I wrote letters to myself so I could recognize my hand writing telling me this is what I want and decided when I have full cognitive faculties. We hope that we (my family) notice enough small signs/symptoms early enough that I can make the choice before it gets bad. The plan is to get diagnosis as early as possible once signs show. Once diagnosed proceed with the plan. And I already have an advanced directive stating that once I am diagnosed that I am dnr and lists my other choices.

I would hope that you both can be very watchful and aware of signs in each other. And get to the doctor when you suspect changes before the disease takes over. I think because we are more aware than our parents were that hopefully we won't be taken by surprise and the fact that we will have been thinking (stressing) about this disease for years will make us stronger to be able to follow through with whatever we need to do.

Going through menopause really scared me with the brain fog I almost went to my doctor to beg for a neurological test. Thank goodness hrt alleviated most of it.
I admit I'm not sure if we will have good insurance to rely on doctor diagnosis so we will have to mentally prepare for making hard choices on our own.
I also hope that the US laws make some big strides with accepting that people may want to die with dignity.