Nerve conduction velocity

What is Nerve Conduction Velocity (NCV)?

NCV is a test that measures how fast electrical signals move through a nerve. Nerves conduct electrical signals from the brain that control muscle movement and help us detect sensations such as pain and heat. Nerve conduction velocity, or NCV, is used to evaluate the muscles, sensory and motor nerves. It measures how quickly electrical signals travel through a nerve.

Types of NCV Test

  • Motor nerve conduction study (MNCS): This test measures how fast an electrical signal travels along a motor nerve and how well the nerve stimulates the muscle it is connected to.
  • Sensory nerve conduction study (SNCS) : This test measures how fast an electrical signal travels along a sensory nerve and how well the nerve sends signals to the brain.
  • H-reflex study: This test measures the activity of the wide, sensory nerve in the calf. It is helpful for diagnosing conditions that affect this nerve, such as sciatica.

Preparing for Your NCV Test

When you arrive, a technician will review your medical history and check your medications with you. Be sure to be prepared to answer questions about any medications, including dosage information, and bring your insurance cards and list of medicines. Dress comfortably in loose-fitting clothes, as the test will take place in a room where you will be asked to undress in some areas. Let your doctor know if you are pregnant or if you have any metal implants.

Procedure of NCV Test

  • The test is painless and involves placing several small electrodes on the skin of the arm or leg.
  • The electrodes measure the nerve impulses that travel along the nerve.
  • The technician will also place a small electrical stimulation device on the skin. This device is used to stimulate the nerve and measure how quickly the nerve responds.
  • After the electrodes are removed, the technician will write down the results and discuss them with your doctor.

Risks of NCV Test

  • The test is not known to cause any harm or complications.
  • There is a small risk of skin irritation from the electrodes.
  • The electrical stimulation may also cause tingling or a mild shock sensation, but this is usually painless.

Why is NCV Test Performed?

Nerve conduction velocity tests are used to diagnose a variety of medical conditions, such as:

  • Peripheral neuropathy, or nerve damage in the arms or legs.
  • Neuromuscular disorders, such as carpal tunnel syndrome or myasthenia gravis.
  • Diseases that affect the nervous system, such as multiple sclerosis and Parkinson's disease.
  • Injuries to the nerves, such as sprains or strains.
  • Tumors that press on the nerves.
  • Diabetic neuropathy.

When is NCV Performed?

A nerve conduction velocity test is usually recommended if you have symptoms of a neurological disorder, such as muscle weakness, numbness or pain. Your doctor may also recommend a nerve conduction velocity test if you have been diagnosed with diabetes or have a family history of neurological disorders.