my 88 year old father recently gnawed his index finger so badly that he factured the bone and the finger had to be amputated. he started out months ago by chewing on his bibs, shirts, towels, etc...then moved on to his fingers. the nursing home came up with some mitts with tubing attached so he would bite that instead of his fingers, but it somehow came off during the nite and he chewed his finger, like a dog a bone. how could he have not felt pain...he doesnt talk and he never cried out in pain when they were cleaning it...do they have no sense of feeling???
Yes it is possible for people with Alzheimer's to injure themselves and not feel pain. This is sometimes a patchy affair with some parts of the body being affected whilst others are not. The cause, not surprisingly, relates to destruction of neural tissue in the brain which disrupts sensory signals from different parts of the body. The same mechanisms can potentially have the effect of misinterpreting information so that scratching or biting might relate to the perception of, say, an itch. Another issue may be that the person senses pain but does not have the capacity to know how to respond appropriately.