Standard median nerve ultrasound in carpal tunnel syndrome: A retrospective review of 1,021 cases.

OBJECTIVE

Carpal tunnel syndrome (CTS) is diagnosed with electrodiagnostic (EDx) studies. Investigations have examined US cross sectional-area (CSA) and wrist to forearm ratio (WFR) cut-offs for screening EDx abnormalities in patients with suspected CTS. The objective of this study is to determine if these US parameters are effective in a real world population.

METHODS

This is a retrospective review of patients presenting to the Duke Electromyography (EMG) Laboratory during 2013-2014 with a final diagnosis of CTS. US diagnosis of CTS was based upon median nerve cross-sectional area of >9 mm2 and/or wrist-to-forearm ratio of >1.4. EDx studies were the gold standard for diagnosis.

RESULTS

A total of 670 patients and 1,021 extremities were studied. US was positive in 97.6% of EDx confirmed CTS.

CONCLUSION

Median nerve US is nearly as sensitive as the gold standard for EDx testing for the diagnosis of CTS.

SIGNIFICANCE: The data here suggest that US may have use as a screening tool prior to performing EDx testing for CTS.