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BackTable / ENT / Article
Adult Cochlear Implant Indications & Evaluation
Varun Sagi • Updated Aug 20, 2024 • 168 hits
A cochlear implant (CI) is a device that electrically stimulates the cochlear nerve. It is typically indicated for individuals with bilateral severe-to-profound sensorineural hearing loss who receive minimal benefit from well-fitted hearing aids. Proper evaluation and screening are crucial to determine candidacy for a cochlear implant. Patient counseling plays a key role, as some individuals may not meet the criteria for implantation.
We’ve provided the highlight reel in this article, but you can listen to the full podcast below.
The BackTable ENT Brief
• The most common candidate for a cochlear implantation among adults is an elderly patient with age-related hearing loss.
• Word recognition scores of less than 60% in the better-hearing ear is a good cut-off for audiologists or general otolaryngologists to use when deciding if a patient would benefit from further specialist workup for cochlear implantation.
• It is important to test hearing in the best-aided condition when evaluating for cochlear implant candidacy. This often requires proper fitting of the patient’s hearing-aids, or even using a different pair entirely for the evaluation.
Table of Contents
(1) Cochlear Implant Indications
(2) Screening For Further Cochlear Implantation Evaluation
(3) Counseling Patients About Cochlear Implants and Hearing Aids
(4) Cochlear Implant Evaluation
Cochlear Implant Indications
Dr. Hunter describes cochlear implant indications in adults. He mentions recent FDA approval for single-sided hearing loss but emphasizes that the majority of individuals who receive implantation are elderly patients with presbycusis, or age-related hearing loss.
[Gopi Shah MD]
…You said when patients get to the max of their hearing aids. Is that for both ears, one ear?
[Jacob Hunter MD]
Traditionally, it was both ears. Back in 2019, the FDA did approve cochlear implantation in single-sided deaf patients, and so what that means is essentially you have normal hearing in one ear and then no hearing in the other. That doesn't necessarily mean insurance would cover it, but we're definitely implanting more people today with single-sided deafness than we were 10 years ago. While I go back to what were the indications when people were at the limit of the hearing aids, the criteria are expanding. I know we're not talking about pediatrics, but the pediatric criteria just recently expanded, and we're kind of reaching out more and more, finding more and more people can benefit from them.
[Ashley Agan MD]
And for your single-sided deafness patients, are most of those patients who have had a sudden sensorineural hearing loss or have had surgery or trauma? Is it just kind of a mixed bag?
[Jacob Hunter MD]
It's kind of a mixed bag. I mean, I can think of a patient yesterday who we don't really know the cause. She recalls, I believe, a sudden loss. The data that was approved by the FDA only included people that had to have had their hearing loss within the past 10 years. That's not a hard and fast rule. There are definitely people that succeed and do well with an implant that have been deaf longer, and so, obviously, the longer the patient goes, you're going to maybe not recall what exactly happened. But it is a mixed bag, some trauma or surgical related, some sudden hearing loss, some Ménière's, meaning it's a slow degradation of their hearing loss over time.
[Gopi Shah MD]
So in terms of your patients, could you tell us a little bit? You have your maybe sudden sensorineural or maybe somebody in the last 10 years that slowly has lost. Then I kind of think of maybe the older ... I think of older, 80-year-old patients, like an older age, I feel like, we're starting to implant. Can you just characterize the buckets ... Is it after a history of meningitis? What kind of history do they usually have?
[Jacob Hunter MD]
I think that's an important distinction. A single-sided deafness is a small, small, small, small, small fraction of the actual cochlear implant practice that we have. I'm actually one of three adult cochlear implantation surgeons at UT Southwestern with Walt Kutz and Brandon Isaacson, and so I would venture to guess that it's somewhere between maybe 5%, maybe 10% are the single-sided deafness patients. But, traditionally, a big portion of these patients are older patients that just have what we call presbycusis, that it's just a natural hearing loss as we get older and that they start getting fitted with hearing aids.
[Jacob Hunter MD]
Sometimes, I think we all know friends and colleagues that are in their 20s, 30s, and 40s that wear hearing aids, but these patients wear hearing aids for many years. Generally, these patients are talking 10, 20, even 30 years, and so then they're at the point where you've turned the hearing up as loud as possible and now we're talking about a cochlear implant, and that is the predominant number. Meningitis in an older adult or any adult is a very rare occurrence, unlike what you might see in the pediatric population. But the biggest, biggest thing is just a natural loss of hearing.
