Terrible way to go. My father in law died from it. His decline was heartbreaking because he was an extremely intelligent man, and the sad irony was that he took care of patients that suffered from it. He wound up passing away at the same hospice facility where he worked.
I beat myself up for awhile for not going out to KC to see him one last time with my wife and kids, but my mother in law told me to save my pto for the funeral instead. That hurt hearing that. She said the only reason she had my wife and her brother come out was so they could make peace with him before he left. My wife told me not to feel bad because she said it was really unsettling to see him in his final stages. She said he would have moments of clarity, but then would either start acting childlike or would just stare blankly at everyone.