Current perception thresholds: a new, quick, and reproducible method for the assessment of peripheral neuropathy in diabetes mellitus.

The Neurometer is a variable constant current sine wave stimulator, and has recently been proposed as a simple non-invasive and quantitative measure of peripheral nerve function. The device is portable and battery operated; assessment of upper and lower extremities takes only a few min, in contrast to conventional assessment techniques. In order to assess its potential in the quantification of diabetic neuropathy, detection thresholds for constant current electric sine wave stimulation were measured at three different frequencies in different sites in 31 healthy control subjects and 90 diabetic patients with and without neuropathy. The device provides good discrimination between neuropathic and non-neuropathic groups (p less than 0.001) and is quick and easy to use. Comparisons with results of conventional tests of nerve function show that high frequency detection thresholds correlate best with tests of large fibre function (r = 0.42-0.69, p less than 0.001), and low frequency detection thresholds correlate with tests of small fibre function (r = 0.34-0.46, p less than 0.005). It is concluded that the device may be a simple and comprehensive way of assessing peripheral nerve function.