Normal EMGs: Neuromyotonia & Myokymia

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D

DrugResistance

Well-known member
The NMT theory sounds great. However, we have all had normal EMGs.

It is my understanding the term "neuromyotonia" and "myokymia" are in reference to specific EMG patternes.

Three NEUROs since Nov 03, three normal EMGs, other than FASICS, they all say "you are under the Radar".....

All three say some sort of "virus"....only one mentioned possible channelopathy, but never pursued it due to normal EMG.

A Mystery....as long as it doesn't progress......
 
Hi PDR

I think people are getting confused about what a normal EMG test is. ie. normal as in ruling out anything serious. As you say yours was normal except for fasics which therefore makes it abnormal.

Fascics on an EMG show as a single motor unit discharge which equates to one spike or repetative single spikes whereas, neuromyotonia EMG shows single, double, triplet and multiple discharges. These findings are one distinction between NMT and BFS, although some patients who were classed as having BFS, on a second or third EMG study would be classed as having NMT. I find it strange that I seem to be the only one on this forum who has been diagnosed with NMT.

From what I have read and been told by my neuro (Mr Hart from the studies) all the evidence for the acquired types is pointing towards an autoimmune channelopathy no matter which type you have. PNH is the term now being used to cover these types of disorders.

ALC. DWL. lets have your views.
Steve.
 
I'm with Steve on this one. I think the Hart paper is the definitive recent work in this area and we should all watch out for any new developments.

I don't know if EMG changes are necessary to diagnose PNH or neuromyotonia - my neuro certainly diagnosed my bfs/pnh on the basis of 2 normal emg's.

David
 
I agree on all your points.

My neuros didn't define NMT due to only FASICS on the EMG....and no pattern of NMT. Sorry for the confusion.

I've had my thyroid checked 4 times and a Chest X-ray. I know they know what they are doing. I did mention ISSACS to one, and he said you have no debilitating cramping or weakness...."under the radar".....however, to let him know if anything progresses.....

I was Rxd Neurontin 200 - 300 mg Three times per day....it seems to help.

In regards to VGKC antibodies......if you tested x amount of normals with no complaints, what % will be + and or -. The same for those of us who complain....what % would be + or -.

I think a double blind study chould be conducted to compare normal to abnormal, or some sort.

I think at this point if I asked for VCKC, acetylcholine anti-body tests I'd get a big :).....I may ask....my ANA was normal last year.....

Great conversation......
 
PDR First name would be better.

My neuro has been treating me for NMT since 2000. He calls me back in for follow ups on a 4/6 monthly basis, bloods taken usually 1/2 times a year. weight checked at every review. He's monitoring my thyroid because I have antibodies. All this might be because I was involved in the 10 year study which is probably still on going, but I'm not sure so will ask him at my next review in Jan.

You mention VGKC tests. If you take a look at the Hart paper you will get some kind of idea of percentages from their results.

Neurontin 300x3 + Lamotrigine 200x2 working well for me, more people should inquire about these combo's.

I saw one of your earlier posts asking about muscle biopsy, I had one 1998 it came back normal.

I was thinking abut EMGs and was wondering if everybody had had their's carried out by their neuros. Hart never performed one on me, mine where done by the Dr B Tedman mentioned in the acknowledgements at the back of his paper I think this guy is what is known as an electrophysiologist anyone else seen one of these Dr's.

If you look at Harts paper it says "we studied ALL patients between 1990 and 2000 who presented with signs of spontaneous muscle overactivity" thats not many people over a 10 year period turning up with PNH. Of these 60 people, 42 had NMT 18 BFS/CFS. I'd like to know why there is such a big difference between the two groups.

I hope my appointment in Jan is the last one of the day because I've a shed load of questions to ask him.
Regards Steve.
 
Steve,

At your next appt., if you get a chance, ask Dr. Hart about the two people in the study that went on to developed MND. I'm curious what there emg findings were. 2 out of 62 seems a bit high for an occurence that isn't supposed to happen. I would guess that they presented with more than just fascics.

