Reproducibility of different methods for diagnosing and monitoring diabetic neuropathy

Conflicting results have been published concerning the reliability of methods to assess diabetic polyneuropathy. Therefore we compared the reproducibility of nerve conduction studies and quantitative measurements of vibratory sensation in 23 diabetic patients with clinically and/or neurophysiologically established neuropathy. Motor nerve conduction of peroneal and median nerves, sensory nerve conduction of sural and median nerves and vibratory perception thresholds of index fingers and big toes (forced-choice method) were assessed on three occasions with an interval of one to fourteen days, within a period of three weeks. We conclude that both nerve conduction studies and vibratory perception threshold measurements are reproducible methods to assess diabetic neuropathy. Determination of vibration perception thresholds has the advantage of being a simple and unobtrusive method. Nerve conduction studies are less variable and therefore more suited for monitoring diabetic neuropathy.