I care for my elderly mother with Vascular Dementia.
She sleeps a LOT! like going to bed at 6:30pm and up after 9-10am (with getting her up for potty breaks) now she's taking naps during the day as well...
I do get her to take a brief walk in the backyard on most days (unless it's raining or cold)
She's up to eat and that is about it. But, she's not in active death or anything like that. Just sleeping.
Plus, her mother had it as well. So, we have a family trait of it.
I know you're wanting the best for your mom, but you must understand that the dementia she has is very aggressive and the fact that she's now sleeping a lot is quite normal with the disease. My husband in his last year of life slept around 18-20 hours a day.
I wish you the best as you take this journey with your mom.
(when my Husband was on Hospice increased sleeping was one of the signs of decline they used when he was recertified for Hospice)
Is your mom on Hospice? She would most likely qualify and you would get more help if you need it. (as well as all the supplies and equipment you need)
There is a pamphlet I read that sort of explained the sleeping. (read Crossing the Creek)
But what is going on is that her body is tired. Staying a wake for a shower, getting changed, eating and trying to follow conversation is exhausting mentally as well as physically. So she sleeps to "recharge"
The body is also "doing a lot", it takes energy to digest the food she eats. It takes energy for her body to breathe, the heart to beat, the brain to function.
the last 4 to 6 months of my Husbands life he was sleeping around 23 hours a day.
What you do have to be cautious of is pressure sores.
Change her position.
A mattress with alternating pressure helps.
When she is sitting adjust her position either by sitting her up a bit more or even just shifting a shoulder or leg.