NERVE CONDUCTION VELOCITY (NCV) TEST
A nerve conduction velocity (NCV) test is used to assess nerve damage and dysfunction. This test is also known as a nerve conduction study and the procedure measures how quickly electrical signals move through your peripheral nerves. It can also help your doctor tell the difference between a nerve disorder and a condition where a nerve injury has affected the muscles, such as:
- Guillain-Barre syndrome
- Carpal tunnel syndrome
- Charcot-Marie-Tooth (CMT) disease
- Herniated disk disease
- Chronic inflammatory polyneuropathy and neuropathy
- Sciatic nerve problems
- Peripheral nerve injury
Preparation
When scheduling this test, your doctor will ask about conditions, medications, or behaviors that might affect the results. These include alcohol abuse, use of certain neurologic medications, such as muscle relaxants, opioids, or psychotropic medications, diabetes, hypothyroidism or other systemic diseases. It’s also important for your doctor to know if you have a pacemaker. The electrodes used in the NCV test may affect the electronic impulses of your medical device.
Stop using any lotions or oils on your skin a few days before the test. These creams can prevent the electrode from being properly placed on the skin. Fasting usually isn’t necessary, but you may be asked to avoid caffeine beforehand.
Procedure
Remove any metal objects, such as jewelry, that could interfere with the procedure. You will need to wear a gown and either sit or lie down for the test. The doctor will place two electrodes on your skin, one that stimulates the nerve and one that records the stimulation. A jelly or some kind of paste to help the electrode stick to the skin will be applied and the nerve will be stimulated by a mild and brief electrical shock from the stimulating electrode. The entire test may take 20 to 30 minutes. The sensation may be uncomfortable but is typically not painful and does not pose any risks.
