Nerve sonography to detect intraneural microvascularity in patients with peripheral neuropathy

•Increased intraneural microvascular could be detected in patients with peripheral neuropathies using sonography.•Intraneural hypervascularization was frequently observed in patients with inflammatory neuropathies.•Superb microvascular imaging is the most sensitive technique for evaluating microvessel flow within peripheral nerves. We assessed microvessel flow within peripheral nerves using nerve sonography in patients with peripheral neuropathy. This study included consecutive patients with peripheral neuropathy who were admitted to our hospital. The patients were divided into two groups: inflammatory neuropathies for immune-mediated neuropathies, such as Guillain − Barré syndrome and chronic inflammatory demyelinating polyneuropathy, and the rest were defined as non-inflammatory neuropathies. We assessed nerve size and intraneural blood flow at four sites on each median and ulnar nerve. Blood flow was evaluated using color Doppler imaging, advanced dynamic flow (ADF), and superb microvascular imaging (SMI) techniques. Thirty-nine patients (median age, 60.0 years; 20 male) were enrolled in this study. An increase in intraneural blood flow was observed in five patients when evaluated by color Doppler, five patients by ADF, and 13 patients by SMI. An overall analysis of the three methods showed that intraneural blood flow was significantly higher in patients with inflammatory neuropathy than in those with non-inflammatory neuropathy (54.2% vs. 0%, p = 0.0005). Intraneural hypervascularization is more frequent in patients with inflammatory neuropathy than in those with non-inflammatory neuropathy. Evaluation of microvessel flow within peripheral nerves may contribute to the diagnosis of peripheral neuropathy.