My FIL has LBD and my MIL has mild dementia. My husband and I have been oddly comparing her to him and realize that her 'forgetfulness' is worse than we thought. She's begun forgetting things she's always known how to do--most recently, how to use their remote control for their TV. She claims it's new and that the TV belongs to the facility they live in. Not true. They've had the TV for 10 years. I tell you that story because she's recently been telling a story, over and over again that we feel certain was a dream. She tells it to anyone who will listen as though it were real. (She woke up in the middle of the night to find Dad not in bed. She saw the light on in the bathroom. Got up and found that he was taking a shower. She got him out of the shower, dried, dressed and back to bed). There's more to the dream, but she repeats it EXACTLY the same way every single time. Like she's memorized it. BTW, we know it's impossible because Dad can no longer walk, dress/undress himself and there's an alarm on his bed to alert staff when he sits up in bed. This facility is a dream as far as caregivers and owners. It could not have happened. I understand her losing memory of things she formerly knew how to do, but how can she be forming new memories?
I am so glad you have access to a gerontology group! They can check if there is any medical reason for this, and explain the psychology of it to you.
It is odd how memory can be so erratic, isn't it? My husband had LBD, and memory issues are not the primary symptoms (though they certainly exist!) Some days he could remember remarkably well, and others the short term part didn't work. Sometimes he would remember something I was trying to recall. I'd say, "Wait a minute, which one of us has dementia?!" That pleased him.
Why can your mother remember this delusion, but not remember how to use the remote? It is a mystery!
Thank goodness the facility they're in has an amazing gerontology group that come to see them. I'll discuss it with them. At the very least, we can be watching/listening for further stories.
I'd discuss it with her doctor to see if there is some explanation, UTI, meds, other infections, etc. or if it's part of her dementia.