Hi, sorry, I don't check this forum too much and rely on email notifs....guess it didn't let me know I got a PM. I'm trying to remember and I think I got an MRI to test for Multiple Sclerosis. I also had several blood tests for iron deficiency, diabetes, and other general problems. They came back completely normal and the neurologists just said that it was stress. Not a helpful answer but it ended up being sort of true. I will say that I still get internal vibrations when I'm very sleepy or have a particular type of IBS going on. But the vibrations are very mild, and I used to literally physically shake from them sometimes.

In the end it came down to psychosomatic symptoms and emotional stress. That's not to say this will be the case for you, but that's what was going on with me. I'm still not ~well~, my GI system is definitely shot to hell. But the vibrations and palpitations at least are still there.