DiversityNursing Blog

LAUREN SILVERMAN

www.npr.org 

Many of us are familiar with the cochlear implant, but did you know it doesn’t work for everyone? We came upon this article featuring information about clinical trials for a new technology that gives the hearing-impaired another option for the ability to hear.

Jiya Bavishi was born deaf. For five years, she couldn't hear and she couldn't speak at all. But when I first meet her, all she wants to do is say hello. The 6-year-old is bouncing around the room at her speech therapy session in Dallas. She's wearing a bright pink top; her tiny gold earrings flash as she waves her arms.

"Hi," she says, and then uses sign language to ask who I am and talk about the ice cream her father bought for her.

Jiya is taking part in a clinical trial testing a new hearing technology. At 12 months, she was given a cochlear implant. These surgically implanted devices send signals directly to the nerves used to hear. But cochlear implants don't work for everyone, and they didn't work for Jiya.

"The physician was able to get all of the electrodes into her cochlea," says Linda Daniel, a certified auditory-verbal therapist and rehabilitative audiologist with HEAR, a rehabilitation clinic in Dallas. Daniel has been working with Jiya since she was a baby. "However, you have to have a sufficient or healthy auditory nerve to connect the cochlea and the electrodes up to the brainstem."

Jiya's connection between the cochlea and the brainstem was too thin. There was no way for sounds to make that final leg of the journey and reach her brain.

Usually, the story would end here. If cochlear implants don't work, you turn to sign language. And the Bavishis did — for years they communicated with their daughter through sign language. But then they heard about an experimental procedure called an auditory brainstem implant.

It is a very rare procedure, according to Dr. Daniel Lee, director of the pediatric ear, hearing and balance center at Harvard Medical School. "There have been less than 200 of these implanted worldwide in children," he says. In the U.S., auditory brainstem implants are approved by the Food and Drug Administration for adults and teenagers who have lost their hearing due to nerve damage, but they have not been approved for use in younger children.

Surgeons in Europe have pioneered the use of the auditory brainstem implant in children who are born deaf and can't receive a cochlear implant, Lee says. "And those data look pretty encouraging."

So in 2013, the FDA approved the first clinical trial in the U.S. for young children. The Bavishis decided to apply for Jiya. It wasn't an easy decision. It would involve surgery to place a tiny microchip into Jiya's brainstem.

"The family was at a crossroads," Daniel says. Did they want to take a chance on a risky, experimental procedure to give their daughter a chance to hear? They decided to try the procedure and traveled from their home in Frisco, Texas, to Chapel Hill, N.C., for the eight-hour surgery. The University of North Carolina is one of four institutions investigating the implant.

Jiya's mom, Jigna Bavishi, pulls back her daughter's purple headband to reveal two of the three parts of the device.

There's the piece that sits on her ear, which works like a microphone to pick up sounds. That microphone is attached to a small black magnet that rests on her head. What you can't see is what the magnet is connected to. And this is what makes it different from a cochlear implant. Below the skin, there's a receiver, and down in the brain stem is the microchip. The idea is that the sounds picked up from the microphone on her ear end up in the implant in the brainstem.

"It's a rectangular shaped element," says rehabilitative audiologist Linda Daniel. "It has two rows of electrodes and each electrode is responsible for a band of frequencies." The electrodes transmit signals directly into the brain.

Daniel says we don't know exactly what Jiya hears.

"I think we could assume that it doesn't sound crisp, distinct, clearly interpretable," she says. "It would take longer to learn to interpret the sound."

Doctors told the Bavishis not to expect any changes for a year or two. But Jiya didn't take that long to start recognizing and mimicking sounds. On the day I visit, Jiya is playing with a yellow toy car. "Beep, beep," she says.

"They actually had to tell us, even though she's doing so good right now, we have to still be careful where we set our expectations," says Jigna.

Doctors will monitor Jiya, and four other children taking part in the study, for the next few years. They'll be studying how their brains develop and incorporate sounds and speech. There are two other clinical trials investigating auditory brainstem implants in children: one at Children's Hospital in Los Angeles, and the other at the New York University School of Medicine.

 James McIntosh

A blind man is now able to see objects and people again, including his wife and family, for the first time in a decade. How? With the help of a bionic eye implant. 

Affected by a degenerative condition known as retinitis pigmentosa, Allen Zderad was effectively blind, unable to see anything but a bright light. As the condition has no cure, Zderad, from Minneapolis-Saint Paul, MN, was forced to quit his professional career. 

He made adjustments to his lifestyle and was able to continue woodworking through his sense of touch and spatial awareness. However, with the help of his new retinal prosthesis, Zderad is now able to make out the outlines of objects and people, and could even register his reflection in a window.

"I would like to say I think he's a remarkable man, when you consider what he's overcome in dealing with his visual disability," says Dr. Raymond Iezzi Jr., an ophthalmologist from the Mayo Clinic. "To be able to have offered him the retinal prosthesis to enhance what he can already do was a great honor for me." 

Retinitis pigmentosa is an inherited condition that causes the degeneration of specific cells in the retina called photoreceptors. The disease can cause some people to lose their entire vision. Mr. Zderad's grandson has the disease in its early stages and, after seeing him, Dr. Iezzi asked if he could meet his grandfather.

The eye implant that Zderad now has works by bypassing the damaged retina and sending light wave signals directly to the optic nerve. A small chip was attached to the back of the eye with multiple electrodes offering 60 points of stimulation.

'Not like any form of vision that he's had before'

Wires from the device on the retinal surface connect to a pair of glasses worn by Mr. Zderad. The glasses have a camera at the bridge of the nose that relay images to a small computer worn in a belt pack. These images are then processed and transmitted as visual information to the implant which in turn interprets them, passing them on to the retina and eventually the brain. 

"Mr. Zderad is experiencing what we call artificial vision," explains Dr. Iezzi. "It's not like any form of vision that he's had before. He's receiving pulses of electrical signal that are going on to his retina and those are producing small flashes of light called electro-phosphenes. These small flashes of light are sort of like the points of light on a scoreboard at a baseball game."

There are only 60 of these flashes of light, but it is enough for Zderad to reconstruct scenes and objects. Although he will not be able to see the details of faces or read, Mr. Zderad will now be able to navigate through crowded environments without the use of a cane, significantly improving his quality of life.

Dr. Iezzi would like to see the technology expanded to patients who have lost the use of their eyes, such as wounded soldiers or people with advanced diabetes or glaucoma.

"In addition, while Mr. Zderad has 60 points of stimulation, if we were able to increase that number to several hundred points of stimulation, I think we could extend the technology so that patients could recognize faces and perhaps even read," he concludes. 

"It's crude, but it's significant," said Zderad happily, as he first used the device. "It'll work."

Zderad will now be able to see his family again, including his 10 grandchildren and his wife, Carmen. And how does he distinguish her, having not seen her for a decade? "It's easy," says Zderad, "she's the most beautiful one in the room."

At the end of last year, Medical News Today reported on the story of a woman with quadriplegia who is now able to use her mind to move a robotic arm, demonstrating "10° brain control" of the prosthetic.

Source: www.medicalnewstoday.com