Can Sonography Replace Electromyography and Nerve Conduction Velocity in Carpal Tunnel Syndrome?

Purpose of the Study: To justify the efficacy of the ultrasonography (US) in the diagnosis of carpal tunnel syndrome (CTS) in the postoperative follow-up in comparison to electrodiagnostic tests [electromyography (EMG) and nerve conduction velocity (NCV)].

Patients and Methods: One hundred CTS patients were documented through clinically, electrophysiologically, and intraoperatively grading by using the Tuncali grading system (TGS), in Mansoura University Hospital, Insurance Hospital, and EL Ahrar, during the period of April 2014 till March 2015. All patients were evaluated pre and postoperatively by both the gold standard invasive electrodiagnostic (EMG, NCV) and the new noninvasive US tests.

Results: All of the 100 CTS cases (24 men, 76 women) showed improvement in pain after releasing incisions (TGS grades 2 and 3). The CTS diagnosis by electrodiagnostic (EMG and NCV) were 90 positive and 10 negative. However, by the US were 86 positive and 14 negative. Six months after surgery, electrodiagnostic tests (EMG and NCV) had improved in 74% of cases, but with US, it showed improvement in the cross-sectional area (CSA) swelling of median nerve after three weeks in 64 CTS cases (64%). The sensitivity and the specificities were 90% and 79.2% for NCV respectively while for the US were 86% and 77.4% respectively.

Conclusion: US showed improvement of morphological criteria (within 3 weeks) than the betterment of the function by electrodiagnostic (after 6 months) in the postoperative follow-up of CTS cases. Therefore, US examination for CTS can possibly be done without the need for other invasive investigations.