GOTTA READ THIS ABOUT EMGS - super helpful

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GOTTA READ THIS ABOUT EMGS - super helpful

Postby SLL on June 27th, 2004, 10:15 pm

found this over at another forum...really great explanation


Because your EMG's are clean now, it means that your current symptoms ARE NOT due to ALS. Think of it like this. You get a cold and you're sneezing, coughing, have a soar throat and a fever. These are symptoms of a virus that causes the common cold. BEFORE those symptoms become noticeable, the virus must be set in and do some damage BEFORE sx become noticeable. ALS, or any other disease works the same way. The motor neurons must begin to die before symptoms surface. It is often estimated that nearly HALF of the body's motor neurons are dead by the time a patient notices symptoms and gets an EMG.

The EMG must show that the motor neurons are being destroyed in 3 of 4 spinal motor neuron regions. These are the lower motor neurons (LMN). So, your legs are innervated by the LMN's of the lumbrosacral region of the spinal cord, your ribs, chest, back, and certain muscles of the hands/forearms are muscles that are innervated by the thoracic spinal region, your arms, forearms, hands etc are innervated by the cervical spinal region, and your throat and tongue are innervated by the bulbar (or brainstem) region of the spinal cord.

On top of that you must show upper motor neuron damage in areas where muscles are innervated by at least 3 of those 4 regions. The upper motor neuron (UMN) damage occurs because the brain's motor cortex dies too. Thus, if your physical exam didn't show any 4+ reflexes or clonus anywhere, then you don't have upper motor neuron damage.

So to have ALS you must have both UMN and LMN damage shown by evidence obtained in the EMG and your physical exam. One other thing. You may or may not have seen the term anterior horn cells before. All you need to know is that anterior horn cells = lower motor neuron roots. The lower motor neuron roots of the spinal cord are called anterior horn cells because they are located and branch out from the anterior (front side) of the spinal cord.

On the LMN end of things it makes no difference which side or limbs got tested by the EMG. Because ALS is a MULTIREGION motor neuron disease, the motor neuron roots in these regions would have to be severely depleted in all these regions before you even notice symptoms. By the time someone who truly has ALS shows symptoms, the EMG will show the associated damage.

I say it makes no difference which particular muscle or which side the EMG is done on, because the motor neuron ROOT is what dies and causes ALS. There are 639 muscles in the human body. Think of a muscle in a particular spinal region as a leaf of a tree. Think of its associated Anterior Horn Cell as the tree's root. You are the tree. When the roots die, the leaves don't get the nourishment they need, and they wither. By sticking the needle in any particular muscle, you're measuring the health of the ROOTS and not the muscle. So, by sticking ANY muscle, the EMG would see the damaged root. So, the EMG measures the HEALTH at the ROOT and not the particular muscle. The ROOT stems to both sides of the body. That's why it makes no difference which particular muscles or side is tested, because MANY DIFFERNET MUSCLES share the same ROOT or ROOTS. SO LONG AS ENOUGH INDIVIDUAL MUSCLES ARE SAMPLED (usually 6-8)TO INCLUDE MOST OF THE LEVELS (ie C1-8, T-12, L1-5 etc) OF AT LEAST 3 OF THE FOUR SPINAL REGIONS, THEN THE EMG WAS THOROUGH ENOUGH TO CATCH LMN DISEASE IF ITS TRULY THERE. SO LONG AS ENOUGH INDIVIDUAL MUSCLES ARE SAMPLED (usually 6-8)TO INCLUDE MOST OF THE LEVELS (ie C1-8, T-12, L1-5 etc) OF AT LEAST 3 OF THE FOUR SPINAL REGIONS, THEN THE EMG WAS THOROUGH ENOUGH TO CATCH LMN DISEASE IF ITS TRULY THERE. NOT A TYPO!REPEAT THIS A BAZILLION MORE TIMES!!Remember, the disease of ALS is CENTRALLY acting, and not PERIPHERALLY acting. The symptoms are what's FELT peripherally, but the damage is CENTRAL! What the tree feels is that it's leaves are withering, but it's because it's roots are dying.

This is about as basic as it gets. I don't mean to be rude, but if you don't get this basic level of motor neuron anatomy and function, then YOU ARE IN NO POSITION TO EVEN BEGIN TO CONSIDER THE PROCESS OF SELF DIAGNOSIS!!!!!!!

What I am stating here is a summary of what's known as the El Escorial Criteria for diagnosing ALS. This criteria was drafted and agreed upon by the members of the World Federation of Neurology (WFN)

So, if you choose to haphazardly paste together random accounts of individuals you do not know and take that as fact over what the WFN has to say, we'll I dunno...

I just wanted to be CLEAR on my SOURCES of information, and where I'm getting this stuff from. If you can't handle reading about ALS, then I would not suggest doing Library or internet searches on the WFN or El Escorial criteria. But, if you so choose, you can check on your own to see if what I'm saying gels with what they're saying.

