My MIL has it. Right about this time last year my FIL had to put her in a nursing home. It's kind of a long story but the bottom line is that her dementia was a result of her decades of smoking. The heart wrenching part of it, to me, is that my MIL is awesome. She was the glue that always held the family together. Everyone came to her to disclose everything, everyone got along with her, she was always funny, consoling, understanding and always there to listen. When anyone had a problem, she would listen, give you her sage advice and she was always there to be an excellent peace maker. On top of all that, she has (had I guess it is now) a great sense of humor. I honestly feel like she died years ago. Her and I have always been very close, we used to talk all the time, share stories, she would tell me all about her childhood, etc. She always had an amazing memory.
I would say it all really started about 5 years ago. Slowly, she became forgetful, hoarding things she didn't need, hiding money all over the house and working extremely hard at trying to cover up her obvious memory loss. The kind, gentle, warm, big hearted MIL I knew, started to become paranoid, angry, bitter and mean and unfortunately my FIL became the center of her fury and rage. My MIL is 85, my FIL is 83. He would tell her that he was going to get groceries, would she like to come along? She would say "no, leave me alone, I want to rest." He would come back an hour later and she would become furious, accusing him of cheating on her, abandoning her, etc. She just really got out of control. It was never cute or funny it was an entire personality change, she would say extremely mean, hurtful, horrible things that she wouldn't recall saying a few minutes later. It got to the point where she was combative and way more than my FIL could handle. Eventually the difficult decision had to be made to put her in a nursing home, she needed full time care, full time attention and most importantly someone to watch her around the clock. She would sleep during the day and be up all night, my FIL would go days on end without sleep, that didn't help matters.
My FIL still blames himself for her bering in a nursing home, still thinks it's all his fault. The difficult part about him, is that he's always been the strong, silent type, the least touchy feely guy you've ever met but my MIL was the center of his world and the crushing part is watching him being completely guilt ridden is also pretty gut wrenching to watch. He visits her at least twice a day, every single day. Some days she hates him, some days she loves him.it's a horrible situation to be quite honest. I wish I could say things will get better, I wish there was a cure, I wouldn't wish this on my worst enemy, I think this horrible disease needs more attention and I hope to God I never, ever have to watch another loved one go through this again.