I went through FCE with my first, Rascal. We did all the tests and pred and some of his functionality came back and some of it didn't. In his case the mobility all came back but he never regained control of his bowel control and the urinary control got weaker with age. After a week and a half at a university hospital my local vet saw him. The first thing he said is that it could get better but I should consider if I could handle him the way he was because it might not get any better. It never really did improve after a few weeks.
We did accupuncture and it really did help but whenever we tried to wean down on the visits his control got worse. It never bothered him really and he lived to be 12 1/2 and this happened when he was 7.