Can talking in your sleep all through the night be an early sign of dementia?

It's not just one symptom but a cluster of symptoms what characterizes Alzheimer's dementia. Have her tested with a neuropsychological test. But it seems that Alzheimer's appears to be obvious already.

I would be very suspicious of dementia myself since you say she has short term memory issues and confusion while awake. That right there is a sign of dementia, so your mother should be tested right away with a mini cognizance exam ie: MoCA or SLUMS. "Just old age progression" does not present itself like this, but with mild memory problems that surface from time to time that do not interfere with everyday life. Now that she's having sleep disturbances (which is also a classic symptom of dementia), it's important you get her cognizance tested. She nor you can function like this, getting no sleep every night!

Here is a link to a helpful article from the Alzheimer's Association: Just Forgetful, Or Is It Dementia?

https://www.alzinfo.org/articles/diagnosis/just-forgetful-or-is-it-dementia/?gclid=CjwKCAjwi6WSBhA-EiwA6Niok8hhq4FTxNTB_Lhz4yLc-MVKHalgWISSQZ1dvpX33lmg_dgtEqSKahoC1qoQAvD_BwE

It never hurts to have a urine culture while you're at the doctor's office, either.

Wishing you the best of luck.

She could have a UTI, which is very common in elderly women and not always has to do with hygiene but rather changes in our pH an physiology. I would do this first before requesting a cognitive exam because if she does have these symptoms from a UTI it will cause her cognitive exam to be inaccurate.

If she is negative for a UTI, there are other medical problems that can cause dementia-like symptoms, such as vitamin deficiency, high blood pressure, diabetes, stroke, tumor, thyroid issues, etc. She should have a thorough exam and when everything else is discounted given a cognitive exam so that you know where you stand in helping her with any other medical treatments in the future.

I'm hoping she has assigned a PoA. Once she has incapacity she will no longer be able to assign one. I wish you much success in helping her receive the proper diagnosis and treatment.