Waveforms of Sympathetic Skin Response from the Sole Skin

Their Relation to Latency, Amplitude, and Habituation

Abstract

The aim of this study was to investigate the relation of sympathetic skin response (SSR) waveform variation to latency, amplitude, and habituation. Twenty SSRs were recorded from the sole skins of 41 normal subjects by electrical stimulations (0.2ms duration and 20mA in intensity) which were given to the median nerve at the wrist. Waveforms were classified as one of two types, namely, the P type, in which the positive component was larger than the negative, and the N type, in which the negative component was larger than the positive. During successive stimulations, 6 of the 41 subjects had only P type waveforms (P pattern), 14 others only the N type (N pattern), and the remaining 21 both the P and N types (M pattern). Latency, amplitude, and habituation were modified by the appearance patterns of the SSR waveforms. The P pattern had a larger amplitude and shorter latency than the N pattern. Habituationwith time was more pronounced for the M pattern. This was compatible with previously reported results for SSR from the palm skins.