Seronegative myasthenia gravis is more common than many doctors seem to realize. The article below says that different studies have shown that between 7 and 34% of MG patients are seronegative. Not only that, but the earlier in the disease, the more likely that the patient's blood tests negative.

"Seronegative" is a misnomer, though. It just means that the blood tests can't find the antibodies. The antibodies are there, because when the immunoglobulin from seronegative patients is injected into animals, the animals show abnormal neuromuscular transmission.

I'm posting this here to tell readers who are seronegative and undiagnosed not to let their neurologists rule out MG too quickly.

http://www.neurology.org/content/48/Suppl_5/40S.short

Abby

All my first tests were negative but I had a neuro-opto tell me that within a year my tests would be positive or he would eat his hat. He was 100% correct. The huge plus is my wife, she would drag me to doctor after doctor until we finally got a DX.
Mike

Just sent your link to my doctor husband. Neuro is not his field, but it helps me when we see the neuro and he is armed with info. Thanks!