A physical medicine specialist explains what to expect during EMG testing.
If you experience tingling, numbness, muscle weakness, pain or cramping in the wrist, arm or leg, your physician may order an EMG, orelectromyography testing. The procedure assesses the health of muscles and nerves. EMG testing can help diagnose conditions such as carpal tunnel syndrome (in which a nerve is compressed in the wrist); a pinched nerve from a herniated spinal disc (in which a spinal disc, which acts as a shock absorber, bulges or ruptures); and other disorders, including diabetes-related peripheral neuropathy.
Charles Markowitz, MD, Medical Director of the Department of Rehabilitation, performs about 100 tests per year. Here, he explains how the test works.
What happens during EMG testing?
There are two parts to the procedure. In the first, called a nerve conduction study, tiny electrodes are placed on the skin. A small electrical current is delivered to stimulate specific nerves. A machine called an oscilloscope—a monitor that displays electrical activity—measures the speed at which an electrical current travels through a nerve. If it takes longer than expected for a nerve impulse to travel to a muscle, that particular nerve may be injured. In the second part of the procedure, called EMG testing, the physician inserts thin pins (similar to those used in acupuncture) into muscles, one at a time. The patient rests, then moves his or her muscles. The oscilloscope measures the muscles’ electrical responses. By placing the pins in different muscles, the physician can determine which nerve is injured or malfunctioning.
Is the test painful?
Many patients are anxious beforehand, but the testing doesn’t cause much discomfort. Patients feel their muscles twitch in a nerve conduction study, but it’s not painful.
Are there any risks?
There may be minor bruising after EMG testing, but it fades after a few days. Sterile pins are used to prevent infection. How quickly will I receive a diagnosis? Results are analyzed in real time, so a diagnosis is usually immediate. I discuss the results with patients. Of course, I always recommend that patients follow up with their physician.
How should I prepare for the test?
Take a shower or bath the night before, but avoid applying any creams or body
lotions. If you have a pacemaker, inform the doctor who is performing the test.
To schedule a consultation for EMG testing, call: 888.724.7123