A nerve conduction test, also known as a nerve conduction study (NCS) or nerve conduction velocity (NCV) test, is a diagnostic test that evaluates the function of peripheral nerves. During the test, electrodes are placed on the skin over the nerve being tested, and a mild electrical impulse is applied to stimulate the nerve. The resulting electrical activity is recorded by another electrode, and the speed of the electrical impulse is calculated by measuring the distance between electrodes and the time it takes for electrical impulses to travel between electrodes.

Nerve conduction tests can help detect the presence, location, and extent of diseases that damage the nerves and muscles. They are often done alongside an electromyography (EMG) test, which measures the electrical activity in muscles. Both tests can help diagnose a variety of muscle and nerve disorders, including peripheral neuropathy, nerve compression syndromes, herniated disc disease, and Charcot-Marie-Tooth disease.

Before the test, patients may be asked to remove clothing, jewelry, hairpins, eyeglasses, hearing aids, or other metal objects that may interfere with the procedure. During the test, patients may feel a mild electric shock or discomfort, but they should feel no pain once the test is finished. After the test, patients may experience muscle soreness or bruising at the site where the needle was inserted during the EMG test.

Overall, a nerve conduction test is an effective way to allow neurologists to determine whether nerve damage has occurred, as well as to diagnose a range of conditions.