Electromyography (EMG) and Nerve Conduction Studies (NCS) are utilized for the evaluation of muscles and nerves to determine if they are working properly. Abnormalities in this test provide information regarding possible nerve or muscle injury, where the injury is located, and on occasion when it occurred and the likelihood of recovery.
An EMG involves use of a small Teflon-coated pin inserted into various muscles to measure their electrical activity—a bit like placing a radio antenna into the muscle. Characteristic findings on the exam can help to identify possible nerve or muscle damage. This test is usually well tolerated by most patients, but can be a bit uncomfortable. Please make sure to tell your doctor if you are on any blood thinners.
Nerve conduction studies are performed with small electrical stimulations applied to nerves to determine how quickly and how fully they conduct electrical impulses. Abnormalities may suggest nerve injuries or illnesses. These electrical stimulations are safe for patients with pacemakers or internal defibrillators.
WHAT SIDE EFFECTS CAN I EXPECT?
An EMG can provide a good deal of useful information with few serious side effects. Occasionally the pin can cause a small bruise. This is more common in patients on a blood thinner (such as Coumadin) or anti-inflammatories (such as ibuprofen). Infections carried into the body by the pin are exceedingly rare (the natural defenses of the skin and the small diameter and slick Teflon coating of the pin reduce this risk). As nothing is injected through the pin, the EMG does not make you drowsy or cause other types of reactions.
CAN I HAVE THIS TEST IF I AM PREGNANT?
Yes. It can be done during pregnancy and will not harm your baby.
DO I HAVE TO STOP MY MEDICATIONS OR FAST?
No. It is helpful to show the doctor a list of medications you are currently using. It is also not necessary to fast before this test.
CAN I DRIVE AFTER THE TEST?
Yes. The test does not affect your ability to drive.
CAN I RETURN TO WORK AFTER THE TEST?
Yes. The test does not affect your work status.
DOES THE EMG HAVE A THERAPEUTIC VALUE?
An EMG/NCS is a test, not a treatment. It is not to be confused with acupuncture, which also uses a pin. Occasionally patients do report decreased pain following an EMG, but this is not a reason to do the test.