Peroneal neuropathy after weight loss: a high-resolution ultrasonographic characterization of the common peroneal nerve

The objective of this study was to use in vivo ultrasonographic imaging to analyze the common peroneal nerve in controls and patients who were diagnosed with peroneal neuropathy (PN) due to significant weight loss. We also looked for a relationship between weight loss (magnitude) and the occurrence of PN. Fifty controls and six patients who were diagnosed with PN after losing a significant amount of weight were examined by means of ultrasonography (US). On the US images, the structure and reflectivity of the nerve were analyzed. Correlations were made between the ultrasonographic measurements and the body mass index (BMI) of controls. In PN patients, these ultrasonographic parameters were compared between the normal and pathological legs. BMI was positively correlated with the transverse cross-sectional area of the nerve and fibular tunnel in controls. In controls with a high BMI, the peroneal nerve appeared thicker and the US reflectivity of the nerve was higher. A lower US reflectivity was observed in the pathological legs of the six patients who developed PN after weight loss. The transverse cross-sectional area and reflectivity of the peroneal nerve on the US images could be viable tools in the diagnosis of PN after weight loss.