On Christmas, she got up at 6am because I was picking her up at... 1pm. When I questioned that, she took a nap and felt better but seemed to be confused again later in the evening. Today, at 3AM she called to ask if I had slept in, because I was supposed to take her to the Dr at 1230. Totally confused and it took her a few minutes on the phone to get it right....thoughts? Stroke? Can dementia come on really quickly? Thanks.
In light of this sudden change, I would have her checked out by her doctor. It could be that she has a Urinary infection. Is she taking any new medications? The doctor should be able to rule out other things or attribute it to the dementia.
But, to answer your question, yes, my cousin's symptoms appeared rather suddenly. She went from running her own household to not being able to care for herself is just a few months. One day she suddenly could not figure out how to get out of her car. I didn't know about it, but apparently, it scared her and she put the keys away. She told someone that a girl had bought her car. (Was not true. She had delusions.) She also could not differeniate between 5 minutes or 5 hours. She would call someone on the phone, talk, hang up, then call again in 5 minutes with no memory of the previous call.
It might be a good idea for you to have her assessed, if it is dementia. Once this type of thing starts, it can be risky to leave them alone. I tried to get things out of my cousin's house like scissors, toaster, knives, cleaners, but, they are still vulnerable by being alone. Similar to a child being alone. I also turned off circuit breaker to the stove and dryer. They can get frightened, anxious and panicky. I would have her assessed to see what her needs are. After our visit, my cousin's doctor said she could not live alone.
A year ago things looked a lot different, she only had 20 hours of care per week, now it is 15 hours a day, and because of her wandering at night we are now placing her in a home. Things can change fast , not sure if this long comment helped or even answered your questions!!!
From your profile it does seem that you know your mother has dementia. Are you asking if new symptoms can appear suddenly? That answer is YES. In fact, many symptoms couldn't really appear gradually. She either understands the ways we tell the difference between night or day, or she doesn't. There is no "gradual" about it.
When our mother lived with her, my sister updated a white board every morning. It said Today is Wednesday. We go to the beauty shop at 1:30. I am making cream puffs for dinner. This helped minimize the daytime confusion, but Mom was still confused at night. A clock that projected the time and AM or PM on the ceiling was somewhat helpful.
Both my husband and my mother lost the ability to judge the passing of time.
Would you like some tea and cookies, Mom?
Oh that would great if it's not too much trouble. (Minutes later): JEANNE, where are you and where is that tea?
I've been in the kitchen. The water hasn't boiled yet.
Oh. Well it seemed like you were gone a long time.
Your profile says that you live very near your mother, and that is a good thing! But as her dementia progresses it may not be sufficient. She may need in-home help, or perhaps spend part of her days in an adult day program. Being connected to you by telephone may not be enough for her, and it may become too much for you, if she calls every time she is confused.
Best wishes to both of you on this very challenging journey.