Electromyography (EMG) and Nerve Conduction Studies (NCS) are the most important tests for evaluation of muscle and nerve disorders. They do not need any preparation and involve electrical stimulation and insertion of small electrodes in the affected muscles to record their activities.
Who does the testing?
The American Association of Neuromuscular & Electrodiagnostic Medicine’s policy is that an appropriately trained doctor should do all needle EMG testing. Dr. Shaibani is board certified in Neurology and Electrodiagnostic medicine. A trained assistant or technologist under a doctor’s supervision can do nerve conduction studies.
What kind of medical training do doctors who do EMGs have?
Doctors who do EMGs go to 4 years of medical school then have 3 or 4 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. It teaches doctors what can go wrong with the human body and how to tell the difference between these problems.
Why am I being sent to the EMG Lab for tests?
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), needle EMG, and evoked potentials. The EMG doctor will examine you to decide which tests to do.
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.
Needle EMG (Electromyography)
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 medical knowledge to figure out what could be causing your problem.
How long will these tests take?
The tests usually take 20 to 60 minutes. You can do any of your normal activities, like eating, driving, and exercising, before the tests. There are no lasting side effects. You can also do your normal activities after the tests.
How should I prepare for the tests?
Tell the EMG doctor if you are taking aspirin, blood thinners (like Coumadin®), have a pacemaker, or have hemophilia. 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.
When will I know the test results?
The EMG doctor will discuss your test results with you or send them to your regular doctor. After the exam, check with the doctor who sent you to the lab for the next step in your care.