Nerve Conduction Velocity and Electromyography

Electrical currents in your organs and tissue control many of your bodily functions. Nerve conduction velocity (NCV) and electromyography (EMG) tests record these electrical currents, helping physicians diagnose nerve and muscle problems. The NCV, which measures the speed at which your nerves carry electrical signals, will be performed before the EMG, which analyzes the nerve impulses within certain muscles.

How to Prepare

Please arrive for this outpatient procedure at the time and location given to you.

Please do not apply lotions or oils to your skin on the day of your exam.

You may eat and drink as usual and remain active right up until the time of your appointment.

Do not take any aspirin or aspirin-containing products including Alka Seltzer, Anacin, Bufferin, and Empirin for one week prior to your appointment. Also, do not take Darvon, Naprosyn, Voltaren, Indocin or any products containing ibuprofen including Advil and Motrin for one week prior to your appointment. You may take Tylenol and acetaminophen.

Please notify your CINN physician if you are taking any aspirin or aspirin-containing products, or if you are on any blood-thinning medications such as Coumadin. Your dosage may be adjusted in preparation for the NCV and EMG.

What to Expect

Once you are settled in your room, you will be asked to disrobe and put on a hospital gown for this examination. Next a neurologist will tape small disks (electrodes) on your skin along each nerve to be tested. Then a small instrument will send an electrical current under the electrodes along the nerve, creating a mild shock. You will experience minor discomfort for only a few seconds. Computerized equipment will record how quickly the current passes between the electrodes.

The EMG will be performed next. To perform this test, the neurologist will gently insert a thin needle electrode into each muscle to be studied. You may experience a brief, sharp pain each time a needle is inserted. A fine wire that leads from each needle to a computerized instrument measures your nerve impulses during the test. During the EMG, the needle electrodes will generate electric stimulation, which may be slightly uncomfortable. The neurologist will ask you to move into different positions so that he or she can evaluate how specific muscles respond.

The NCV and EMG together take approximately 45 to 60 minutes to complete, depending on how many of your nerves and muscles are tested.

You may experience some soreness for a few hours after the exams. Feel free to resume your normal activities whenever you wish.