It's not that they don't know, it's that they pretend they do, they don't want to discuss uncertainty and they dismiss when you bring it up. I'm on my 5th treatment that they're "very confident will really help a lot" but can't quite quote a percentage change of recovery for.

At least that's been my experience with very similar issues.

Sorry for your condition. You're not the only one in the boat. So at least we have company. I hope that helps.