is your mom diagnosed with alzheimers? My stepgrandfather has alzheimers. Narcissistic personality disorder and alzheimers are two seperate illnesses...so i am confused by the title of your post and your general post.....As people get older they do tend have memory problems which bring about negativity and anger ...they get to feel hopeless and angry at themselves for not being able to do simple things...and therefore take it out on others. If you think its really too unusual perhaps talk to her doctor about your concerns and ask for his opinions and any suggestions that he might have. Notice if she forgets things like what month or year it is....its harder to forget things like that .....unlike days....or her name.....As for feeling guilty. You should realize what you feel is completely understandable especially after how she affected you throughout your life.....If you hit a dog time after time and then randomly expect the dog to not be afraid of you...to not flinch when he comes near you....its unreasonable....No one blames you for feeling this way. Is there any other family to help? So you are not constantly with her, handling all of the stress? Or if there isnt anyone, any time she is becoming negative, just randomly start a different conversation...bring her attention to something else....ask her about the weather...whatever...if she continues to be nasty......then simply leave. Explain to her that if she wants to be rude she can do it alone and be rude to herself. Explain you will come back on such a date as long as she is civil as an adult. I am also an certified nursing assistant and take care of the elderly, I dont care if they are mean, I will tell them they cant talk to me like that. Or I have a few pts that have a wry sense of humor...anyone who cant take a joke will be offended...so i play there game....i joke with them...and they end up loving it....and stop eventually .....is she in a nursing facility? If not, depending on her age and abilitly to get around in her home, perhaps its time to look into it. Even a assisted living facitily which isnt a nursing home...but they have their own apartment which nurses and cnas like me visit them and make sure they are safe and taken care of ....i hope i have helped a bit. good luck
love, inny