An electromyography, or EMG test, is often used to better diagnose and detect a wide range of neuromuscular disorders.
Learn more about EMG tests and what to expect from a UVA specialist in neurology.
What is an EMG?
Featured Speaker:
Dr. Sarah Jones
Dr. Sarah Jones is a board-certified neurologist whose specialties include clinical neurophysiology and EMG testing. Transcription:
What is an EMG?
Melanie Cole (Host): Electromyography or EMG test is often used to better diagnose and detect a wide range of neuromuscular disorders. My guest today is Dr. Sarah Jones. She’s a board certified neurologist whose specialties include clinical neurophysiology and EMG testing. Welcome to the show, Dr. Jones. Tell us, what is an EMG?
Dr. Sarah Jones (Guest): Hi, thanks for having me. An EMG is a test called electromyography which can be primarily used to help evaluate the health of the nerves and muscles. It’s also used to ascertain nerve dysfunction or muscle dysfunction and also disorders of communication between the nerves and muscle.
Melanie: Why would you use an EMG?
Dr. Jones: Well, there are several reasons why an EMG could be used. Most of our patients come to us because they're having symptoms of tingling or numbness and possible muscle weakness, muscle pain, cramping, or sometimes, neck or back pain. And so, an EMG can be used to figure out, are these symptoms a sign of some kind of dysfunction of the neuromuscular system? Physicians use the test to help support a diagnosis or rule out a diagnosis. So for example, somebody has tingling in their hand, there’s a few different nerves that can cause that. It can be caused by carpal tunnel syndrome, for example, or it could be caused by a pinched nerve in the neck. An EMG is a very useful test to help distinguish those two things.
Melanie: Are there any risks to this test? Does it hurt at all?
Dr. Jones: That’s a very good question. That’s probably one of the biggest questions that our patients ask us. So before I go into the risks and does it hurt, I want to talk a little bit about what an EMG is, what a patient would experience. There are two different parts to the EMG test. The first part is something called nerve conduction studies. With that first part of the test, what we’re looking for is how the large sensory and motor nerves are transmitting electrical impulses, because your nerves actually act like wires. So during this part of the test, an electrical impulse is applied with tiny electrodes at one part of the nerve, and then it's recorded at the other part of the nerve. This is just done with electrodes that stick on to the skin. The specialist is measuring how quickly those impulses travel, how strong they are, and whether there’s any distortion of the impulse’ signal. The second part of the test is called the needle EMG, and, yes, unfortunately it does involve a needle. But what is really interesting is most people, when they're going through this test, they're pretty amazed to see how their muscles are working, because you can see it in real time. So, what happens is your motor nerves are transmitting electrical signals to the muscles, and what we’re doing is recording it with a tiny needle. The needle is placed into the skin and into the muscle. What we’re doing is ascertaining what the muscles are doing while they're relaxed and also what they're doing when you activate the muscle. The EMG machine is translating these signals into graphs and sounds and numerical values that the electromyographer then interprets to determine, is it healthy or unhealthy? So in regards to does it hurt, that’s a very good question, and most people would say, yeah, probably getting electric shocks and needles is not a walk in the park. It’s not something you want to do every day. But we actually did a very brief evaluation in our neurological EMG lab last year. We asked everybody who came through the lab to document at the end of the test how bad was it on a scale of 1 to 10, what exactly was their experience and which part was worst for them. It was actually pretty split as far as which part was worse. I would say 50 percent said that the first part, the nerve conduction, was worse with the shocks, and then about the other half said the needle part was worse. But surprisingly, most people rated that as far as how bad the pain was, it was really only a 3 out of 10. So most patients’ experience was that, yeah, it's not comfortable, but it's not too awful compared to what their anticipation, what their anxieties about the test were. In regards to risks, there are very few risks involved in this test. Complications for this test are pretty rare. There is a small risk of bleeding and infection because, of course, we use needles. It would be very important for you to tell the person doing the test if you take any kind of blood thinners, because we would want to avoid any deep muscle on our evaluation. We do the test with folks who have pacemakers, and there is no risk to doing the test when we’re studying the arms and legs. If a person has a pacemaker, it's not going to necessarily disrupt the pacemaker. Or if they have an ICD, it's not necessarily going to discharge it. But doing studies around the neck, that would be something that we would take with a little bit more caution and just make sure that we have any kind of additional precautions available if we’re going to go ahead and do any of those more proximal neck or arm studies.
Melanie: Dr. Jones, who does this test, where is it performed, and are there other tests that can be used instead?
