The most important diagnostic study in the evaluation of peripheral nerve problems is electromyography (EMG) with nerve conduction studies (NCS). This study provides accurate, quantitative information on the function of nerves and muscles. Sometimes it is the only way to reliably localize a lesion, quite crucial if surgery is being contemplated. Unfortunately, this study can make some patients uncomfortable, as it involves placement of tiny needles into the muscles. Most patients, however, tolerate the procedure just fine.

Patients who have peripheral nerve tumors almost invariably require an MRI. This study uses harmless magnets (NOT ionizing radiation) to created highly detailed pictures of the relevant anatomy, including the tumor. Such detailed pictures facilitate the planning of surgery to treat peripheral nerve tumors.

CT myelography is used to evaluate brachial plexus traumatic injuries. The brachial plexus represents the network of neural structures that connects the nerve roots exiting the spinal cord in the neck to the individual nerves in the shoulder and arm. Patients who have suffered severe brachial plexus trauma may actually have one or more avulsion injuries, in which the nerve roots are actually pulled out from the spinal cord in the neck. A CT myelogram is really the only way to reliably document this type of injury. To perform a CT myelogram, contrast dye is injected along into the spinal canal. Then spinal X-rays and a spine CT is performed.