Chapters Transcript Assessment and Management of Hearing Loss Dr. Speaker discusses the assessment and management of hearing loss. So, I'm Doctor Ben Speaker. I'm one of the pediatric otolaryngologists at Saint Louis Children's Hospital. I joined the faculty just about a year ago, um, and I'm delighted to have the opportunity to talk to you a little bit about what we do on a day to day basis, specifically one of my own passions, which is pediatric hearing loss. So, um, I also wanted to acknowledge that um some of the work today, I was helped out by our audiology department, particularly Julia Webb, one of our Um, senior audiologists, um, just particularly in the assessment section. So, um, I have no financial disclosures, um, and And today, we're gonna start by just doing a quick overview of different kinds of hearing loss. We'll talk about the audiologic testing as well as some of the diagnostic testing. Then we'll talk about management and we'll spend a brief amount of time talking about where this is going in the future, right? So, um, hearing loss is quite a common thing to see in children at birth. Somewhere between 1 and 2000, 1 and 2 children per 1000 live births has a detectable hearing loss. Um, and transient hearing loss in childhood is extremely common, as certainly I'm sure everyone in the audience knows, um, up to 90% of children will haveitis media with effusion at some point before the age of 4. Um, and it's thought that more than half a billion people worldwide suffer with hearing loss, and this has all sorts of downstream effects both directly affecting healthcare as well as economic effects, effects on quality of life. So extremely common and a very, very impactful, um. Form of um health problem. So, um, when we talk about the physiology of hearing loss, I'm sure everyone remembers, um, that, uh, roughly speaking, they're kind of like several big broad categories of hearing loss. There's what we call conductive hearing loss, um, and that's hearing loss that is something that's decreasing the conduction of sound from the external ear to the cochlea itself that then turns the signals into sound signals into nerve signals, and then, so that's conductive hearing loss that can happen anywhere along the external ear or middle ear. And then you have sensory neural hearing loss, which happens in the higher centers. So from the cochlea, where you're unable to convert sound into uh nerve signals and then process it um in the higher centers in the brain, right? Um, there is also mixed hearing loss, which can occur from some single pathologies, um, particularly pathologies directly in the cochlea. Um, but very often it is a combination of two different etiologies of disease being present. Right. So, um, Then assessment of hearing loss. So, um, There are many different types of tests, um, and a lot of the workup of hearing loss is done by our audiology department. Um, and one of the important tasks that our audiologists do is determining what type of hearing tests specifically is most appropriate for, um, working up a patient. Um, and many of these are based on developmental age, um, as to what exactly the best test is that it's appropriate. Um, now there are both behavioral and objective tests, behavioral being the more traditional, um, where we rely on a response from the patient, um, to obtain hearing information, and objective being physiologic tests where we're looking for, um, uh, action potentials and things like that to indicate what the level of hearing is. But there are age appropriate tests for every age. Um, it's just about determining what the best way one is at the time. So one of the earliest things we can do, which was called behavioral observation audiometry, um, and this can even be done in children that are too young to have any head control. Essentially, um, what we do is we present them with a stimulus, either speech or tones at a known level of decibels, and then we're looking for some sort of behavioral indication that they have heard the sound. Um, and as you might suspect, this has an extremely high level of variability based on test retest and on, um, the actual observer that's doing the test. Um, but it is often, um, used as kind of one of the simplest tests, and this is kind of analogous to, um, the old, um, distraction testing or startle testing that you might see where you distract a child and then, you know, make a noise next to them. Um, but it does give us slightly more, um, threshold information, um, but again, very variable. Um, uh, the test that happens when you're a little bit older, um, once you've got enough head control that you can sort of turn or respond, um, to a sound, we'd move on to do what's called visual reinforced audiometry. Um, and this is usually appropriate up until about 2 years of age. Um, once you hit 2 years of age, there are other tests that are a little bit more, um, reliable from test to test, and, um, aren't as likely to give a super threshold, um, responses. Um, but with visual audiometry, what you do is you condition the child to look at the toy that lights up and makes a sound. Um, and then eventually you take away the visual stimulus, um, and you see, do they respond to only the sound, and you're able to determine with fairly good accuracy what their actual hearing thresholds are. So this is