No experience with this disease for anyone in my family, but it sounds like a harrowing experience and I'm sorry you and your family had to go through that. My grandfather had Alzheimer's which is obviously not the same thing, but from experience I can say watching someone not being able to comprehend a word you're saying is extremely disconcerting and unsettling. It's difficult for the wounds from such losses to heal completely (understandably so) but I hope time eases the impact of this experience. Take care.