A 12-year-old had one-sixth of his brain removed. He feels ‘perfectly normal.’
IT WAS a solution no parent wants to hear: To get rid of a brain tumour and stop their young son’s seizures, surgeons would need to cut out one- sixth of his brain.
But for Tanner Collins, it was the best option.
A slow-growing tumour was causing sometimes- daily seizures, and medications commonly used to treat them did not seem to be working, his father said. But removing a portion of his brain was no doubt risky. That region – the right occipital and posterior temporal lobes – is important for facial recognition and, without it, Tanner’s parents wondered if he would recognise them.
At six, Tanner underwent surgery at the University of Pittsburgh Medical Centre’s Children’s Hospital. Although his brain has had to work to adapt since then, he’s had no major problems.
Other than some visual impairment, Tanner, now 12, said he’s “perfectly fine.”
His case was published Tuesday in the scientific journal Cell Reports, explaining how Tanner’s brain learned to adapt after a part largely responsible for visual processing was taken out.
Marlene Behrmann, a cognitive neuroscientist and lead author of the paper, said Tanner was one of the first paediatric patients studied over the past several years in her laboratory at Carnegie Mellon University to determine the extent to which a child’s brain can reorganise itself after certain sections are surgically removed. In Tanner’s case, she said, surgeons took out his right occipital and posterior temporal lobes, which made up about one-third of the right hemisphere of his brain.
Once that section of Tanner’s brain was surgically removed, there was a risk that he would have trouble recognising the faces of those around him, including his own parents, said Behrmann, a psychology professor at Carnegie Mellon. But Tanner’s brain ultimately found a solution: The part of the brain that assists with visual processing in the left hemisphere took on the task. “Today he is a bright, curious, introspective 12year- old who does pretty much everything that other 12-yearolds do,” Behrmann said, noting that his case illustrates the “plasticity” of children’s brains.
But because Tanner is missing part of the right side of his brain responsible for visual processing, he has a large blind spot on the corresponding left side of his universe, Behrmann said. He can compensate by moving his eyes to stitch images together but will never be able to drive.
Tanner’s parents, Carl and Nicole Collins, both nurses from New Stanton, Pennsylvania, first noticed something was wrong when he was four.
He had a grand mal seizure and was diagnosed with a brain tumour on the right side of his brain. It was later identified as a benign and slow-growing tumour called a dysembryoplastic neuroepithelial tumour, Behrmann said.
The Collinses chose to watch and wait, opting for surgery when the tumour kept growing and the seizures recurred.
Surgeons ran extensive tests to determine exactly where the seizures were originating and the minimum amount of brain tissue that had to be removed to make them stop, Carl Collins said.
When Tanner woke up from surgery, he was looking around the hospital room, and they could tell he was having trouble with his vision, Collins said. Tanner said he knew who his parents were but he remembers not being able to match their faces with their names, so, for a time, he said he would poke them when he wanted their attention.