Why nerve conduction test

EMG and nerve conduction studies are used to help diagnose a variety of muscle and nerve disorders. An EMG test helps find out if muscles are responding the right way to nerve signals.

Nerve conduction studies help diagnose nerve damage or disease. When EMG tests and nerve conduction studies are done together, it helps providers tell if your symptoms are caused by a muscle disorder or a nerve problem. You may need these tests if you have symptoms of a muscle or nerve disorder. These symptoms include:. Tell your health care provider if you have a pacemaker or cardiac defibrillator. Special steps will need to be taken before the test if you have one of these devices.

Wear loose, comfortable clothing that allows easy access to the test area or can be easily removed if you need to change into a hospital gown. Make sure your skin is clean. Don't use lotions, creams, or perfumes for a day or two before the test. You may feel a little pain or cramping during an EMG test. You may have a tingly feeling, like a mild electric shock, during a nerve conduction study. If your results were not normal, it can indicate a variety of different conditions.

Depending on which muscles or nerves are affected, it may mean one of the following:. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.

What are electromyography EMG and nerve conduction studies? Kashouty finds the form and function of the nerves and muscles the most interesting part of neurology, which is what led him to specialize in neurophysiology with more emphasis on neuromuscular conditions. He treats all neurological diseases, but his main focus is to treat and manage headaches , movement disorders and neuromuscular diseases.

Care Credit. Patient Portal. Make a Payment. Premier Neurology and Wellness Center. Send Request. Open toolbar. In a nerve conduction study, several flat metal disc electrodes are taped or pasted to your skin. A shock-emitting electrode is placed directly over the nerve to be studied. A recording electrode is placed over the muscles supplied by that nerve.

Several, brief electrical pulses are sent to the nerve. You will feel a brief, burning pain, a tingling sensation and a twitching of the muscle when the electrical pulse is applied. It feels like the tingling you feel when you rub your feet on the carpet then touch a metal object.

The testing can be quite uncomfortable and makes some people nervous. Keep in mind that only a very low-voltage electrical current is used. Each pulse is very brief less than a millisecond. The time it takes the muscle to contract in response to the electrical pulse is recorded.

Once the person is ready, a doctor will locate the nerves and attach a recording electrode to the skin over the nerves. A second electrode will be placed a short distance away. This second electrode will produce a mild and brief electric shock to stimulate the nerve. It should not be painful but may cause minor discomfort. There will be no pain after the test is complete. During an EMG test, needles are put into the muscles, and the person will then stretch the muscles to test their function.

This can be uncomfortable and may cause soreness and bruises at the needle sites. The voltage used in NCV testing is very low, and risks are minimal. However, it is essential to discuss any concerns with the doctor requesting the procedure. People with pacemakers or cardiac defibrillators may need to take extra precautions when doing an NCV test. Some additional factors, including pain before the procedure and body temperature, may affect test results.

NCV tests can measure the speed and strength of nerve signals. Nerve conduction velocity between 50 to 60 meters per second is considered normal.

A damaged nerve may send a slower and weaker signal than a healthy one. It is possible to have normal results even if a person has nerve damage. Anyone concerned about their NCV test results should speak with a doctor for individualized diagnosis and treatment.

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