[Sympathetic skin response: reference data for 100 normal subjects].

INTRODUCTION. The sympathetic skin response (SSR) has been used since its description in 1984 to test the integrity of the sympathetic autonomic nervous system to investigate peripheral and central nervous system diseases. AIM. To present a neurophysiological examination protocol for SSR and the normal parameters for a population of 100 normal subjects. SUBJECTS AND METHODS. To evaluate the characteristics of 200 SSR tests for 100 normal subjects adequately informed: latency, amplitude (peak to peak) and persistence. The subject lays supine and relaxed, with no visual nor auditory stimuli for several minutes. Cutaneous electrodes are used for stimulation and recording, the latter in palm (active) and back (reference) in both hands simultaneously (second interosseous space). The stimulus is applied in the glabela at irregular intervals. RESULTS. We studied 100 normal subjects aged 12 to 89 years (mean: 45.6), 21 men and 79 women. The parameters measured in the 200 SSR are: latency, 1.42 ± 0.03 s; amplitude, 2.44 ± 1.84 mV; persistence, 67.2 ± 19.8%. CONCLUSIONS. SSR is an objective, reproducible, measurable, easy to perform and unpainful for the patient and serves as a basis for further study of other diseases in which there is a dysfunction of the sympathetic autonomic nervous system.