The paper has the warning phrased differently. "He can at least be an organ donor", basically, in the summary.

Your comment and the thread it started helps me a little with dealing with a close person's father's dementia.

I really recommend the book "Being Mortal" by Atul Gawande. It helped me process the drawn out and unpleasant death of my grandfather and look at end of life care in a different light. There's an important difference between extending life and providing quality of life that a lot of patients and doctors both misunderstand.

The book is written from the author's own experience as a doctor but also includes his experience with his own father's death from cancer.

When Breath Becomes Air was a great book that seems relevant here

I wish you strength in dealing with your situation. Neurological problems are really hard to deal with, especially when you come to realize it really is what it is and have to let go of futile hope.