Nerve Conduction Velocity

What is a Nerve Conduction Velocity
(NCV) test?

A nerve conduction velocity (NCV) test is used to assess nerve damage and dysfunction. Also known as a nerve conduction study, the procedure measures how quickly electrical signals move through your peripheral nerves.

The NVC test helps your doctor differentiate between an injury to the nerve fiber and an injury to the myelin sheath, the protective covering surrounding the nerve. It can also help your doctor tell the difference between a nerve disorder and a condition where a nerve injury has affected the muscles.

How Do I Prepare for an NCV test?

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.

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.

What Should I Expect During an NCV test?

  • You’ll be asked to remove any metal objects, such as jewelry, that could interfere with the procedure.
  • You may need to remove some clothing and wear a gown.
  • You will sit or lie down for the test.
  • Your doctor will find the nerve to be tested.
  • Your doctor will place two electrodes on your skin, one that stimulates the nerve and one that records the stimulation. They may use a jelly or some kind of paste to help the electrode stick to the skin.
  • The nerve will be stimulated by a mild and brief electrical shock from the stimulating electrode. One common test, for example, stimulates nerves in the finger and records the stimulus with an electrode near the wrist.

The entire test may take 20 to 30 minutes. The sensation may be uncomfortable, but it typically isn’t painful.

What Happens After the NCV test?

After the NCV test is complete you are free to leave and resume your normal activities.