Can a clean single fiber EMG become abnormal with progression?

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Active member
Nov 28, 2008
Just wondering if a clean EMG means anything definitive or if it can change with time?
Thanks so much.
A clean EMG means definitively that you DO NOT have ALS. No ands, ifs, buts or maybes.

Can an EMG change? Of course it can. If I would've had an EMG when I was 15 it would've been clean. Now I have ALS. My question is are you going to spend your life worrying about what will most likely never happen or live? Hundreds of thousands of people are killed or seriously injured every year in car accidents and yet how many people think about what they're doing when the get behind the wheel? Do you? Better yet, more people are injured in falls in their bathroom than are diagnosed with ALS each year. Does that mean we should stop taking showers?

I don't mean to come across as harsh but you have definitive proof that you do not have ALS and yet you're looking for a reason to keep worrying about it. Let it go.

Erica's husband has severe swallowing problems due to choking, and has clinical weakness of the tongue..... I'm thinking you may have missed this.

I'm wondering what his doctors have said about possible PLS with it being a pseudo-bulbar onset? What are his reflexes like? are they brisk? I think you may have posted this on an earlier thread, but I can't take the time to search. I still wonder how the MG was ruled out, as blood tests come back negative frequently.

Shatzie, a forum member, was originally diagnosed with bulbar onset of ALS and that was later changed to MG and her blood work was always normal.

Also, I've read that when swallowing problems present before speech, the doctors use that to help guide them away from an ALS diagnosis.

However, if a person has UMN weakness due to PLS, this would come back as a normal EMG.

Keep us posted.
Thank you, Rose.
Do you know any more about your interesting fact regarding dysphagia before speech issues?
P.S. Rose

P.S. Rose - I forgot to say that the doctors said this clean single-fiber EMG rules out myasthenia. Clearly this test trumps blood tests which you correctly point out are often false negatives. He also doesn't present with any MG signs (dropped eye, fatigue progressing during the day).

My question was - how encouraging is a clean EMG even with symptoms at this point?

What is PLM?

What I don't find consistent is one doctor saying symptoms are one of three things (MG, ALS, myopathies) and these doctors (from the same Neuro center) saying that these symptoms can be one of many, many conditions. The latter is also what NIND says).

Your input is always valued and it's always nice to hear from you. BTW, I wrote about a blind date, responding to something you said on another thread. We need some funny in our lives (but only when we choose it).
All the best,
Hi Erica,

There actually is a PLS forum within this group here (go back to the main page where all the forums are listed)
PLS stands for Primary Lateral Sclerosis.

The following is from a Johns Hopkins webpage:

Like ALS, PLS is a disease of motor neurons. It’s progressive and causes nerve degeneration. But unlike ALS, PLS affects primarily upper motor neurons—those whose nerve cell bodies are in the brain and which deliver impulses to, and thus control, the activity of lower motor neurons. The latter innervate the muscles of the face, throat, larynx and limbs, the trunk and respiratory muscles. With ALS, there’s degeneration of both upper and lower motor neurons.

The disease progresses gradually—usually over 20 years—and, though life-changing and disabling, it isn’t fatal

PLS may also resemble one or two other diseases early on, such as progressive multifocal leukoencephalopathy, but they’re fairly quickly crossed out because of faster progression.

I do know that some people start with bulbar onset of PLS, I am not very familiar with the statistics etc, for this condition, as in my personal experience, the first hint of MND was an abnormal EMG, so PLS was not explored really.

If I can find the information about swallowing versus speech problems presenting first, I'll post it for you.

Be encouraged that his doctors think he still has many possible causes, as frustrating as it is to not know, there is always hope they will find a treatable cause.

If he has not had a modified barium swallow test performed by a speech pathologist, I'd think this is something that should be done in the interim while he waits for diagnosis, to get a feel for how severely his swallow is compromised.
As always Rose, thanks.

He had the modifed barium swallow - the speech pathologist attending said what everyone else said, that it was the epiglottis that was weak/not working. But saying why is the clincher.
We'll touch base soon, I'm sure!
I did not realize it was his epiglottis, was thinking it was his tongue. I wonder what cranial nerve innervates this? Was the EMG done at that site? (I'm assuming so). It could still be originating from the cranial nerves up in the motor cortex, (UMN) rather than the brain stem proper, so its malfunction would not show up on EMG.

I'm glad he had the swallow function tested, its amazing what they can learn from it.

I did surf around on the computer looking for the information about swallow versus speech, but did not turn anything up. I've run across a couple scholarly articles dealing with this, over the last year or so, but did not bookmark them, unfortunately.

If nothing else, take comfort that the best of the best doctors love a good mystery, so he will keep their attention. Any patient that falls out of the norm, but clearly have something wrong with them is of interest to them. I've actually had my doctors tell me that, and have found it to be true, even without it being said.

take care, :)
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