导航经颅磁刺激定位国人右利手汉字示图书写功能区

目的运用导航经颅磁刺激探索国人右利手汉字图示书写功能区的皮层定位,并分析研究该技术下与手运动中枢的皮层位置关系。方法对10例健康受试者完成汉字示图书写的任务,在进行书写的同时予以导航下经颅磁刺激,根据出现书写障碍的阳性位点,测绘书写功能区的区域和面积;通过导航经颅磁刺激刺激右手运动功能区出现运动诱发电位,记录右手肌肉肌电数据和阳性刺激坐标,计算右手运动功能区面积,进行书写功能区与右手运动功能区大小和距离的对比。结果 10例健康汉语母语受试者均可以在导航经颅磁刺激下定位书写中枢。书写功能区的皮层定位较为固定,阳性位点主要位于额中回后部(86%,55/64)。书写功能区面积小于右手运动功能区的面积,差异具有统计学意义(161.03 mm~2±62.58 mm~2 vs.589.50 mm~2±227.34 mm~2,t=-4.050,P0.001)。书写功能区的位置与手运动区的皮层定位存在一定距离(d=12.58 mm±2.71 mm),并没有功能区的重合。结论导航经颅磁刺激技术可以辅助定位示图书写功能区位置,并且书写功能区与手运动功能区没有重合。

Study on Chinese character writing related cortical areas mapped by navigated transcranial magnetic stimulation

Objective To identify Chinese character writing related cortex (WRC) and its relationship with hand motor cortical areas. Methods Ten native Chinese-speaking, right-hand volunteers were recruited in the study. NTMS mapping was conducted during picture naming task. The WRC were mapped based on nTMS-induced impairment of Chinese character writing. The extent and area of WRC was calculated. The right-hand motor representations were mapped while motor-evoked potentials were produced under nTMS stimulation. EMG data and coordinates of positive stimulus were recorded. The relationship between WRC and hand motor cortex (HMC) was analyzed on the basis of area comparison and distance calculation. Results The cortical areas related to Chinese character writing were mapped successfully in all subjects by nTMS. WRC was primarily centered in left posterior middle frontal gyrus (pMFG) (86%,55/64). The mean WRC area (161.03 mm2 ±62.58mm2) was significantly smaller than the mean HMC area (589.50 mm2±227.34mm2) (P<0.001). The WRC and HMC were not conjoined or overlapped in the dominant hemisphere. The distance between those two was 12.58mm±2.71mm. Conclusions NTMS can provide reliable assistance in mapping WRC areas. The WRC is relatively fixed and centralized in pMFG but is not overlapped with the HMC.