Effects of auricular acupuncture stimulation on healthy adults' upper limb motor-evoked potentials: A randomized, crossover, double-blind study

Objective The aim of this study was to determine whether auricular acupuncture has neuromodulatory effects on the motor cortex of healthy adults. Methods Fourteen healthy subjects received a real auricular acupuncture stimulation (SF1) session and a sham acupuncture stimulation session. The interval between the two types of stimulation was more than 24 h. A finger dexterity test (taping score and taping speed by using ipad) was assessed, and motor-evoked potentials (MEP) were assessed before and after each stimulation. Results Before the treatment, there were no significant differences in MEP amplitude, tapping score, or tapping speed (P > 0.05) between the real and sham stimulation conditions. After the treatment, the MEP amplitude, tapping score, and tapping speed in the real stimulation condition increased significantly compared to the pre-stimulation measurements and were significantly higher than those in the sham stimulation condition (P < 0.01). In the sham stimulation condition, the MEP amplitude, tapping score, and tapping speed decreased significantly compared to the pre-stimulation measurements (P < 0.05). Conclusion Acupuncture of auricular points can modulate the excitability of the motor cortex area of controlling the upper limbs.