Does anyone have experience with a ketogenic diet for dementia?

I put my mother on a ketogenic diet seven days ago. At least I hope she's in, or going into, ketosis. I haven't tested her blood or urine. The diet may be a bit heavy in protein, but apparently there are concerns about lower protein for an elderly person who spends most of her time lying down. I'm supplementing her diet with MCT oil to encourage the production of ketone bodies.

How soon can I expect to see improvement, if any? What kinds of improvement? How long will she continue to improve if she does at all?

My patience is in tatters. I'm on the verge of just giving up and put her in a nursing home. If anything, she's more irritating than she was before, but maybe that's a sign that she's improving? Or maybe it's just a sign that I'm wearing out.

One of her favorite statements is "I can't wake up." She says it several hundred times a day at two minute intervals. It's like a Chinese water torture. Not responding isn't an option, because she'll insist I say something back, although I have nothing to say to it. I'm not even sure what she means, since obviously she's awake when she says it.

Any thoughts? Or, even better, any personal experience with this?