less variable, um, than the behavioral, um, observed audiometry. However, um, still not the most refined test and will occasionally give some results where the thresholds won't reflect the actual hearing thresholds of the child. Um, Then, um, once you get a child who's into sort of the preschool toddler age, um, that's when you start to be able to do what's called condition play audiotry. Once they're able to understand how to play a simple game, um, you set them up with a game where you present them with a sound stimulus, and you ask them to do a fun task. This has the advantage of being a lot easier for younger children to pay attention to, um, rather than the Really traditional hearing test where um you have them listen for a sound and either raise their hand or push a button, um and um it does allow you to repeatedly reinforce with the child and re-explain the rules, um, and it does take a little while, um, but this gives us very accurate information and very young children, um. And so, um, as you can see, then once we get to, um, kids that are school age, they're usually able to pay attention long enough to do a real traditional conventional purit tone audiogram. These can sometimes take a while, and one of the things that we do sometimes find, particularly in the younger school age children or children with like attention deficit hyperactivity disorder, sometimes, um, you need to take breaks, pause, um, let them do something else for a while and go back. So, occasionally, um, these audiologic um testing days can take a significant amount of time if you want to get truly accurate information. And that's why. Um, it's so good to have really talented, experienced, um, audiologists that work in our department. Um, one of the other tests that we often do once you've reached school age is we asked to do, um, speech audiometry. Um, the disadvantage of pure tone audiometry and the auiologic tests I've already asked about is, um, they do test your awareness of sound. Um, but they don't really effectively test the higher centers very well, so, um, you don't have to process the sound very well, and sometimes you can miss particular children with central processing disorders or children with serious speech problems, um, when you do traditional audiograms, and you may get fooled and see a relatively normal pure tone audiogram and then a child with retrocochlear pathology who um has really terrible speech recognition. So, um, we do try and do speech audiometry as part of our sort of standard assessment for any child that comes to the clinic that's old enough to have it done. And there's a bunch of different ways of doing speech audiometry. Some of the more common ones are, um, you'll say words out loud like spondees, which are two syllable words, and get have them, um, presented with these pages of pictures and have them point at the, the, the word that you've said out loud. But obviously this is one of the more complex tasks we would ask a child to do in an audiogram, right. Um, So, um, there's a number of different types of audiogram, and you get back all of these, um, different forms. Um, essentially, if you're ever looking at one of these, um, there should be a legend at the bottom that explains what all the symbols mean. Um, but the really common things you'll see, you may see an S. An S means that the stimulus was what we call a sound field. And a sound field is where we're not doing ear specific testing, we're just playing the sounds through a speaker, um, and effectively when you do sound field testing, you're really only testing the better hearing ear. So, um, it's important if you see sound field testing that looks normal, that you understand. Um, they may have normal hearing in one ear, but, um, they may not have normal hearing in both ears. You can miss a unilateral hearing loss if you've just done sound field testing. Unfortunately, sometimes kids just won't tolerate the ear specific testing. They won't put on the headphones. Um, they don't like ear inserts, um, and occasionally they won't put on a bone conduction probe. So, um, you just have to adapt and get the information that you can get from them. Um, other symbols you may see, you may see a, a circle or um an X. Um, circles are usually air conduction in the right ear, and an X, uh, the standard is that this air conduction in the left ear, right? So if you see circles and Xs, we've done your specific testing. There's a couple of objective tests that we should talk about as well before we move on to other things. Um, objective tests are tests where you don't have to rely on a behavioral response to get the hearing information, um, that you need, and probably the two most common things, one would be auto acoustic emissions, which is a good screening test. And then, um, probably one of the more common tests that we spend a lot of resources doing is acoustic brain stem response testing. And so to explain those a little bit, um, auto acoustic emissions are good screening test, and I think a lot of community um pediatricians offices now have auto acoustic emissions, um, machines. These are also widely available um at a lot of school screening programs, and these are part of the Missouri State newborn hearing screening program. Um, but in oacoustic emission, in a nutshell, they were discovered in the 