So, a NORMAL NEURO EXAM + CLEAN EMG means there is no evidence that your UMN's and LMN's are dying. Thus, that's why you don't have ALS.

A few more points:
1)Remember, No doctor in his/her right mind can NEVER say that you will NEVER get any particular disease (including ALS) in the future. The following is quoted from Kytkatz (Belinda - The Happy KytKat) in the same thread linked at the beginning of this post:
"A clean EMG at 30 doesn't mean you won't get ALS at 70. It's the same thing as not having cancer at 30 doesn't mean you will never get cancer. Here's another way of saying it - just because you haven't had a car wreck at 30 doesn't mean you will never have one.

A clean EMG now mean that your symptoms are NOT caused by ALS. No doctor or test can tell you that you will never get something. We don't have one test that you can have now that can tell you what you will or won't have something in the future. It means that you don't have it now. Odds are, you'll never have it.

Make sense now? "
(Thank's KytKat )

2) Twenty, Thirty, Forty etc EMG sticks ARE WASTEFUL and UNNECESSARY to rule in or rule out ALS. I saw Yale's co-director (Dr. Novella) of their MDA/ALS clinic and research center, and he gave me my definitive EMG. These people at Yale see more ALS than your typical ALS SPECIALISTS, and INFINITELY more than Dr. Joe Local Neuro. He gave me 8 total sticks on my right side, and that was enough to prove that I don't have ALS. He even told me afterwards that if something bad showed up in those 8 sticks, that he would have only had to do another 3 or 4 to confirm that my sx were due to LMN death. Altogether, that adds up to 11-12 sticks max, and not 20, 30, or 40 in all 4 limbs, the trunk and throat/tongue!

3) FYI: that clean EMG was done a little more than 4 months into twitching. SEVERAL MONTHS TO A YEAR OR MORE ARE NOT NEEDED TO CONFIRM THAT THE SYMPTOMS ARE NOT RELATED TO ALS. Before that, I had a 100% clean EMG at only 3 weeks into twitching by Joe Local Neuro. The clean EMG at 4+ months by the specialist confirmed the original. Remember, DAMAGE TO THE LMN'S & UMN'S MUST BE DONE BEFORE SYMPTOMS BECOME APPARENT!!!
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Postby Johnny on June 28th, 2004, 9:28 am

I'm not trying to be a naysayer and I'm certainly not trying to dampen this post, but I'm not sure if this person's theory on EMG is valid. First of all, this did not come from a medical doctor. Second, if only a few sticks were needed to check the "root" as he describes, then why is it recommended that the EMG performer turn the needle after insertion in different directions in order to check more fibers/motor units??? According to the poster, that wouldn't be necessary. (Bradley, I'd like to see you weigh in on this point) Third, while he is correct about the El Escorial requirements for diagnosis, El Escorial does not say anything about his tree/roots analogy. Finally, if you research this person's posting history on the old braintalk, you will note that he went on to have a third EMG (why?) after he posted this information and he seemed to still be concerned about the possibility of having ALS - despite his two previously clean EMG's that according to his post would be more than enough to rule it out.
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Postby Pole on June 28th, 2004, 9:48 am

Johnny wrote:why is it recommended that the EMG performer turn the needle after insertion in different directions in order to check more fibers/motor units???


what???????????? I have never heard about that!!!!! I's impossible - when you have a needle in your muscle, your every (even the smallest) move makes emg signals false (a lot of noise etc). If neuro wants to have more fibers checked he must do more insertions - not to move a needle during one insertion. I was told that 3-4 insertions per muscle are enough.

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Postby Johnny on June 28th, 2004, 10:44 am

Ok, whether it be the number of insertions or if the doctor turns the needle - my point is - why would any of that be necessary if the EMG as stated by the poster checks the nerve "root"? I mean, why would you need to stick a needle into two different spots in the same muscle if that muscle is innervated at the same "root"??? That's why I'm questioning the poster's theory.
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Postby SLL on June 28th, 2004, 11:12 am

Uh oh...I thought this post would be HELPFUL. It helped me. It IS my understanding that it is indeed the nerve root that is dying in ALS. When I read this, it helped me understand so much and was greeted over at BrainTalk with lots of commentary as to how accurate it was... Everything I have read it makes sense to me, and helped me understand why my ALS/MDA doc did only about 9 sticks and declared me definitively devoid of neuromuscular illness.

