Accuracy of in-office nerve conduction studies for median neuropathy: a meta-analysis

Carpal tunnel syndrome is the most common focal neuropathy. It is typically diagnosed clinically and confirmed by abnormal median nerve conduction across the wrist (median neuropathy [MN]). In-office nerve conduction testing devices facilitate performance of nerve conduction studies (NCS) and are used by hand surgeons in the evaluation of patients with upper extremity symptoms. The purpose of this meta-analysis was to determine the diagnostic accuracy of this testing method for MN in symptomatic patients.

We searched the MEDLINE database for prospective cohort studies that evaluated the diagnostic accuracy of in-office NCS for MN in symptomatic patients with traditional electrodiagnostic laboratories as reference standards. We assessed included studies for quality and heterogeneity in diagnostic performance and determined pooled statistical outcome measures when appropriate.

We identified 5 studies with a total of 448 symptomatic hands. The pooled sensitivity and specificity were 0.88 (95% confidence interval [CI], 0.83-0.91) and 0.93 (95% CI, 0.88-0.96), respectively. Specificities exhibited heterogeneity. The diagnostic odds ratios were homogeneous, with a pooled value of 62.0 (95% CI, 30.1-127).

This meta-analysis showed that in-office NCS detects MN with clinically relevant accuracy. Performance was similar to interexaminer agreement for MN within a traditional electrodiagnostic laboratory. There was some variation in diagnostic operating characteristics. Therefore, physicians using this technology should interpret test results within a clinical context and with attention to the pretest probability of MN, rather than in absolute terms.