Diagnosis of diabetic polyneuropathy in type 2 diabetes mellitus: focus on changes in peripheral nerves according to ultrasonic research method

BACKGROUND: Diabetic polyneuropathy remains a significant and urgent problem in the context of diabetes mellitus, affecting more than a quarter of patients with type 2 diabetes mellitus. Currently, the method of peripheral nerve examination using ultrasound is gaining worldwide popularity. In the Russian Federation, however, it remains widely used only in some medical institutions. The ultrasound method employs the indicator “nerve cross-sectional area” to diagnose this complication, exhibiting a high degree of sensitivity (93%) in comparison to magnetic resonance imaging data (67%). Foreign and Russian studies [3, 4] confirm the observed increase in the cross-sectional area of the nerve in patients with diabetes mellitus. AIM: The study aimed to assess the diagnostic value of the ultrasound method of peripheral nerve examination in the detection of diabetic polyneuropathy in patients with type 2 diabetes mellitus. MATERIALS AND METHODS: The Philips Epiq 7 ultrasonic diagnostic device (USA) with a linear transducer, operating at a frequency of 4–18 MHz, was used. The comparison group consisted of 30 volunteers. The main group comprised 25 patients with type 2 diabetes mellitus and confirmed diabetic polyneuropathy, as determined by electroneuromyography and physical examination methods. The median cross-sectional area of the sciatic and common peroneal nerves in patients with type 2 diabetes mellitus and healthy volunteers was calculated. The criterion for a difference in area values was calculated using the Mann-Whitney test. RESULTS: The cross-sectional area thresholds were determined based on the 95th percentile of a cohort of healthy volunteers. In patients with type 2 diabetes mellitus, the following median nerve cross-sectional area values were found: for the sciatic nerve, 0.579 cm2 (at the gluteal crease) and 0.553 cm2 (2 cm proximal to the bifurcation); for the common peroneal nerve, 0.11 cm2 (1 cm distal to the bifurcation of the sciatic nerve) and 0.08 cm2 (at the level of the head of the fibula). In healthy volunteers, the values were as follows: for the sciatic nerve, 0.46 cm2 (at the gluteal crease) and 0.37 cm2 (2 cm proximal to the bifurcation); for the common peroneal nerve, 0.08 cm2 (1 cm distal to the bifurcation of the sciatic nerve) and 0.06 cm2 (at the level of the head of the fibula). A significant difference was found between the control and target groups using the Mann-Whitney test (p 0.01). CONCLUSIONS: In patients with type 2 diabetes mellitus and diabetic polyneuropathy, a significant increase in the cross-sectional area of the nerves of the lower extremities (sciatic and peroneal nerves) was revealed, which allows for the use of ultrasound as an additional method for the instrumental diagnosis of diabetic polyneuropathy. However, due to the small sample size, further study is required to confirm these findings.