Mother has been diagnosed with "Sundowner Syndrome." How should my brother and I react when she has one of her negative comments to us?

My MIL and my dad both had sundowners,, they didn't get nasty per se,, just agitated and confused. My MIL was at the river house with us once, and it got dark and the kids ( in their late 20s ) were still in the water, all was fine and safe. She just could not stop looking out the window, going on the deck, telling them to come in and get in their PJs.. another time, she and FIL were going back home after dinner ( FIL liked to stay until 9 or so and go home late) I had packed up some leftovers for them to take home and we were all sitting on the deck. I could see her through the window watching TV. And then I saw her in the kitchen putting leftover ribs and burger patties in her purse.. NOT the wrapped ones, the unwrapped ones.. Oh boy, what a mess.. She could not understand they were not the wrapped ones.. Dad would wander about the house and check all the doors, and go look at the cars, and wonder when he was going home.. So I guess I was lucky? I agree, plan your visits when you think she may be calmer,, better for all of you. Let the home keep her on schedule

My father was actually 'sundowning' while in the hospital and rehab, but he did not have dementia. I would not visit your mother during the time of day that she's exhibiting her symptoms. She may not be able to help her nasty mouth, but it's hurtful to you nevertheless, so visit her at a different time of day. That's my suggestion.

Good luck!

I would simply tell her that you don't intend to listen to her nasty comments and if she continues, you'll leave.  Then do it. 

Don't mean to sound cold-hearted, but we have to have boundaries - not just for our own sanity, but it's good for them as well.  Bless you.  I know it's hard. 💙

Sun-downing is most definitely a symptom of Alzheimers, and is apparently significant in other forms of dementia as well. Some people also call it late-day confusion or late-day agitation. Although there is no proof, the consensus seems to be that the fading daylight has some bearing on the brain, hence the sun-downing moniker. Going with that theory, try to have the lights turned on from the early afternoon. If necessary close curtains so afternoon shadows cannot be seen growing outside. If you are only visiting late in the day ask the staff to attend to this well before she goes into this awful phase.
Apart from the obvious confusion, a sufferer's behaviour can be abominable. It is certainly that way for my mother, who has at least 3 forms of dementia. Negative is too mild a word for some days. Add agitation, aggression, wilfulness, waling, crying, yelling....and lots of other adjectives. The fact that she can purposely slide from her wheelchair or lounge, or roll out of bed if she is resting, would suggest there may even be self-harm in her case.
There are other times, even when she is confused, she can be so sweet, concerned, interested, even animated. Honestly, she is Jeklyll and Hyde reincarnated. Unfortunately those occasions are rarer these days.
Really the best solution is to visit when your mother is less likely to be sun downing. Otherwise if you are present when this comes on, don't try logic or any form of explanation. It only compounds matters. Try deflection by changing the subject, taking her for a walk, bringing her a tasty treat she loves, telling her how pretty her hair is. Try not to ask questions, that is confusing. By no means try to give her a detailed account of any events, that compounds the confusion too.
As far as the abuse and hurtful comments are concerned, simply ignore them. I would not normally advocate tolerating bullying, but the rules are thrown out the window when dementia walks in the door.

"Sundowning" is usually related to cognitive decline of some sort from what I know and can range from passive behavior to violent, I'm not sure if it has to do with the brain just being tired at the end of the day or the lack of daylight or a combination but the patient doesn't have control over their behavior. I know my mom tries and some days is more able to function than others but her behavior or lack of clarity in her case isn't something she can control. We call it her bewitching hour and we know anything that needs to be accomplished with her help needs to be done before this.

Your mom is in a NH so she's safe and cared for, I would recommend trying to remember it isn't in her control or aimed at you personally and end visits before the Sundowning happens. Usually there is a bewitching hour when the decline begins, if that's 6pm say your good nights by then and let her mind rest.

You should react with understanding that it is the "disease talking". And you should, if you are able to, use humor to deflect. Such as a sweet smile and commenting back "Really, Mom? Is that your honest opinion? I am gonna take that into careful consideration!". And on you go. You are the one able to sort through what is real and what isn't, not your Mom. The hardest part of all this is loosing the ones we love but their still being there, dismantling their entire lives, but having them still living. So sorry for the grief that is a normal part of all this.

I agree "sundowning" is related to a Dementia.

So, now she is in a NH? Is this a permanent placement or just for rehab?

Your profile indicates someone who was barricading herself in her home and refusing help and medical attention. I hope that you can all see that she needs a permanent facility placement.

Has anyone mentioned dementia? I find that it's pretty rare for an elder to "just" have Sundowners that is not associated with dementia as part of the bigger picture.

Have you and your wife watched any Teepa Snow videos? She has good techniques for dealing with dementia outbursts.

Have any meds been recommended or trialed?

Unfortunately she is going to permanently be in a negative state. This isn't going to go away, even if/when her fractures heal.

There isn't much you can do. You can't talk her out of it or reason with her. Maybe visit her during the daytime only.

If she gets unreasonable, just walk away and tell her you'll be back to visit when she is feeling better.