Nerve Conduction Velocity Testing
This testing procedure is used to detect whether the patient has suffered nerve damage or injury. It is often done in conjunction with an electromyography (EMG) to help a physician determine whether a problem is occurring between the nerves or the muscles. This facilitates proper diagnostics and directs the appropriate treatment plan.
A nerve conduction velocity test may be ordered if the patient is experiencing tingling, numbness, or burning sensations, any of which can indicate nerve damage. During the test, adhesive patches with electrodes are placed on the skin and a mild electrical impulse is emitted from one electrode. A nerve is then electrically stimulated and the electrical impulse is measured and recorded by the other electrodes. This measurement is taken from the distance between the electrodes and how long it takes for the electrical impulse to travel between them. Nerves that are healthy send signals more quickly than damaged nerves, so the speed of the impulse will indicate the current nerve function.
Nerve damage or injury can occur either to the nerve axon or the myelin sheath and can include possible injury (such as carpal tunnel syndrome) or disorder (such as neuropathy). The results of this test help the physician accurately determine the type and extent of the nerve damage, which enables proper diagnosis and treatment plans.
An accompanying EMG can also provide important information to the physician, such as whether there is abnormal electrical muscular activity, damage, or inflammation. These tests can be an important step in treating neuromuscular disorders such as amyotrophic later sclerosis (ALS), myasthenia gravis (MG), or a herniated disc.