Electrodiagnostic Testing

Dr. Jerry Sobel is a board certified Physiatrist that has been performing EMGs for almost 30 years. There are two specialties that are trained in performing this valuable test are Physical Medicine and Rehabilitation (Physiatry) and Neurology.

Electromyography

Electrodiagnostic testing or EMG is a test that evaluates nerve and muscle function. The test has two parts and usually takes between 45-60 minutes. There are two parts to the test, with the first part called nerve conduction testing and the second is known as electromyography or EMG. The nerve conduction testing involves giving small electrical stimulations to nerves in the arms and/or legs. It is used to evaluate pain, numbness and weakness in a limb. The EMG involves the use of a small needle that is inserted into selected muscles in order to determine if the muscle has lost its nerve supply and therefore there is nerve injury. There can be discomfort with the test, but this can be easily controlled by the doctor performing the exam. Some people experience muscle tenderness for a day or two after the test, and some have minimal bleeding from the EMG needle sites.

Conditions frequently tested by EMG

• Carpal tunnel syndrome

• Radiculopathy (pinched nerve)

• Peripheral neuropathy

• Nerve problems in the arms or legs

• Diseases of the muscles

Preparing for an EMG

Few preparations are needed on the day you have an EMG. You do not need to fast, or eat any particular kinds of food before the test. You can drive yourself to and from the appointment, do you do not need to bring a friend or relative with you. You can count on resuming your regular activity after the test is complete. As for clothing, it is best to wear loose fitting clothing so the doctor can evaluate your arms and legs easily.

Please do not apply lotions to your skin on the day of the exam as it can interfere with the test.

Please inform the doctor prior to the start of the test if you have any one of the following:

• Have a pacemaker or any other electrical medical device

• Take blood-thinning medications- medications such as Coumadin, Plavix, Eliquis, etc because they will need to be stopped a few to several days prior to the test. Click here to see a list of medications that typically need to be discontinued before the examination. Please let Dr. Sobel’s staff know if you are taking any blood thinners when you schedule your appointment..

• Have hemophilia, a blood-clotting disorder that causes prolonged bleeding

Electrodiagnostic (EDX) studies (sometimes called EMG for electromyography) are a commonly used technique to test the function of muscles and nerves. These studies are ordered by physicians to help determine the cause of back or neck pain, numbness/tingling and strength loss. Commonly diagnosed conditions include “pinched nerves” (radiculopathies), peripheral nerve injuries and muscle disease.

They are usually two parts: one testing nerves (referred to as “nerve conduction studies”) and the other testing muscles (referred to as “electromyography”). These studies allow the physician to learn how nerve and muscles are functioning. This testing process often helps to narrow down the possible causes of back/body pain and muscle weakness.

Nerve Conduction Studies

The doctor performs these studies by placing sensors over nerves in the arms and legs and then stimulating those nerves with small electric sensations. Most patients report that these studies are “uncomfortable” but not necessarily painful. The doctor is able to see how fast or slow nerves are functioning. Comparisons are made to averages to see if see the nerves are working properly.

Electromyography (EMG)

EMG is performed by placing small needles in the muscles of the arm, leg or back to directly evaluate the electrical activity caused by a muscle contraction. Most patients state that the needles feel like a small cramp or a splinter in the muscle. EMG allows the physician to evaluate how well muscles are functioning. In addition, the EMG study can help determine if muscles are receiving the proper signal from nerves.

When would my doctor consider an electrodiagnostic study?

This study is considered when the reason for pain or tingling or weakness is not clear. This study can also be used to determine the severity of a nerve injury or how badly a nerve is being pinched in the neck or back. Occasionally other conditions can mimic a pinched nerve in the back or neck. Electrodiagnostic studies can also help determine if other conditions are occurring.

What should my doctor know about me to determine if I should have an EDX?

The doctor performing the electrodiagnostic test will ask questions about the nature of your pain, tingling and weakness. This will help them determine which nerves and muscles to test. The physician may also ask questions about other conditions which may affect the nerves and muscles, such as diabetes and thyroid problems. Your doctor should know if you have ever had a neck or back surgery.

Are there any reasons I should not have an EDX study?

If you are on blood thinning medications, such as aspirin, plavix, heparin or warfarin (Coumadin), the physician may not perform certain portions of the test. If that information is absolutely necessary, you may be asked to stop blood thinning medication prior to the electrodiagnostic test. If you have a pacemaker or similar device, certain portions of the test may not be able to performed.