Serena, on a bad day I can't talk long on the phone because my arm isn't strong enough to hold it up. If my arm gets really weak and I use it anyway, it shakes. I think what you describe is consistent with myasthenia gravis.

I think you're smart to be careful not just to assume that any new symptom must be part of the same disease you're already diagnosed with, especially when it's known that people with one autoimmune disease are prone to others. I'm glad you're planning to ask for further testing. I was diagnosed by my third SFEMG (the first two were borderline and mildly abnormal; the third was done by a different neurologist, whom I traveled to Boston (from RI) to see).

Abby