Nerve conduction velocity
Key points
- Nerve conduction velocity (NCV) is a test of the speed of conduction of impulses through a nerve.
- The nerve is stimulated, usually with surface electrodes, which are patch-like electrodes (similar to those used for ECG) placed on the skin over the nerve at various locations.
- Normal body temperature must be maintained (low body temperature slows nerve conduction).
- The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experiences, and level of trust.
Alternative names
NCV
Definition
Nerve conduction velocity (NCV) is a test of the speed of conduction of impulses through a nerve.
How the test is performed
The nerve is stimulated, usually with surface electrodes, which are patch-like electrodes (similar to those used for ECG) placed on the skin over the nerve at various locations. One electrode stimulates the nerve with a very mild electrical impulse.
The resulting electrical activity is recorded by the other electrodes. The distance between electrodes and the time it takes for electrical impulses to travel between electrodes are used to calculate the nerve conduction velocity.
Electromyography is often done at the same time as the NCV test.
How to prepare for the test
Normal body temperature must be maintained (low body temperature slows nerve conduction).
Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experiences, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:
- Infant test or procedure preparation (birth to 1 year)
- Toddler test or procedure preparation (1 to 3 years)
- Preschooler test or procedure preparation (3 to 6 years)
- School age test or procedure preparation (6 to 12 years)
- Adolescent test or procedure preparation (12 to 18 years)
How the test will feel
The impulse may feel like an electric shock. Depending on how strong the stimulus is, the patient will feel it to varying degrees. It may be uncomfortable for some patients during the actual test. There should be no residual pain once the test is finished.
Often the nerve conduction test is followed by electromyography (EMG) which involves needles being placed into the muscle and the patient contracting that muscle. This can be uncomfortable during the test, and muscle soreness at the site of the needles may be experienced afterwards as well.
Written and revised by
Gerald Hurowitz, M.D.
Our doctors write and review articles for accuracy and keep them up to date.
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