1970s, um, and, um, they rely on the function of outer hair cells. So within the cochlea, you have the inner hair cells, and those are the hair cells that are responsible for generating the action potentials that go up the nerve to the brain stem when you hear a sound, right? So there's a reflex arc then. The outer hair cells create an action potential that goes up to the brain stem. And then signals come back down the eighth nerve to the outer hair cells, and the outer hair cells stiffen in response to sound. And this is part of how the cochlea is able to get such fine discrimination of different pitch and loudness is because the basement membrane stiffens in response to sounds, and it's actually responsible, this reflex arc for um 20 to 30 decibels of our our level of hearing. Um, the advantage of an OAE is it's quick, um, and the outputs are pretty simple and easy to understand. Um, the disadvantage is there are a bunch of things that can cause you to have an absent OAE, and having an absent auto acoustic emission is, um, not an indication that there's actual hearing loss. It just suggests that. Um, and so what you're looking for with an auto acoustic emission is those outer hair cells, when they stiffen, they make a sound. Um, and so the signal goes in and then the machine actually listens for the auto acoustic emission that's being emitted by the outer hair cells. Um, the disadvantage of an OAE is that um if you have Wax in the way, if you have a middle ear effusion, if you have an extremely narrow canal or a very loud environment, you may miss OAE. So OAs are um great when you've got a very normal um otologic system. Um, and normal middle ear function. However, um, they're not reliable when you've got something in the conductive system that's that's blocking the sound from getting out. Um, the other thing that's kind of nice. About OAEs is, um, when you see the result that's printed out, it says usually in bold and very simple language that it's a pass or it's a refer, um, and so, um, this is often a very quick way in a child that you can get to sit still for a little while to get a good idea of whether or not they have normal hearing, right. Um, the other really common type of objective hearing test we do is what's called auditory brainstem response testing. Um, this is a test that's actually measuring whether or not you're generating action potentials that are going into the brain stem and midbrain. Um, and the way this test works, um, is that we attach electrodes, one onto the forehead for reference and one behind the mastoid, and then we play sound into the ear. Those can be clicks or tones or warbles. Um, I won't delve too deeply into that, but, um, the disadvantage of it is um you're trying to measure action potentials that are in the. You know, 10 to 15 millivolt range, um, and so, um, any sort of noisy electrical activity, and the biggest one in the human body would be, um, skeletal muscle movement can throw off the test, um, and so this either needs to be done under natural sleep, under sedation, or under general anesthetic. Um, occasionally in a very cooperative teenager or adults, they can lie still long enough, um, because there's a lot of noise in the recordings, you have to do Fourier transforms, so. When we're running this test, you'll see the audiologist sitting there, and sometimes This test can take up to 2 hours under general anesthetic if you're trying to get really refined thresholds, um, and they will run the same stimulus 30 or 400 times and use a Fourier transform to find the signal in all of the noise. So you have to run the same test over and over and over and over again in rapid succession in order to get the actual hearing threshold information. And Ideally what we're looking for is we're looking for these named waves from 1 to 51 being the action potentials right at the origin of the cochlea, and 5 being the wave at the lateral lemniscus, which is one of the higher centers that we can measure. Um, with the, but each point on the auditory pathway, the nerve, the cochlear nucleus, the olives, the lateral lemniscus, and the inferior colliculus all generate a wave that you can detect on a good quality ABR. Um, this is obviously very skilled auiologic testing and very resource intensive, um, and so, um, in many, um, much of the time we try as much as we can to do behavioral testing and get as much information that way. Um, and then sort of the last objective test, um, a couple that I put on here, um, tympanometry is something that we use to look at the movement of the eardrum. A tympanometer will push pressure, air pressure into and pull pressure out of the ear canal while emitting a sounds to see how reflective acoustically the eardrum is. Um, it essentially lets us know, um, With very high sensitivity, is there fluid behind the drum? Is there possibly a perforation? Is there negative middle ear pressure that's indicating Eustachian tube dysfunction? So this is extremely useful in an ear, nose and throat clinic. Um, and then, um, one of the last tests that we do on a pretty limited basis, cause you have to usually use a significant amount of sounds to determine whether or not these are present or acoustic reflexes. Um, the acoustic reflexes, you have two muscles in your middle ear that attached to the scicular chain that are protective