What is the nerve conduction velocity test?

The nerve conduction velocity test (NCV) is a diagnostic procedure used to evaluate the health and function of nerves. It measures how fast electrical signals travel along the nerves.

Procedure

During a nerve conduction velocity test, small electrodes are placed on the skin over the nerve being tested. Additional electrodes are placed on nearby skin as well as the muscle the nerve controls (if this is applicable). The electrodes send and receive small, painless electrical impulses. The impulses travel through the nerve, and their speed is measured.

The electrodes placed on the skin near the first electrode are close enough to pick up the electrical activity and measure how long it takes the impulse to travel to them. This helps calculate how fast the electrical signal is traveling along the nerve.

Interpretation

Nerve conduction velocity can vary depending on the type of nerve and its location in the body. The results of the test are compared to normal values for that particular nerve, which can help determine if the nerve is functioning properly or if there is damage or dysfunction.

Uses and Effectiveness

NCV tests are used to evaluate a variety of conditions affecting the nerves, including:

- Carpal tunnel syndrome

- Guillain-Barré syndrome

- Multiple sclerosis

- Pinched nerves

- Peripheral neuropathy (damage to the nerves outside the brain and spinal cord)

Nerve conduction velocity tests are generally safe and well-tolerated. However, they may be uncomfortable for some people, and there may be some mild discomfort during or after the test. There may also be potential risks from the use of needles or electrical impulses.

NCV tests are often performed alongside other diagnostic tests, such as electromyography (EMG), to obtain a more comprehensive evaluation of nerve and muscle function.