High-resolution ultrasonography of the sural nerve in diabetic peripheral neuropathy

To study the cross-sectional area, the maximum thickness of the nerve fascicle and the thickness/width ratio of the sural nerve in patients with diabetes mellitus and non-diabetic subjects using high-resolution ultrasonography and to correlate the results with nerve conduction studies. Material and methods: This prospective study was conducted among 60 patients divided into two groups: A and B. Group A consisted of 30 patients >18 years of age with a history of type 2 diabetes mellitus, and Group B consisted of 30 nondiabetic patients >18 years of age. High-resolution ultrasonography was performed using a linear transducer with the frequency of 5-18 MHz in all the patients in the prone position with the transducer placed in a transverse position at the junction of the middle and lower thirds of the calf. Nerve conduction studies were performed using Aleron 201 (RMS) in all the patients. Results: As compared to the control group, the sural nerve in the diabetic group showed increased cross-sectional area, maximum thickness of the nerve fascicle and thickness/width ratio (p <0.05). Nerve conduction studies showed decreased amplitude, increased latency and decreased velocity in the cases as compared to controls (p <0.05). The crosssectional area, maximum thickness of the nerve fascicle and thickness/width ratio showed statistical significance when compared with amplitude, latency and velocity in the cases as well as controls (p <0.001). Conclusion: This study suggests that high-frequency ultrasound of the sural nerve is a useful tool for evaluating changes typical of peripheral neuropathy in patients with diabetes mellitus.