NEW YORK, July 4 (UPI) -- Cornell University researchers have documented an Arkansas man's brain that rebuilt nerve pathways after 19 years in a coma-like state.
In 2003, Terry Wallis emerged from a minimally conscious state at the age of 39 and said the word "Mom." He had been injured in a pickup truck that fell 25 feet and landed on its roof.
Using PET scans and an imaging technique called diffusion tensor imaging, researchers from Cornell University's Weill Medical College Citigroup Biomedical Imaging Center in New York examined Wallis' brain after he regained full consciousness, the Los Angeles Times reported.
They found cells in relatively undamaged areas had formed new axons, the long nerve fibers that transmit messages between neurons.
"In essence, Terry's brain may have been seeking out new pathways to reestablish functional connections to areas involved in speech and motor control to compensate for those lost due to damage," said the study's senior author, Dr. Nicholas Schiff, a neurologist.
Wallis has regained the ability to form sentences and has recovered some use of his limbs, but still can't walk or feed himself.
The research appears in the Journal of Clinical Investigation.
