What is the dying process of those with dementia?

Not sure if I posed this question correctly but:
I was just given a book to read about dying and the work that hospice does in support of that. The first case I read about had to do with an 83 year old woman dying of cancer and her attempts at saying good bye to her husband. It appears that because she had all of her faculties, she was able to do this. It also described the reaction of her husband to this.
In the case of a person who has dementia, what kind of “closure” is there during the process of dying? What is their process for saying goodbye and what reaction will their caregiver have as they are actively dying? It seems that the cruel disease of dementia also robs them of their dignity even in death. Do any of you have any thoughts you can share in terms of your experience with a dying loved one with dementia?