Finding the source of your pain, weakness, numbness or tingling often takes some investigation. One of the tests your physician may use to help diagnose your symptoms is an Electrodiagnostic test. This test measures the electrical activity in muscles and nerves and indicates if there is damage. This helps our specialist narrow down the source of your pain. For example, muscle weakness or paralysis might be a problem in the muscles, the nerves supplying the muscles, the spinal cord or the area in the brain that controls the muscles.
There are two components to Electrodiagnostic testing. They include an Electromyograph (EMG) and a Nerve Conduction Study (NCS).
Electromyography (EMG) measures electrical activity within the muscles using a very small needle. It can detect the severity and/or degree of nerve or muscle damage that may result in muscle weakness. It can evaluate the healing of a damaged nerve or muscle. It is also used to predict the degree of nerve or muscle recovery.
For patients who are experiencing weakness, spasticity or poor muscle control as it relates to walking (gait), our specialist is uniquely qualified to perform a functional EMG. This may help your surgeon determine if surgery is needed to regain ankle and foot balance to improve your gait.
A Nerve Conduction Study (NCS) test measures electrical impulses as they travel through the nerves that provide both sensation (feeling) and movement (muscle control) and help our experts detect signs of nerve injury. Examples of a nerve injury might include nerve entrapment at the wrist (i.e. carpal tunnel) and peripheral polyneuropathy (i.e. tingling in your hands and feet), to name some common types of nerve damage. Other studies, such as CT or MRI, look at the anatomy whereas EMG looks at the physiology (function) of your nerves and muscles. Therefore, these studies are complementary.
How should I prepare on the day of the test?
Shower or bathe the day of the test. However, do not apply lotions or oils.
The test can be performed if you are taking a blood thinner (i.e. Aspirin, Plavix, Coumadin, ELIQUIS or XARELTO), however, it is important to inform your EMG physician.
The EMG test generally takes 45 to 90 minutes.