From Comatose man’s brain rewires:
Doctors have their first proof that a man who was barely conscious for nearly 20 years regained speech and movement because his brain spontaneously rewired itself by growing tiny new nerve connections to replace the ones sheared apart in a car crash.Terry Wallis, 42, is one of the few people known to have recovered so dramatically so long after a serious brain injury. He still needs help eating and cannot walk, but his speech continues to improve and he can count to 25 without interruption.
[...]
Wallis was 19 when he suffered a traumatic brain injury that left him briefly in a coma and then in a minimally conscious state, in which he was awake but uncommunicative other than occasional nods and grunts, for more than 19 years.“The nerve fibers from the cells were severed, but the cells themselves remained intact,” unlike Schiavo, whose brain cells had died, said Dr. James Bernat, a neurologist at Dartmouth-Hitchcock Medical Center in New Hampshire, who is familiar with the research.
Nerve cells that have not died can form new connections; for example, nerves in the arms and legs can grow about an inch a month after they are severed or damaged. However, this happens far less often in the brain.
The new research suggests that instead of the sudden recovery Wallis seemed to make when he began speaking and moving three years ago, he actually may have been slowly recovering all along, as nerves in his brain formed new connections at a glacial pace until enough were present to make a network.