Do people dream in comas

I have researched this phenomena quite a bit though I do not practice medicine I believe it is still somewhat of a mystery. Some people dream and some do not. Alot of people can actually hear their surroundings while in the coma state which can be incorporated into their dream. One man had been in a coma for two months after a car accident and his wife inquired about the experience, he said his dreams were extremely lucid, like a parallel existence. In fact, he was heard by the staff to actual yell seemingly random things out, but when he came to they later deciphered that he was expressing himself in his 'dream' and as people talk in their sleep so did he. One of his comments was about a Baseball player trade, while in his coma the tv in his room was on that announced the trade, this angered him and caused him to not only dream about his reactions but comment on the subject without being conscious of it. D.J. Newville