A nerve study measures how fast electrical impulses travel through your nerves. Your doctor uses it to learn if your nerves have been injured. Damaged nerves slow down or even interfere with an electrical pulse during an NCVT.
An NCVT is often used in combination with electromyography (EMG) tests, which measure how your muscles respond to electrical impulses. If your muscles aren’t responding correctly, your doctor must assess the results of the two tests to decide whether there is a problem with your muscles or the nerves sending signals to them. Once identified, your doctor begins the appropriate treatment.
When Do You Need a Nerve Conduction Test?
While you’re explaining to your doctor what sort of problems you’re having, your doctor may decide to bring in an endocrinology specialist. No matter what you need, you’ll find a specialist for it.
The endocrinologists who administer the NCVT use the latest equipment, and they provide any follow-up treatment you may require. If your doctors decide you need an NCVT, it’s usually because your symptoms include:
- Discomfort that varies from mild to more severe
- Unusual muscle cramping or pain
- Noticeable muscle weakness
- Tingling or numbness in a specific area
What Conditions Signal the Need for an NCVT?
When diagnosing your problem, the doctor needs to determine whether it’s the muscles or nerves that are behind your symptoms. Your treatment differs, based on the diagnosis. Conditions that affect your nerves include:
- herniated disc The discs separating your vertebrae may rupture, allowing the soft inner portion to ooze out through the hard casing. The damaged disc can put pressure on your spinal nerves, causing pain, tingling and nerve damage.
- Carpal tunnel syndrome. The median nerve that runs from your forearm down to your hand may be compressed by overused or damaged ligaments and tendons. If this is the case, you may notice numbness and pain in your fingers, and you may have trouble grasping objects.
- Charcot-Marie-Tooth disorder. You may become aware of sensory nerve and motor dysfunction in your lower leg and foot muscles. This is an inherited disease.
- Guillain-Barre syndrome. With this disease, your body’s immune system malfunctions and begins attacking your peripheral nervous system. You often notice tingling or weakness in your lower legs and feet as a first sign.
- Sciatica. The sciatic nerve runs from your spine down through your legs. Pressure from a herniated disc can pinch the nerve, sending the pain down the length of the nerve. Common symptoms include tingling, numbness, pain and weakness. Sciatica is usually confined to one leg.
- Chronic inflammatory conditions. If you suffer from alcoholism or diabetes, you may note tingling or numbness in one or more parts of your body, especially in your hands or feet.
What Happens During a Nerve Conduction Test?
A few days before your exam, stop using lotions or oils. Make sure you have a normal body temperature, since lower body temps slow the electrical impulses, skewering the results. Tell your doctor about any prescription or over-the-counter medications you’re taking. The test proceeds with several steps that include:
- Your specialist asks you to remove any metallic objects — such as jewelry, hearing aids or eyeglasses — so they don’t interfere with the electrical impulses. You need to wear a hospital gown so your doctor can access the area being tested.
- After the doctor attaches the electrodes to your skin and confirms that you’re comfortable, an electric pulse is sent from one to the other. The test involves measuring the time required for the impulse to travel the length of your nerve.
- You may notice a mild, brief shock from the electrode during the pulses. While most people tolerate the test well, it may cause a little discomfort.
- Your doctor records the nerve response, including the strength and speed of the signal, to use for determining the diagnosis.