WE NEED BRADFORD!!!
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Postby Johnny on June 28th, 2004, 11:18 am

SLL - don't get me wrong. I want to believe this theory because I too have had a clean EMG. I'm just not sure I can hang my hat on it since it seems flawed - or should I say contradictory - with regard to the points I made above. And - the original poster abruptly stopped posting on the old braintalk and some questioned his health.
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Postby jcavan4125 on June 28th, 2004, 1:08 pm

Forget about who posted what, when. A clean EMG (and I mean totally normal, not inconclusive) plus a normal physical exam means no ALS, period! I have extensively looked for even one entry in any medical journal (not anecdotal he said/she said stories, but a real medical journal) about anyone, anywhere having an initially normal EMG that went on to develop ALS. To date the number of entries is zero, none, not one anywhere!! I have also asked other members on this board to check behind me and let us know if they find anything different; todate no one has. That should give folks some confidence.
Joe... "That which does not kill us makes us stronger"! - Nietzsche
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Postby thetwitchkid on June 28th, 2004, 1:23 pm

Yeah Joe ! :D
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Postby SLL on June 28th, 2004, 3:29 pm

FOUND THIS, too on "teleemg":

ALS is a generalized process affecting all the muscles. When muscles twitch in this disease, it is safe to say that these particular muscles would show signigicant abnormalities on EMG. If a physician does not find abnormalities within the first two or three muscles he checked, he is not going to find them anywhere else, no matter how hard he checks. In my experience he performed a VERY thorough exam from your explanations.
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Postby Pole on June 29th, 2004, 2:25 am

Yes, clean emg means no ALS

Muscle is innervated at one root and when this root is affected by ALS starts to send false signals to that muscle. Fibers in that muscle starts to die and that process may be detected by emg. Not all fibers at the same time - it's true. And it is possible to check a healthy fiber despite a muscle (other fibers) is affected. But I read on teleemg that if 3-4 insertions are made in an affected muscle, a propability of that kind of mistake is VERY VERY SMALL (one neuro on teleemg show a mathematical formula and propability was close to ZERO when 4 insertions were made)

Clean emg means no ALS

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Postby SLL on June 29th, 2004, 9:57 am

PLEASE CLARIFY! insertion definition BOTH my EMGs - one by an ALS/MDA center medical director - the neuro put only one needle in each muscle BUT moved it around poking in there several different ways. By feeling, it felt like a good 6-7 times poking around in the muscle. One even said, OK go this way, not the other direction poking around once the needle was in, as example, my bicep. WHAT is an insertion - is it the actual poke into the muscle through the skin, or is it the pokes once inside the muscle?

are you saying at least 4 needles per muscle should be inserted through the skin - e.g. they poke into the bicep 4 different times through the skin, or that once the needle has been inserted through the skin into the muscle that the poking/moving around once in there should number 4-5??
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Postby Johnny on June 29th, 2004, 10:55 am

Whether the needle is inserted 4 times or moved 4 times is irrelevant to this thread. My original point is - why would a doctor need to insert or move the needle more than once if the EMG tested the nerve "root" as described in the post SLL attached??????
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stick it to me baby oh! one more time

Postby terryg on July 5th, 2004, 9:33 am

There appears to be a difference in what you find in text and real life. In the chapter "Electromyography as a Clarifying Tool" by Dean P Currier From the textbook "Electrotherapy" edited by Steven L Wolf published 1981. It talks about getting 15 different sites with one insertion by moving the needle around center north east south and west at three different depths.However when talking to a neuro about this she looked aghast and said no one would do that in a clinical exam(she said maybe only in an controlled experiment)She said she varied the amount of sticks and the movement of the needle based on the clincal presentation.

The idea with moving the needle around is that you are theoretically getting a different motor unit to test. From the same book and chapter "The motor unit is the functional unit of the neuromuscular system. It consist of a cell body(anterior horn cell) an axon(myelinated) neuromuscular junctions, and each muscle fiber is innervated by the terminal branches of the axon.....Each terminal branch then innervates a muscle fiber.... a single axon may innervate nine fibers in the external rectus...and 1900 fibers in the gastrocnemius....Muscle fibers of a single motor unit may not be in contact with other fibers of the same unit but are confined to a small area( 5 to 20mm) of muscle."

My understanding then is by moving the needle or reinserting you are looking for different motor unit which reflect back to the different anterior horn cells in the case of als. In the hands of a neuro they will decide how many sticks they will do based on your clincal presentation. It appears to be like taking a poll after a certain amount of sampling they have ruled you out by statistics. The question is wether they want to be 99.9% sure or 99.9999999999999999999 % sure.

Take care

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Postby dwl on July 5th, 2004, 9:49 am

I agree - from everything I've read and heard, neurophysiology is an art and not a science. Everything hinges on the experience of the operator.

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Postby SLL on July 5th, 2004, 9:26 pm

so what I do not get - on the telemeg website there is a quote from an EMG technician - " the general rule is if a Motor Neuron Disease is suspected, if one side shows nothing test the other". I don't get it as I thought - and had read and heard - testing one side gives the neuro the picture of what, or not, is going on - it is not needed to test both sides unless something is discovered on the one side and the extent of disease is to be measured by going further.

Now in all our cases, I am guessing we do not fall into the "if a Motor Neuron Disease suspected" category...given we have normal neuro exams with no upper motor neuron signs. Our clinical picture does not support further testing I guess...but it still seems risking not being thorough.
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