EMG / NCS
What are Nerve Conduction Studies (NCS) and Electromyography (EMG)?
Nerve Conduction Studies (NCS) involves using small electric pulses to stimulate the nerves in the arms and/or legs to see how fast your nerves send their messages. Electromyography (EMG) involves putting a very fine electrode like an acupuncture needle into selected muscles to see how well your muscles are working. Depending on the problem being examined, you may require one or both procedures.
Who gets an NCV test?
An NCV test can be used to diagnose a number of muscular and neuromuscular disorders, including:
- Carpal Tunnel Syndrome
- Herniated Disk Disease
- Chronic Inflammatory Polyneuropathy and Neuropathy
- Peripheral Neuropathy
- Sciatic Nerve Injury
- Peripheral Nerve Injury
- Damaged Nerve
- Back / Neck pain
- Muscle weakness
An Electromyography (EMG) Test is often performed alongside an NCV Test. An EMG test records the electrical signals moving through your muscles. This helps detect the presence, location, and extent of any disease that may damage the nerves and muscles.
Before the procedure:
It is essential that you inform us as soon as possible (please telephone) if:
You have a cardiac pacemaker (especially if it is the type that can deliver shocks to restart your heart such as an Implanted Cardiac Defibrillator) or any other implanted device for which you have had batteries inserted under your skin. Please bring any details you have about your pacemaker with you.
You are taking Warfarin or another tablet to thin your blood for which you must attend for blood test monitoring (aspirin is not a problem). The doctor will need to see your latest INR result (bring your booklet with the results and test dates if possible).
It is helpful if you wear loose fitting clothing such as a short-sleeved top, loose fitting trousers (which can be rolled up above the knee) or a skirt are advisable or you will be asked to change into a hospital gown for the procedure. You will be asked to take off your shoes and socks/tights/stockings. If the weather is cold, it is helpful if your hands and feet are kept warm by wearing gloves and socks.
Please do not apply any lotions or oils on your skin on the day of the examination as this may interfere with the study. You will also need to remove any rings, watches or bracelets.
Continue to take any medicines as usual and please bring a list of your current medication with you.
During the procedure:
The tests usually take 30 minutes to 1 ½ hours depending on the complexity of the problem. Our doctor and a nurse will perform these tests. There is also room for someone to come with you.
First, we may need to warm up your hands and/or feet in warm water or wrap in blanket and then there may be two parts to your test:
In Nerve Conduction Study (NCS): We put sticky pads on your arms or legs. You need to relax your muscles in this procedure. When the machine is turned on, this feels a little like someone is tapping on your arm or leg. Sometimes it makes your arm or leg jump. Some patients may find this uncomfortable but it is tolerable.
In Electromyography (EMG): If you need this part of the test, we will use a very thin needle to put into some of your muscles. This is like a microphone and we can hear your muscle working.
After the procedure:
Nerve Conduction Studies do not have any side effects. After Electromyography, the muscles into which the needle has been placed may ache a little for a few minutes. Rarely, there may be a small bruise. If there is any persistent pain or swelling you should inform us.
The results of the study will be sent to the referring doctor or you can get it from us. You will not get the results immediately after the test as it takes time to analyze. If you have any queries or concerns, please do not hesitate to contact us before your appointment.