Dr. Jones: The test can be performed by a variety of different doctors at UVA. We have the physiatry team over at the Fontaine location who performs the EMG, and then we also have the neurological team. At this time, we’re performing the test at three different locations: at the main hospital, the primary care center, and the neurology clinic there, also the neurology clinic at Fontaine and the neurology clinic at Zion Crossroads. The team who performs this test includes a technician who has been trained specifically to do the nerve conduction studies, and this is completely supervised by a board certified neurologist at any one of these locations. And then the needle EMG is performed by a variety of neurologists. At UVA, we have EMGs that are performed by the attending physicians and also by our neurophysiology fellows, and that is then supervised by the attending physician.
Melanie: So why should patients with neurological conditions come to UVA?
Dr. Jones: That’s an excellent question. EMGs are something that you certainly can train over a weekend and learn how to do or you could do a year-long fellowship. At UVA, everybody who is participating in the EMG has been specifically trained for this purpose. Our technicians are very skilled, and the physicians supervising are all board certified and have trained for over a year or more for this specific procedure. We feel that the neurology department is able to take the EMG and use it along with the other team members in a multidisciplinary kind of approach and apply it to help clarify the diagnosis to allow the patients to have the best care possible.
Melanie: Dr. Jones, we have just a few minutes left. Tell us a little bit about what patients can expect from the results. How long does it take to get results? Do they get them immediately, right there in the room with the doctor conducting the test? Do they wait a few days? And what do the results tell them?
Dr. Jones: That’s a great question. Depending on the EMG and how complicated the test is, most often, the patients will have some kind of preliminary results when they're there in the clinic. But oftentimes, we will have to go through the numbers, go through the patient’s evaluation if they were seen in the clinic, or go through their history and compute the data before knowing exactly what the final results are. That report though, we generate the same day and send it to their doctor. So although they don't necessarily have the finalized results while they're still here in the clinic, they will have a finalized report sent to their doctor within 24 hours.
Melanie: And then you can help them understand what it is that the results even showed.
Dr. Jones: Right, right. It certainly is something that can be used to help guide additional treatment. Of course, when we’re seeing patients in the clinic just for the EMG test, we don't necessarily have the full context. So oftentimes, we may not have our MRI results or necessarily know all about their family history and so on, so it really oftentimes will take a full clinic evaluation to really be able to use the EMG results in the clinical context to give an accurate diagnosis and develop an accurate treatment plan.
Melanie: Thank you so much, Dr. Sarah Jones. You’re listening to UVA Health System Radio. For more information, you can go to uvahealth.com. This is Melanie Cole. Thanks so much for listening.
What is an EMG?
Melanie Cole (Host): Electromyography or EMG test is often used to better diagnose and detect a wide range of neuromuscular disorders. My guest today is Dr. Sarah Jones. She’s a board certified neurologist whose specialties include clinical neurophysiology and EMG testing. Welcome to the show, Dr. Jones. Tell us, what is an EMG?
Dr. Sarah Jones (Guest): Hi, thanks for having me. An EMG is a test called electromyography which can be primarily used to help evaluate the health of the nerves and muscles. It’s also used to ascertain nerve dysfunction or muscle dysfunction and also disorders of communication between the nerves and muscle.
Melanie: Why would you use an EMG?
Dr. Jones: Well, there are several reasons why an EMG could be used. Most of our patients come to us because they're having symptoms of tingling or numbness and possible muscle weakness, muscle pain, cramping, or sometimes, neck or back pain. And so, an EMG can be used to figure out, are these symptoms a sign of some kind of dysfunction of the neuromuscular system? Physicians use the test to help support a diagnosis or rule out a diagnosis. So for example, somebody has tingling in their hand, there’s a few different nerves that can cause that. It can be caused by carpal tunnel syndrome, for example, or it could be caused by a pinched nerve in the neck. An EMG is a very useful test to help distinguish those two things.
Melanie: Are there any risks to this test? Does it hurt at all?
