EMG testing

[buddy77]

Well, I finally had my EMG/NCV done, and it turned out normal. I was able to have it bumped up due to a cancellation. This Dr. is a neuromuscular specialist and he is very knowledgeable/helpful and takes the time to explain. He did tell me that he really doesn’t know what it is that is wrong with me, and that unfortunately, in some patients, that isn’t uncommon.

He indicated that all my tests have come back normal, and now including the EMG, it is reassuring. I asked him about ALS, and he indicated that because my symptoms have a tendency to wax and waine, that it doesn’t fit with ALS, (Somewhat contrary to what some have posted here) and also because of some the sensory issues I also have. He also stated that the EMG would have shown some sort of issues if it was ALS, and he was very confident about saying that. (This is also somewhat contrary to what some have posted here). To follow up, he is asking me to do a Single Fibre EMG in just over three weeks time to test for other possibilities, but indicated that he is fairly sure that this test will turn out normal as well.

I also have another EMG scheduled next month which would have been the first EMG with another Dr. Should I now cancel this EMG? I had two booked in hopes of having one bumped up due to a cancelation. It’s almost a three month wait here for an EMG and I don’t want to take up an unneeded appointment… However, I’ve seen so many posts here regarding EMG’s about some people having several and the tests contradict each other etc, (Clean, then not clean, then clean again with a ?). How reliable is the EMG test? This Dr. was very confident, at least in my case anyways.

Thanks,

 

[ktmj]

Depends on the confidence you have in that doc, and the one that the next one is scheduled with.

Since this one is a neuromuscular specialist, I would tend to stick with him and go for the next EMG he wants to do. It is a different type and might show something, or nothing. Most likely he knew what he was doing and you will not get a different result in such a short period of time.

Is the next one with a nm specialist? If so I might consider it just for peace of mind if cost is not a factor. However, I would not expect a different result. My $.02.

Also, if you get face time with the next doc, and you believe in his abilities, he might recognize or go down a path with your symptoms that could help you. This stuff is weird and each doc processes info differently, so a 2nd opinion never hurts.

 

[rose]

Buddy, the single fiber EMG is the most sensitive of tests. It takes considerable skill, so the doctor who does it would be a step above a doctor who does standard EMGs. Definitely go for the single fiber. The other EMG you have had an appointment for, would be redundant after the single fiber.

Single fiber will show if there is MG or ALS, but cannot differentiate between the two, so that is why your other test results ( NCV, for example) are important, and your clinical exam findings will also have added weight to them if any abnormalities do show with the single fiber test.

If your single fiber is normal, then you absolutely need to cross fears of ALS off of your list. In a clinical trial of (? maybe 45?) confirmed ALS patients, along with a control group, 100% of those with ALS had abnormal single fiber EMGs.... I believe that this test detects MG in about 90% of people who have it.

good luck to you

 

[buddy77]

Thanks for the insight!. I decided to cancel the second EMG. No sense in wasting resources when others are waiting in line. KTMJ, this is actually the third nuro that I have seen, and they all pretty well are stumped. The second nuro actually worked at the Mayo clinic in Minnesota for several years which is supposedly one of the best clinics in the world. I had a good discussion with him and he really doesn't know what’s going on with me. His attitude was to wait and see. The neuromuscular Dr. basically said that after the Single Fibre, there is nothing left to test for, and to basically sit back and wait this out. He said that in cases where all the tests are normal and over a 6 month period, that they may never really know what is causing this, and that in such cases, it's possible that one may actually heal/improve with time. I did have a neurological issue many years ago and I recovered from that. It was similar, but this time much worse with several additional symptoms (Like breathing issues and tongue and lip partial paralysis.) I suppose that this bears some weight in their assessment.

Rose, I had a look at Single Fibre EMG and you are right, it is very sensitive in detecting any nuro-muscular conditions that may be present. It isn’t used for diagnosing ALS, but according to the studies performed, if it comes back normal, it’s fairly certain that you don’t have ALS. However, from some of the studies that I seen, the EMG is also fairly accurate and is still the baseline that Dr’s use in ruling out ALS. One study indicated that a clean EMG anywhere in your body (including non symptomatic areas) was over 80% accurate in clearing you of MND, and another study indicated that it was basically 100% accurate ( Single fiber electromyography in 78 patients with amyotrophic lateral sclerosis ) Apparently EMG’s performed on the tongue and general area however are somewhat suspect and some Dr’s won’t even perform those.

You see quite a few discrepancies on this forum, but I suppose that a controlled study should hold more weight in this analysis. I suppose that the quality of the EMG could be an issue in some cases, and also the timing as some people have an EMG done at a very early stage of the disease. All in all, I would say that if you have fairly severe symptoms and you have had them for several months, and then have a clean EMG, you pretty well can almost rule out MND. That was the impression that I got from the nuro, and I would say is supported from some studies performed. Their can always be exceptions, but those should be few and far between.

Thanks for your help! It’s greatly appreciated.

Buddy

 

[buddy77]

Well,

I did my single fiber EMG yesterday, and he performed it on my forehead only. He indicated that the forehead yields the most reliable result and that this test is solely to test for MG. At the end of the test, he indicated that he didn't see major nerve damage off hand, and thus he needs to run the data through the computer for it to be analyzed to see if I might have a mild case of MG. He did ask me during the testing if I ever used Botox? I said no, and I then asked him why? What does Botox do? He said it affects the test results. I had a look on the internet, and yes, Botox does skew the data and can actually cause a false positive. So my guess is that he did see "something somewhat abnormal" during the test but not hugely abnormal. Guess I will have to wait to find out more during the follow up.

I asked him what the single fiber EMG test can detect, he said, MG, Lambert, and Botulism. He didn't mention ALS and I didn't ask further.

So I guess I will be in a wait and see mode. Looks like every test has been done and I don’t “fit” into any category…. Not sure if this is good or bad….