抄録
This study aimed to evaluate the neurophysiological effects of gentle cutaneous stimulation by acupuncture on muscle tone in patients with chronic spastic paresis. We conducted a randomized, double-blind, crossover trial comparing the effects of contact acupuncture on the H/M ratios of soleus muscles between 8 patients with spastic paresis and 17 healthy volunteers. The study subjects were randomly assigned to two groups, and then they received gentle stimulations to their lower limb (affected side) using skin attachment-type contact acupuncture and sham acupuncture in different order. Fourteen acupuncture points were selected according to the Meridian-Test (M-Test). The soleus muscle in both stimulated and unstimulated limbs was analyzed by electromyography following tibial electrical stimulation at the popliteal fossa, and the H/M ratios were then calculated. Paretic subjects showed a significant decrease in H/M ratio after both contact and sham acupunctures in the stimulated limbs, but not in the unstimulated limbs (unaffected side), and this result was not affected by the order of stimulation. Healthy subjects showed a significant decrease in the H/M ratio after both contact and sham acupunctures in both stimulated and unstimulated limbs. The H/M ratio decrease indicates a decreased overall percentage of activated α-motor neurons. Our results therefore suggest that gentle cutaneous stimulation could reduce α-motor neuron excitability at rest under some conditions.
