Millions of Americans suffer from chronic pain. Chronic pain is the leading of cause of disability and interferes with all aspects of daily living. People who suffer from chronic pain lose time off work and often alienate their families due to complaints and inability to partake in some activities.
Help may often be found at a pain management center. The first step is to identify the cause of the pain. This requires certain diagnostic testing. An electromyography (EMG) may be used to identify the function and activity of nerves.
Overview of an EMG
An EMG is a test that determines if the nerves that control the muscles, called motor neurons, are acting the way they are supposed to and whether or not the muscles are healthy. It is often done at the same time as a nerve conduction velocity test.
The results of the test provide valuable information to a pain control practitioner and help identify whether the chronic pain is the result of muscle weakness, a neurologic disorder, or some other nerve dysfunction that may be causing the pain. Some symptoms patients may have that indicate the need for an
- Muscle cramping and pain.
- Tingling sensation and numbness in the arms, legs or both.
- Muscle weakness.
- Other types of pain involving the arms, legs or both.
There are certain types of conditions that are commonly diagnosable from an EMG. They include:
- Disorders of the peripheral nerves, which are nerves that are outside the spinal column. Some of these disorders include peripheral neuropathy and carpal tunnel syndrome.
- Disorders of nerve roots, such as a herniated spinal disc resulting in sciatica pain.
- Uncommon disorders and diseases like muscular dystrophy or myasthenia gravis.
There are a number of other neurological disorders practitioners can identify through the EMG results. The information enables them to determine if other tests are needed and what types of pain management techniques may be the best.
There is no preparation required before for the test. Patients just arrive at the testing center at the appointed time. There is no requirement to abstain from food or drink prior to the test. The practitioner performing the test will ask patients if they have a pacemaker and may inquire as to what medications they are taking.
The EMG Exam
Patients may be asked to change into a hospital gown. Patients lie down and get comfortable on an examination table. Electrodes are placed on various places on the surface of the skin depending on where the pain is located and the types of symptoms that have been expressed by the patient.
Very thin needles are then inserted into the skin and into the muscles. A topical anesthetic is used to reduce any pain or discomfort that might occur when the needles are inserted.
As the test proceeds, the electrodes are activated and transmit just enough electrical current to test the reaction of the muscles and the nerves. When the electrodes are activated, patients may feel a spasm or twinge. At times during the test, patients may be asked to contract muscles, and then relax them. If there is any pain or discomfort, it will only be momentary.
On a graph or chart, the electrodes record muscle activity both while the muscles contract and while the muscles are at rest. The pain practitioner will evaluate the test results and determine if any abnormality exists that is the cause of the pain.
EMGs are low risk procedures. There may be some tenderness of the muscles for a few days after the test is over. Any slight bruising of the skin where the needles were inserted, if it occurs at all, will not last more than a few days.
End of Procedure
When the procedure is over and the needles and electrodes removed, patients return to their homes. The practitioner who performed the test will analyze the results and send a report to the patients primary care physician or pain management specialist, depending on which professional ordered the test.