NEI Inc. of St. Louis

14825 North Outer 40, Suite 330
Chesterfield, MO 63017

AANEM Accredited Laboratory Exemplary Status

About Your Electrodiagnostic Test

There are two different types of electrical tests of nerves and muscles: a nerve conduction velocity test (NCV) and a needle electromyogram (EMG).  NCVs test how well a nerve sends electrical signals, and EMGs test the electrical activity of muscles.  These tests help evaluate symptoms such as numbness, tingling, pain, weakness, fatigue and cramping, and may help your referring doctor diagnose your condition and determine your appropriate treatment.

On the day of your test

Before your test, Dr. Phillips will enter general information about you into the computer and tell you about the test.  He will also tell you approximately how long the test may take, but this is only an educated estimate; the test may change as he works through the process. You may require a more detailed study to accurately diagnose your problem, and Dr. Phillips always says, “I’m done when I’m finished."  What you feel or hear during your test does not indicate the severity of your condition, so you do not need to worry about comparing things or describing what you are feeling during the test.
This is a technical study and involves many measurements and calculations. Dr. Phillips will be paying careful attention to the testing process and will be intently focused on the NCV/ EMG machine.  So do not worry if he is not very talkative.

Nerve conduction velocity (NCV) tests

A nerve conduction velocity test is a study of your nerves.  Nerves are small cables that connect the brain and spinal cord with the rest of the body. Nerve damage can cause tingling, pain, loss of sensation and weakness. Nerve tests allow the doctor to study the electrical signals along the nerves to help determine where the problem may be located.

In preparation for the test, Dr. Phillips will place small painless metal discs (electrodes) on your skin and hold them in place with medical tape. Dr. Phillips uses hypoallergenic tape, but it’s still a good idea to wash up after the test.  He will mark the points where the nerves will be stimulated and will ask you to hold the extremity being studied in certain positions (for example, your palm up or your elbow flexed). The nerve is then stimulated with small electrical shocks delivered to the surface of the skin. These shocks are very brief (a tiny fraction of a second), and feel something like the electric shock from touching a metal door knob after walking on carpeting.  After stimulation, the nerve responds by sending its own signal.  This signal is recorded and analyzed by the computer. These small shocks have no lasting effects and cannot cause any harm. There are no side effects from nerve conduction studies.

Usually several nerves are studied depending upon the location and type of symptoms you are experiencing.

Dr. Phillips has had the test many times and knows that it can be uncomfortable, so he tries to do it as quickly but carefully as possible. Dr. Phillips has performed tens of thousands of nerve tests throughout the course of over 25 years.

 Electromyography (EMG) tests

An EMG is a test of the function of muscles.  A very small, thin needle is inserted through the skin into the muscle. It is the same size needle used by diabetics to give themselves insulin shots. A new sterilized needle is used on each patient and is thrown away after the test. The needle records the electrical signals inside the muscle and sends these to the computer. The doctor can see and hear how your muscles and nerves are working by the electrical signals made by your muscles. Again, don’t be concerned about comparing the sounds, or alarmed by any differences that you hear.  Being stuck by a needle, even a tiny one, is not very comfortable, but Dr. Phillips will do it as quickly and easily as possible. 

Preparing for your test

Please tell the doctor if you are on any blood thinners such as Coumadin (Warfarin), or have a blood clotting or bleeding disorder, or have a pacemaker or any implantable device in place. These conditions generally do not preclude performing the test.

Let the doctor know if you have a latex allergy and he will use latex-free gloves.
In the past, people who had to take antibiotics prior to dental procedures (usually for heart valve conditions) also took antibiotics for EMG tests. However, current standards do not require prophylactic antibiotics. You might think of it this way: if you would take an antibiotic if you stuck yourself with a small sewing needle, then you should take an antibiotic if you have an EMG test; otherwise, antibiotics are not necessary.
You may eat, drink and take your medications, including pain medications, before and after the test. Please don’t put any creams or lotions on parts of your body to be examined, or wash them off prior to the test.

After your test

You may drive and return to work and any normal activities after your test.  Dr. Phillips will analyze your test results and fax a report to your doctor on either on the same day or within 24 hours. You should follow up with your referring doctor for your test results