There are few disorders on the differential diagnosis for carpal tunnel syndrome. Cervical radiculopathy can be mistaken for carpal tunnel syndrome since it can also cause abnormal or painful sensations in the hands and wrist.  In contrast to carpal tunnel syndrome, the symptoms of cervical radiculopathy usually begins in the neck and travels down the affected arm and may be worsened by neck movement.  Electromyography and imaging of the cervical spine can help to differentiate cervical radiculopathy from carpal tunnel syndrome if the diagnosis is unclear.  Carpal tunnel syndrome is sometimes applied as a label to anyone with pain, numbness, swelling, and/or burning in the radial side of the hands and/or wrists. When pain is the primary symptom, carpal tunnel syndrome is unlikely to be the source of the symptoms.  As a whole, the medical community is not currently embracing or accepting trigger point theories due to lack of scientific evidence supporting their effectiveness.
Why is this happening? High dose steroids are bad news. While this stuff is injected with wild abandon because it’s a potent anti-inflammatory, it’s also very toxic to local tissue and cells. In addition, the vast majority of carpal tunnel injections are performed blind, which is also not a good idea. It’s quite easy to hit the very superficial median nerve and inject toxic steroid into the nerve itself. IMHO, all of these carpal tunnel injections should be performed under ultrasound guidance so that the doctor can easily see the nerve and the needle and regrettably, this is rarely the case.
All of the listed physical exam findings, except for loss of small digit adduction (Wartenberg sign), has been found to be predictive for diagnosing carpal tunnel syndrome.
Szabo et al in a Level 3 study used a regression model to analyze the most predictive factors for correctly diagnosing carpal tunnel syndrome (CTS). Their analysis found that with an abnormal hand diagram, abnormal sensibility by Semmes-Weinstein testing in wrist-neutral position, a positive Durkan's test, and night pain, the probability that carpal tunnel syndrome will be correctly diagnosed is . They found the tests with the highest sensitivity were Durkan's compression test (89%), Semmes-Weinstein testing after Phalen's maneuver (83%), and hand diagram scores (76%). Night pain was a sensitive symptom predictor (96%). The most specific tests were the hand diagram (76%) and Tinel's sign (71%). The authors concluded that the addition of electrodiagnostic tests did not increase the diagnostic power of the combination of these 4 clinical tests, and proceeding with surgical release is appropriate even if the EMG is normal.
Wartenberg sign is persistent abduction and extension of the small digit when a patient is asked to adduct the digits and is seen in cubital tunnel syndrome, but not carpal tunnel syndrome.
Illustration V demonstrate the Durkan's Compression test for carpal tunnel syndrome.