Monday, August 17, 2009

Cochlear implants get smaller, faster, smarter

From USA Today:


Six-year-old Serena Rush (pictured) loves to belt out It's a Hard Knock Life, her favorite tune from the musical Annie, and someday she hopes to be a stage actress, when she's not being a lifeguard. Which is pretty splendid considering she was diagnosed as deaf when she was 1.

"I am very smart," says the ballet-dancing, iPod-jamming, theatergoing, soon-to-be second-grader from Silver Spring, Md.

Serena is now able to hear much of her world with the help of a cochlear implant she received when she was 2½.

A cochlear implant is a small, complex electronic device that helps children and adults with little or no hearing pick up sounds — including human voices, music and environmental noises, says Johns Hopkins cochlear implant surgeon John Niparko.

Cochlear implant technology has been around since the early '80s, when adults first received them, says Gordon Hughes, program director of clinical trials at the National Institute on Deafness and Other Communication Disorders. More recent scientific advances have made them more amenable to being implanted in the less fully formed skulls of babies and toddlers, Hughes says.

Researchers are also now finding that placing implants in both ears (the protocol had previously been one ear), as well as using combo cochlear implant/hearing aids, appears to significantly improve a deaf person's ability to hear more nuanced sounds, Niparko says.

"It's a fascinating story that's unfolding," Niparko says. "The advances we've been able to achieve represent a combining of developments on several fronts, in neurobiology and technology. The technologies are getting smaller, faster and smarter."

About 150,000 people worldwide have received cochlear implants. In the USA, roughly 30,000 adults and more than 30,000 children wear them, says Niparko, quoting industry figures.

Cochlear implants are more effective when they are implanted as early as possible in children born deaf because a developing brain is better at adapting to the flow of new information, Niparko says.

Hughes says toddlers — even babies in some cases — are now garnering superb results. "Their brains are like sponges. They absorb all the potential benefits of that sound stimulation," he says.

Children can develop very normally, says Debara Tucci, associate professor of otolaryngology-head and neck surgery at Duke University Medical Center. "They are mainstreamed in school. They do beautifully. These kids won't need sign language," Tucci says.

Serena's mom, Lauri Rush, a clinical psychologist at Gallaudet University, a college for the deaf in Washington, D.C., says she is thankful for the technology that allows her daughter to make hearing friends and sing to her favorite songs and attend the theater, but she says she still encourages Serena to use sign language so she can be part of both the hearing and deaf communities she spans.

"My issue is that the implants are not perfect. The implants make her hard-of-hearing. She has about 70% hearing," Rush says.

She says Serena cannot hear her in a car, at the mall or in other crowded spaces because of too much ambient noise interfering. Serena's brain simply is not receiving enough auditory information via the auditory nerve to understand each separate sound in a noise-challenged environment.

"It is obviously a less sophisticated signal than what God or nature provides," says Jeff Greiner, president and CEO of California-based cochlear implant maker Advanced Bionics, who says fairly intense hearing and speech therapy is required after an implant. "They're still deaf kids with cochlear implants, but it enables them to actually hear a tremendous amount and be able to do well in school."

But Rush says that in her work, she's seen kids with the implants struggle socially with their hearing peers when they reach dating age.

Cochlear implants have improved quality of life for many adults who are not helped by hearing aids. Tucci says adults who have recently lost their hearing because of disease, medications that cause hearing side effects or trauma seek the devices, usually encouraged by a family member who has noticed their increasing withdrawal from conversation and increased isolation due to hearing loss.

Says Hughes: "Some adult patients do so well, you might not know if they have a hearing device on."