"Dr. William Breitbart, chairman of the psychiatry department at Memorial Sloan Kettering Cancer Center, who has written about delirium and palliative care, said that a team’s response must also consider bedside caregivers: “These dreams or visions can be interpreted by family members as comforting, linking them to the legacy of their ancestry.

But if people don’t believe that, they can be distressed. ‘My mother is hallucinating and seeing dead people. Do something about it!’ Dr. Breitbart trains staff to respect the families’ beliefs and help them understand the complexities of delirium.

Some dream episodes occur during what is known as 'mixed-state sleep' — when the boundaries between wakefulness and sleep become fragmented, said Dr. Carlos H. Schenck, a psychiatrist and sleep expert at the University of Minnesota Medical School. Jessica Stone, the teenager with Ewing’s sarcoma, spoke movingly about a dream of her dead dog, Shadow. When she awoke, she said, she saw his long, dark shape alongside her bed.

Dr. Banas, the neurologist, favors the phrase end-of-life experiences. 'I try to normalize it for the family, because how they perceive it can push them away from that bedside or bring them closer,' she said."