@tracidw The FDA has a black box warning against using Seroquel for Alzheimer / Dementia patients. It can cause increased agitation, strokes, etc. Please look into this and consider stopping that prescription.
My LO was recently in the hospital (an excellent Boston-area hospital). By day 2, my LO's anxiety was off the charts and she was much weaker and unable to manage routine tasks. She also has severe sundowners. I had suspected there was an issue with Seroquel, researched it, and called the hospital to order the dosage stopped immediately. My LO was better the following day and increasingly better since.
https://www.mayoclinic.org/drugs-supplements/quetiapine-oral-route/description/drg-20066912

@tracidw My husband takes saraquel for sundowning. I usually can tell when it will be worse as he starts talking about going to where he grew up and meet his buddies. Of course he doesn't drive and has talked to no one. I have learned to go along with it and give him 1/2 of a seraquel and it seems to calm his mind. I used to argue about him going anywhere-- now I agree to take him but we have gotten in the car and I go every where he wants and he realizes it is his delusional state and wants to go home. So usually he says maybe tomorrow and I go along. I also, use a white board so he knows are schedule.