SYMPATHETIC SKIN-RESPONSE IN DIABETIC NEU ROPATHY

The sympathetic skin response was measured in 30 diabetic subjects wit h clinical signs of polyneuropathy and in 30 sex- and age-matched cont rols. Regular responses were obtained in all healthy subjects and the majority of diabetic patients (hand: 94 %, foot: 79%). Mean coefficien ts of variation for repeated measurements were low for latencies (hand : 12 %, foot: 13%), amplitudes showed a comparatively high variation ( 37% and 38%). In the control group mean onset latency was 1.54 +/- 0.2 2 s for hand responses and 2.20 +/- 0.31 s for foot responses. In most diabetic subjects latencies were clearly delayed (hand: p < 0.001), a mplitudes were reduced by half on an average. Subclinical autonomic dy sfunction was found to be an early and consistent feature of diabetic neuropathy. The sympathetic skin response latency (hand) was establish ed as a sensitive electrophysiological parameter in diabetic neuropath y. When using a cut-off value of 1.68 s for the latency of hand respon ses, the correct attribution to diabetic and control group was of high est efficacy (sensitivity and specifity > 90%).