Comparison of the utility of sympathetic skin response and current perception threshold examinations with conventional examinations for the early electrophysiological diagnosis of diabetic polyneuropathy.

摘要

We compared the utility of sympathetic skin response (SSR) and current perception threshold (CPT) with that of conventional electrophysiological examinations like sural sensory conduction velocity, sensory nerve action potential (SNAP), peroneal motor conduction velocity, compound muscle action potentials, and F-wave latency. Twenty-two type II diabetic patients (mean age, 69.6 years) without sensory symptoms and with a mean glycosylated hemoglobin (HbA1c) level of 7.1%, along with 26 age-matched control patients, were examined. Among the conventional examinations, only the sural SNAP was considerably (although not significantly) depressed in the diabetic group. On the other hand, the mean SSR amplitude in the diabetic group was approximately half of the value in the control group. All the CPT values were also considerably lower in the diabetic group than in the control group, although only the values for hand stimulation at 2000 and 250 Hz were significant. No correlations were observed between the SSR amplitudes and the CPT values at any of the test frequencies. However, a positive correlation between the mean HbA1c level and the CPT value was seen at all frequencies. We concluded that SSR amplitude measurements are superior to conventional examinations and CPT studies with regard to the early electrophysiological diagnosis of diabetic polyneuropathy. Furthermore, CPT values may be useful as an electrophysiological surrogate indicator of recent glycemic control.