The role of ultrasound in the diagnosis and evaluation of diabetic neuropathy in nerve roots of the foot

Background
Neuropathies are characterized by a progressive loss of nerve fiber function. Diabetic peripheral neuropathy is the presence of symptoms and/or signs of peripheral nerve dysfunction in people with diabetes after exclusion of other causes. The diagnosis of diabetic neuropathy is based primarily on characteristic symptoms and is confirmed with nerve conduction studies (NCS), which are time-consuming, slightly invasive, and occasionally not well tolerated for repeated evaluations. In contrast, ultrasonographic (US) examinations can be performed to assess peripheral nerves with less discomfort and have already been used for the evaluation of several disorders of the peripheral nervous system such as carpal tunnel syndrome.
Patients and methods
A total of 50 patients were included in the study, with 40 patients with type 2 diabetes and 10 controls. All cases underwent clinical history, local clinical examination, NCS, and real-time high-resolution US.
Ultrasound examination
The patients were examined in supine position, and the foot was bolstered with a pillow to expose the anterior and medial portion of the lower leg and foot. The transducer was placed immediately above the medial malleolus to locate the tibial nerve in the transverse (short axis) and the longitudinal (long axis) views. The 5.0–12.0-MHz multifrequency linear array probe was used for tibial nerve scanning. The instrument used was Philips HD3 ultrasound scanner.
Result
There was a statistically significant difference between case and controls regarding US cross-sectional area done for right and left tibial nerves, with high mean among cases (0.18±0.02 and 0.17±0.02, respectively). There was a statistically significant difference between US and NCS. There was no statistically significant difference between the two groups regarding the other measurements.
Conclusion
High-resolution US can be used as adjuvant tool for the NCS for diabetic patients suspected to have neuropathy.