Nerve conduction velocity

Alternative names:

NCV; stimulation myelographic study

Normal values:

NCV is related to the diameter of the nerve and the normal degree of myelination (the presence of a myelin sheath on the axon) of the nerve (tables of normal values are used). Newborn infants have values that are approximately one-half that of adults, and adult values are normally reached by age 3 to 4.

What abnormal results mean:

Most often, abnormal results are caused by some sort of neuropathy (nerve damage or destruction) including:

• demyelination (destruction of the myelin sheath)
• conduction block (the impulse is blocked somewhere along the nerve pathway)
• axonopathy (damage to the nerve axon)

Some of the associated diseases or conditions include:

• alcoholic neuropathy
• diabetic neuropathy
• nerve effects of uremia (from kidney failure)
• traumatic injury to a nerve
• Guillain-Barre syndrome
• diphtheria
• carpal tunnel syndrome
• brachial plexopathy
• Charcot-Marie-Tooth disease (hereditary)
• chronic inflammatory polyneuropathy
• common peroneal nerve dysfunction
• distal median nerve dysfunction
• femoral nerve dysfunction
• Friedreich's ataxia
• general paresis
• Lambert-Eaton Syndrome
• mononeuritis multiplex
• primary amyloid
• radial nerve dysfunction
• sciatic nerve dysfunction
• secondary systemic amyloid
• sensorimotor polyneuropathy
• tibial nerve dysfunction
• ulnar nerve dysfunction

Any peripheral neuropathy can cause abnormal results, as can damage to the spinal cord and disc herniation (herniated nucleus pulposus) with nerve root compression.