Not long ago, I read of the ruling on Terri Schiavo and when it wasn't her decision, she has no living will, it is legalized murder because it's on the say-so of another human being.
And this seems to run through the whole of life in disability issues. If one cannot be cured, you cannot be used as a success statistic by the doctors, so you are nowhere near top of their priorities, and probably nearer the bottom. If you cannot work, through the disability, (and therefore contribute to society in that way) and have no dependents, you are disposable. There have been cases here in England of even life-saving heart surgery not being given as spending the money, (in a socialized medicine system) could not be justified when people who can be fixed up as good as new, go back to work, and have people who need them and depend on them, can have the money better spent.
It all comes down to figures in the end. Whether it be statistics in success rates, or financially. The elderly who are infirm will often be given preferential treatment over the long-term disabled because they have been contributing up until they retired and often have families.
As a severely disabled person, I've also considered recently the value of making perhaps a living will or Advanced directive which is basically the same thing. And that can seem a huge temptation for someone in my shoes. Yet, it also speaks of defeatism, and assuming an eventual outcome of this disease. Yet it's just as likely for madness to take hold permanently somehwere down the line, and that to me, is far more of a dread than being helpless in the ways these living wills cover.
I just think the value of human life is grossly under-rated in whatever its form. Ask how many parents who have Downs Syndrome children, or an autistic child, if they regret having the child. The answer will invariably be no. Samuel, My Joy Yet, those with downs, autism, or a multitude of other disabilities, are some of the offcasts of society too.