When I took mestinon regularly ( which got rid of my ptosis!) If I took too much I would get horrible twitches. A lot of my problems with mestinon was that I suffer with gastroparesis intermittently so on occasions I would get a lot of mestinon dumped into my system in one go.

As for the band feeling - my back is very temperamental and the slighted thing can cause me to have back spasm. They aren't really badly painful unless a lot of muscle groups are involved. However I describe the feeling that its as if I'm wearing a corset. It goes from the middle of my back and around.

MG causes muscle weakness - we all know. Could it be that those muscles have been working extra hard to support you and have gone into spasm? Causing the band feeling around your back and chest? Have you tried getting someone to massage your back when its like this? When its in spasm this can be painful but it will release the muscles.

Have you tried applying heat and seeing if that helps? A physios therapist friend of mine suggested applying ice to the muscles for a few minutes to shock them into releasing the spasm that works as well.

I hope this helps

Rach x