Abstract:

Objective  To investigate the feasibility and safety of using navigated transcranial magnetic stimulation (nTMS) to map hand motor cortex and further analyze its clinical application.  Methods  The first dorsal interosseous (FDI) was selected as target muscle. The location and area of bilateral FDI were mapped by using nTMS in 10 healthy right-handed volunteers. In order to identify the accuracy of nTMS, all individual MRI volumes and the coordinates of hotspots were normalized to Montreal Neurological Institute (MNI) space using SPM8. Positive sites and motor-evoked potential (MEP) were recorded. The areas of hand motor representations were calculated and compared between bilateral cerebral hemispheres.  Results  nTMS was capable of identifying hand motor cortex area in both hemispheres in all cases. It took 45 to 60 minutes to finish the whole nTMS procedures of each side of hand motor area. The motor cortex was found at the Ω area of bilateral precentral gyri. The right hand motor representation area was significantly larger than that of left area [(6.22 ± 0.76) cm² vs (4.30 ± 0.40) cm²; t = 7.078, P = 0.000]. Four cases presented sleepiness, but no side effect such as headache or epilepsy was found.  Conclusions  nTMS is a reliable and safe technique to map hand motor cortex. It can be a very useful supplementary tool for preoperative motor cortex mapping and study on motor functional remodeling.

Key words: Transcranial magnetic stimulation, Neuronavigation, Evoked potentials, motor, Hand

摘要：

目的 探讨导航经颅磁刺激定位双手运动功能区的准确性和安全性。方法 采用导航经颅磁刺激对10 例右利手的健康志愿者双手第一骨间背侧肌进行刺激，定位双手运动功能区及其边界，记录阳性位点坐标和运动诱发电位，并计算双手运动功能区面积。结果 10 例受试者均成功定位双手运动功能区，主要定位于中央前回“Ω”区及其周围；右手运动功能区面积大于左手［（6.22 ± 0.76）cm² 对（4.30 ± 0.40）cm²；t = 7.078，P = 0.000］；其中4 例表现出困倦，无一例出现头痛、癫发作等不良反应。结论 导航经颅磁刺激定位手运动功能区准确、安全，可作为术前定位运动功能区和研究运动功能重塑的辅助方法。

关键词: 经颅磁刺激, 神经导航, 诱发电位, 运动, 手