Assessment of nerve fibers dysfunction through current perception threshold measurement in diabetic peripheral neuropathy

Abstract

Diabetic neuropathy is a group of clinical syndromes that may occur separately or in various combinations and may affect various components of the nervous system. The involvement of different types of nerve fibers in the natural history of diabetic neuropathy is selective, being considered that the first affected in diabetic neuropathy are small unmyelinated nerve fibers and by measuring the current perceptions threshold (using the Neurometer®) we can quantify the status of three different types of nerve fibers. The aims of our study were to assess diabetic peripheral neuropathy (DPN) by measuring the rapid current perception threshold (R-CPT) using Neurometer, to estimate the prevalence of DPN using this method, and to analyze the possible correlation between R-CPT and clinical, biochemical and metabolic parameters. In our study, 52.6% of patients had abnormal (R-CPT) values to at least one of the three frequencies used (2000 Hz, 250 Hz, 5 Hz). Our results showed higher anthropometric parameters, higher values of glycated hemoglobin (p=0.004) and lipid fractions and higher percentage of diabetic retinopathy (p <0.001) and peripheral artery disease (p = 0.001) in patients with abnormal R-CPT values that in patients with normal values. Hyperesthesia was present in a higher percentage when frequency of 5Hz was applied compared with frequency of 250 Hz or 2000 Hz. We found higher R-CP values in patients with higher diabetes duration and we obtained positive and significant correlation between duration of diabetes and R-CPT values for all three frequencies of alternative current. The results of this study provide valuable information on the types of nerve fibers affected in DPN. The study highlighted a number of positive risk factors associated with the presence of DPN and demonstrated correlations between duration of diabetes and the subpopulation of nerve fibers affected.