Don,

Has anyone tested your thyroid? Hyperthyroidism causes weight loss, tremors, and sometimes muscle weakness. Even if all your symptoms don't indicate thyroid disease, you should be tested, because it's common for people with MG to have Graves' (hyperthyroidism) as well.

Here's my story, in case it helps. I don't have ptosis or eye involvement (except sometimes a bit of eye strain). My antibodies tests all came back negative. I don't respond to Mestinon. I am diagnosed with MG on the basis of a single-fiber EMG (SFEMG) (and it took three of those before the doctor was reasonably sure).

I think in your situation, many neurologists would try you on Mestinon to see if it helps. It's a very quick- and short-acting drug. You'll either see a response right away or you won't (I mean it's not like you have to wait weeks for it to kick in), and if it doesn't work, or gives you bad side-effects, it's out of your system quickly. Just make sure you're not on Mestinon when--if--they give you a SFEMG, because it can cause false negatives.

Welcome, and I hope you get some solid answers. It's so hard to be in diagnostic limbo!

Abby