Nerve conduction velocity is the speed at which an electrochemical signal propagates down a neural pathway. Many things can affect this, including axon diameter, myelination, the internal resistance of the axon, and temperature. Nerve conduction velocity differs from species to species, and to a lesser degree, from individual to individual.

NCV is related to the diameter of the nerve and the degree of myelination (the presence of a myelin sheath on the axon) of the nerve. Newborn infants have values that are approximately half that of adults, and adult values are normally reached by age 3 or 4. The Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

An NCV test shows the condition of the best surviving nerve fibers, so in some cases the results may be normal even if there is nerve damage.