What is perseverance exactly? Is there any way to change a person's mind after they have gotten the idea that they are holding onto? Is there anything at all I can do to get the truth across?

Fevre,
Perserverence is getting stuck on an object, thought, desire or attitude despite evidence to the contrary. I can drive, the driving test was rigged. I can live by myself, I need a new... (insert whatever). In a nutshell...no, you can't get the truth across to someone with this symptom.
In time they will move through it but it takes a long time and just when you think you've gotten through to them...here it comes again. Sorry but that's my experience with this symptom. Maddening!

Carla

It's actually perseveration and it means the pathological repetition of a word, phrase, or act. You are thinking of a fixed idea. It is very difficult to correct a false idea in an HD patient because of mental inflexibility. It's virtually impossible to do when the person is emotional. Sometimes you can talk to the person when they are calm and get through. Even then you may find that they remember the false information later because that is what is stored in their memory.

I remember once my ex misheard me as saying to a friend that he had NOT been helpful during my grandmother's illness when I actually said he had been VERY helpful. He exploded in anger! I corrected him immediately and so did our friend. I still had to leave the house for 24 hours because he could not calm down.

This is all too familiar to me with my wife over the last 6 years. The "fixations" seem to become imprinted and the repetition can become infuriating to deal with. In my experience sometimes one of these fixations will resurface after months of being absent but thankfully that is usually short-lived. The way I deal with it is to be persistant in my opposition to the fixation by finding a good reason to respond with and sticking to it (that is every time she voices I respond). My wife's new (as of the last few weeks) one is she doesn't want to go out of the house because of her walking difficulties. I'm not sure how I'm going to cope with this one as it's a vicious circle, if she doesn't keep walking he walking will deteriorate even quicker (I have held her hand to support her for over 6 years when we go out and she has rarely fallen). I think this one may be related to a recent realisation that there is "something wrong" instead of the denial previously manifested. Just be careful as some of these fixations can lead to psychotic episodes and mood stabilizing medication is usually necessary. But then I may be wrong, bugger it, it's just so bloody hard to deal with! I hope you have some good support and believe me, receiving a "big hug" is often required.

Thank you so much! Because we don't live together I feel there is very little I can do to help him. I have asked for an apology over and over because I just want him to acknowledge that he was wrong but every bit of mail (three by snail mail in the last week) I get seems stranger than the last. I have finally decided the best thing I can do for myself and my son is to cut off all communication. Hopefully that means he will start bothering someone else that he actually trusts and they will be able to get him the help he needs.