Cochlear Implants Are Better Early in Life

From: WebMD - May 17, 2004

Language Skills Develop Sooner When Hearing-Impaired Kids' Get Implants as a Baby

By Sid Kirchheimer
WebMD Medical News
Reviewed By Brunilda Nazario, MD
on Monday, May 17, 2004

May 17, 2004 -- Getting cochlear implants as a baby does more than just allow deaf or severely hearing-impaired children to experience sound; it may help them learn language and other skills once considered difficult -- and sometimes at the same rate as fully hearing kids.

Cochlear implants are electrical devices that are internally implanted and convert codes from an external processor into electrical activity that the brain interprets as sound. They are typically used to treat children with profound hearing loss who can't get help from traditional hearing aids.

This month's issue of Archives of Otolaryngology - Head & Neck Surgery is devoted to the use of pediatric cochlear implants. Although their use has been linked to an increased risk of infection in the fluids surrounding the spinal cord and brain (meningitis), the new studies indicate that these devices can provide remarkable benefits to deaf children.

In one, researchers tracked 107 hearing-impaired children who received cochlear implants between ages 1 and 3 -- an age group considered too young for this surgery. Their listening skills were evaluated before the surgery, and three times in the year following it.

The Earlier, the Better

"What we found is that regardless of the age they got cochlear implants, they experienced huge improvement in auditory skills in the year follow-up period," says researcher Susan Zimmerman-Phillips, MS, audiologist and manager of clinical studies for Advanced Bionics Corp., which manufactures cochlear implants.

"But the children who received implants between ages 12 and 18 months had even higher scores," she tells WebMD. "They actually fell into the normal range of hearing and they learned at the same rate as fully hearing children their age."

Two other studies in the same journal back this up. In one, Greek and British researchers show that cochlear implants before age 7 helped children develop grammar and other language skills that are normally "considerably delayed" in deaf children -- and these skills developed faster the earlier the implants were placed. In other studies, American researchers show that deaf children who got the implants before age 3 were able to learn a second language.

"The bottom line on cochlear implants seems to be the earlier, the better," Zimmerman-Phillips tells WebMD.

Agreed, says Bruce J. Gantz, MD, professor and head of the otolaryngology-head and neck surgery at the University of Iowa and a spokesman for the American Academy of Otolaryngology. He expressed no surprised at any of the published studies

Findings Known for 15 Years

"We have been doing work with cochlear implants on children for over 15 years, and we've been able to demonstrate here that language skills occur more rapidly the earlier that we implant the children," he tells WebMD. "Getting implants between 9 and 18 months seem to make a difference compared with getting them between 2 to 4 years."

Cochlear implants are allowed for children at age 1, according to FDA guidelines, but younger children can get the surgery under certain circumstances, says Gantz. However, until recent years, the surgery was often reserved for older children -- largely because of concerns over anesthesia required during the procedure and other safety risks and that severity of hearing loss in babies couldn't be measured as easily as in older kids.

Another aspect that scared some parents away from the surgery: Evidence that cochlear implants increase a child's risk of bacterial meningitis, which prompted an FDA warning two years ago. A study published last summer in the New England Journal of Medicine found only 26 cases of bacterial meningitis among nearly 4,300 children who got the implants.

"We know that kids who have profound hearing loss may have anatomic abnormalities in their inner ear that set them up for meningitis, and that group has a higher risk than hearing kids," Gantz says. "The risk is greater among deaf children, whether or not they get cochlear implants."

SOURCES: Robbins, A. Archives of Otolaryngology - Head & Neck Surgery, May 2004; vol 130: pp 570-574. Nikolopoulos, T. Archives of Otolaryngology - Head & Neck Surgery, May 2004; vol 130: pp 629-633.Robbins, A.Archives of Otolaryngology - Head & Neck Surgery, May 2004; vol 130: pp 644-647. Reefhuis, J. New England Journal of Medicine, July 31, 2003; vol 349: pp 435-445. Susan Zimmerman-Phillips, MS, audiologist and field manager of clinical studies, Advanced Bionics Corp., Sylmar, Calif. Bruce J. Gantz, MD, professor and head, department of Otolaryngology, University of Iowa College of Medicine, Iowa City; spokesman, American Academy of Otorlaryngology.

© 2004 WebMD Inc. All rights reserved.