My mother is in assisted living near my home. What I initially thought was just "aging issues" is clearly now dementia of some sort. She has stopped reading, watching television, and recently has given up her adult coloring. She has trouble showing up for meals at the appointed time (no longer understands clocks). This week I accompanied her to the AL Christmas party, and she totally freaked out. The large crowd, music, noise, and she could not sit at her regular table for dinner. I could not calm her down and finally just took her back to her apartment. The next day she doesn't remember any of it. We got to this place over about 2 years and she is now 92 years old. Her regular primary care doctor will refer her for a complete neurological work up, which I know she will fight tooth and nail. The doctor says it is up to me. And I keep thinking, what good will it do to put her through this? While I was typing this, I had to quit for a 1/2-hour freakout on the phone from her because the AL folks were trying to get a urine sample from her to check for UTI.
You already know that she has dementia, so now it's time to face reality and more than likely have mother transferred to a memory care facility, which hopefully her current AL has one, as they will better be able to deal with her issues and keep her more calm.
And educating yourself about the disease of dementia will help you going forward as you travel this road with your mother. Teepa Snow(a dementia expert)has a lot of great videos on YouTube and is a great place to start.
I wish you and your mother well.
If she has no UTI and other physical medical issues (like dehydration, thyroid, vitamin deficiency, diabetes, etc.) has been ruled out or treated, then her behavior is most likely advancing dementia. I don't think a neuro work-up would be worth the stress, time or money. Talk to the facility admins about moving her to MC. I'm so sorry for this distressing situation. Everything about age-related decline and dementia is hard. Take it one day at a time and just be confident that you are doing your best for her under challenging circumstances.