An Electromyogram (EMG) is an electrical test for the muscles and nerves. There are two types of EMG tests, the Nerve Conduction Studies and the Needle Examination. These tests can be done in-office and take on average between 30 minutes to two hours, depending on the extensiveness of the test. A physician may order an EMG for a patient who is having problems with their muscles or nerves. More specifically, for a patient who has a pinched nerve in the back or neck, tingling or numbness in the arms or legs, and weakness of the muscle or fatigue.
During an EMG, the patient will lie on the examination table beside the EMG machine, which looks very similar to a desktop or laptop. The Nerve Conduction is the first part of the EMG testing. The physician will begin by attaching small recording electrodes to the surface of a limb, and touching other points of skin to deliver the electrode shocks. During this part, short electrical shocks will be administered to the arm or leg indicating the speed at which your nerves are conducting the electrical current. This will provide the state of health or disease your nerves may be in. If the nerve is not functioning properly it will be evident due to the failure of the current not moving through it properly. This will create a tingling sensation, which may or may not cause pain during each shock. This may be repeated three to four times for each extremity being studied.
The second part of an EMG includes the needle examination. This begins by inserting a needle into the relaxed muscle, moving it inside to record the muscle activity. The physician will begin hearing a radio-static like sound, which is the sound of the muscle activity being amplified by the EMG machine. The needle insertion is usually performed on five to six muscles depending on the amount of muscles affected. This test is used to see if there is a nerve problem, or if the disease is in the muscle instead of nerve. When the needle is first inserted there may be pain, but when the needle is inside the muscle the patient may only feel discomfort or pressure.
There is minimal preparation for an EMG. The patient may drive to and from the test and may continue to take most prescribed medicine. Patients who are taking blood thinners or any medication for Myasthenia Gravis need to talk to their physician before beginning the EMG. After the EMG, you may immediately resume regular activity.Back To Top