Ultrasound-Guided Carpal Tunnel Injection

Michael N. Brown

Michael Gofeld

Background and indications: Carpal tunnel syndrome (CTS) is the most frequent entrapment mononeuropathy due to the compression of the median nerve at the wrist. The clinical examination, consisting of a history, physical examination, and provocative tests, has been considered sufficient for CTS diagnosis. Ultrasound has been extensively studied as an alternative tool to diagnose CTS.¹ Ultrasonography is operator-dependent, but shows high reproducibility after adequate training. It is not an alternative diagnostic tool to electrodiagnostic tests and vice versa in CTS, but they are complementary; one provides anatomic information of the nerve and its surrounding structures, whereas the other provides information on the level of the lesion and the function of the nerve fibers with the largest diameters.²

Cochrane data shows that local corticosteroid injections for CTS provide symptom relief for 1 month.³ Symptom relief beyond 1 month compared to placebo has not been demonstrated. Further research is required to determine the length of benefit of a local corticosteroid injection and the benefit for mild and moderate CTS. The corticosteroid injection should be only a component of the comprehensive management of CTS.