Many patients with T2DM have a late complication at the time of diagnosis,most commonly diabetic peripheral neuropathy (DPN).We explored whether clinical indiced of polyneuropathy correlate with large and small nerve fiber pathology.

The goal of this study is to analyzed various diagnostic techniques for the detection of lesions of nerve fibers in patients with T2DM and subclinical and clinical stages of DNP by electrophysiology study and nerve conduction velocity (NCV),skin biopsy and corneal confocal microscopy (CCM) with use of the author's algorithm for calculating the tortuosity and orientation of the nerve fibers of the cornea.

Materials and methods: Electrophysiological study of large nerve fibers and microscopic examination of small nerve fibers in patients with T2DM with subclinical (n=50) and clinical stages of DPN (n=50) were performed.

Results: The changes in the S-response and in NCV were received the most frequently in patients with subclinical and clinical stages of DPN in the study of the sensory gastrocnemius nerve.At stimulation of the motor nerves,the changes were related to the M-response and NCV of the peroneal and tibial nerves.At skin biopsy,we saw that the intraepidermal nerve fibers density (IENFD) in patients with T2DM was significantly reduced in subclinical and clinical stages of DPN.In the subclinical form of DPN,some values of CCM significant correlate with IENFD and with NCV along the gastrocnemius nerve in the entire studied population,but this correlation was not strong.At symptomatic DPN,a strong correlation was found between IENFD and parameters of NCV (p<0.05),as well as with data of electroneyromyograpry (p<0.05).

Conclusion: The results of the study showed that the changes in large fiber function accompany the loss of small nerve fibers and occurs in patients with T2DM already in the preclinical stage of DPN. CCM can be a powerful tool for non-invasive early diagnosis of neuropathy in subclinical stage DPN.


A. Fokina: None. A. Zilov: None. I. Strokov: None. Z. Surnina: None.

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