高频重复周围磁刺激对正常人身体特异性注意的影响初探

The effects of high-frequency repeated peripheral magnetic stimulation on body-specific attention among healthy adults

目的观察高频重复周围磁刺激对正常人身体特异性注意的影响及其随时间的变化。方法采用Excel随机函数将正常受试者40例分为重复刺激组20例(其中1例脱落)和假性刺激组20例。重复刺激组采用Pathleader周围磁刺激仪刺激非优势侧上肢桡神经深支,强度设置为在受试者可耐受范围内能引起明显的腕背伸运动,频率50 Hz,刺激时间2 s,间歇时间1 s,刺激序列36个;假性刺激组仪器及参数设置均同重复刺激组,将线圈旋转90°,无实质刺激。以身体条件下两侧反应时间差减去对照条件下两侧反应时间差的差值作为身体特异性注意,观察刺激前、刺激后和刺激10 min后身体特异性注意的变化。结果刺激前,2组受试者身体特异性注意的组间比较,差异无统计学意义(P>0.05)。刺激后和刺激后10 min,2组受试者身体特异性注意组间同时间点比较,差异均无统计学意义(P>0.05),重复刺激组刺激后和刺激后10 min的身体特异性注意与组内刺激前的(2.77±16.54)ms比较,差异均有统计学意义(P<0.05),假性刺激组刺激后和刺激后10 min的身体特异性注意与组内刺激前比较,差异均无统计学意义(P>0.05)。结论高频重复周围磁刺激可能以先抑制后增强的方式增强正常人的身体特异性注意。

Objective To explore the effect of high-frequency repeated magnetic stimulation on the body-specific attention of healthy adults.Methods Forty healthy adults were recruited and randomly divided into a repeated stimulation group and a sham stimulation group,each of 20.A"Pathleader"medical device which can produce magnetism was used to stimulate the initial segment of the deep branch of the radial nerve on each subject′s non-dominant side in the repeated stimulation group.The intensity was set within the subject′s tolerable range but sufficient to induce obvious dorsiflexion of the wrist joint.The frequency was 50Hz,the stimulation time was 2s with 1s intervals.The entire stimulation sequence lasted 36min.In the sham stimulation group,the device and parameters were the same but the coil was rotated 90°so there was no actual stimulation.The difference between the reaction time in the body condition and the reaction time in the control condition was defined as body-specific attention.Body-specific attention was quantified before stimulation,right after stimulation and 10 minutes later.Results Right after stimulation body-specific attention was no different from before stimulation in either group.Ten minutes after real stimulation,body-specific attention had increased significantly,but there was no significant difference in the sham stimulation group.Conclusion High-frequency repeated magnetic stimulation of a peripheral nerve can improve the body-specific attention of neurologically-intact healthy adults.The effect may arise from initial inhibition followed by enhancement.