Cochlear implants slightly less beneficial in older patients

Cochlear implants have become an accepted treatment for adults with age-related hearing loss or the progression of early-onset hearing loss, according to background information in the article. Adults age 65 and older are becoming an increasing proportion of the current U.S. population. "As such, the number of older cochlear implant candidates is expected to increase, as well as their mean [average] age at presentation," the authors write.

David R. Friedland, M.D., Ph.D., and colleagues at the Medical College of Wisconsin, Milwaukee, studied the medical records of patients who received cochlear implants at age 65 or older between 1999 and 2008. Each of 28 older patients was matched to a younger patient (receiving an implant at ages 18 to 64) with similar pre-implantation hearing test scores.

One year after implantation, 55 of the 56 total patients showed improvement on hearing testing. Regardless of their age at implantation, higher test scores before surgery predicted higher test scores afterward. However, the older patients performed more poorly than younger patients on some speech perception tests at the one-year follow-up.

"One explanation for these results is that the elderly patient may have a prolonged adaptation phase and reach levels attained by younger users at one-year postimplantation at a later point," the authors write. "Alternatively, elderly patients may have inherent limitations in processing the high-rate stimulation paradigms used in current cochlear implants. Central cognitive or associative processes may also influence the performance in the population of elderly patients."

The results may help clinicians set realistic expectations for post-implantation results in older patients, the authors note. "This study also found that better pre-implantation performance predicts better post-implantation scores in the elderly and younger patient," they continue. "These data question whether implant criteria in elderly patients should be expanded. This would allow those with significant progressive presbycusis [age-related hearing loss] (i.e., destined to meet implant criteria) to undergo implantation earlier, thus maximizing their postimplantation performance."