Clinical and electrophysiological follow-up after local steroid injection in the carpal tunnel syndrome

Objective Local steroid injections are used for treatment for the carpal tunnel syndrome (CTS). Study of changes in neurophysiological parameters after such treatment for idiopathic CTS might be a supportive argument for the effectiveness of steroid treatment. Methods Twenty-one patients with CTS were included and evaluated before and at 1, 3 and 6 months after treatment. At the inclusion date patients received a single 1 ml local steroid injection. Various electrophysiological tests were used. For clinical evaluation, we used the Boston Carpal Tunnel Questionnaire (BCTQ) and the General Outcome Score. Results The mean nerve conduction parameters had significantly improved at 1 month, except the SNAP4 and CMAP. This improvement was still present at 3 months. At 6 months follow-up, the improvement in the SDL4, SNAP4, M-U, DML and CMAP remained significant. In 6 patients (29%), the nerve conduction parameters normalized and remained so until the end of the study. The BCTQ and the General Outcome Score significantly improved as well. However, there was no correlation between the electrophysiological data, the BCTQ and the General Outcome Score. Conclusions The improvements of nerve conduction parameters independently support the ideas on effectiveness of steroid injection therapy in CTS.