dementia and PTSD

Since my mother has begun to suffer from dementia, she has been constantly worried that the place is on fire.

We couldn't figure out why, until I remembered her telling me that when she was a small child the cabin she and her family were living in caught on fire, and she had to help get the kids.

which has me wondering if there is a connection between dementia and PTSD. And whether I'm going to be reliving my rapes if I get dementia as well ...