What is an EMG/NCS
Your doctor has ordered an EMG (electromyogram) and an NCS (nerve conduction study) for you. An EMG/NCS is the electrical study of your nerves and muscles. This study helps your doctor to decide on the cause of your symptoms and plan the best treatment for you. There is no special prep for the test. If you have any questions about an EMG/NCS, be sure to ask your doctor or nurse.
Location of the EMG/NCS lab
If you are an inpatient, we will come to your bedside for the test.
If you are an outpatient, you will register in the clinic lobby on the 2nd floor of the UWHC. After registration, please come to the J5/2 lobby at the scheduled time. Volunteers at the information desk can direct you to the lab.
Nerve conduction study (NCS)
The NCS is the first part of this test. It studies your nerves. Small metal discs are taped on your skin based on the nerves that are going to be tested. Then, a small electrical current is used to stimulate the nerve. This electrical testing will be done on several nerves and may be done at different sites along the nerve. The electrical current produces a tingling, slightly uncomfortable sensation. The testing room may be darkened so that the electrical activity can be seen easily on a computer monitor.
Electromyogram (EMG)
The second part of this test is an EMG, which studies your muscles. First, a small metal disc (about the size of a fifty-cent piece) will be taped to your skin. Then, the EMG doctor will insert a small needle into your muscle in order to record your muscle’s electrical activity. EMG testing may be done on several different muscles but each muscle is tested one at a time. During the test, you will hear a crackling speaker sound. This is the electrical activity from your muscles, which has been changed into sound waves. You do not receive any electrical stimulation for this part of the test. The EMG can be somewhat uncomfortable because of the small needle sticks. For a day or two after the test, you may feel some tenderness or notice a small bruise around the sites where the needle was inserted.
The entire EMG/NCS testing takes about 1 to 1½ hours. After the test, we will send the test results to the doctor that referred you to us for testing. If you have further questions, please feel free to call us at (608) 263-7247 or 1-800-323-8942. Ask for the EMG/NCS department.
The Spanish version of this Health Facts for You is #7118.
The information provided should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Any duplication or distribution of the information contained herein is strictly prohibited.
Last Updated: 07/11/2011
Copyright © 07/08/2011 University of Wisconsin Hospitals and Clinics Authority. All rights reserved. Produced by the Department of Nursing. HF#4303
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