It's also something that has been in the news recently:
http://abcnews.go.com/US/wireStory?id=818244 This, of course, happened after DT finished the album, so it's not releated to this particular situation. Here's a few examples of various awakenings over the years:
AWAKENINGS
Other people who have suddenly "awakened" after comas or long periods of semiconsciousness.
Tracy Gaskill, 30 - She suffered internal and head injuries when her pickup truck rolled over on a Winfield, Ark., highway in September 2002. She has been at a long-term nursing facility since the accident. In April, she began speaking and swallowing. Her improvement began gradually about a year and a half ago, and she continues to make progress.
Donald Herbert, 43 - The Buffalo, N.Y., firefighter emerged from a near-comatose state last month. He was injured during a 1995 fire when a roof collapsed and ripped away his oxygen mask. On April 30, he talked with his family for 14 hours, then fell into a 30-hour sleep. He has communicated since then and has had moments of clarity, but not at the level he had on April 30. His road to recovery will be long: He is blind, needs a wheelchair and has no short-term memory. Herbert will undergo extensive physical and speech therapy in hopes of more improvement.
Sarah Scatlin, 38 - Hit by a drunken driver as she walked to her car in 1984, she had been in a coma for 20 years when she began talking and regaining her memory in February. For years, she could only blink her eyes - once for "no," twice for "yes." She is at the University of Kansas Medical Center, where she continues to improve.
Kelly Anne Barker, 35 - Barker, of Pontiac, Mich., was admitted as a "Jane Doe" after she was hit by a pickup and suffered extensive brain injuries in September 2003. She was identified nine days later and was moved to a nursing facility by her family after being diagnosed as being in a persistent vegetative state. But by that Thanksgiving, she was sitting up and speaking with family. She is receiving therapy.
Terry Wallis, 39 - The Mountain View, Ark., man was in a truck crash in 1984 that left him paralyzed and in a vegetative state for 19 years. On June 11, 2003, after two years of treatment with an anti-depressant drug, he spoke. He continues to receive speech and physical therapy at Baptist Medical Center in Little Rock.
Gary Dockery, 43 - Dockery, a Tennessee policeman who was shot in the head in 1988, spent seven years grunting and nodding to questions, then started speaking normally in 1996 after a course of intravenous Valium. He cracked jokes and chatted with his family for 18 hours before slipping back into silence. He died the next year of a blood clot on his lung.