[AnnieB3]

This was quite interesting, especially in view of how many neurologists tend to dismiss patients with clinical weakness who do NOT have either the ACh or MuSK antibodies.

http://www.mayomedicallaboratories.c...-mg/index.html

I thought you guys might like to have a look, in case you haven't already seen it.

Annie

[alice md]

Thanks Annie,

I have been asking myself how rare is MuSK MG? Is it really that rare or is it mostly undiagnosed?

Seeing this algorithm of the diagnostic process in patients with clinically suspected MG from a large/leading medical center, made me ask myself how often do neurologists dismiss patients without even checking for MuSK.

Furthermore, what is the true sensitivity of the currently used serological tests to detect AchR and MuSK antibodies?

How many patients with MuSK are still managed as " nothing"?

[southblues]

Thanks for this.

Did I interpret the slide show correctly in thinking if you are AChR negative, then that rules out thymoma?

[AnnieB3]

Alice, I had an odd situation back in 2002 - to say the least. Anyway, the lab drew blood for the AChR test and the MuSK test. They never ran the MuSK test. I didn't find out why not until nearly 7 years later. They had sent the one tube to one lab for the AChR test. Because of the "indication" of activity (not outright positive), they sent the other tube onto another lab for a 2nd AChR test. Well, that one was positive. No, I was never told about it. It's a long story, which I've talked about before.

What that showed me is that all labs aren't created equally. Mayo "invented" their test and even though it's not "FDA approved," it has stood up as the better place to send serum for MG antibody testing.

What's ironic about the slide show is that I've personally seen the opposite in clinical practice there. So I guess I also found it funny.

I think there are patients with ACh and MuSK antibodies who are never diagnosed. And doctors are very uncomfortable diagnosing seronegative MG. It's as if they don't trust the clinical evidence. And while this is only a slide show algorithm, it is the first one I've seen from a major institution that shows actual guidelines. That sounded ludicrous even as I wrote it. It's very sad that MG is so unnecessarily difficult to diagnose.

Celeste, I don't think they can conclude that, given what I've read. But this is an "algorithm" and there are exceptions to any rule! I'd love to know if anyone was an exception to it. Not to prove Mayo wrong or anything but to know what the whole truth is. If a blood test can "prove" you don't have a thymoma, then why radiate a patient with a CT scan?

Annie

[catie]

Originally Posted by AnnieB3

I think there are patients with ACh and MuSK antibodies who are never diagnosed. And doctors are very uncomfortable diagnosing seronegative MG. It's as if they don't trust the clinical evidence.
Annie

Annie,
Thanks for sharing this slide show with us. It's very informative.

In terms of seronegative MG, I'll have to say that I've received a lot of support from Mayo. Multiple neurologists back home refused to diagnose my MG b/c of negative antibody tests, even in the face of a fairly clear clinical picture. Fortunately, Mayo reviewed my testing (and put me through most of the testing again) and then gave me a tentative diagnosis of "seronegative MG" and recommended some treatment to determine response. My neurologist there has not wavered, even with my EMG being negative.

I count myself as one of the fortunate ones. I now have a neurologist back home who is very supportive. I try to put the very negative experiences I had with neurologists previous to all this, behind me.

Cate

[AnnieB3]

Cate, Who doesn't like to put bad experiences in the past? The problem is that so many patients keep encountering them. So it's hard to get to the "acceptance" phase of doctor grief when you keep being put back into the "shock" phase.

I'm glad you had a great experience at Mayo, whichever location you went to (they have 3). I hope more patients do!

Annie