Characteristics of Sympathetic Skin Response in Healthy Humans

Lee, Kyoung Min

Abstract

Although electrodiagnostic sympathetic skin response (SSR) has been widely assessed the detail procedure, such as filter setting and stimulus intensity, has not been standardized yet. This study was performed to establish optimal settings for SSR recording. In 18 healthy subjects, SSRs were recorded in the left hand while stimulating the right median nerve. The data were analyzed for frequency and amplitude domains and statistically evaluated using the methods of analysis of variance (ANOVA) and regression analysis. The peak frequency of SSR signal was 18.59?8.26 Hz, and the frequency of major signals ranged from 0.5 to 2 Hz. The amplitude of SSR was linearly regressed on the intensity of electical stimulus according to the equation: y=2.60x+277.89 (p<0.05). The latency of SSR was linearly decreased with the intensity of electrical stimulus with the relationship: y=1445.46+/-1.60x (p<0.05). On the bases of these results, we conclude that a proper filter setting for SSR measurement would be 1-100 Hz, and at stimulus intensity below 128 mV, the higher the stimulus intensity, the amplitude was bigger and the latency was shorter.