区位于颞中回、颞上回、缘上回,Wernicke区先于Broca区出现。胶质瘤患者术中电刺激所定位的Broca区、Wernicke区均产生言语障碍。结论母语为汉语的正常人的Broca区与Wernicke区与经典的语言中枢基本相符,MEG定位语言中枢的技术是可行的。
