My EMG (Nerve Conduction and Electromyography)
What does EMG stand for?
EMG stands for electro myo graphy.
Why am I having an EMG?
Usually another doctor looking after you will have referred you to a clinical neurophysiologist for an EMG. The clinical neurophysiologist will be a doctor who specialises in doing EMG tests.
There are many reasons why your own doctor may have referred you for an EMG and it is not possible to list all of them here. It is perfectly reasonable for you to ask the doctor sending you for the tests for the reason. Common reasons include trapped nerves or other nerve and muscle problems.
What does an EMG investigation involve?
The test usually involves two things. Firstly, we use mild electrical pulses to stimulate different nerves so that we can work out whether or not your nerves are working properly. We call these nerve conduction studies. Secondly, we may use fine needles put into muscles to test muscle function. This is the EMG (electromyography) part.
Does it hurt?
The electrical nerve tests or nerve conduction studies feel like little electrical shocks. Most people will find these a bit uncomfortable but will be able to tolerate it okay. Many people who have used a TENS machine say the feeling is very similar. The needle tests are also a bit uncomfortable but usually quite tolerable as the needles used are very thin similar to acupuncture needles. If there is anything that you feel you is too uncomfortable let the doctor know. Tests will be done in a different way or even stopped if you find them too uncomfortable. The doctor performing the tests should try to minimise your discomfort at all times but needs to do enough to try to come to a diagnosis.
Is it dangerous? Are there any side effects?
The equipment used is extensively tested and is safe. Some precautions need to be taken with certain patients who have heart pacemakers or are on blood thinning drugs such as warfarin. Inform the person doing your test if this affects you or if there is anything else about your medical history you think they should know about.
There are no serious side effects from an EMG. The electrical tests can sometimes make hands or feet tingle for a few minutes after but soon pass. The needle tests may result in slight bleeding as in a pinprick. Your muscles may also ache for a few hours after the needle tests but this is usually very minor.
Does a doctor always do my investigation?
No. Who does your tests depends on your particular problem and can also depend on how different clinical neurophysiology departments are organised. A trained person who is not a doctor may perform the electrical tests but a doctor will look at the results and write a report. Only doctors perform the needle tests in the United Kingdom.
Any practical advice?
You can help by wearing clothing that is loose and easily removed. Short sleeved clothes can make tests a bit easier to do. If possible do not wear jewellery that would be difficult to remove. Avoid wearing any skin moisturisers as they make it difficult to get good recordings.
How do I get my results?
Usually a report will be sent to the doctor who referred you for the EMG. This doctor will then pass on the information to you and your own GP. It is not always possible to give you the results on the day of your test. Sometimes it is better for the doctor in charge of your overall care to look at all the different test results he or she has ordered before discussing specific conditions. In some cases the doctor doing the EMG needs more time to study the results before coming to a conclusion.