The question of how best to pray with people with dementia as they approach the end of their life is one that has surfaced recently.
Anna Chaplaincy Church Lead, Julia Burton-Jones recommends a book by Richard Behers who is a hospice chaplain working with people with dementia:
Spiritual Care for People Living with Dementia Using Multisensory Interventions - A Practical Guide for Chaplains, by Richard Behers (2018, Jessica Kingsley Publishers - UK (jkp.com)
The book features original methods drawn from the author's experiences of working with more than a thousand individuals with dementia. Included are links to online resources of the author's video presentations and photographs for use in treatment. It is a useful resource for all chaplains working with people living with dementia.