EMG/NCV
What is an electromyogram?
An electromyogram (EMG) is a test that is used to record the electrical activity of muscles. When muscles are active, they produce an electrical current. This current is usually proportional to the level of the muscle activity. An EMG is also referred to as a myogram.
EMGs can be used to detect abnormal muscle electrical activity that can occur in many diseases and conditions, including muscular dystrophy, inflammation of muscles, pinched nerves, peripheral nerve damage (damage to nerves in the arms and legs), amyotorpic lateral sclerosis (ALS) (also known as Lou Gehrig's disease), myasthenia gravis, disc herniation and others.
What is a Nerve Conduction Study?
A Nerve Conduction Study (NCS) is a test used to diagnose problems related to nerves, muscles, spinal cord or the brain. The test measures the speed and intensity of electrical signals that travel along the nerves and the time it takes muscles to respond to these signals. Nerves actually produce small amounts of electricity and their activity can be affected by disease, injury or other conditions.
How does the NCS equipment detect changes?
Electrodes record the activity of muscles and nerves, which is then displayed in wave form on the monitor.
Preparing for your test
Bathe or shower on the day of the test. Wash your arms and legs to remove body oils. Do not use any bath oils, lotions or creams. Oils can interfere with your test.
Day of Exam
Be prepared to fill out a form and answer questions. Your medical history will be taken. Describe any symptoms and past illnesses. Allow plenty of time to avoid feeling rushed. Be sure to ask any questions you may have.
Clothing
Wear comfortable, loose-fitting clothes.
History
Inform your health-care provider if you are currently taking any medications or suffering from any conditions, such as diabetes or heart disease.
Relax
It is important you try to relax during your neurological test. The Doctor is specially trained to provide you with a comfortable, relaxed atmosphere.
Testing Procedure
Depending on the are of your body that is being tested, you may be asked to lie down or sit upright. Certain areas of your skin may be cleaned.
Recording electrodes will be attached to your skin. A gel may be applied first. Other electrodes are also attached for electrical grounding and to serve as reference points.
A tiny electrical impulse is sent through your nerves and the response are recorded. You may feel tingling, like when you hit your "funny bone". In addition, your muscles, fingers or toes may twitch.
Total testing time is about 30 - 60 minutes.
Who performs the test?
A specialist performs the testing and interprets the results. He or she is a physician who has training in nerve and muscle disorders.
After your test
There are no side affects. You may resume normal activities unless your health-care provider tell you otherwise.
Your test results will be analyzed and returned in several days. Your health-care provider will develop a treatment plan based on your findings.
