Hi. I'm so very sorry you're going through this. My story is very similar. I had Graves, which I treated with thryoid suppressants (PTU) on and off for 15 years. There is new evidence that PTU and methimazole can make MG worse. In my case, I suspect I had MG but the symptoms weren't apparent, and then the PTU triggered it and made it worse. http://www.ncbi.nlm.nih.gov/pubmed/1798220

I tested negative for all the antibodies tests. My first SFEMG was "borderline." My second was "mildly abnormal but not enough to justify a diagnosis of MG." I have no response to Mestinon. My neuro, upon my impassioned plea (I can't live like this! We have to do something!) sent me to another neuro an hour and a half away. My local neuro is the neuromuscular expert in the area, but the one he sent me to has a special interest in MG. He did a third SFEMG and diagnosed me on the basis of it.

The neurologist who diagnosed me was an neuro-ophthalmologist. See if you can get to one of those!!! There are many of us on this list who got a diagnosis from a neuro-ophthalmologist when we couldn't get one elsewhere. The strange thing is that I hardly have any eye symptoms, and the neuro-ophthalmologist insisted on doing the SFEMG on my face, around my eyes, anyway.

My understanding is that a clear response to Mestinon is evidence that you have MG, but not all neurologists would consider it conclusive evidence. A neuro-ophthalmologist might give you a very easy test you can do at home, which is to ice your droopy eye and see if it perks up. If it does, some neuros consider this to be very strong evidence of MG. There's also a tensilon test, where you're given a shot of a drug similar to Mestinon, to see if it has an effect on the ptosis. I think a neuro-ophthalmologist might be most likely to use these tests.

Abby