Hi there, well I have "possible MS" diagnosis now. Finally.
I have MG for 4 years now, RA for 3 years, but around the same time I got other weird symptoms. First it was like "yeah but you have all kinds of diseases, etc" however, 3.5 years ago 2 different docs said, have you been tested for MS?
No I wasn't, but it wasn't until this month they tested me. (I kept asking, why not a brain mri or something??)
I haven't had all tests yet, but they're sure there's MS like stuff to see on my brain MRI.

So, it's possible I have both, yes.

I also have a lock jaw (no bananas for me!) but that's not related, I got it because I had an operation on my jaw 10 years ago.