应用脑磁图对人脑初级体感皮质功能定位的研究

目的　通过脑磁图确定脑初级体感皮质的位置。方法　对 16名右利手健康受试者腕部正中神经进行电刺激 ,引起支配手的脑初级感觉皮质兴奋 ,脑初级感觉皮质的兴奋产生微弱的颅外磁场 ,用脑磁图机对这个微弱的颅外磁场进行测量。脑磁图检查后 ,受试者进行MRI检查 ,扫描序列为SE序列 ,矢状T1WI。结果　所有受试者均出现M 2 0波峰及M 3 5波峰 ,只有 2例出现明显的M 60波峰。将同一受试者M 2 0波峰及M 3 5波峰的等电流偶极与MRI叠加 ,即可明确显示手区初级体感皮质在左、右侧半球的位置。同一受试者M 2 0偶极位置与相应半球的M 3 5偶极位置相近。结论　将脑磁图获得的脑电生理学资料与MRI获得的解剖学资料叠加到一起所得到的磁源性影像可准确地确定脑的手区初级体感皮质的位置。

Functional Localization of the Human Primary Somatosensory Cortice: A Neuromagnetic Study

Objective To localize the primary somatosensory cortex of healthy subjects by Magnetoencephalography(MEG). Methods Sixteen right handed healthy subjects were examined by MEG and 1.5T MR unit,including 8 men and 8women,aged 20 to 48 years. Spin echo was utilized. Giving all the subject's left and right wrist median nerve electric stimulation, functional brain activity primary somatosensory cortex could be evoked, the excited cortex generated weak magnetic field out of the brain, which could be measured by magnetoencephalography. Results The peaks of M20 and M35 were seen in all 16 subjects and 2 had M60 peak. To combine the same subject's M20 and the M35 with the MRI, we got the location of the hand area of the primary somatosensory cortex. The dipole's location of the M20 and M35 was quite near in the same subject. Conclusion Combining the electrophysiological data of the brain gained by magnetoencephalography with the anatomic structural data gained by MRI, we can get the magnetic source imaging(MSI), and precisely localize the location of the somatosensory cortex.