My Dad's wife has been embellishing facts about her life for decades. When it escalated we didn't realize she had narcissism or dementia until the memory loss became more apparent. We then thought she had a version of the dementia for decades but eventually ruled that out to a diagnosis of Narcissistic Personality Disorder and now Frontaltemporal Dementia. We could not tell the difference between her grossly inflated stories of her education, jobs, money, travel and control of my Dad due to her narcissism versus confabulation due to memory loss. It has been a roller coaster ride and difficult for everyone who knows her because she is completely self absorbed, controlling and a little paranoid and has been for decades, but now with memory loss. Even now, she won't let my Dad talk to me without standing nearby or interrogating him after a phone call with me. Has anyone else had to deal with a person with dementia and a personality disorder, which doesn't go away when they get dementia apparently?
One thing I've thought about that's hard to articulate, but it sounds like you may understand what I mean: because we watched her all of our lives be "not quite right" emotionally and mental health-wise, once the Alzheimers symptoms started, for years we just felt like it was more of the same ol' same ol' from her. I think her prior lifetime of showing a personality disorder stripped us of the ability to feel much of a sense of urgency when the Alzheimers symptoms started. It didn't feel like much out of the ordinary to see her "losing her mind." That's sad to say now, but I look back and know that we just never felt things like "oh it's so sad and unusual for mom to act this way." No, instead, we watched her decline into Alzheimers and thought "yeah, that's how she's always been." So sad. I hope no one judges me for admitting that. Until you've lived with a very mentally ill parent, you just can't imagine what it's like.
And, by the way, at the end, there was one neurologist who believed she did not have Alzheimers but instead had FrontoTemporal Dementia, just as you have mentioned.
Best wishes to you. It can be a long hard road to navigate. Use this site for support. It's what got me through!