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

Abstract

ObjectiveCarpal 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. MethodsThis 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 >9mm2 and/or wrist-to-forearm ratio of >1.4. EDx studies were the gold standard for diagnosis. ResultsA total of 670 patients and 1,021 extremities were studied. US was positive in 97.6% of EDx confirmed CTS. ConclusionMedian nerve US is nearly as sensitive as the gold standard for EDx testing for the diagnosis of CTS. SignificanceThe data here suggest that US may have use as a screening tool prior to performing EDx testing for CTS.