Reply to "intraoperative dynamic pressure measurements in carpal tunnel syndrome: correlations with clinical signs"

We have read with high attention the paper of Lee et al. entitled “Intraoperative dynamic pressure measurements in carpal tunnel syndrome: Correlations with clinical signs” [1]. The authors have pre- and postoperatively assessed the carpal tunnel pressure in neutral position, passive flexion and passive extension. This dynamic evaluation of carpal tunnel pressure could be important to understand the association between the changes in pressure and carpal tunnel syndrome (CTS) symptoms and, consequently, the best surgical management. The paper is very interesting because it provides tools to better understand the pathological events that occur in CTS. However, the findings of this study are focused on the functional aspects of CTS. In future, correlations between tunnel pressure, nerve morphological changes and relationship between nerve and surrounding structures should be desirable. The use of imaging may be considered for this type of evaluation. In particular, the dynamic morphological evaluation of nerves can be performed by the use of ultrasound (US). This tool allows visualizing and measuring median nerve in carpal tunnel. Furthermore, it is possible changing the position of wrist (neutral, flexed and extended), to assess the relationship between median nerve and other structures, and register the modification of nerve dimensions, in terms of cross sectional area and antero-posterior and latero-lateral diameters [2]. This assessment let us know, for example, the point where the nerve presents the greatest compression and likely the greatest suffering. Finally, US is well-tolerated and relatively fast technique, which is usually used for surgical planning and in follow-up after operation. Moreover, US may be considered as a guide for the catheter positioning, as in authors’ study, and especially for the depiction of anatomical variations (i.e. bifid median nerve, accessory muscles, etc.) [3,4]. The possible integration of these above mentioned values and the values of carpal tunnel pressure may give morphofunctional information useful for a comprehensive understandi