Sympathetic skin response in diabetic polyneuropathic patients triggered by deep inspiration and electrical stimulation

The aims of this study were to compare sympathetic skin response (SSR) latency and amplitudes using deep inspiration and electrical stimulation in healthy subjects. In addition, we wanted to determine the absence of response rate in diabetic patients with polyneuropathy, and to compare latency and amplitude of healthy subjects with that of patients, Thirty-six patients with abnormal nerve conduction measurements were evaluated for sudomotor activity using SSR induced both by deep-inspiration and electrical stimulation. Their SSRs were compared with those of a control group comprised of 36 healthy subjects. Using electrical stimulation, SSR was absent in 24 (67%) patients in the foot and 17 (47%) in the hand. Using deep-inspiration, 21 (58%) patients had no SSR in the foot while only 11 (31%) patients had no SSR in the hand. In the healthy control subjects, SSR latency was significantly longer (p<0.05) during electrical stimulation than deep inspiration. As for polyneuropathic patients with positive SSRs, latency in the hands was significantly longer (p<0.05) than that found in healthy control subjects, and electrical stimulation showed a significantly higher percentage of abnormal hand SSRs (p<0.05) in the patients. The rate of no SSR was higher in the foot of the patients with diabetic polyneuropathy and electrical stimulation had a significantly higher percentage of abnormal SSR in the hands of these patients. The absence of SSR was unquestionably abnormal, however, the application of changes in latency and amplitude to define abnormal SSRs needs further study.