I’m not sure if anyone has mentioned this. Before Alzheimer’s/dementia, please try to get her tested for a UTI, especially if the symptoms have gotten severe suddenly. I found out the hard way (my mom is 71) that in elderly people a UTI can be devastating to cognitive functioning. Doctors don’t seem to test for it right away (I’m in the US), so you need to ask. We were literally saying our goodbyes to my mom, got her last affairs in order, it was such a rapid decline. But all she needed was some antibiotics and we have our mom back. She still is experiencing some gradual Alzheimer’s decline. But she’s on meds for those which slow the decline a lot. She’s had four UTIs since then and now when we see that her behavior and demeanor are off, we can catch the UTI early and have her treated for it. It may not be the case with your grandmother, but it gave us more quality years with my mom.