Electrophysiological responsiveness and clinical outcomes of local corticosteroid injection in the treatment of carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is the most common mononeuropathy caused by entrapment of the median nerve at the wrist. Common treatment options for CTS include oral analgesics, splinting, hand therapy, local injections with steroids or surgery. Objective: The aim of the present study was to assess the short-term clinical and electrophysiological outcomes of local corticosteroid injection (LCI) in patients with symptomatic CTS. Methods: Electrophysiological parameters were evaluated before and three months after LCI. Moreover, the Numeric Rating Scale (NRS), the Boston Symptom Severity Scale (SSS) and the Functional Status Scale (FSS) were administered before and after the injection. A mixture of 1 mL (40 mg) of methylprednisolone and 1 mL of 0.5% bupivacaine were injected blindly on the volar side of the forearm between the tendons of the radial carpal flexor muscle and long palmar muscle. Results: A total of 25 patients (45 hands) were enrolled in the study. Twenty women and five men with a mean age of 49.28 +/- 11.37 years were included. A statistically significant difference was noted for improvement of sensory conduction velocities, sensory peak latency, and motor distal latency (p = 0.001) after LCI. A significant difference was recorded between pre-and post-injection for NRS, SSS and FSS scores (p = 0.000). Conclusion: Local corticosteroid injection for CTS provides a short-term improvement in neurophysiological and clinical outcomes such as pain intensity, symptom severity and functional ability.