What is an EMG?
An Electromyography (EMG) is a technique used to evaluate and record the electrical activity produced by muscles. An EMG is performed using a machine which detects the tiny bit of electricity that is produced by muscles when they are active. Muscles typically produce an electrical signal of a specific size, shape, and sound. A damaged muscle produces an altered electrical signal which can be analyzed with an EMG.
What are the uses of EMG?
An EMG is used to detect an abnormal muscle electrical signal. The EMG results help your clinician and referring doctor to distinguish between muscle conditions that begin in the muscle and nerve disorders that cause muscle weakness.
Is the EMG test painful?
There can be some discomfort during an EMG. The discomfort is generally mild and does not require sedatives or anesthesia. Laying in a comfortable position and being calm with relaxed muscles helps to lessen and discomfort during the test.
What is an NCV?
A Nerve Conduction Velocity (NCV) is an electrical diagnostic test. In an NCV, the nerves to be evaluated are stimulated with small electrical impulses by one electrode. Other electrodes are placed down the nerve path to receive the impulse signal. The received impulse signals are measured to provide more information about the nerves. The NCV test evaluates nerves by measuring how fast the electrical impulse travels through the nerve being tested. A NCV is often done at the same time as the EMG.
What are the uses of NCV?
A NCV is done to find damage to the peripheral nervous system. The clinician performing the NCV with interpret the results by calculating the speed of impulse transmission by using the distance between electrodes and the time it takes for electrical impulses to travel between electrodes. If the speed is considered to be slower than normal, it could indicate nerve damage.
Are the impulses in the NCV test painful?
As with the EMG, there may be some discomfort. With an NCV, you may feel a quick burning, or tingling sensation and a twitching of the muscle with each pulse applied. The sensation can be related to when you rub your feet on the carpet then touch a metal object. Each electrical pulse is a very low voltage and is very quick (less than a split second). Most people find the test to be easier than they expected.
What to expect during the tests?
For each of these tests you will be in a private room. You may be given a hospital gown to allow the clinician to properly examine the muscles to be tested. Depending on the test being performed you may have surface electrodes placed on your skin and the clinician may use a very small needle electrode (about the size of an acupuncture needle). You should remain comfortable and relaxed throughout the tests; the clinician may ask you to contract and relax specific muscles to better evaluate the muscles and nerves.
What to expect after the tests.
After the tests, you may experience a small amount of muscle soreness. Most people are able to return to all of their normal daily activities and work right after the tests. The clinician will discuss your exam with you; this may include results of the tests. A full report will be sent to the ordering doctor who will discuss the results with you when you return for a follow up appointment.
How long do the tests take?
These tests can last 30 to 90 minutes depending on whether you are getting an EMG alone or an EMG combined with NCV. We reserve a two hour time period for you; this allows the clinician to fully assess your nerves and muscles.
How to be prepared for the test?
- Please inform the clinician if you are taking any blood thinner, have a pace-maker or have been diagnosed with a bleeding disorder.
- Tell the clinician if you are taking any medications. There are certain medications which can affect EMG results.
- Do not smoke for 3 hours before the test
- You can do any of your normal activities (eating, driving, exercising, ect) before and immediately after the tests.
- You should take a bath or shower before the test to remove extra oil from the skin.
- Avoid applying body lotions or skin oils on the day of the test.
What are the benefits of these tests?
EMG/NCV are specialized electrical nerve tests. These tests are the only test that are able to directly assess the functioning of the nervous system. Due to the very beneficial and informative nature of the EMG/NVC tests, you will learn more information that will help you to understand your condition and what is causing your symptoms. After the test, a detailed report will be sent to your doctor; the results from an EMG/NCV can help your doctor to diagnose the cause of your symptoms and therefore, determine the best treatment plan to provide you relief.
What types of conditions are diagnoses with NCV/EMG?
- Carpal Tunnel Syndrome
- Ulnar Neuropathy at the wrist or elbow
- Pinched Nerve (Cervical Radiculopathy)
- Brachial Plexus Injury
- Radial Neuropathy
- Thoracic Outlet Syndrome
- Myopathy (Muscle Weakness)
- Muscular Dystrophy
- Myofascial Referred Pain
- Lumbosacral Radiculopathy
- Peroneal Neuropathy
- Sciatic Neuropathy
- Tarsal Tunnel Syndrome
- Lumbosacral Plexopathy
- Peripheral Neuropathy
- Pinched Nerve in the neck or back (Possibly disc problems or arthritis)
- Amyotrophic Lateral Sclerosis (ALS)/Lou Gehrig’s disease
- Myasthenia Gravis (MG)
- Guillain-Barre Syndrome
- Muscular Dystrophy
Who performs these tests?
At Coastal Rehabilitation, Inc., the owner and physical therapist, Bernie Blystone, PT performs the EMG and NCV tests. Bernie is a expertly trained clinician and has performed countless numbers of EMG/NCV tests.
EMG/NCV tests are avialable by appointment in our Elizabeth City office.
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At CRI, treatment sessions are typically 1 hour each, giving clinicians time to address both physical and functional impairments.