[Sympathetic skin response--physiologic principles, normal values and clinical use]

Sympathetic skin reflex (SSR) was evaluated in the lower extremities of 60 normal volunteers aged 17 to 72 (mean age 38 +/- 16 years, 28 females, 32 males). SSR was obtainable in all volunteers and most often consisted of a biphasic wave with initial negative deflection. Mean latency was 2.16 +/- 0.20 s. Mean variation in a second repetitive measurement was 0.21 +/- 0.14 s. The SSR was not age- or sex dependent. There was a weak positive correlation of the SSR with the height of the volunteers (r = 0.271; p = 0.037). SSR was investigated in 39 patients with polyneuropathy (age 59 +/- 18). SSR was pathological in 51% on one or both legs. There was no correlation of the SSR to the aetiology nor to the type of lesion (axonal versus demyelinating polyneuropathy) nor to clinical symptoms. The applicability of the SSR is reviewed from the literature regarding polyneuropathy, erectile dysfunction, central degenerative diseases, multiple sclerosis, sympathetic reflex dystrophies, spinal and peripheral nerve lesions. SSR is briefly compared to alternative methods. SSR appears to be a reasonable method to describe a small section of the autonomic nervous system (sympathetic sudomotor function) and to calculate group differences. There appears to be no close correlation to any of the autonomic disturbances in individual patients.