In the first place, it is important to understand that all the things we feel-touch, pain, temperature, and even the “pins and needles” sensation of paresthesia-are products of our own brain interpreting the stimuli it receives. So what is going on with these patients? This is a big question, but in this post, I hope to shed a little light as we explore a few of the possible causes for carpal tunnel-esque symptoms (pain, numbness, and tingling in the hands) which lie outside the realm of peripheral nerve dysfunction. Indeed, of the 338 patient records I examined, 14% of those referred with suspicion of CTS had no evidence of nerve damage found with electrodiagnostic testing. A third possibility is that the test may yield normal results. In most of these patients, EMG/NCS serves to confirm the presence of median nerve pathology and to describe how severe it is, but other disorders like radiculopathy and ulnar nerve compromises can also be found masquerading as carpal tunnel syndrome.
Several weeks ago I published a blog describing the kinds of neurologic disorders revealed by electromyography and nerve conduction studies (EMG/NCS) in patients who are suspected of carpal tunnel syndrome (CTS) on clinical grounds.
