Hi, and welcome. I'm so sorry you've been through so much and are still undiagnosed. Not having a diagnosis is a huge burden emotionally.

A lot of us here are seronegative (that means we tested negative for the MG antibody) but have a diagnosis of MG anyway. Some of us (like me) got that diagnosis based on a Single Fiber EMG, and some are diagnosed based solely on symptoms, or based on other tests (like a tensilon test).

I've seen various numbers for how many people with MG are seronegative, but it could be as much as 20%. You need a single fiber EMG (SFEMG), which is a test that studies the electrical impulses in your muscles. It's a more accurate test for MG than the blood tests are. Not every neurologist knows how to do this test. You need a neuro who specializes in neuromuscular diseases. You can get a recommendation from your local chapter of the Muscular Dystrophy Association (MG isn't a form of muscular dystrophy, but it's a "covered disease" of the MDA).

There are also other antibodies besides the acetylcholine receptor antibodies that can cause MG (or related diseases). The most common is the MuSK antibody. There are blood tests for it. You should also be tested for Lambert-Eaton Myasthenic Syndrome (LEMS).

I hope you can get to a neurologist who is willing and able to do these tests. In my opinion (I'm just a patient, but I've read a lot) any patient with symptoms like yours who tests negative for the AChR antibodies should have a SFEMG and be tested for LEMS and the MuSK antibodies.

Many neurologists with a patient like you would also prescribe a trial of a drug called Mestinon (generic: pyridostigmine bromide) that is used to treat MG symptoms. It's a very fast-acting drug, and safe. If it helps you dramatically, that's pretty good evidence that you have MG.

Please feel free to ask questions here. Many of us went a long time without a diagnosis, so we know what you're going through and would love to be able to help in some way.

Abby