A network meta-analysis of randomized controlled trials compared the effectiveness of corticosteroid injections with placebo injections and wrist splints for carpal tunnel syndrome, focusing on symptom relief and median nerve conduction velocity. Within 3 months of the corticosteroid injection, there was a modest statistically significant difference in symptom relief compared to placebo injections and wrist splints, as measured by the Symptom Severity Subscore of the Boston Carpal Tunnel Questionnaire; however, this did not meet the minimum clinically important difference. Pain reduction with corticosteroids was slightly better than with wrist splints, but it also failed to reach clinical significance. Electrodiagnostic assessments showed transient changes in distal motor and sensory latencies in favour of corticosteroids at 3 months, but these changes were not evident at 6 months. The best current evidence suggests that corticosteroid injections provide minimal transient improvement in nerve conduction and symptomatology compared with placebo or wrist splints.
Keywords: Carpal tunnel syndrome; corticosteroids; idiopathic median neuropathy at the carpal tunnel; placebo; splint.