Sudden decline. How quickly can this happen?

Yes, such a thing is possible. The thing about dementia/Alzheimer's disease is that the decline is not linear. The changes aren't the same from hour to hour, never mind day to day. Today your mom could be back in time to when she was 25, a point in time before you were born perhaps, which may be why she's not recognizing you. Tonight or tomorrow she could be at 50 years old, and remember you quite well as her daughter. Then revert back again to 20 or 25 years old, expecting to see those people she knew in her life at THAT TIME. If you keep in mind how your mom's brain is functioning now, it'll be easier to understand why she's acting as she is. Doesn't make the scenario easy, I know, but makes it more understandable.

Good luck to you

When I visited my mother this week, she didn’t know my name.

It was the first time that had happened, and even though I knew it would come, it jarred me.

Dementia is SHATTERING. 😩

There were declines that my Husband had that were literally overnight. And I can pinpoint each one.
My Husbands "official" diagnosis was Alzheimer's but I think he also had Vascular Dementia.
With that type of dementia there can be a mini stroke that can cause an "over night" change and depending on what part of the brain was effected by that damage will effect what is "lost". It could be the ability to recognize you, it could be how to use a utensil or how to button a shirt.
So simple answer is yes it is possible.

Yesterday, my mother greeted me with a paragraph of Word Salad. 😢

2 minutes later, she asked, “Is there a toilet in there?”, pointing to her bathroom. 😩

Both were for the first time.

I walked out of there, praying out loud for The Lord to JUST TAKE HER, ALREADY. 🙏

My mom changed almost overnight. This disease is awful. Even today, although she lives with me, she doesn’t know my name but refers to me by her brother’s name. I respond to it because I know she’s trying to remember my name but just can’t. Every once in a while she will call me by my real name and I’m in shock to hear my name being called. This disease is awful.

i was looking at old videos I took of my husband last summer, june , july and august2021 and he was still walking around, no cane, eating non stop, watching tv for short periods of time but I did have a caregiver just to stay with him about 4 hours a day so I could do errands, my medical appointments, pay bills ect.I was doing all his personal care and grooming, helping him to the bathroom and cleaning up accidents. Fast forward 4 months… still eating and snacking, but falling, trying to leave the house, trying to jump from the car while I was taking him for a ride to see the ocean, incontinent of both urine and stool. Insisting someone was trying to hurt us, insisting I was holding him hostage and wasn’t his wife and thought he’d abandoned his kids, which led to severe depression. I had no choice but to place him In LTC after I ruptured a disc In my back and was unable to even lift a half gallon milk jug.His admission date was December 15,2021 and I was heartbroken. Now 6 months later on June 27,2022 my wonderful husband who ive been with since we were 16 years old, passed away. He had a fall, thru no ones fault but him climbing out of bed over the half rails, ended up in the hospital via ambulance for a cat scan of the head which showed NO head Injury, I knew he was on a downward spiral , he was a DNR/DNI and I had him sent back to be with staff who adored and took good care of him.( I’m a retired nurse and I can honestly say he was NOT treated very nicely at the hospital ER… apparently the nurses feel the way to calm someone with dementia these days is to scold and verbally antagonize them while trying to insert a catheter which resulted in trauma and bloody urine the remainder of his life).I’m thankful that I placed him on comfort care with the staff who loved him and gave my VietNam Veteran the respect and dignity he deserved and he died peacefully 12 days after he was discharged from the hospital. I’m sad and grieving but also feel proud of the life we had together .we both kept all of our promises right to the end. If I can say anything, I’d say “ make the very most of the time you have left with your love ones. Be kind to the staff, especially the CNA because they are the angels who make a difference .advocate for your loved one In a respectful way. This is a difficult job for EVERYONE. Never stop telling your loved one how much they are loved”. Love and hugs to everyone💔💔🇺🇸

Msblcb, the problem might be a case of Urinary Tract Infection {UTI]. Such an infection in an older person can cause all type of problems. Your Mom can have a test done at her primary doctor's office or at an Urgent Care. This can be treated.

If you think that she still remembers you, at least most of the time, it might help you both if you make a habit of saying your name, calling her Mom, even referring to yourself as daughter, each time you first see her. That will help keep her memory fresh, and probably be less difficult for you.

At some point many people with dementia get muddled about relationships, as they go through stages of decline. My mother eventually forgot who I was. She recognized me as someone she knew and trusted, but didn't recognize me as her daughter. Sometimes the memories come and go; there are good days and bad days. Accept her for where she is day by day, and try to channel your love for her. Dementia is often called the "long goodbye." You may find that you experience grief at her loss of capabilities. Seek support groups and grief counseling if it will help you deal with being a caregiver for a loved one with this terrible disease.

I remember asking my mom's doctor this same question -- "How could this happen so suddenly?" He said that decline in the elderly often follows a pattern of drop>plateau>drop>plateau rather than a steady downward slope, and I have absolutely found this to be true in our case.

Having said that, within each "plateau" my mom will have good and bad days/weeks depending on how well she's been sleeping, her anxiety level, and who knows what other factors. Some days she's not even sure who SHE is; other days she's having philosophical discussions about Roe v. Wade. The "bad" periods can be upsetting but I've learned (ok... am still learning!) to just roll with whatever the day brings.

Do definitely check for signs of a UTI, as that can cause severe and sudden (and temporary) changes in cognition.

My heart goes out to you... the first time my mom didn't know who I was, I felt absolutely shattered. The grief literally brought me to my knees. Sending lots of comfort and strength to you!