My RNS and EMG were negative for MG signs as were my blood tests.Still, I respond to the Mestinon. I'm possibly part of that small percentage that has MG and they don't have a test for it? Or possible congenital? I don't know, but am grateful for Mestinon.

Carly

Did you have the RNS? If so, did it show anything?

Back when I was first diagnosed with MG, I passed all my EMG tests with flying colors.
Including Repetitive-Nerve-Stimulation (RNS) - and Single-Fiber EMG (SFEMG).

And yet?
My AChR Antibody test results - were ''off the scale'' - as it was put to me.
I was as seropositive as they come.

There are people here, on DS?
Who don't at all - get very much help - from diagnostic tests of any kind.
They have to rely on their doctors, for clinical observations of MG symptoms, or MG-like syndromes.

Point being? Just keep in mind, should you ''pass'' your EMG tests? These tests are just not as definitive, as some testers will claim.

Some advice, on preparing for any EMG test.
Ask to have warm blankets used, to warm the test areas.

Before your appointment, do some sort of moderate physical activity, involving legs and arms and neck. Exercise to the point of muscle exhaustion, if you can. Light resistance training of some kind - sounds good, even very light weightlifting.
BUT - don't put yourself in any danger, with your MG symptoms.

- Ross

I am seronegative and was diagnosed with MG based on RNS testing and a tensilon test a year ago. The neurologist that did the testing did it on my arm, my hand, and on my face. At the time, my symptoms were mainly ocular; the decrement in response that he got from the test on my face qualified as MG. A decrement was present in the test he did on my hand but did not meet the criterion for MG. I don't remember doing anything special to prepare for the testing, other than postponing a trial of Mestinon until after the testing was done.

Pat

I have had the RNS done and it was positive. I also assist in doing EMG with the neuro muscular specialist that I work with. All of the EMG/NCS are unreliable to some degree. You can have many false negatives depending on the doctor performing the test and multiple variables such as the amount of sleep you've had, how long you were off of the mestinon prior to the study, if it's done earlier in the day vs. later, temperature of the skin, etc.

We had a patient yesterday that was completely negative for all of the blood work but his RNS was a screaming positive. We had another patient today though that was positive for the antibodies but negative on the RNS. We later found out that she continued to take her mestinon up to 2 hours prior to the study. Bad patient!! lol

I agree with Ross to some degree about doing some exercise prior to the study. Don't kill yourself or anything but just do a moderate amount of exercise to fatigue your muscles. Particularly the arms, hands and neck/shoulder muscles. Those are the areas that are focused on generally for that study.

If you are already on Mestinon, make sure that you do not take mestinon for at least 48 hours prior to the exam also.

There is little chance that there will be a false positive only a false negative. They typically do the RNS test first and then if there is any question still remaining they will move on the the SFEMG for additional diagnostic support. Perhaps you will be able to avoid going through the SFEMG if the RNS is positive. Just a thought.

My neuro told me from the beginning that he was convinced that it was MG regardless of what the EMG said so if that's what they are thinking from your clinical presentation that is likely what it is.

Good luck to you. What is the date of your test?
Much aloha and hugs to you.

Angie

My regular neuro wanted to do that test real bad. I was AChR antibody positive and the Mestinon already helped. I felt like it was something she could bill for - but perhaps it could set a benchmark??? I never did it.

My MG specialist at a teaching hospital never even asked about it or wanted to do it. He saw my blood test and saw me and said we needed aggressive treatment fast. MG can get worse real quick as your receptors get taken-over (hurt) by the antibodies.

Thank you for your replies.

Carly - I haven't had the tests yet but thank you for your post - I am glad the Mestinon helps :)

Thanks again Snowbeltfolkie for your help - I will do what you suggest and try to warm and exercise the area. I worry that if nothing shows on this test that will be it for me....the Dr's here don't seem to acknowledge that MG can be present without a positive test!

Thank you PAt - I am not on Mestinon either and your story gives me hope that my face (which is where they are doing the test and where my main problem is) will finally give the answers to what is going on!!

Angie - Wow, you are a good woman to know!! Thank you so much for replying and for the information. I am having the test done on my face and hope the RNS will save me from any further testing and will show what is/isn't going on here. My test is the 16th September...so I have plenty of time to panic about it all!! lol

007Dan I am so pleased that you got the treatment you needed without the endless testing - I hope you are doing well on it :)

Many thanks again to you all
Eve.x

I had a neuro visit yesterday and in order to completet my Mg Patient Registry I had to ask about my test results. I did test positive for RNS, although, I am not sure what that is. I didn't feel well and frankly, I am not as good as some of you are about know all about every test etc. etc. For everything else I tested negative, EXCPET for my SFEMG of which the results were not in my file! I have to check up on that one. Barbel