She’s blind to everything that isn’t moving
U.K. WOMAN’S RARE DISORDER
Atennis-ball sized clump of brain tissue crucial for vision is missing from both sides of Milena Canning’s brain, which means she really shouldn’t see a thing. And she doesn’t — unless it’s moving.
Years of testing by Western University scientists in London, Ont., have revealed a 48-year-old Scottish woman has a rare phenomenon that lets her see objects in motion, like clothes tossing in a front-loading washer or bathwater as she swirls it with her hand. But static objects are mostly invisible.
The phenomenon is known as Riddoch syndrome. It was first described by Scottish neurologist George Riddoch in 1917 after five of his patients with injured occipital lobes — the back part of the brain where the lion’s share of visual information is processed — swore they could see moving targets, but not stationary ones.
It’s the same part of the brain that turned Canning’s world black in 1999 after she suffered severe respiratory collapse from a lung infection. When her organs began shutting down, doctors put her in a drug-induced coma, where they kept her for 52 days, during which time she suffered at least one stroke.
When she woke up, “I realized I was blind,” Canning said Tuesday from her home just outside Glasgow.
The damaged brain tissue died and was cleared out. The big black holes on her brain scans today are just fluid.
Despite such “humongous” damage to her occipital lobes, she had a tiny area of tissue, about the size of a teaspoon, that was still intact in both hemispheres, said Western neuropsychologist Jody Culham. “And that particular piece of tissue is an area that responds vigorously in everybody — in her, in you and me — to things that are moving,” Culham said.
She and her colleagues believe those tiny pieces of spared tissue are allowing Canning to see things in motion, including steam rising from her coffee cup, water in a glass if it’s moved and her daughter Stephanie’s long ponytail swinging left and right.
“It’s almost as if everything is under water, and it’s all fuzzy and hazy,” said Canning, who used to work in an eye clinic.
There’s colour in the background sometimes, she said — a glistening, like the green, shiny gift bag a friend had set down on the right side of her hospital bed weeks after Canning came out of her coma.
Eventually, Milena was referred to Western’s Brain and Mind Institute. She first arrived in 2007, and she’s been tested several times since. Her case appears this week in the journal Neuropsychologia.
“This may be the richest characterization ever conducted of a single patient’s visual system,” Culham said in a statement released with the study.
Although Riddoch syndrome has been recognized for 100 years, today’s sophisticated brain imaging lets scientists better understand some of the neural circuits involved.
In experiments at Western, Canning could catch balls that were rolled or thrown at her. She could see rainwater running down a window, but not through the window. She has, the team reports, “a remarkably robust preserved ability to perceive motion.”
But she wonders if she’ll one day see more.
“Am I ever going to get even a little bit back in one eye so that I can at least see my family and friends? I hope it keeps on improving. But this might be it. Nobody knows.”