|
Questions About EMG Testing
What does EMG/NCS stand for?NCS is the abbreviation for nerve conduction study. NCS entails using a small electrical stimulus to record nerve activity. EMG is the abbreviation for needle electromyography. Needle electromyography is the study of electrical activity of the muscles and is done by inserting a small needle directly into the muscle to record the electrical activity. Surface electromyography uses electrodes placed on the surface of the skin and records non-specific electrical activity of the muscles beneath. Surface EMG is not allowed to be used in place of needle EMG in the EMG/NCS study. Why is my doctor sending me for this test?EMG/NCS is the "gold standard" test for evaluating nerve and muscle disease. This test can help to determine nerve damage, where it is, how bad it is and if it is old or new. Whereas an MRI creates a picture of anatomical structures, the EMG/NCS can evaluate the actual physiology and function of the nerves and muscles.Is this test painful?Each patient will have a different experience during this test and each test is specifically designed to address the particular problems that the patient is experiencing. Typically patients report that the test can be uncomfortable, but very tolerable. While there can be some nerves and muscles that are more sensitive than others, most patients report that the test was not as bad as they had previously assumed. Do I need to do anything special to prepare for this test?Patients should continue to eat and take their medications as normal. Taking pain medications will not change or "mask" the physiologic abnormalities of a damaged nerve even if they make the pain go away. Patients should avoid applying any creams, lotions or oils on the day of the exam prior to being tested. It is often helpful to wear shorts, tank tops or loose clothing to the visit to allow for easy access to the extremities. Depending on the nerves and muscles being tested, patients may need to remove additional clothing.
Who is qualified to perform this exam?Three groups of providers typically perform this exam: Physical Therapists, Neurologists and Physiatrists (Physical Medicine and Rehabilitation). These providers are qualified to perform both the nerve conduction and needle EMG portions of the exam. Some physicians will use a technician to perform the nerve conduction portion of the exam, but the needle EMG must be performed by either a physical therapist or a physician. Can you make a diagnosis based solely on this exam?The medical literature is clear that a diagnosis cannot and should not be made based solely on the EMG/NCS exam. A diagnosis is made only after incorporating the patient's history, physical examination, lab work, imaging studies, other tests, etc. Making a diagnosis based only on the findings of an EMG/NCS is inappropriate and at best poor healthcare practice. |
