My cat is almost 16 years old and in good physical health but I think she is getting dementia.?

She sometimes makes a yeowling sound as though she's scared and we go to comfort her. She does this about once or twice a day. This we can deal with but its the meowing all night for attention that is hard to deal with. Its a persistant " come downstairs and feed me " meow as opposed to the scared souding one. If she is given attention and fed/cuddled she only starts again a few minures later. We are going to the vet later this week for her booster and of course I will speak about this. Does anyone have experience of this and what can be done to help my poor cat in her twilight years?