Thanks,

Gary
 
Steve,

Also, the dr that did my emg was a neuro., but he was not the same one that did the physical exam. He made no mention of NMT/PNH in his report, but did mention benign fasciculation. Here is a link to his profile:


He has pretty impressive credentials.

Take care,

Gary
 
Steve:

Each Neuro did the EMG, however, a Fellow in Neurology did the last with an Attending watching. First showed no FASICS, second showed one in the left quad, the the third showed one in the Left Tricep. So they were not very impressive abnormal EMGs. That is why I think they don't get too excited with a normal clinical exam without weakness. I've had a battery of tests, all normal, to include MRI of Head and Spine (last year).

I actually called my Neruo and spoke with the Nurse Pracitioner and asked her if he thought this was a Channelopathy. He is currently away. He actually is involved in Channelopathy research. He started me on the Neurontin, the first too just said to pretty much live with it.

The muscle biopsy showed a decrease in Myoadenolate enzyme. Not a big deal either according to the third neuro. ~20% of the population have some sort of defieciency and said it had nothing to do with the FASCICS.

I suppose either way you slice this "phenomenon" and call it what you want, Neouro's don't get very excited. Neurontin seems to be a good drug for this. Adding Lamotrigine may be a reach.....

Thanks for your response.....
-----------------

Gary:

Glad to see your still here......Happy Holidays......



Paul
 
GARY:

It says in the article that the TWO patients who presented with isolated nerve hyperexcitability later developed neuropathy confirmed by NCS to both have DIABETES.

I conclude the point being made is the association with:

1) Myasthenia
2) Thyoma
3) Lung Carcinoma

Paul
 
Paul,

It's good to see you come back to the board, kinda :confused: . I was hoping that your sxs had resolved. Anyway, you have a great holiday season also.

Here is the part of the Phenotypic variants of autoimmune peripheral nerve hyperexcitability study I was talking about and would like a little more info about:

"Follow-up was between 1 and 11 years. No patient had a history of exposure to toxins, a family history of parental consanguinity or primary neurologic disease (including hereditary neuropathy or episodic ataxia). We excluded only two patients from our analysis, who had developed motor neurone disease. "

To my untrained eye, that seems to contradict the mayo study. That is why I'm curious to know what there emg studies revealed. I would guess that they presented with more than just fascics.

Take care,

Gary
 
Gary:

I'm a "silent" ABOUTBFS.com person.......

I too wish my symptoms would "go away"......but hey, after 13 months of this, three EMGs with nothing BAD, no weakness or atrophy, and still walking.....I can't complain.....I see people with real diseases everyday......I often ask those on Neurontin if it works.....some are also on pretty hefty dosage too....

Weird symptom of BURNING sensation in the legs lately.....like I was sun burnt....have you had that? Just the past couple of days......I took five days off from exercise, and BAM.....my wife said to exercise....:) I had it last year in the calfs when this all started and my Right Thigh, but now it is both.....waxes and wanes......I'd rather "twitch".....

Played Racquetball this AM, and felt good....paying the price now, since it has been a year since I last played.

Good point on the article.....I don't know why the did not elaberate.


Paul
 
Garym and others worried about that reference to nmd (as I am, or was), Tell me what you think of my thoughts on what that study says.

First, the entire paragraph wasn't cited, which read:

 
"Patients
We studied all patients presenting between 1990 and 2000 to our neuromuscular clinics in Oxford (1990–2000) or in Liverpool (1996–2000) with symptoms or signs of acquired spontaneous muscle overactivity (muscle twitching or muscle cramps) affecting at least two regions of skeletal muscle other than the calves. Follow-up was between 1 and 11 years. No patient had a history of exposure to toxins, a family history of parental consanguinity or primary neurologic disease (including hereditary neuropathy or episodic ataxia). We excluded only two patients from our analysis, who had developed motor neurone disease."

