Electrodiagnostic Testing (NCV and EMG)

What is Electrodiagnostic Testing?
The human body is an incredible powerhouse that sends information via electrical signals. Nerves and muscles create these signals so the brain can send them to activate the motor system. Everything from running, lifting your hand, chewing and every other action requires a certain amount of energy and electricity. When nerves and muscles are damaged these electrical signals are blocked or slowed down. If you experience pain, weakness lack feeling in some areas you may need to ask your doctor about electrodiagnostics tests. Some of the conditions that EMG testing can discover include: Carpal Tunnel Syndrome, radiculopathies (i.e. pinched nerves in the neck or back), neuropathies (generalized nerve damage) among many others. There are two main tests utilized in most offices the first is Electromyography (EMG) which is the reading of electrical activity in the muscles. The other test is Nerve conduction studies (NCS), which allows the doctor to pinpoint the area where the nerves are damaged most. With the use of theses tests combined doctors can help patients find out exactly what they are suffering from and find the best possible solution.

What is the procedure for Electrodiagnostic Testing?
Before pursuing Electrodiagnostic testing, one must inform their  doctor’s office of any blood thinning medications as the needles required for the procedure may cause slight bleeding, as well as any recent infection, history of cancer or of an implanted defibrillator so that appropriate safety measures for the patient’s sake may be undertaken.

EMG testing requires a few very thin and small needles that are placed into the muscles. These needles then pick up the electrical activity when the patient tenses and relaxes the muscle being tested. The electricity is transferred to a screen that translates the electricity into sound and images. The needles are then removed and the patient is free to go, the results are typically shown immediately after the tests. Slight pain and bruising may occur, but there no other severe side effects.

NCS testing is typically done  prior to EMG testing to evaluate the nerve at a closer level. During this test the doctor tapes wires, electrodes, to the body along certain nerve pathways to be stimulated by an electrical current. This current is followed and recorded by the electrodes. The speed of electrical impulses in the body’s nerves can reach up to 120 meters per second, so when the results are reviewed the speed and health of the nerves can be observed and addressed. Doctors can then continue to test the nerves at certain points to find the problem area. The only pain experienced during this test are the electrical current that can be felt for only a few seconds, other than that the patients are free to go and view their results immediately after completing the test.

Why use Electrodiagnostic Testing?
With the advancements of medical technology doctors are finding more ways to detect and determined exactly what an injury or condition may be. With tests like EMGs we can use science to discovered symptoms that are invisible to the naked eye and avoid incorrect diagnoses. Compared to other testing methods needle EMG and NCS cause only a small amount of discomfort, no/minor side effects and show immediate results unlike other available techniques such as blood samples, urine tests, and CT scans. In the last few decades physicians have learned how to read and understand the body’s complex electrical system and what it can tell us about our health.

EMG testing can provide information about nerve and muscle problems that cannot be determined by other means, and can greatly help in interpreting the findings of other studies like an MRI or CT scan (these studies show structure, but an EMG will show nerve function that may help explain what abnormalities on the imaging study are ones most likely causing the problem).