I hope your Gretchen is doing ok..... I am just seeing this thread.
I have not had a pup with the same condition, but did have a foster who had multiple neuro issues and I think perhaps his thread might help you a bit. He was a senior when he came to me so he had lived a very long life with neuro issues. There is a lot of information on that thread and videos of him. He was adorable. Because he had so many issues, surgery was not an option for him.
In the end, Sammy passed from an unrelated medical issue...so there is hope for some with neuro issues.
http://www.yorkietalk.com/forums/sic...ro-issues.html
As for a second opinion....I am quite sure your vet will welcome it. You mentioned she is reaching out to others. That is a good thing.
Please keep us posted on your girl.