电针合谷穴所产生的运动皮层手面区之间的可塑性

Electroacupuncture-induced plasticity between hand and face representations in the motor cortex in healthy subjects

目的:观察电针合谷穴后健康志愿者运动皮层手面区之间的可塑性,为“面口合谷收”取穴理论提供科学依据。方法:采用交叉设计(同体自身前后对照),将健康志愿者10例随机先后分配至针刺组及假针刺组(两组间隔2周的洗脱期)。针刺组受试者左手合谷穴接受电针刺激(频率2Hz,强度0.5~1mA,时间30min);假针刺组采用胶粘垫安慰针,不刺入皮肤,安慰针连接至连接线内线断裂的电针仪。运用经颅磁刺激技术,分别于针刺及假针刺前后记录对侧运动皮层手面区磁刺激诱发的第一骨间背侧肌、眼轮匝肌的运动诱发电位(MEPs),计算MEPs总波幅、有效刺激面积及重心。结果:与电针前比较,针刺组对侧运动皮层手区的MEPs总波幅显著升高(P<0.05),面区的MEPs总波幅明显下降(P<0.05);手区的有效刺激面积明显增大(P<0.01);手区X轴重心明显向外侧移动(P<0.05)。与电针前比较,假针刺组对侧运动皮层手、面区的MEPs总波幅、有效刺激面积及重心的差异无统计学意义(P>0.05)。与假针刺组比较,针刺组针刺前后对侧运动皮层手区MEPs波幅差值增大(P<0.05),面区MEPs波幅差值减小(P<0.05);针刺组对侧运动皮层手区针刺前后有效刺激面积差值增大(P<0.05)。结论:电针合谷穴能诱导健康志愿者运动皮层手面区之间的可塑性(兴奋运动皮层手区,同时抑制运动皮层面区),为面口部疾病的针灸治疗及循经远道取穴理论提供了科学依据。

Objective To observe the plasticity between hand and face representations of the motor cortex of healthy volunteers after electroacupuncture(EA)at Hegu(LI4),so as to provide a scientific basis for the theory of“Hegu is indicated for orofacial problems”.Methods Using a cross-over design(self-controlled study),10healthy volunteers were randomly assigned to an acupuncture group and a sham acupuncture group(two-weeks wash-out period between the two groups).Subjects in the acupuncture group received EA stimulation(2Hz,0.5to 1mA,30min)at LI4on their left hands.Adhesive pads sticked on the left hands of subject in the sham acupuncture group,thus,the placebo needle provided participants with a similar appearance to that in the acupuncture group but no skin penetration,and the placebo needles were connected to an EA device with a broken wire inside.Using transcranial magnetic stimulation technology,the motor evoked potentials(MEPs)of the first dorsal interosseous muscle and the orbicularis oculi muscle in hand and face representations in the contralateral motor cortex were recorded before and after EA and sham EA,and the total amplitude,effective stimulation area and center of gravity of MEPs were calculated.Results Compared with that before intervention,for acupuncture group,the total amplitude of MEPs in hand representation in the contralateral motor cortex was significantly increased(P<0.05),while the total amplitude of MEPs in face representation was significantly decreased(P<0.05).The effective stimulation area in hand representation was significantly increased(P<0.01),and there was no difference in face representation(P>0.05).The difference in the center of gravity of the X-axis in hand representation was statistically significant(P<0.05),with the center of gravity moved an average of 0.6cm to the outside,and there was no difference in face representation(P>0.05).There was no difference in the center of gravity of the Y-axis in hand and face representations(P>0.05).For sham acupuncture group,there were no differences in total amplitude of MEPs,effective stimulation area and the center of gravity in hand and face representations(P>0.05).Conclusion EA at LI4can induce plasticity between the hand and face representations of the motor cortex in healthy volunteers(exciting the hand representation of the motor cortex,while inhibiting the motor cortex representation),which provides a scientific basis for treating facial and mouth diseases by acupuncture at LI4and the theory of selecting acupoints of the corresponding meridian distal to the disease location.