Superior canal dehiscence syndrome (SCDS) is a debilitating and rare inner ear disorder that affects hearing and balance. People who suffer from this can hear things like their eyeballs moving — the sounds are amplified constantly in their ear. (Fun fact: SCDS was featured on season 6 of "Grey's Anatomy").
A recent segment on WHYY (NPR's flagship radio station in Philadelphia) put a spotlight on the disorder and featured a patient who endured this life-altering medical condition for two years before finding relief from none other than Lloyd Minor, MD, dean of Stanford's medical school. One of her earliest, most persistent symptoms was an enhanced sense of hearing: "Those sounds were unshakable. There wasn't any way to turn them down, they never went away. I could hear the bones in my neck cracking, kind of like sandpaper. At one point I could hear my eyes move," Pam Gilbert described in the piece.
Minor discovered SCDS when he was at Johns Hopkins University School of Medicine and found that the debilitating problem was caused by an opening in a bone of an inner-ear balance canal. He also developed a surgical procedure to correct it. During the segment, Minor described the anatomy of the vestibular system and shared a neat little nugget about how pigeons helped lead to his groundbreaking discovery:
"Pigeons became involved because the way people over a century ago discovered that the inner ear had a role in control of eye movements and in balance, a lot of those original studies were done in pigeons," Minor says.
Researchers, including an Italian biologist named Pietro Tullio, would make a hole in the pigeon's bone that protects the canals.
"They would remove the bone from one canal, and then they would push on the membranous portion of the canal—the fluid filled portion of the canal—and they would observe that the pigeon's eyes, and often times, its head, moved in the plane of that canal," he explains.
Just like his patient who sings in the shower, the eyes of the pigeon would jolt.
"And therefore, it seemed to me there had to be a similar problem in these patients. Somehow, the bone was likely to be missing over that top balance canal."
The full story is worth a listen.