Abstract
It has been known that sympathetic nerve activity increases to various pain. This study was designed to clarify whether favorite essential oil or music affects sympathetic response to pricking pain and has an effect in relieving pain. Skin conductance level (SCL) and skinblood flow (BF) of palmar side of the finger-tip were measured to evaluate autonomic function in 25 healthy female subjects. Painful stimulation was applied to the antebrachium or brachium by electrical stimulation. Each subject was tested under 5 different conditions, i.e., control, cooling or warming the stimulus site, inhaling essential oil or listening to the music which each subject likes. Visual analogue scale (VAS) was used to evaluate subjective pain sensation. Painful electrical stimulation produced an increase in SCL and a decrease in BF, resulting from increased sympathetic nerve activity. Both autonomic responses were significantly augmented during warming the stimulus site, whereas during cooling both responses were reduced significantly compared to that under control. Autonomic responses decreased by essential oil or music, but they were smaller than that in cooling. Subjective pain sensation by VAS also showed similar results to the autonomic responses. These results suggest that cooling must be the most effective in relieving pricking pain, and that essential oil or music might contribute to the relief of the chronic pain.
