Neuro Appt tomorrow, what to ask during EMG?

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Jun 11, 2008
I have a 2nd EMG tomorrow. The last time I had one (3 months ago) my neurologist said it was 'fine' and left it at that. I'm having more fascics now. My questions would be:

1) Would BFS show up on an EMG? I had a brisk reflexes last time but no atrophy/weakness. Does the EMG differentiate between benign and als fascicilations?

2) If i don't actually twitch during the EMG, does that mean the nerve damage will not be picked up?

Hi ... I'm no expert on any of this, but about Question #2, my impression from the 2 eMGs I've had is that they are not measuring "twitches," or anything visible like that. They will stimulate the nerve, and determine if its response is normal, and determine if denervation is present.

Not sure about Question #1.

Good luck on the test!

I am not an expert either, but if you are have benign fasciulation these would not show on 'EMG'. They are looking for 'acute and chronic denervation', positive sharp waves, fibrillation, fasciculation, and motor units that are increased during polyphasic part of exam.
Mine showed mild and acute axonal involvement with some of the other things from above.
If the doctor does the 'EMG' he/she will likely tell you right then and there that they see trouble.

Good luck with your exam.

Benign fascilations do show on emg, if they are combined with other spontaneous activity fibs, sharpwaves.
then most likely the dr will say they are not benign. Yes the needle can pick -up fascilations that you aren't feeling at the time. good luck, and keep us posted....hopefully your emg will be clean and put your mind at ease.
oops! sorry if I made a mistake!

loveliy- don't worry about the mistake... i just wanted to correct it..... I am no expert either. How are you doing, I read some of your posts and you are still in limboland as well. What are the drs saying about the 2 different results from the muscles biopsies. Can I ask you what your symtoms are?

rjteach- A sharpwave is a form of spontanious activity as far as I know, they say it is similar to a fibrillation.
Hello sigmafloyd

1) As crystal said, fasics will be picked-up by EMG if they are benign or pathologic and even if there aren't any fibrillations and postive sharp waves (I'll explain what those are in just a second) present, they can still differentiate a benign and pathologic fasic (some time ago they couldn't do that, but new studies show that they can).

2) Nerve damage will be picked-up regardless of whether twitching is present or not.

RJ . . . what is a positive sharp wave. A positive sharp wave is spontaneous electrical activity generated by single muscle fibers. They are present when a muscle is denervated (i.e. loses contact with a nerve, which can be caused by many reasons) and that causes the muscle fibers (individual muscle fibers make-up a muscle) to become electrically active all by themselves (under normal conditions, muscle fibers should be electrically silent when they are not being stimulated by the axons of nerves . . . and bundles of axons make-up a nerve, much the same way that bundles of strings make-up a rope). There is another type of spontaneous electrical activity that is picked-up by the EMG called fibrillations that are also caused by denervation. The presence of these indicates that the muscle is being actively/acutely denervated.
If there is chronic denervation (i.e. it has been or had been occuring for some time), the motor unit potential (MUP) will be increased. This type of electrical activity is generated by groups of muscle fibers that are innervated by a single axon.

The presence of all of these (positive sharp waves, fibrillations and increased MUP's along with pathologic twitching) is what is seen in ALS. However, these all can be seen in other conditions as well (e.g. pinched spinal nerves due to a slipped disc or compression of a nerve or some autoimmune syndrome that "eats" nerves). The neuro will also have to look at the clinical symptoms to come up with a diagnosis. The EMG is just a part of it all.

wright. asked u a series of other questions from my morning post that u originally replied to last night about dents atrophy, etc. when u have a chance can you reply to some added questions i had. thank you.
Hello crystalkk...

Nice to meet you. Lets see where to start. About 5 years back I started with major balance issue, and I felt like both my legs had severe bone pain in the front of my calves.

I had an uncle who died of bone cancer so I thought I should check myself out. I had a bone scan and every thing was fine. At the same time I was getting very bad muscle spasms in my feet....all I needed to do was stretch them and they came on. I was really tired.

That went on for a while and I had no muscles moving and I had no thought process about 'ALS' what so ever. One day while taking a drive with my husband, I was resting my elbow on the passenger door. When I looked at my elbow it was all sunk in. I still had not noticed any muscle movement, but became worried as to what it was.

Still I ignored it...we were moving. I was having some trouble going walking for a long distance. My legs (both) got tired. I had trouble holding my pocket book without fatiguing
that arm. My hands started to get stiff, but I have arthritis in my wrists.

Then I have a series of small strokes. I couldn't stand up....even though doctors thought I should be able to. I showed them the atrophy of elbow, they asked about family history, and told them that there was 'ALS'. That's when they did the first muscle biopsy, but it showed myopathy, so they did another looking for ALS. Then the denervation showed (acute and chronic) then 'EMG' but only one other part showed acute and chronic denervation.

Shortly after, the muscles started to move in certain locations. Not all over. They actually found the denervation before I had any fasciculation. Now the muscle moves frequently. Those areas have 'thinned', that is what the neuro has said.

My left hand has perpetual fasciculation beneath the thumb and pinky and center of palm. It is a quiet movement. I just know it's there. The side of that hand (pinky side) has sunk in with in the month. Now I feel the same thing in the underside of the wrist, around my mouth, twice in the tongue.

It is upsetting me....but I am trying not to become a basket case until (or hopefully not ever) they figure it out.

Last NCS was normal. I just saw a spine doctor to rule out anything in the spine to be a cause of this situation.

Yes...I have brisk reflexes and when the toes spread and go up? I forget what you call that.

Well...I have confused the doctor's. We will see. It's been a long wait. I will wait until I get my answer. God knows. When He wants to tell me He will.

One more thing...once in a while I chock...did I spell that right? And I wake up not breathing. Just with my mouth opening and closing and nothing going in or out. maybe someone will understand that one.

Thanks for your concern
take care
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