Terry was a subject of a major study that showed how a damaged brain could heal itself after he regained his ability to speak after a traumatic brain injury. He was older.
His brother George said that he had heart problems.
Terry was in a pickup truck with two friends when it skidded off a bridge and landed upside down in a dry riverbed. He was in a coma for a short time after the accident and was in a persistent vegetative state for several months. One of the friends died and the other recovered.
Mr. Wallis was able to blink or track objects with his eyes while in a nursing home.
He came back to the world when he saw his mother, who was six weeks old, and he told her he was the father of her child.
He had regained his verbal dexterity within a few days. The findings were presented in a journal.
He was confused when he emerged, according to a phone interview with Dr. Schiff.
The first ever brain scans of a late-recovering patient revealed changes in the strength of apparent connections within the back of the brain, which is believed to have helped his conscious awareness.
Mr. Wallis was diagnosed with severe quadriparesis, a weakness in his limbs, after he regained some movement.
He emerged so late that he's a unicorn. He said that they will never know why he emerged after 19 years.
His brother George said that regular visits home while he was minimally conscious had an impact.
Two years before the death of the Florida woman who had suffered brain damage and was in a persistent vegetative state, Mr. Wallis recovered. Her feeding tube was removed after a bitter national debate.
Terry Wayne Wallis was born in Marianna, Ark. Jerry was a mechanic and a farmer. His mother worked in a shirt factory.
His brother said that Mr. Wallis was a little wild and lived on the edge, doing what he could to enjoy life.
Terry's father said in an interview that he enjoyed flirting with the nurses but couldn't get up after waking up.
He said that time had stopped for him, but he could talk to us. He remembered people when he wrecked.
George and his wife, Lindsey, went to visit his brother, who had been through a lot in his recovery, eight years ago.
Terry, do you know who this is, my wife is a bit younger than me, and my mom asked. This is Lindsey. She's too pretty and old for him.
Until he was moved to a rehabilitation facility eight months ago, Mr. Wallis was living at his parents' home, cared for by family members.
His brother George, his daughter and his father are all dead. His marriage ended in divorce.
Mr. Wallis and other patients are teaching us about the potential for the brain to deal with trauma.
Terry's legacy to neuroscience is to instill our deep interest in understanding how human consciousness may recover after a serious brain injury.