Take heart, Liz, they're rarely in pain if it's neurological. Lonzo has a few problems, and he's seen my vet a few times, he has a twitch in his tail, he clicks & shakes his head (and it's not an RI) and is losing the use of his left front leg, but he still runs around as best he can and he loves to sit in the sun in the am, so he gets to be out in the am before anyone else, even diva Didi (who doesn't appreciate being in his tank, that's for sure :lol: ). Then there's the non-functioning lung. In Lonzo's case a lot of it is age related, but he's had the tail twitch since about a year after part of his tail was amputated. His lung problem is related to when he was flipping over all the time, yet he stopped doing that over a year ago. He also has arthritis in his back, so I give him Serrepetase 3-4 times a week, it's the silkworm enzyme that is a natural anti=inflammatory and painkiller. He will live out his lifespan regardless of what is wrong with him, so just wanted to let you know that Ava can do the same. I think you'd know if she was in pain.
Good luck at the vet tomorrow! And please keep us updated. Praying that she won't have anything serious wrong with her.
Deb