Nerve Conduction Study (NCS) and Electromyography (EMG)

Nerve conductions studies (NCS) and electromyography (EMG) are two separate, and very high-yield tests that are done to allow the physician to examine your nerve function and see how the nerve communicates with the muscles in your arms and/or legs. The NCS is done first and is followed by the EMG. The entire process takes anywhere from 45-60 minutes. The NCS is done by the technician placing small electrodes over the skin while sending small electrical signals through an instrument. This allows the physician to assess how the nerves are able to transmit a signal. This component usually is painless. Some patients say it is uncomfortable while others have said it feels good. During the EMG component of the test, the physician will insert a very thin needle (smaller than an acupuncture needle) into the muscle and ask you to activate the muscle. This is the best test to check how the nerve is communicating with the muscle. Many patients claim they can’t even feel this part of the test while others may say it is uncomfortable. Either way, the EMG test is not long and is done relatively quickly compared to the NCS. After the NCS and EMG are done you can go about your normal day as planned. The physician will interpret the data and later discuss the results with you.

How to prepare for the NCS and EMG

  1. Please arrive 15 minutes prior to your test time.
  2. Do not wear any lotion or oils on your arms or legs before the test.
  3. No small children please.
  4. Eat, sleep, and take your medications as you would normally do prior to your test.
  5. If you smoke, please do not do so until after your test.
  6. Notify the technician and physician if you are on any blood-thinning medication (Coumadin, Warfarin, Pradaxa) before the test and the day of the test.