Electromyography (EMG) clinic

Sunnybrook’s policy is that an appropriately trained doctor should do all needle EMG testing. A trained technologist under a doctor’s supervision will do the nerve conduction studies.

Doctors who do EMGs attend four years of medical school then have three or four more years of training in a residency program. Most work as neurologists or physical medicine and rehabilitation doctors.

Medical training helps the doctor decide which tests to perform based on your symptoms.

You are being sent to the electromyography (EMG) lab because you have numbness, tingling, pain, weakness, or muscle cramping. Some of the tests that the EMG doctor may use to diagnose your symptoms are nerve conduction studies (NCSs) and needle EMG. The doctor will examine you to decide which tests to do.

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 technologist may test several nerves during the study.

For this part of the test, a small, thin needle is put in several muscles to see if there are any problems.

A new needle is used for each patient and it is thrown away after the test.

There may be a small amount of pain when the needle is put in. The doctor tests only the muscles necessary to decide what is wrong.

The doctor will look at and listen to the electrical signals that travel from the needle to the EMG machine. The doctor then uses his/her medical knowledge to figure out what could be causing your problem.

The tests usually take 30 to 90 minutes.

You may go about your regular activities, like eating, driving, and exercising, before the tests, and you may resume your normal activities after the tests are complete.

There are no lasting side effects to the tests.

Tell the EMG doctor if you are taking aspirin, blood thinners, have a pacemaker, or have hemophilia.

Prior to the tests, take a bath or shower to remove oil from your skin. Do not use body lotion on the day of the test.

If you have myasthenia gravis, ask your EMG doctor if you should take any medications before the test.

The EMG doctor will discuss your test results with you. The results will be sent to your referring doctor.