MY TAKE: I think it may be an issue of semantics and does not in fact contradict the Mayo study:

They stated they included ALL patients PRESENTING with SYMPTOMS of hyperexcitability. That would include people with MND because that is a symptom of MND. It would be reasonable that a percentage of people presenting with those symptoms might turn out to have MND. At the point of presenting symptoms, naturally, they had not yet been dx'd with MND and therefore were elligible for inclusion since they had decided to sample ALL people presenting with those symptoms. Appropriately, they were excluded once the tests showed the true underlying disease, which would have been at a later time (I believe this would stand up to reason even if the study had been done later, based entirely on patient records, after the 1990-2000 sample window).

Also, later in the study I found this:

"EMG findings
Group A patients had, by definition, myokymic EMG discharges [i.e. doublet, triplet or multiplet motor unit (or partial motor unit) discharges], as well as fasciculations (single spontaneous motor unit discharges) and fibrillations (single spontaneous muscle fibre discharges). The occurrence of doublet discharges was the commonest abnormality; these had a mean intraburst frequency of 168 Hz (range 40–280 Hz). Denervation was only observed in patients who had abnormal nerve conduction studies.

Prolonged surface EMG recordings over 30 min from eight different limb muscles in six patients revealed that the greatest number of myokymic discharges occurred in distal rather than proximal muscles. Ten was the maximum number of different motor units (or partial motor units) showing myokymic activity detected on surface EMG recording. The extent of the electrophysiological abnormality did not relate to the clinical"


MY TAKE: I missed what the difference between groups A and B were, but it seems clear at least to me that there were clear EMG abnormalities, some of which, like fibs and denervation, sound pretty familiar to those of us who have worred about MND. I would be surprised, very surprised, if all of the people sampled had EMGs that were considered clean by ours or the Mayo clinic's standards. I would like to hear what others think, but presently I don't think this contradicts the Mayo study, and I presently feel my reasoning is stronger than mere technicality.

best,
dave
 
A couple more thoughts... Those two out of sixty, or whatever it was, actually is pretty close to the 6.7% study of those presenting with similar symptoms haveing MND.

You could make an example like this: "Five people were nominated to run for the office of President of the United States. One was excluded because he was Arnold Schwarzenneger and was not legally entitled to run"

Even if they had known the two had MND within five minutes of arriving, they would have to be mentioned in the study because they were part of the group that showed those symptoms upon arrival (no matter what the cause). There is no suggestion that they presented, were given a clean EMG AND clinical examination other than for fasciculations (don't forget the clinical exam is also an important part of the Mayo study--it's not just about the EMG) and later turned out to have MND. I don't think it even comes close to suggesting that.

So... that's where I'm at on this question.
 
Dave,

while your explanations make sense, I would still like to know the actual process that was involved and the emg findings of the two people excluded. For me, the fact that group A presented with other sxs in addition to fascics (such as fibrillations) is re-assuring.

As for the 6.7%, I believe that refers to people that presented with twitching as their intitial sx and went on to develop als. I don't think there was ever any clarification what their emg study revealed. I would like to believe that it showed something besides fascics. Anyway, that doesn't mean that 6.7% of people that present with twitching will develop als, it simply means that of the 1/500,000 people that get als, 6.7% will twitch first. Based on the membership of this board, BFS has to be more common than als and it is quite obvious that 6.7% of us aren't coming down with als.

I haven't gone back and re-read the Mayo clinic study lately, but I seem to remember that none of their patients went on to develop als/mnd. The difference between the two studies could be who they included and what criteria was used to decide who was included. Again, i would guess that the mayo study didn't include patients that showed fibrillations/psw and other abnormalities along with fasciculations. Thankfully, I think the majority of the members here have reported fasciculations only on emg.

Take care,

Gary
 
Gary and others,

I asked the neuro I saw who is an expert on ALS, "When would someone start to show weakness in ALS if they noticed the fascis as a first symptom? Her reply, "At or about the same time that fascics are noticed."

Even if someone has ALS with fascics first there would be real weakness quickly. It is so hard to analyze these studies in the first place as they relate to BFS -- I would tend to believe what my doctor said.

