DISCUSSION

The sympathetic skin response is a slow reflex response to internal and external stimuli. It is gaining importance in neurological investigations. The present study showed that maximum amplitude was seen with LF 0.1 Hz and HF = 70 Hz. However, being a slow response the HF filter was of less importance and even with a HF of 15 Hz a good response was seen (Figure 1), though at HF = 15 Hz there were no significant differences between the maximum amplitudes for the three LF settings. Care should be taken to avoid high frequency artifact contamination (e.g., EMG) if HF = 35 or 70 Hz is used.