I'm having a a nerve conduction studies test for possible cts will this show if the problem is in my neck or shoulder?

Discuss with MD. The nerve conduction study (ncs) will measure the speed of a signal through a nerve after being stimulated, this test is often coupled with an electromyogram (EMG) which can help us determine muscle involvement after prolonged decreased conduction from the neck. Symptoms can be from both the neck and wrist, these are tools that your doc may use with physical exam and history to help diagnose.