Sympathetic skin responses in different regions of the hand

Objective To investigate the differences of sympathetic skin responses (SSR) in various regions of the hand and its clinical significance. Methods Sixty-four healthy volunteers were involved in the study. SSR was elicited by electrical stimulation and SSR latency and amplitude were recorded on the center of palm, index and little finger pulps, respectively. Statistic analysis of these data was condcuted. Results SSR waveforms could be elicited and recorded on the three regions of the hand in 60 volunteers (4 were excluded). The latencies of SSR of palm, index and little fingers were (1.37± 0.16) s,(1.54± 0.24) s, and (1.60 ± 0.25) s, respectively, the difference of which was statistically significant ( P 0.05) in latency and amplitude between index and little finger pulps. Conclusion Latency is a reliable indicator to assess SSR because of its stability. Index and little finger pulps are sites for recording SSR, which may represent SSR of median and ulnar nerve distribution, respectively. Key words: Electromyography;  Hand;  Sympathetic skin responses