Dr. Jones: That’s a very good question. That’s probably one of the biggest questions that our patients ask us. So before I go into the risks and does it hurt, I want to talk a little bit about what an EMG is, what a patient would experience. There are two different parts to the EMG test. The first part is something called nerve conduction studies. With that first part of the test, what we’re looking for is how the large sensory and motor nerves are transmitting electrical impulses, because your nerves actually act like wires. So during this part of the test, an electrical impulse is applied with tiny electrodes at one part of the nerve, and then it's recorded at the other part of the nerve. This is just done with electrodes that stick on to the skin. The specialist is measuring how quickly those impulses travel, how strong they are, and whether there’s any distortion of the impulse’ signal. The second part of the test is called the needle EMG, and, yes, unfortunately it does involve a needle. But what is really interesting is most people, when they're going through this test, they're pretty amazed to see how their muscles are working, because you can see it in real time. So, what happens is your motor nerves are transmitting electrical signals to the muscles, and what we’re doing is recording it with a tiny needle. The needle is placed into the skin and into the muscle. What we’re doing is ascertaining what the muscles are doing while they're relaxed and also what they're doing when you activate the muscle. The EMG machine is translating these signals into graphs and sounds and numerical values that the electromyographer then interprets to determine, is it healthy or unhealthy? So in regards to does it hurt, that’s a very good question, and most people would say, yeah, probably getting electric shocks and needles is not a walk in the park. It’s not something you want to do every day. But we actually did a very brief evaluation in our neurological EMG lab last year. We asked everybody who came through the lab to document at the end of the test how bad was it on a scale of 1 to 10, what exactly was their experience and which part was worst for them. It was actually pretty split as far as which part was worse. I would say 50 percent said that the first part, the nerve conduction, was worse with the shocks, and then about the other half said the needle part was worse. But surprisingly, most people rated that as far as how bad the pain was, it was really only a 3 out of 10. So most patients’ experience was that, yeah, it's not comfortable, but it's not too awful compared to what their anticipation, what their anxieties about the test were. In regards to risks, there are very few risks involved in this test. Complications for this test are pretty rare. There is a small risk of bleeding and infection because, of course, we use needles. It would be very important for you to tell the person doing the test if you take any kind of blood thinners, because we would want to avoid any deep muscle on our evaluation. We do the test with folks who have pacemakers, and there is no risk to doing the test when we’re studying the arms and legs. If a person has a pacemaker, it's not going to necessarily disrupt the pacemaker. Or if they have an ICD, it's not necessarily going to discharge it. But doing studies around the neck, that would be something that we would take with a little bit more caution and just make sure that we have any kind of additional precautions available if we’re going to go ahead and do any of those more proximal neck or arm studies.
Melanie: Dr. Jones, who does this test, where is it performed, and are there other tests that can be used instead?
Dr. Jones: The test can be performed by a variety of different doctors at UVA. We have the physiatry team over at the Fontaine location who performs the EMG, and then we also have the neurological team. At this time, we’re performing the test at three different locations: at the main hospital, the primary care center, and the neurology clinic there, also the neurology clinic at Fontaine and the neurology clinic at Zion Crossroads. The team who performs this test includes a technician who has been trained specifically to do the nerve conduction studies, and this is completely supervised by a board certified neurologist at any one of these locations. And then the needle EMG is performed by a variety of neurologists. At UVA, we have EMGs that are performed by the attending physicians and also by our neurophysiology fellows, and that is then supervised by the attending physician.
Melanie: So why should patients with neurological conditions come to UVA?
Dr. Jones: That’s an excellent question. EMGs are something that you certainly can train over a weekend and learn how to do or you could do a year-long fellowship. At UVA, everybody who is participating in the EMG has been specifically trained for this purpose. Our technicians are very skilled, and the physicians supervising are all board certified and have trained for over a year or more for this specific procedure. We feel that the neurology department is able to take the EMG and use it along with the other team members in a multidisciplinary kind of approach and apply it to help clarify the diagnosis to allow the patients to have the best care possible.
Melanie: Dr. Jones, we have just a few minutes left. Tell us a little bit about what patients can expect from the results. How long does it take to get results? Do they get them immediately, right there in the room with the doctor conducting the test? Do they wait a few days? And what do the results tell them?
Dr. Jones: That’s a great question. Depending on the EMG and how complicated the test is, most often, the patients will have some kind of preliminary results when they're there in the clinic. But oftentimes, we will have to go through the numbers, go through the patient’s evaluation if they were seen in the clinic, or go through their history and compute the data before knowing exactly what the final results are. That report though, we generate the same day and send it to their doctor. So although they don't necessarily have the finalized results while they're still here in the clinic, they will have a finalized report sent to their doctor within 24 hours.
Melanie: And then you can help them understand what it is that the results even showed.
Dr. Jones: Right, right. It certainly is something that can be used to help guide additional treatment. Of course, when we’re seeing patients in the clinic just for the EMG test, we don't necessarily have the full context. So oftentimes, we may not have our MRI results or necessarily know all about their family history and so on, so it really oftentimes will take a full clinic evaluation to really be able to use the EMG results in the clinical context to give an accurate diagnosis and develop an accurate treatment plan.
Melanie: Thank you so much, Dr. Sarah Jones. You’re listening to UVA Health System Radio. For more information, you can go to uvahealth.com. This is Melanie Cole. Thanks so much for listening.