If you are experiencing symptoms such as numbness, tingling, weakness and/or pain, a nerve conduction (NC) and electromyography (EMG) test can offer answers. This test evaluates the health of your nerves and your muscles.
A NC and EMG test can help determine if your symptoms are due to a neuromuscular disease, including the following:
- Amyotrophic lateral sclerosis (ALS)
- Diabetic neuropathy
- Entrapment neuropathy (such as carpal tunnel syndrome)
- Muscular dystrophy
- Myasthenia gravis
- Neuropathy from other causes
Do you need a NC and EMG test?
Some neuromuscular problems may be difficult to diagnose. Often, a physical exam and/or blood tests cannot provide a diagnosis. A NC and EMG test can help.
Your doctor may order a NC and EMG test if you are experiencing some of the following symptoms:
- Numbness/loss of feeling
What does a NC and EMG test do?
Nerves and muscles naturally produce electricity. A NC and EMG test measures the electrical activity generated by your nerves and muscles, respectively, to determine if they are healthy or not.
The test typically has two parts, namely a nerve conduction (NC) study and an electromyography (EMG) study, and typically, you will have the two parts done in the same setting — usually the NC study first and the EMG study second. The entire test usually takes about one-and-a-half hours total, but it may be shorter or longer depending on your condition.
Nerve conduction study: step by step
To perform this study, your technician or doctor will do the following:
- Tape electrodes on your skin over certain nerves and muscles that may be involved in your symptoms.
- Stimulate the nerves, one at a time, and obtain a nerve response or a muscle response displayed on a computer screen.
- Compare the responses to normal data to determine the health of your nerves and muscles.
EMG test: step by step
To perform this study, your doctor will do the following:
- Insert a very thin needle electrode into certain muscles, one at a time, that may be involved in your symptoms.
- Ask you to either relax or activate the muscles (e.g., relax or bend your elbow, relax or push down with your foot, etc.). This will allow your doctor to analyze the activity of the muscles — by listening to it and by looking at it on a computer screen — at rest and during activation.
Does it hurt?
Generally, the test is well tolerated, and your technician and doctor will make every effort to minimize any discomfort.
The NC study feels like static electricity or like a rubber band slapping against your skin. You may feel your muscles twitch.
During the EMG study, you may feel some discomfort or pain when the doctor inserts the needle into the muscle. Similar to bruising that can occur after a blood test, there may be bruising and/or soreness of the muscle for one or two days after the test.
Your test results
Your doctor will thoroughly explain your test results before you leave and address questions that you may have. If necessary, your doctor will educate you about your condition and discuss additional testing or treatment options with you.
Why choose Rush for NC and EMG testing
- Specialists in the Neuromuscular Disease Program at Rush are skilled at identifying and treating these diseases, even in their earliest stages.
- The program uses state-of-the-art electrodiagnostic technology for detecting neuromuscular diseases.
- The neurology and neurosurgery programs at Rush are consistently ranked among the best in the country in U.S. News & World Report.