Study shows cochlear implants to be slightly less effective for adults over 65

From Reuters Health:

NEW YORK -- People over age 65 are likely to see significant although less pronounced improvement in hearing from cochlear implants (pictured) than their younger adult counterparts, a new study released today suggests.

Researchers from the Medical College of Wisconsin in Milwaukee compared the post-implant hearing scores of 28 people who received cochlear implants when they were aged 65 or older, with that of 28 people who received cochlear implants at ages 18 to 64. All of the study subjects had similar levels of hearing impairment before they received the hearing device.

When tested one year after the implant, hearing scores indicated that both the younger adults and the elderly benefited significantly from the implants, but the elderly patients benefited less.

On a standard hearing test that measures the ability to distinguish words in sentences, the average pre-implant score for the 65 and older crowd was 22. Their score jumped to 70 one year after the implant. For the younger group, the average pre-implant score was 23 and their score jumped to 83 at one year.

In a test of word clarity performed one year after cochlear implant surgery, the average score for elderly subjects was 38 compared to 53 for the younger subjects.

Cochlear implants have become an accepted treatment for adults with age-related hearing loss or the progression of early-onset hearing loss. With the graying of the US population, the number of older cochlear implant candidates is expected to increase, as well as their average age at the time of implantation.

More studies are needed to determine why the scores of elderly cochlear implant recipients tend to be slightly lower, cochlear specialist and first author Dr. David R. Friedland and colleagues note in the Archives of Otolaryngology - Head and Neck Surgery.

The elderly may need more than a year to overcome past adaptations to their hearing loss. They may have "limitations in processing" the implant signals, or, perhaps, the lower test scores reflect chronic medical conditions that affect hearing and are more common in the elderly.

Previous research has found that cochlear implants can benefit older patients. The current study, Friedland said, suggests the benefit is greater if the implant is done earlier in the hearing loss process and that counseling guidelines should be changed for elderly implant recipients.

"If a 70-year-old comes in and we have five years worth of audiograms that show that their hearing is continuing to decline, the data might suggest, why wait until they're 75 and their hearing is gone to implant them? Why not implant them at 70? They'll do much better," Friedland told Reuters Health.

At the same time, elderly patients should also be warned that their best results may not match those of younger patients and may take longer than a year to achieve, he added.

The Food and Drug Administration approved cochlear implants for adults in 1985 and since then an estimated 41,500 adults have received one. The implants require surgery and extensive post-implant follow-up for programing the device and monitoring, leading to costs of around $40,000 per patient.