by Dr. Katrina Stidham.
I have been a practicing neurotologist for 20 years. During that time, many significant changes have occurred in the management of hearing loss. Technology has taken leaps and bounds. Hearing aids have transitioned from analog to digital technology with access to Bluetooth, directional adaptive microphones and FM compatibility becoming commonplace. Cochlear implants have progressed with implantable technology now being much smaller with improved potential to preserve residual hearing, and implant processors providing much clearer signal processing. These changes in turn have allowed greater success with cochlear implants and expansion of implant candidacy with both younger patients, and those with more residual hearing now being considered for cochlear implantation. However, one of the biggest changes I have seen in the past 20 years is the expansion of cochlear implantation in the elder population.
When I was about 5 years into practice, I implanted a senior citizen who was 75 at the time of his surgery. He happened to be a relative of one of my audiology staff and I am certain would not have been referred to me or even considered cochlear implantation if he did not have that relationship. He had experienced severe-profound hearing loss for several years prior and was significantly impacted both socially and professionally. He was still working as an accountant and while he was very proficient with numbers, he was having difficulty hearing his clients in conversation. At the time of his surgery, it was considered a bit of a departure to implant someone his age and there was some anxiety about both the surgery and equal concern about how he would function with the implant. Would he be able to really gain benefit from a cochlear implant in the same way that younger adults did? While we would occasionally implant older adults in the early 2000s, in general these surgeries were few and far between. Following his surgery, he recovered well and quickly improved his communication abilities, allowing him to continue to successfully work for another 10 years. He was thrilled with the technology and the opportunity to hear again.
Flash forward to 2021 and what a difference 15 years has made in our approach to cochlear implants in the advanced age senior population. In general, as surgeons we are more open to considering surgery for the 75 and older population than we were in prior years. That is likely due to a combination of factors. There are more older adults in relatively good health seeking our services, surgical time for cochlear implants has decreased, and anesthesia has become safer than ever for all patients. Also, with advancements in cochlear implants, the technology has become not only more robust in its ability to help individuals with severe to profound hearing loss, but has also become more user friendly, making it more facile for patients of any age to manage and care for the external processors. Currently in my implant population, I have two big peaks of patient age groups; babies and young children, and adults 75+ with many of my older adult patients presenting for implant evaluation in their mid-late 80s. Almost without fail in my older adults the reason for considering implantation is the same. Hearing loss is affecting their ability to communicate and is isolating them from family, friends and colleagues. While their health may not be perfect, their hearing loss seems to be the overriding ailment that impacts their quality of life.
As we place more implants for the advanced senior population, questions have arisen regarding the potential benefits and limitations of cochlear implants for older adults. There are two questions that I am often asked regarding cochlear implantation in the advanced elder population.
The first question has to do with the potential impact of hearing loss on cognitive decline and whether or not cochlear implants can halt or reverse that deterioration. Over the last few years there have been several publications addressing hearing loss and its potential impact on decreased cognition and dementia. Many studies have demonstrated more significant cognitive decline in individuals with hearing loss compared to those who do not have demonstrable loss. There are two main theories relating hearing loss and cognitive decline. The first theory proposes a central combined cause where general decline in brain function leads to both the cognitive decline and concurrent hearing loss. The second theory suggests a cause-and-effect model where hearing loss leads to cognitive decline either due to the brain not being as actively engaged or due to social isolation which commonly occurs when someone cannot hear. For any given individual, either or both of these theories could be in play in effecting changes in cognition. However, if the first of the two theories is the driving force, then amplifying an individual’s hearing with hearing aids or providing a cochlear implant would not be beneficial at all in preventing cognitive slip. If the second theory is correct, then a hearing aid or cochlear implant could potentially halt cognitive decline or even improve cognitive function.
Fortunately, there are several reputable studies that have demonstrated improvement in cognition scores in individuals with hearing loss who use hearing aids compared to those with similar hearing loss who are not amplified. One of the more prominent of these is a study published in JAMA Otolaryngogology-Head &Neck Surgery (Jama Otolaryngol Head Neck Surg.2018:144(10):876-882) that demonstrated hearing loss had an effect on cognition only in individuals who did not use amplification. Although fewer in number, there are also studies emerging that demonstrate improved or stable cognition in older adults who receive cochlear implants (J Am Geriatr Soc. 2018 Aug;66(8), Clin Interv Aging. 2016;11:603-613.). At our Cochlear Implant Center and others, prospective data is being collected on patients prior to cochlear implantation and after implantation to assess whether improving patients’ hearing with cochlear implantation can translate into longer term benefits for cognition.
The second question that frequently arises from patients and families is whether an advanced age adult can benefit from cochlear implantation in the same way that a younger adult can. It goes back to the age old question of “can you teach an old dog new tricks” and is the brain still capable at an advanced age to learn how to use a cochlear implant. Fortunately, the answer to that question is a resounding yes. Our implant center recently completed a study comparing the response to cochlear implantation in older adults 60-74 years of age to advanced geriatric patients 75 years and older. Patients in the 75+ group demonstrated significant improvement in post implant speech understanding that matched their younger peers. Both groups benefited equally from cochlear implantation and had equal satisfaction with their implants.
It is estimated that our geriatric population will more than double in the next 40 years. With advanced age, hearing loss increases with over 50% of people 75 and older having some degree of hearing loss. As many older adults are leading healthier, more active lifestyles, hearing loss for many can become an impediment that significantly impacts their quality of life, and as discussed above, even their cognition. Fortunately, we can offer even our advanced age geriatric population options for hearing that will allow them to continue to hear, communicate and enjoy life. While it may not be the right option for every older adult with severe hearing loss, age alone should never be the deciding factor against considering a cochlear implant.