Ten years ago, all of medical science would have been poured into the intensive care of this patient to bring about his recovery. In modern hospitals where coma arousal programs are known and practiced, this same process continues. However, in less modern hospitals the comatose patient has never been understood or treated. He has always been viewed as hopeless. In the past, he has been provided with emergency care to save his life but no treatment for his injury.
Time is the critical factor here.
During that period, he was given the time for the edema to subside. If edema was the cause of the coma, he might wake up and walk away. If there was a substantial injury, then the coma might well persist even after the edema had subsided. A patient, in this instance, would then have the opportunity to receive treatment for the injury. The coma patient needs time.