Is it CTS or Double Crush Syndrome?

Many patients with carpal tunnel syndrome (CTS) may also have median nerve entrapments further up the course of the nerve (in the neck, shoulder, elbow, etc). When the median nerve is encumbered at two anatomical locations, it’s described as a double crush syndrome (DCS). In this study, researchers compared the results of nerve conduction velocity (NCV) tests on patients with CTS and patients with CTS and cervical spondylotic radiculopathy (an example of DCS). The results showed worse nerve function in the patients with DCS, supporting the possibility of more severe CTS symptoms with a lower likelihood of resolution if treatment only focused on the wrist.
Journal of the Chinese Medical Association, September 2015