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Screening For Further Cochlear Implantation Evaluation
Dr. Hunter discusses the utility of the audiogram, and specifically word recognition scores, as a potential screening tool for audiologists or general otolaryngologists to use when selecting patients who may benefit from further cochlear implant evaluation. He states that a word-recognition score of less than 60% in the better hearing ear is usually a good cut-off to consider further specialist evaluation. He also touches upon the differences between single-word and full-sentence hearing test evaluations.
[Jacob Hunter MD]
Now, you can dive deeper into the audiogram ...that consists of … the pure tone audiogram, but a big component [of the audiogram] is the word recognition score, and so if they do significantly poorly on that….our data demonstrated under 60%-word recognition in the better hearing ear, and that has been reinforced by a couple other studies...then it is reasonable to talk to the patient about a cochlear implant. That's not a hard and fast rule. The audiogram is not what determines who does or does not qualify for an implant, but I do think it gives the general otolaryngologist, the audiologist, someone who has these audios in their office a good idea of maybe when …they should send them to get further testing. There are obviously people that qualify that have better word recognition scores. There are obviously people that have terrible word recs that don't qualify. But 60% [word-recognition score] in the better ear is generally a good rule of thumb.
[Gopi Shah MD]
Yeah, no, it's helpful. For word recognition, is that the same thing as speech discrimination, …or is there a special test, like the word and sentence? Can you kind of go over that?
[Jacob Hunter MD]
Yeah, it's speech discrimination, word discrimination. These are words that are presented to the patient in a soundproof room without their hearing aids. So it doesn't mean they'll understand the context of the sentence. It's just single words that sometimes ... There are 25-word lists, 50-word lists. I think most of the time most practices are administering 25-word lists. There's data to suggest that you could administer 10 and then depending on how they do the 10, then maybe you should expand to 25. But I think, at least, our audiologists predominantly do 25. It is how many they get correct that were asked. That's not on all audiograms, but every audiogram that we see, at least that we conducted at our centers, that is tested.
[Ashley Agan MD]
And you said that's without the hearing aid?
[Jacob Hunter MD]
Without the hearing aid, yeah.
[Ashley Agan MD]
Without. And that's just a word, right? There's no context, there's no sentence.
[Jacob Hunter MD]
Correct. I'm maybe jumping the gun here, but this is different than when we determine who is a good cochlear implant candidate because when an adult goes for a cochlear implant evaluation, one of the tests that can be administered are actually sentences with their hearing aids. Another test is actually giving them words with their hearing aids, and there are pros and cons to doing that versus sentences. But many times, and most of the time, at least at our centers, we're administering sentences.
[Gopi Shah MD]
Yeah. So, you have a referral for a cochlear implantation. What's your clinic visit like? Let's go into that a little bit. What are some key things that you ask for in your history? What do you look for?
[Jacob Hunter MD]
So I always ask, "We're here to talk about your hearing loss. Tell me about your hearing loss." I like asking how long they've had hearing loss, how long have they worn their hearing aids, how old are their current set. Sometimes, patients come in and they haven't worn hearing aids, and that's not to say that they can't still benefit from a cochlear implant, but we'd probably just fit them with properly fitted hearing aids and have them test them out before actually taking them to the next step on an implant.
Counseling Patients About Cochlear Implants and Hearing Aids
Dr. Hunter describes his approach for counseling patients who come in with the expectation of getting a cochlear implant. He emphasizes the importance of validating patient frustration. He also tries to take patients through the evaluation process step-by-step, so they understand the importance of ruling out other causes for their hearing concerns.
[Ashley Agan MD]
Sorry to interrupt you, but as you're talking, I'm thinking about so many patients who come in and have hearing loss, you talk about that, and they're like, "I tried hearing aids and they didn't work." Do you have any pearls on how to talk to patients about how that's just about giving hearing aids a good shot and when you know that they've truly given them a good shot?
[Jacob Hunter MD]
That's a very good question. I personally don't have any pearls. I'm jumping ahead a little here, but when we do that cochlear implant evaluation, the audiologists do test the fit of their hearing aids. They see if they're fit appropriately to the hearing profile of the patient. I'm unaware of data, but I personally was surprised to see how often those hearing aids are not fitted appropriately for the patient. There can be many reasons for that. Maybe they hadn't seen an audiologist for a while. Maybe they just weren't fit appropriately. So we fine tune the hearing aids so that they are at the maximum benefit to the patient, and sometimes we don't even like them. We'll have the patient borrow our own hearing aids to really, really make sure we're testing. The key here is testing in the best aided condition.
