Generally, the procedure follows this process:
1. You will be asked to remove any clothing, jewelry, hairpins, eyeglasses, hearing aids, or other metal objects that may interfere with the procedure.
2. If you are asked to remove clothing, you will be given a gown to wear.
3. You will be asked to sit or lie down for the test.
4. A physician will locate the nerve(s) to be studied.
5. A recording electrode will be attached to the skin over the nerve with a special paste and a stimulating electrode will be placed at a known distance away from the recording electrode.
6. The nerve will be stimulated by a mild and brief electrical shock given through the stimulating electrode.
7. You may experience minor discomfort for a few seconds.
8. The stimulation of the nerve and the detected response will be displayed on an oscilloscope (a monitor that displays electrical activity in the form of waves).
We use nerve conduction studies for the evaluation of paresthesia (numbness, tingling, burning) and/or weakness of the arms and legs. Some of the common disorders we can diagnose or rule out by nerve conduction studies are:
• Peripheral neuropathy.
• Carpal tunnel syndrome.
• Ulnar neuropathy.
• Guillain-Barré syndrome.
• Facioscapulohumeral muscular dystrophy.
• Spinal disc herniation.
• Charcot-Marie-Tooth disease.
• Sciatic nerve problems.
During the test, the nerve is stimulated, usually with surface electrode patches attached to the skin. Two electrodes are placed on the skin over the nerve. One electrode stimulates the nerve with a very mild electrical impulse and the other electrode records it. The resulting electrical activity is recorded by another electrode. This is repeated for each nerve being tested.
The nerve conduction velocity (speed) is then calculated by measuring the distance between electrodes and the time it takes for electrical impulses to travel between electrodes.
A related procedure that may be performed is electromyography (EMG). An EMG measures the electrical activity in muscles and is often performed at the same time as NCV. Both procedures help to detect the presence, location, and extent of diseases that damage the nerves and muscles. Please see this procedure for additional information.
The benefit of the Nerve Conduction Test is a better understanding of the health of your nerves. This test can also benefit you by helping diagnose nerve issues.
In a similar way, the EMG test will benefit you by giving more information about how well your muscles work and respond to nerve signals.
Together, these tests can give your doctor at Atlantic Endocrinology & Diabetes Center important information about problems with your nerves and muscles. Your doctor can then use the information about your nerves and muscles to help manage your pain.