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March 6, 2006

The Consumer Risks Fall, Hopes Rise for Hearing Implants

From: New York Times, United States - Mar 6, 2006


A few years ago, when an exceptionally high incidence of meningitis was found in deaf children who had cochlear implants, it revived early fears about the devices.

Deaf children already stand a higher than normal chance of contracting meningitis, an infection of the fluid surrounding the brain and spinal cord, because they often have abnormalities in their inner ears. In the 1980's, when cochlear implants started to be widely used in children, some doctors worried that the devices, implanted near the brain, might push the risk to unacceptable levels.

A study of more than 4,000 children with cochlear implants published last month in Pediatrics confirmed that the increased risk had mostly been borne by children with an implant type that was no longer on the market. The implant used a positioner to hold the device closer to the auditory nerve, and it is thought that this positioner may form a seal that encourages bacterial growth.

The children with this implant have a higher than normal risk of meningitis for up to four years after the operation, according to the study by the Centers for Disease Control and Prevention and the Food and Drug Administration.

Since 2002, 11 more episodes of meningitis have been reported among 829 children with the discontinued implant, the study found.

This is a concern, because removing the implants entails surgery, raising the chance of infection. Advanced Bionics, the company that made the discontinued model, is now owned by Boston Scientific, in Natick, Mass. Paul Donovan, a spokesman for Boston Scientific, noted that fewer than 200 children under age 6 have that type of cochlear implant. "The overwhelming majority of patients who have one are at a low level of risk and there is no need to have the device removed," he said in an e-mail message.

Other implants were not linked to such a high risk. Only one child among the 3,436 in the study who had different models was reported to have meningitis since September 2002. That underscores the need to ensure that children with implants are fully vaccinated against infections and monitored for signs of meningitis like high fever and stiff neck. The findings also suggest that with the offending model off the market, the incidence of meningitis may fall significantly.

That is a relief to doctors and educators, because for the most part the story of cochlear implants — which enable users to hear through electrical signals delivered directly to the auditory nerve — has been an increasing, even surprising, success.

"Kids who are implanted at 1 by age 3 and 4 have language that is pretty normal," said Ann Geers, a psychologist who has studied the effectiveness of cochlear implants. "That's something we've never seen before in profoundly deaf kids."

Cochlear implants do not help all deaf children understand language. Dr. Geers, an adjunct professor at the University of Texas Southwestern Medical School at Dallas, said they worked in enough children that they had "turned deaf education upside down."

"More kids now are being educated in regular mainstream classes with their age mates and not in special schools for the deaf anymore," she said.

In the last 20 years, 11,000 American children have received the implants, according to data from the manufacturers. An estimated 50,000 to 70,000 Americans younger than 18 are profoundly deaf, said Dr. John K. Niparko, an otolaryngologist at Johns Hopkins.

The cost of an implant runs $60,000 a child, including the price of the device, the surgery, therapy and other expenses, said Dr. Niparko, a consultant for all three companies that make the implants.

Early implantation is encouraged, so that the children can hear in the crucial months and years to learn language. A recent study of 36 children with implants found that those who got implants before 2½ were better able than children who got implants later to integrate sound with a speaker's lip movements, a sign of expertise in using language. "It was a dramatic difference after 30 months," said Nathan Fox of the University of Maryland, a co-author of the study. The Food and Drug Administration has approved implants for children as young as 12 months. Some surgeons implant them in even younger babies. A recent trial at New York University found that implantation in children as young as 6 months was safe.

Whether it confers any greater advantage in learning language has yet to be studied. Dr. J. Thomas Roland Jr., an otolaryngologist who is a co-director of the N.Y.U. Cochlear Implant Center, said he had seen remarkable language skills in some of his youngest patients. Typically, an implant needs to be tuned up once a month or more in its first year. Regular but less frequent adjustments are required subsequently.

A crucial consideration in deciding on implants is whether the child lives in an environment conducive to learning speech, in which people continually talk to the child and encourage the child to respond. "Birds learn to sing because when they practice, the mother gives them a worm," Dr. Niparko said. "Cochlear implant success depends on the same kind of encouragement."

The implants do not provide perfect hearing. In noisy places, it can be hard to pick out voices. Nor do they hear all the details and nuances of music. But when children with implants are in a "one-on-one quiet situation," Dr. Niparko said, "80 percent of them are hearing something pretty close to what a normal hearing person hears."

Copyright 2006 The New York Times Company