Has anyone ever heard of or experienced sudden onset dementia?

Have your mum checked out by a neurologist who should order cat scan and/or mri of her brain, neuropsychology testing and the like. She may have had a stroke. There are other forms of dementia than Alzheimer's. Some of them can have this sort of rapid onset. Get her in to see someone who specializes in geriatric neurologist asap. I'm sorry that you're dealing with this, best of luck!

My husband's dementia was sudden onset. Looking back there were some very minor hints that something was amiss, but nothing significant. He was at that time having a neurological exam about every 18 months in conjunction with a sleep disorder. In May 2003 that exam concluded he was "normal for a man his age." In June he had a meltdown in a restaurant ordering breakfast and was never the same again. He had Lewy Body Dementia, confirmed by autopsy. One other loved one in my local caregiver support group also had sudden onset. Everyone else had a more gradual decline.

You have certainly done the right things to rule out some of the treatable possibilities.

Do any of you live close enough to see her regularly? Does she have symptoms in addition to these delusions/hallucinations? How is she at managing her finances? Not paying bills, paying some bills twice, sending money to the wrong places ... these kinds of things can indicate the beginning of dementia. Is she having a difficult time with decisions that she used to make easily? Any changes in her depth perception? Any problems falling? I know that we think of dementia as a disease mainly of memory, but there are many other aspects to dementia, and different kinds of dementia have different primary symptoms.

I would suggest that you (especially any of you living near her) observe her closely for a while. Keep a notebook of anything unusual that you notice. If/when you are able to get Mom to a specialist, "for a baseline evaluation", you can summarize your observations for that doctor, in advance of the appointment.

I know by experience that sudden onset dementia is certainly possible. A few episodes of delusions do not prove dementia, but they are suggestive enough to warrant further observation.

Good luck! Keep in touch.

That's the thing: there's nothing to see, nothing much, nothing you can put your finger on, for ages and ages, then all of a sudden you're thinking "whoa! What's going on?" Then maybe, when you look back at those little nothings, you think "Oh."

If your mother is anxious about the thought of having tests, explain that (this is true) you're concerned she might have had a small stroke and could be heading for a much worse one - which can easily be prevented, so it's terribly important to get checked out as soon as she possibly can. Then have a quiet word with her doctor before the appointment, and s/he should be able to take it from there. Good luck, hope it turns out well.

If none of you are in the local area, the onset may have been more gradual. Go behind her back to her friends and neighbors to see if she has had other trouble that you haven't heard about.

There was a TV show where a woman would "sundown" because she was restricting her fluids too much at night. Once the genius doctor figured it out, everything was hunky-dory. I hope you get a magical cure too - but it's not likely.

thank you she is awfully stubborn (comes with the Irish lol) but that is our next step if she even will go through with it. Now she is just denying that she is seeing things and laughs them off nervously saying the episodes aren't happening to her anymore.

I was thinking stroke too.

Good luck from one Irish Lass to another. :-)