Episodes of extreme confusion - could they be TIAs?

It could very well be a TIA. In my experience a TIA will only effect one tiny part of the brain so the symptoms can be very focused, unlike a stoke which may cause more widespread and recognizable symptoms. In my mom her TIA's were noticeable in her speech, in the first I witnessed she and I were gossiping when she suddenly began to speak gibberish, the weird part was that she didn't seem to notice at all. I got her to stop talking and checked for signs of a stroke, but there was nothing else and her speech quickly returned to normal, afterwards she admitted that she felt a "little queer", but seemed perfectly fine. Even though she seemed fine I eventually took her to the ER. For some time after that day she would have days where she would stutter, I always figured that was a sign that she had another one.

The thing about strokes (even the little TIAs) is that always leave damage.

A stroke is a loss of oxygen to the brain. This is instant death to those cells effected. It will show on an MRI. Those brain cells do not recover. By comparing her most recent to the one takes before that...Radioloist will see the increased damage ... no matter how much time passes.

But, there also comes a time when Medicare and insurance will not pay for another MRI. Since there is no treatment that she isn't already receiving, they will find no value to getting the diagnosis.

When this was happening to my Mom is was caused by her heart Her heart rate would sky rocket...causing the blood to rush past her lungs that little oxygen had time to be picked up. This was always sudden, near complete collapse. She would be so tired her had to be carried. Then, for a couple days she would be totally exhausted. Then back again...sort of knowing what happened..but no idea how long she was "gone".

I've been dealing with very similar (often scary and dangerous) episodes like you describe with my old mother for at least 8-9 years... they were almost always a UTI. ALSO test for LOW SODIUM.. a not as common as UTIs but definitely something that is not that uncommon with the very elderly. Her low sodium episode was the scariest mental decline event I've ever witessed (and it's very dangereous). So I would always recommend a simple UTI and specify you want not just a generic electrolite screen, but a blood screen that will specifically note SODIUM (you always hear the doctor/nurses mention potassium... but check SODIUM... ) By the way, during the initial month or so before she'd allow me to get her the simple urine tests for a UTI, I would begin to see those short 5 minute lapses that I learned were signs... they'd get a bit more frequent. I would call them "the loopy brain" signs. If a UTI had gone undetected too long (and in my case, my mother is a control drama queen, so even if I'd managed to get her to have a urine test and it was positive and she's get another round of antibiotics, I learned she would NEVER take them as prescribed. She just would NEVER believe she had to take all 5 in a row, or 2-3 a day for 10 days... She believes her thyroid and bladder med works, so she dutifully takes those... so she's a different problem in that I believe she's caused her body to become resistant to antib's... ). But had several serious sepsis episodes when UTIs progressed into systemic infections. Those were long, arduous hospitalizations then to rehab for more time to recover. She was "loopy brained most of those weeks. It's awful).

BUT a simple urine test the quickest easiest way to discover or rule out if UTI is possibly causes this (and you may be at the beginning of the UTI) so her mental lapses are early signs... maybe? I've discovered the quickest easiest way to get a UTI and electrolyte test is to take her to the nearby Urgent Care. Her doctor's office often cannot schedule an appt for THAT same day, fyi. Sometimes when she couldn't get a hold of me by phone (she rarely if ever remembers I have a CELL phone and I'm not always home... sigh), so she'd call one of many of her church friends until one of them would take her to Urgent Care... several of those times I'd get a call from the friend and then the Urgent Care staff saying, "We're putting your mother into an EMS to take her to the ER..." That's when her infections were really bad... and what a personality change she would have with those UTIs... combative, hysterical, too.. (well, those aren't exactly personality CHANGES... but with the UTIs she wouldn't try to hide her bad behavior in front of "friends" and strangers...!) Let us know what you find out... bless you.. these are difficult days for us caretakers...

She was immediately tested for a UTI after the first episode (it was clear), and a blood screen done that came back normal. I will check to make sure the blood screen included Sodium.