Correspondence between clinical presentation and electrophysiological testing for potential carpal tunnel syndrome.

The diagnosis of carpal tunnel syndrome (CTS) is often applied in the absence of objectively verifiable pathophysiology (i.e. electrophysiologically normal carpal tunnel syndrome). The primary purpose of this study was to determine whether depressive symptoms, heightened illness concern, and pain catastrophizing are associated with an absence of electrophysiological abnormalities. The secondary purpose was to examine the correspondence between the Levine scale, the CTS-6, and electrophysiological abnormalities. Ninety-eight participants completed validated questionnaires assessing psychosocial factors at the initial visit, and surgeons recorded clinical data and their confidence that the diagnosis was carpal tunnel syndrome. Symptoms and signs that are characteristic of carpal tunnel syndrome (e.g. the CTS-6 and Levine scale) significantly, but incompletely coincided with electrophysiological testing. Psychological factors did not help distinguish patients with normal and abnormal objective testing and it remains unclear if symptoms that do not coincide with abnormal tests represent very mild, immeasurable median nerve dysfunction or a different illness altogether. Future studies should address whether outcomes are superior and resource utilization is optimized when surgery is offered based on symptoms and signs (e.g. the CTS-6) or when surgery is offered on the basis of measurable pathophysiology.