Peripheral sympathetic neuropathy evaluated by recording the evoked electrodermal response using an impedance reactometer.

Autonomic nervous dysfunction was indirectly evaluated on the basis of the skin electrical resistance relative variation (SERV), recorded by our recently developed system, with two pairs of surface electrodes placed on the palm and on the sole of the foot, after the application to the subject of a sensory stimulus (sound 60 dB, 860 Hz, 0.5 s duration) or in the course of a Valsalva manoeuvre. The results were digitally measured and recorded on thermosensitive millimetric paper analysing the following parameters: latency (LT), i.e. the time interval(s) between application of the stimulus and onset of SERV, both at palm (LTh) and foot (LTf); amplitude of the response (mm) recorded and evaluated in the form of SERV; velocity of the response as rate of time change (Vr) and autonomic conduction velocity, -ACV (m/s), calculated by the height/LT ratio. The present study refers to a group of 60 diabetic patients: 32 F/28 M; mean age +/- SD 46.8 +/- 11.8 years; 29 insulin-dependent, 21 non-insulin-dependent; duration of diabetes 8.6 +/- 4.6 years. The data were compared to those recorded in a group of 50 nondiabetics (22 F/28 M; mean age 47.5 +/- 14.1 years) who were apparently healthy. A significant statistical difference (P less than 0.001) was found between diabetic patients and controls for all studied parameters: LTh (s) 2.65 +/- 1.2 vs. 1.91 +/- 0.6; LTf(s) 3.6 +/- 1.4 vs. 2.6 +/- 0.7; SERV (mm) 7.5 +/- 4.8 vs. 18.5 +/- 6.6; Vr (mm) 4.4 +/- 2.1 vs. 13.5 +/- 5.3; ACT (m/s) 0.41 +/- 0.23 vs. 0.97 +/- 0.18.(ABSTRACT TRUNCATED AT 250 WORDS)