Correlation between nerve conduction studies and clinical scores in diabetic neuropathy

Polyneuropathy, a frequent complication of diabetes, can be assessed clinically and electrophysiologically. Neurological examination can be quantified by validated scores, e.g., the neuropathy symptom score (NSS) or the neuropathy disability score (NDS). Such scores exclude electrophysiological aspects of the neuropathy. A software tool was designed to convert electrophysiological data into one single index of polyneuropathy (IPN). This index was calibrated to grade the severity of a polyneuropathy from 0.00 to 1.00. In a series of 38 diabetic patients, we have calculated NSS, NDS, and IPN. We found correlations between these variables, NDS and IPN exhibiting the more significant association. The use of IPN allowed us to demonstrate that nerve conduction values correlated with clinical scores in diabetic polyneuropathy. Such a software tool, by providing a single electrophysiological index, may facilitate clinico-electrophysiological assessment in large descriptive studies or therapeutic trials of diabetic polyneuropathy.