Ava
 
I don't think you can compare the two studies. The Mayo paper only looked at people with BFS who had been diagnosed previous to the study. In other words they cherry picked only those patients where MND had allready been ruled out. Hart took all patients who, after EMGs where classed as having NMT or CFS/BFS, so therfore the two who went on to develop NMD could only be ruled out at a later date. If they had presented with MND features they would not have been included in the study. In which case. had these two patients had been removed from the equation as in the Mayo study, then none of Harts patients have gone on to develop MND. I hope you get the meaning of what I'm saying here.

From another paper of by Hart he says. Two patients with motor neuron disease with typical clinical and electrical features of anterior horn cell loss also had neuromyotonic discharges on EMG, the word here being neuromyotonic which equals group A and not Group B CFS/BFS. So hopefully this should further put your mind to rest.

Come what may, on the 25th Jan, I'll have the definitive answer to this.

What a good discussion this is turning out to be.

regards Steve.
 
Stevepaul,

I see your point, and it's a good one, but I'm having a tough time deciding if you're right or not. Here is the passage again:

"Patients
We studied all patients presenting between 1990 and 2000 to our neuromuscular clinics in Oxford (1990–2000) or in Liverpool (1996–2000) with symptoms or signs of acquired spontaneous muscle overactivity (muscle twitching or muscle cramps) affecting at least two regions of skeletal muscle other than the calves. Follow-up was between 1 and 11 years. No patient had a history of exposure to toxins, a family history of parental consanguinity or primary neurologic disease (including hereditary neuropathy or episodic ataxia). We excluded only two patients from our analysis, who had developed motor neurone disease.

Patients were separated into two groups determined by the presence (group A; n = 42) or absence (group B; n =  18) of doublet, triplet or multiplet (‘myokymic’) EMG discharges."


I can't help but wonder if "all" means literally "all", including the two people with MND because those were the symptoms they "presented" with. The chronology suggests to me that the subdivisions into categories A and B based in part on EMG findings came after that point. This study was probably done after 2000, by revisiting old records. The first things on peoples charts are their presenting symptoms--EMG findings and the dx's come later. That would have been the first test.

In other words, the two with MND were included in the initial qualifying round, passing the first test of presenting symptoms, but failed the second test of diagnosis into groups A or B and were expelled before being classified into group A or B because they had MND. So, technically the two with MND were never part of Group A or B.

And let's say for a minute I'm wrong--does that necessarily fly in the face of the mayo clinic considering all of group A had at least fibrillations, which would excluse the possibility of a "clean" EMG and therefore not meet the requirements of the Mayo study?
 
OK. I read it again and there is no other mention of the two with mnd.

At this point I would have to politely question the accuracy of ; "Hart took all patients who, after EMGs where classed as having NMT or CFS/BFS, so therfore the two who went on to develop NMD could only be ruled out at a later date."

They didn't take them based on their diagnosis or group classification--they took them based on their presenting symptoms. Only after that did they exclude the two with nmd from the study because they did not fit either category A or B (you'll notice they are not mentioned again).

So-- As I read it, the two with MND were NOT mistakenly diagnosed and put into either category A or B--they were never part of either group. They were weeded out before then. So it's not a matter of either an NMT or BFS diagnosis later turning out to be MND. Those two were never part of either group and can even be presumed to have shown MND findings upon presenting with symtpoms including nerve hyperexcitability. They could have had ALS findings out the wazoo immediately and still have to be mentioned, for accuracy sake, because they presented with hyperexcitability.

I am definitely over-thinking this one.
 
David,

I beg to differ. A lot of people cling to the Mayo study to keep them afloat mentally (at least in part). It is the "gold standard" of proof for people with BFS that their fasciculations won't turn into something very bad.

Depending on how you read the other study, this paper might contradict the Mayo study in a rather big way. It would be a bad thing if that were the case, and it's worthy of concern (though there's not point in worrying about something you can't control, I suppose).
 

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