Relationship between ultrasound measurements of the median nerve and electrophysiological severity in carpal tunnel syndrome

Introduction. Ultrasonography is a tool that has advanced a great deal in the diagnosis of neural compressive pathologies, such as carpal tunnel syndrome (CTS). In order to plan the treatment it is important to establish the severity of the pathology, which means that it would be important to know the capacity of ultrasonography to determine the extent to which the median nerve is compromised at this level. Aim. To investigate the correlation between ultrasound measurements and electrophysiological severity in patients with CTS. Patients and methods. Ultrasound measurements were performed with 59 subjects (97 wrists) who were referred to have an electroneurogram (ENG) due to suspected CTS. According to the ENG, the subjects were classified as healthy, mild, moderate or severe CTS. The relationship between the ultrasound measurements and the results of the ENG were later analysed in terms of their severity. The ROC (receiver operating characteristic) curves were calculated for the optimal cutoff values in each group, taking into account their severity. Results. Both ultrasound measurements showed a correlation with the severity of the CTS determined by ENG. The cross-sectional area of the median nerve in the wrist (CSA-W) showed the highest correlation (r = 0.613). Conclusions. There is a relation between the ultrasound measurements of the median nerve, especially in the CSA-W, and the severity of CTS in the clinical context. These measurements could be used as complementary data to diagnose CTS and to determine its severity.