Electromyography (EMG) and nerve conduction studies (NCS) are tests that evaluate and measure muscle and nerve function.
These two tests are performed together, EMG usually follows the NCS.
NCS is performed by mild electrical currents applied to the skin overlying the particular nerve that is being tested. A response is recorded from the corresponding muscle. This is done to measure how fast the electrical impulse travels between the examining points. EMG assesses the muscles function as well as gives information regarding the health of the nerves which control that particular muscle. To do this a fine needle is inserted into the muscle this needle then sends information to the recording device. No electrical currents are applied with the needle. These needles are specially designed to carry the electrical information back to the instrument, they are disposable and Teflon coated. There is minimal pain upon insertion into the skin and the muscle.
During the test wave forms appear on the screen. Measurements will be performed over the areas of test and transmitted to a computer which is incorporated in the instrument. These measurements and the wave forms and their shapes will help to determine the test results and the condition of the nerves and the muscles that have been tested.
Prepare for the test as instructed. Shower or bathe before the test. Avoid applying oil, cream, or lotion. You skin must be clean and free of oil. Beware that you may be asked to change into a hospital gown. Let the technician and the doctor know if you are taking any blood thinners, especially coumadin, have any bleeding conditions or any immune system disorder including HIV and AIDS. This is both for your protection as well as the technician and your doctor.
The entire test will take about one hour.