Electromyography (EMG) and nerve conduction studies (NCS) are tests that measure nerve and muscle function. In most cases, both tests are performed and NCS is often done first.
The NCS portion of the test consists of mild electrical currents applied to some parts of your body. This helps determine how quickly impulses travel between your nerves. EMG determines muscle function. A fine needle on a wire is placed under the skin at each muscle testing site. This needle determines electrical muscle activity, though no electrical currents are applied with the needle. It is non-evasive, which means that the needle does not enter your bloodstream.
During the test, there will be wavy lines on the screen of the EMG machine. These lines represent how well your nerves and muscles are functioning and help Dr. Tashjian determine your test results.
EMG/NCS testing does not require fasting. Simply shower or bathe, but don't use powder, oil or lotion. You may be asked to change into an examination gown. You may also be asked questions about your overall health. The entire test will take approximately 30 minutes. Be sure to allow extra time to check in.
Once you are in the exam room you will be asked to prepare for the test depending upon the extremities to be tested. For upper extremity examinations, we ask patients to remove everything from the waist up and anything on the wrists such as a watch or bracelet. Women may leave on their brassiere and put an examination gown on. For lower extremity examinations, we ask patients to remove everything but their underwear, including shoes and socks and put on an examination gown. All gowns should be worn with the opening in the back.
During the nerve conduction study portion of the test, small metal disks called electrodes will be taped or held to your skin on the area of your body that is being tested. Dr. Tashjian uses a small amount of conductive electrode cream at the electrode areas. You will experience muscle twitching during the test; however the test will not harm you. Testing may continue on other parts of your body as needed.
For the electromyographic portion of the test, most of the electrodes will be removed and Dr. Tashjian will clean the area being tested with an alcohol swab. A fine needle at the end of a wire will be inserted into the muscles of the region being tested. When the needle is inserted there will be a slight pinching sensation.
Before you leave, all electrodes will be removed. You can get right back to your normal routine, as there are no side effects to the EMG/NCS test. Dr. Tashjian will let you know when your test results will be ready.