外加刺激对针刺穴位时大脑皮层体觉区诱发电位地形图的影响

Influence of external stimulation on topographical mapping of cortical somatosensory evoked potentials during acupuncture

目的:探讨外加刺激与皮层体觉诱发电位地形图变化的内在联系。方法:观察对象为33名健康成年无感传志愿者,以脑电信号采集处理系统自颅外记录SI的体觉诱发反应地形图。外加刺激的方法:①以柔软的画笔仅在头面部、下肢部、躯干部轻轻刷动;④以柔软的画笔分别在下肢部、躯干部以及沿胆经的路线并绕行上肢模拟感传的速度轻轻刷动。结果:①以柔软的画笔仅在头面部或仅在下肢部或仅在躯干部轻轻刷动刺激时,在SEP地形图上只在下肢代表区出现了高电位反应。②以柔软的画笔分别在下肢部、躯干部以及沿胆经的路线并绕行上肢模拟感传的速度轻轻刷动时,毛刷下肢和躯干部时SEP地形图上的表现与前面一样,只在下肢代表区出现了高电位反应;而当沿胆经的路线模拟感传的速度轻轻刷动刺激时,在皮层第一体觉区的下肢和面部代表区同时出现了高电位反应,与循经感传时皮层体觉区诱发电位地形图的表现相一致。结论:沿经脉路线施加的外加刺激可以改变刺激穴位时SI诱发反应的分布,而仅仅在头面部或下肢部或躯干部施与的无规则的外加刺激不能改变刺激穴位时SI诱发反应的分布,再一次证实了外周动因激发是产生循经感传现象的决定因素。

Objective：The topographical mapping technique of cortical evoked potential was used to observe the changes of the functional activities in the primary somatosensory area of cortex （SI） during external stimulation,the immanent relation between external stimulation and topographical mapping of cortical somatosensory evoked potential （CSEP）. Methods：33 healthy adult volunteers were under observation. Cerebral electric signal processing system was used to lead CSEP on the scalp. The external stimulation was applied as following：①A soft paintbrush was used to slightly brush the face only. ②Paintbrush was used to slightly brush the lower limb only. ③Paintbrush was used to slightly brush the trunk only. ④Paintbrush was used to slightly brush the lower limb or the trunk or the Gallbladder Meridian （GBM） and passing the upper arm by imitating the speed of meridian transmission phenomenon respectively. Results：①Evoking responses appeared in the foot areas in SI,without meridian transmission phenomenon when brushing the face,lower limb or trunk only. ②Healthy volunteers were offered imitation of sensation conduction along the GBM as well as brushing through the upper arm in addition,while,the results showed that the evoking responses appeared in the foot,the upper arm and the face representation area of SI simultaneously. Conclusion：The external stimulation along the meridian course was able to change the distribution of evoking responses in SI during stimulating acupoint. But the local stimulating on face,lower limb or trunk can not change the distribution of CSEP. The results provided experimental evidence for the supposition that ＇activation in sequence in periphery＇was the decisive factor for the formation of meridian transmission phenomenon.