Comparison of proximal and distal corticosteroid injections for carpal tunnel syndrome.

INTRODUCTION: Evidence for the efficacy of distal corticosteroid injection compared with proximal injection in carpal tunnel syndrome (CTS) is inadequate. METHODS: We conducted a randomized, double-blind noninferiority trial of 131 wrists with CTS. Forty milligrams of methylprednisolone was injected medial to the palmaris longus tendon 2 cm proximal to the wrist crease, or at the volar aspect, 2 to 3 cm distal to the wrist crease. Proximal & distal groups received a placebo. The primary outcome was difference in CTS Symptom Severity Scale (SSS) score at 1 month. Secondary outcome measures included the difference in SSS score at 3 months, Functional Status Scale (FSS) score at 1 and 3 months, and pain of injections. RESULTS: No significant differences were noted between groups in scores on the SSS and FSS. Pain was lower in the proximal group compared with the distal group. DISCUSSION: Corticosteroid injections for CTS distal to the wrist are not inferior to proximal injections, yet they are more painful.

Role of Ultrasound to Monitor Patients With Carpal Tunnel Syndrome Treated With a Local Corticosteroid.

OBJECTIVES: Carpal tunnel syndrome (CTS) is an entrapment neuropathy resulting from compression of the median nerve at the carpal tunnel (CT). We assessed the role of high-resolution ultrasound (US) in monitoring patients with CTS treated with corticosteroid injection. METHODS: We performed high-resolution US evaluations of the wrists of patients with CTS before and after treatment with local corticosteroid. Thirty-nine and 17 wrists were included for analysis at the end of 1 and 3 months, respectively. The cross-sectional area (CSA) and anteroposterior diameter (APD) of the median nerve at the CT and clinical and electrophysiologic data were recorded. We assessed whether changes in US measurements before and after the treatment correlated with clinical and electrophysiologic parameters. RESULTS: The Boston symptom severity scale (p < .01), Boston functional status scale (p < .01), median nerve motor latency (p = .017), median nerve sensory velocity (p = .003), and difference in motor latencies (p = 0.03) and difference in sensory latencies (p = .03) between median and ulnar nerves showed significant changes over 1 or/and 3 months compared to baseline values. Changes in the CSA and APD correlated with changes in some clinical and electrophysiologic parameters. However, measurements of the CSA and APD at 1 or 3 months were not significantly different from baseline values. CONCLUSIONS: High-resolution US parameters such as the APD and CSA of the median nerve at the CT inlet were not useful to monitor patients with CTS treated with corticosteroid injections.