What is the best test for AChR negative patients?
 

Hi everyone :) I just wondered what test I should push for as my neuro doesn't seem very pro-active and I don't see him offering to do them all!

As some of you know, I've been pursuing this for 9years but thankfully had a few years of mild symptoms so just got on with it as I didn't get very far with a diagnosis! I am now 3 months into a relapse and at the same stage (bloods clear, chest x-ray clear, MRI clear and a negative AChR test) this is as far as I got last time but this time my neuro has said this doesn't rule out MG (as we all know too well!) and he is clearly looking in that direction.

So....back to the question (sorry-I do ramble on!) would someone with a negative AChR test be more likely to test positive for the anti MuSK or an EMG (or SFEMG)??? The more I research the more I see there are patient groups who show negative on both who still have MG and I am scared I am to push for either one as I don't want another negative test and therefore no answers when all my symptoms point to MG! I would ideally like both but if he is resistant to that what would you advise as the best test? My main symptoms are one sided facial droop and eyelid droop, my legs and breathing become involved during bad days when I have tried to continue normal life but they seem to fluctuate the most and maybe more fatigueable than weak like my face at this stage.

Thanks again for your help :) x

I am negative for all antibodies including MUSK. My doctor made the decision to call my illness myasthenia gravis based on two things.

1. He ruled out everything else.

2. Then he did a trial with mestinon. Since it was miraculous, and I get much worse without it, he said that we have an adequate basis for a myasthenia diagnosis based on clinical exam and drug response.

Exactly the same here. My neuro told me that about 10 percent of MG patients are negative on all tests. Mestinon produced an instantaneous improvement in my walking, swallowing problems, etc. This was the basis of my diagnosis.

I am also AchR negative. I was diagnosed with a positive Tensilon test and repetitive stimulation nerve conduction test. I was having diplopia, ptosis, facial drooping, slurred speech, and moderate weakness of my neck and shoulders.

My neuro doc says this is enough for diagnosis. I think the other tests are much more expensive and insurance may not pay for them. He says if I don't respond to his treatment plan then we can look further
Hang in there
Sandy

Though response to mestinon will never be a profound as the response to tensilon, basing diagnosis on a mestinon trial is the same idea or philosophy.

My antibody test was also negative which was done while I was in the hospital with moderate left side ptosis, diplopia, weakness to the point that i couldn't get up without someone around because i was so weak... but MG was ruled out. My neuro already had me diagnosed with peripheral neuropathy after positive nerve conduction studies.

I was referred to a neuro-opthomalogist who made the diagnosis with mestinon a couple of weeks ago.

Fortunately my CT is negative... So no surgery at this time!!!

I am now on ER Mestinon twice a day and the short acting for break through as needed.

Good luck, don't give up! I have fought these symptoms on and off for over 5 years and thugh it absolutely sucks to have this diagnosis, but at least I now know what I am fighting!!!
Lindsay

I want to add my voice. I tested negative for AChR antibodies three times, negative for LEMS and MuSK once each. I was diagnosed with MG by my third SFEMG.

Look at all of us seronegatives. I really think the number is much higher than 10%. I bet that many people with seronegative MG don't get diagnosed, so they're not counted.

My neuro said to me the other day that he thinks I probably have antibodies we haven't discovered yet, directed against one of the other proteins in the neuromuscular junction. One clue is that I don't respond at all to Mestinon.

The way I got diagnosed when my neuro wasn't willing to pursue the matter was to ask him to refer me to someone who specializes in MG. He was happy to do it. He sent me to Boston (an hour and a half away) to Dr. David Weinberg, who does a special kind of SFEMG (stimulated).

Abby