EMG test and EMG testing procedure with NCV test and NCV testing procedure in Utah

EMG Test and NCV Test

Electromyography and nerve conduction velocity procedures are available at Western Neurological Associates, PC, (WNA) in Salt Lake City, Utah. An electromyography (EMG) test and a nerve conduction velocity (NCV) test are two forms of electrodiagnostic testing neurologists use to diagnose diseases of the nerves and muscles. An EMG test measures the electrical activity of muscles. An NCV test measures the speed and intensity of electrical signs as they travel along the nerves and the time it takes for the muscles to react to the signals.

EMG Testing Procedure

For an EMG test, small needle electrodes are inserted through the skin into the muscles. Other electrodes may be taped to the skin. The electrical activity of these muscles is then recorded with the muscles at rest and again when contracted. Normally, there is no electrical activity in a resting muscle. There may be some discomfort as the electrodes are inserted, which may result in some tenderness for a while after the EMG procedure has been completed. The EMG test is performed sitting or lying down in a comfortable position and usually takes 30 minutes to an hour.

NCV Testing Procedure

During an NCV test, surface electrodes (which are patch-like electrodes similar to the ones used for an EMG test) are placed on the skin over the nerves in different spots. Stimulating electrodes (the "stimulator") are held against the skin and send a very mild electrical impulse through the nerves. The resulting electrical activity is recorded by the other electrodes. The distance between electrodes and the time it takes for the electrically activity to travel this distance is used to calculate the nerve conduction velocity. Most people experience an unusual tingling sensation during the NCV procedure. Some may also experience slight, temporary pain or discomfort. The NCV test is performed lying down or sitting, depending on the area being tested, and may take 15-30 minutes.

What do EMG and NCV tests show?

EMG tests and NCV tests are used to detect the cause of muscle weakness, numbness, spasms, paralysis, or pain. The EMG test and NCV test can determine if the problem involves the nerves, muscles, spinal cord, or brain. EMG/NCV testing helps in the diagnosis of:

Pinched nerves and inflamed muscles due to injury, a ruptured disk, disease, or other conditions.
Carpal tunnel syndrome--pressure on the major nerve going into the hand causing pain and weakness of the wrist and hand.
Primary muscle disorders such as muscular dystrophy (a disease causing certain muscles to waste away).
Nerve disorders such as amyotrophic lateral sclerosis (Lou Gehrig's disease).

Additional Information

For additional information on EMG testing, visit the Discovery Health Channel and Neurology BC.

For additional information on NCV testing, visit the Discovery Health Channel.