Why is it that my mom will recognize me one minute and not the next?

So, Marty, what have you read about dementia?

Various kinds of dementia have varying symptoms; seeing a CAT scan of my mom's brain a couple of years before she died told me and my brothers everything that we needed to know: that there was very little actual BRAIN left and we should be glad that mom recognized any of us, that she still had some speech and that she was content..

Dementia should be called (IMHO) "Broken Brain Syndrome". It would give all of us a better idea of what we're dealing with; an organ that is no longer functional and which when it does function, works in mysterious ways.

Part of the explanation, I think, lies in the brain's electrical system. When neurons are firing, connections get made. When they don't, things don't line up.

This is not a scientific explanation by any means, but I hope it helps a little!

Marty Barb has pretty much coved all the bases. There is a lot of useful information about dementia so take the time to learn about what happens in various stages.

Yup. The brain is broken. Be glad when it works, but not surprised when it doesn't. These fluctuations can be very hard on caregivers!

Try not correcting her and see if things go more smoothly.
"Where's Mart?"
"What do you need, Joan?"
"I want my daughter! Who are you?"
"I'm the person here to help you until Mart can get here. Do you want a snack (to go to the bathroom, to sit on the couch, to play cards, whatever seems appropriate.)?

She is confused enough. Try not to add to her anxiety by arguing about who you are.

Thank you Barb and Veronica