A systematic review of the utility of electrodiagnostic testing in carpal tunnel syndrome

Carpal tunnel syndrome (CTS) comprises a complex of symptoms in the hand, including pain and paresthesia and weakness of hand muscles thought to result from compression of the median nerve. Many clinicians either refer patients for electrodiagnostic studies to aid diagnosis or conduct electrodiagnostic studies, which may be useful as an aid to decisions on treatment. The aim of this systematic review is to evaluate the evidence base for the use of electrodiagnostic tests in the diagnosis and management of carpal tunnel syndrome. A systematic search was undertaken for studies that included patients with clinical diagnosis of CT5 who were undergoing electrodiagnostic tests and surgery together with reported outcomes of surgery. A published systematic review found that electrodiagnosis was not a useful diagnostic test in patients with clinical signs of CTS. Seven primary studies of prognosis reporting electrodiagnosis and surgery outcomes were found, however, one of them was subsequently retracted. The remaining six were retrospective case senes of poor quality. Four of these studies reported outcomes of surgery in patients with clinically identified CTS, comparing both positive or negative electrodiagnostic results. No study found any statistical difference in surgical outcome between those who were electrodiagnostic test positive and those who were negative. Despite the limited quality of the evidence, in cases of clear-cut clinical CTS, electrodiagnosis is not warranted either as a diagnostic test, where clinical symptoms are well defined, or as a predictive indicator of surgical outcome. It may still be useful in cases where the clinical diagnosis is not clear.