Following the nerve conduction velocity (NCV) test, the special paste or tape will be removed from the patient’s skin. In most cases, patients can resume their normal daily activities following the test. However, in some cases, a physician may recommend avoiding certain strenuous activities.

Results are usually available immediately after the test. However, it may take a day or two before a patient receives a complete analysis of the test results. NCV results may show the following:

• Normal results. Measurements recorded on the NCV should show the nerves transmitting electrical impulses to the muscles or to sensory nerves (which allow the brain to respond to various sensations) at normal speeds. Normal values may vary depending on the patient’s age. Newborn infants have values that typically are half those of adults, while adult values are typically reached by the age of 4 years. A normal result does not automatically preclude nerve damage. Hypothetically, nerve damage could occur, but still leave some unaffected axons (nerve fibers) that can efficiently transmit an electrical signal, and may result in a normal NCV result. In addition, normal results may indicate a patient’s nerves are functioning, although they may have disease or disorder of the muscle in the area tested.
  
  
• Abnormal results. NCV measurements may be slower than normal or there may be no response to the electrical impulses. This usually indicates injury or damage to a nerve or group of nerves. NCV tests also measure the strength of the electrical impulse in a nerve. This strength is directly proportional to the number of axons involved with a particular nerve. Axons that degenerate or become clogged with debris may generate weaker electrical impulses.

Before a diagnosis is made, NCV test results are usually combined with information gathered from other sources, including a patient’s medical history, physical and neurological examinations as well as other tests (e.g., electromyography, quantitative sensory testing).