[Jacob Hunter MD]
I like to share the experience with the patient to understand. I'm sure they're frustrated. That's why they're here talking with me. I validate their frustration and tell them that, obviously, there's many different types of hearing aids and perhaps there might be a better hearing aid that might work better for them. At the other end of the spectrum, it's also like, well, maybe a cochlear implant is right. It's an interesting question to ask. Many times, these patients are coming to me, and they're like, "I need a cochlear implant. Just put it in." It's like, "Whoa, whoa, whoa, whoa, we need to appropriately counsel, make sure that this is actually going to help your hearing."
[Jacob Hunter MD]
I feel I'm talking people back a little more than saying, "A cochlear implant's not going to help you," which I do think speaks to the fact that these patients are coming in late. They're not coming in early, so to speak. Maybe they were fitted appropriately. I don't really know. Maybe they weren't. So, again, trying, I guess, just validating the patient's frustrations and taking it one step at a time. Let's get the hearing test. If they're here for an evaluation, let's see what your evaluation shows, and let's talk some more.
Cochlear Implant Evaluation
Dr. Hunter touches upon his main focus when eliciting a patient history. He likes to gather information regarding hearing aid use, previous ear surgeries, and family history. He also ascertains if the patient knows someone who has gotten an implant. He emphasizes the importance of testing hearing in the best-aided condition, which often requires proper hearing aid-fitting. He also discusses the relationship between hearing loss and cognition, and the role of the MoCA (Montreal Cognitive Assessment; a cognitive screening test for detection of mild cognitive impairment) in patient evaluation.
[Ashley Agan MD]
Back to walking through the visit with you and what to expect.
[Jacob Hunter MD]
I ask their ear history. I ask about whether they've had any infections or any drainage, any pain. Have they ever had any ear surgery? I ask about, I think I mentioned, their hearing aid experience. I ask about a family history. I ask if they've ever had any head or neck imaging that would include the ears. I also, not always, but I also ask do they know anybody with a cochlear implant. Some of our research suggests that people who do know people with a cochlear implant generally do proceed with surgery. Not everybody who qualifies for an implant elects to proceed with surgery, but the people who generally know somebody do, which kind of makes sense. They know somebody that's been down that path, so to speak. That's generally the big picture of what I'm asking.
[Jacob Hunter MD]
Then it depends. So we generally always get an audio. If they're coming from within a practice, say, Ashley, you're sending somebody, they've already had that audio, so then they'll actually get their cochlear implant evaluation before they see me, whereas if it's coming from the community, most from the community, we're getting the audio. They see me, then getting an audio, then getting a cochlear implant evaluation, and then I generally talk with them more after that evaluation, but if a patient’s [hearing aids are] poorly fitted or if we feel hearing aids are best for the patient, they might not be back in my office. The audiologist might send them out. I always am aware of that. I'm always more than happy to talk to a patient, but sometimes they're like, "Listen, if we're not talking about the surgery anymore, I don't need to talk with Dr. Hunter anymore."
[Ashley Agan MD]
And do you do any formal cognitive testing, or is that only if you're concerned about that? Because you have a lot of patients, elderly patients, and I feel like there's a gray area before things are very obvious, like if a patient is very confused and there's obvious signs of memory loss or dementia or other things, you can pick that up, but then I feel like there's time leading up to that where unless you really test for it, you could miss that.
[Jacob Hunter MD]
I would love to test everybody for a cognitive screen. But my dad taught me when I was young, money doesn't grow on trees, and so we can't do that.
[…]
I am running, I guess, a research study that is looking at the role of cognition in hearing loss, so if they're interested in participating, we do administer the MoCA, the Montreal Cognitive Assessment, which isn't perfect but it's definitely a, I guess, next generation outside of the Mini-Mental, if you recall learning that from med school. There's also a hearing impaired MoCA, but, again, these are only patients that qualify for this study. This has been done at a number of other centers, and I do think it might become more prevalent as we continue to move forward for the reasons you highlight - to understand the link between hearing loss and cognition. But it's a small fraction of our patients that are getting it.
Podcast Contributors
Dr. Jacob Hunter
Dr. Jacob Hunter is Assistant Professor of Neurotology in the Department of Otolaryngology-Head and Neck Surgery at UT Southwestern Medical Center.
Dr. Gopi Shah
Dr. Gopi Shah is a pediatric otolaryngologist and the co-host of BackTable ENT.
Dr. Ashley Agan
Dr. Ashley Agan is an otolaryngologist in Dallas, TX.
Cite This Podcast
BackTable, LLC (Producer). (2021, February 2). Ep. 15 – Adult Cochlear Implantation [Audio podcast]. Retrieved from https://www.backtable.com
Disclaimer: The Materials available on BackTable.com are for informational and educational purposes only and are not a substitute for the professional judgment of a healthcare professional in diagnosing and treating patients. The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.
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