Needle EMG
For this part of the test, a small, thin needle is put in several muscles to see if there are any problems. It is used once for each patient and is thrown away after the test. There may be a small amount of pain during this part of the examination. The doctor tests only the muscles necessary to decide what is wrong. During the EMG test the doctor will be able to hear and see how your muscles and nerves are working by the electrical signals made by your muscles. The doctor then uses his medical knowledge to figure out what could be causing your problem.

Nerve conduction studies
Nerve conduction studies (NCSs) show how well the body’s electrical  signals are traveling to a nerve. This is done by applying small electrical shocks to the nerve and recording how the nerve works. These shocks cause a quick, mild, tingling feeling. The doctor may test several nerves.

Evoked potentials
Evoked potentials are painless tests that check the nerve pathways through the spinal cord or from the eyes and ears. The signals for these tests can come from small electrical shocks, light pulses, or clicks of sound in the ears. The nerve responses are recorded over the scalp and other areas of skin.