Nerve Dysfunction Testing in Logan with Spring Creek Medical Center

What Is a Nerve Conduction Velocity (NCV) Test?

A nerve conduction velocity (NCV) test determines how quickly electrical signals move through a particular peripheral nerve. It is also sometimes known as a nerve conduction study. It is used to diagnose nerve damage or nerve dysfunction.

What is the Purpose of an NCV Test?

The peripheral nerves are the nerves outside the brain and the spinal cord. These nerves help you control your muscles and experience important senses. Healthy nerves send electrical signals quicker and with greater strength than damaged nerves. For this reason, an NCV is helpful in determining the existence, type, and extent of nerve damage.

The NCV test allows the physician to tell the difference between an injury to the nerve fiber and an injury to the protective covering surrounding the nerve. It is also useful for telling the difference between a nerve disorder and a condition where a nerve injury is affecting the muscles. It is important to know these distinctions for diagnosis and to be able to determine the appropriate course of treatment.

When is an NCV Test Necessary?

This test is useful for diagnosing a variety of different muscular and neuromuscular disorders. A doctor may use this test if they suspect a pinched nerve. Alternately, they may use it if they are checking for the presence of nerve disease. It is often performed with a test that records electrical signals moving through the muscles (electromyography).

How is an NCV Test performed?

Flat, patch-style electrodes are placed on the skin at intervals and over the nerve that is being examined. These electrodes give off low-intensity electrical impulses and stimulate the nerve. The stimulation feels like a slight electric shock, but it is not particularly painful.

The impulses produced by this electrical current are viewed on an oscilloscope or computer screen. The monitoring system allows the physician to determine how fast the impulses are traveling through the nerves.


Understanding the Test Results of an NCV

If the response from the electrical current is slower than normal then it is likely a sign of damage to the myelin sheath. On the other hand, if the response shows a decreased response but with a normal speed, then there is probably nerve fiber damage. The results of the test and the cause of the nerve damage help determine the proper course of treatment.

A few of the possible causes for abnormal results are:

  • Axonopathy (damage to the nerve cell)
  • Conduction block (an obstacle to the impulse within the nerve)
  • Demyelination (damage to the myelin sheath)


If the cause of the nerve damage is known and understood, then addressing the cause should make your symptoms better. Some possible treatments for nerve damage include physical therapy, surgery, and pain medication. The best treatment depends on the severity, extent, and type of nerve damage.

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