What happens when... I get an EMG and nerve conduction study?
This post is a two-in-one, because an EMG and nerve conduction study are almost always done together. The EMG section comes with a serious trigger warning for needles, so the start and end of that section are clearly marked if you just want to read about nerve conduction studies.
Both of these tests are done to measure how well your nerves are working- specifically your peripheral nerves, which is everything but your brain and spinal cord. By measuring how those nerves send electrical signals through your muscles, the doctors can determine a lot more about the possible cause of any weakness, tingling, numbness, or pain youâre having. Donât worry, your nerves always function using electricity, thatâs not anything unusual!
Both of these tests are typically done by a doctor, often the same one who ordered it. The doctor may take measurements all the way up your arm/leg to your spine, meaning your upper back and/or butt might get poked and prodded too. If you wear a tank top or loose shorts, you might be allowed to stay in your clothes, but often youâll have to wear a cloth gown instead.
A nerve conduction study is typically done first, and involves absolutely no needles! Before or during the test, theyâll take some measurements of your limbs, and use a marker or pen to draw some little dots and lines on you. Theyâre just marking reference points to be consistent with their testing. Next youâll be connected to a few wires, using some combination of goopy stickers (like for a heart monitor) and wire loops that go around your fingers or toes. These all feed back into a machine that looks quite a bit like an old computer.
This part measures how quickly your nerves send signals by sending a quick pulse of electricity between the wires youâre attached to. If youâve ever used a TENS unit or had iontophoresis done at physical therapy, it feels almost the same as that. Just a split second of tingling/zapping sensation that makes your muscles twitch. Theyâll start pretty low (I barely felt the first ones) and turn it up until they get the measurement they need. For me, it was just unpleasant, but for some people it can be painful. Itâll take a few zaps for each spot theyâre measuring (shouldnât be more than 10) and then the wires get moved to the next spot. Even if youâre only getting one side tested, they may do a couple spots on the other side to compare.
***trigger warning for needles starts here****
EMG is short for electromyography. I had one doctor describe it as, âInstead of zapping you with electricity (like the nerve conduction study), you get to zap the machine!â What he meant was, instead of sending electricity through you like the nerve conduction study, the EMG measures the electricity your nerves are making on their own. Unfortunately, this is measured by sticking a needle in you- itâs between 1 and 3 inches long, but never goes all the way in. They choose the needle size based on how deep they need to go to get good test results in that spot. Some of that depends on your body shape, but it also depends on where particular muscles and nerves are inside you (itâs a little different for everyone!) The doctor pokes the needle perpendicular into a muscle, then slides it in a quick in-out motion a few times. So thereâs a little pinch when it goes in, and then it might hurt when they move it up and down. Iâve had three EMGs, and one I barely felt, one was excruciating, and one was in the middle. So I think it depends on the doctor, your body, and the size of the muscle theyâre measuring. For example, the needles in my hand hurt a lot. The one in my thigh was fine. While the needle is in there, theyâll ask you to make some small gentle movements (which will probably make the pain worse. Sorry.) Some of the spots might bleed a little when they pull the needle, and youâll probably have some little bruises the next day, but the doctors do try to avoid sticking you where it will bleed a lot.
An interesting thing about this test is that it gives results by transforming the electrical signals from you into static noises. Youâll hear moderate volume staticky-crackling noises whenever you or the needle moves, which I think is equal parts cool and annoying.
****trigger warning for needles ends here****
Itâs different for everyone, but you might be some level of sore after, ranging from âoh I have a tiny bruiseâ to âholy cow nerve pain I donât want to move.â If youâre worried and/or prone to nerve and muscle pain, definitely ask if youâre allowed to premedicate!
Since itâs usually the doctor doing the test, youâll probably be told basic results right away. Between the ouch of the test and the immediate results, it can be pretty draining so please take some time after to recharge if you can. đ
