reflexes that will protect you from sudden onset loud noise. Um, one's the stapedius muscle, um, which is, um, innervated by the, the 7th cranial nerve, and the other is the tenor tympanine muscle, which is innervated by the 5th cranial nerve. Um, and for, um, Acoustic reflexes, it can be very useful in determining whether or not there's a secular chain fixation. Um, they can also help detect um retrocochlear problems, so problems with the nerve. Um, and, um, they're also useful because you do ipsilateral and contralateral reflexes where you're looking at stiffening of the drum in the ear that you're stimulating and also the contralateral ear to see whether there's crosstalk between the two sides of the brain stem. So, Um, There are some things that with all the tests I've mentioned so far in isolation, you may sometimes miss, and one of them is a condition called central auditory processing disorder. I hinted a little bit at this with um talking about speech audiometry, but um central auditory processing disorder um is where you have perception of sounds, the lower portions of your um acoustic, uh, your auditory pathway work. Um, but when you go and try and process that sound, when you try and recognize, say, speech, for example, or when you're trying to process, um, sounds from the outside world and determine their meaning, um, occasionally the higher centers fail you. This is a relatively underdiagnosed thing, um, and it does sometimes go with some of the other, um, developmental conditions like autism spectrum disorder. Um, but if you've got a child who has had multiple hearing screenings where they're normal, but they're struggling with their speech development or they're struggling with their sort of language tasks in, um, school, or there's a lot of information coming back from the school that They just really don't seem to be doing well with, you know, verbal instruction. Sometimes they do OK with written instruction, but they're really struggling with with following spoken instructions. This is something that you should consider. Um, now, in order to do proper central auditory processing testing, a child has to be relatively well into their school years, so we usually like to see that there are at least 7 before we start um testing for this. Um, and they need to be otherwise pretty developmentally normal, um, for us to say that it is an isolated central auditory processing disorder. There are other disorders that, that can affect this, um, you know, um, but you can have children that are otherwise very developmentally normal that simply have difficulty with their auditory processing at a higher level. Um, another thing that you may hear about that's, um, becoming a much more diagnosed condition as we understand it a little bit better, um, and this is probably more of a struggle for me and, in my job where I'm trying to determine cochlear implant candidacy is um ANSD, um, so this is a slightly unusual condition in that, um, it stands for auditory neuropathy spectrum disorder. Um, and with auditory neuropathy spectrum disorder, um, it is, you have a normal functioning cochlea. So the most common site in which you have sensory neural hearing loss is at the cochlear hair cells or at the synapse of the hair cells with the cranial nerve. Um, with auditory neuropathy spectrum disorder, um, that part works normally, um, but then the higher parts of the auditory pathway don't work. So, um, the way we diagnose this is in on acoustic brain stem response testing. Um, the thing that's puzzling about these children is sometimes they can have relatively good pure tone audiometry or visual reinforced audiometry and yet develop little to no speech. Um, this is common in the kind of children that have had, um, insults to the central nervous system. So, um, it's common in children that have had, um, high bilirubin, um, early on in childhood with jaundice. It's common in children that are born premature and spend extended times in the NICU. Um, there are some genetic conditions that seem to predispose to it. But essentially this is like having um a microphone that's working, but everything else on the pathway, um, is not working well. And so when we do an ABR for um a child who has ANSD, what you'll see is early on in the trace, you'll see some big um spikes or waves, and then once you get past. Um, the cochlea and wave one, you'll start to see either really abnormal waves or absent waves. Um, and so, um, this can be a challenging thing for us to deal with, um, because sometimes these children seem like they have relatively good access to sound on pure tone audiogram, but, um, occasionally we'll be quite disabled from a hearing point of view. And some kids who seem like they're relatively good on standard audiometry end up needing cochlear implants. So I wanna change gears for a minute and talk a little bit about what the state of Missouri's newborn hearing screening program is like. Um, our current clinical lead for this is one of our audiologists, Janet Vance, um, and at the moment, um, we look like we're doing really well with complying with the state of Missouri's mandates, um, and every child that's being born at a BJC, um, hospital, almost without exception, is being screened for hearing loss. Um, and our targets right now, we wanna make sure that every child is screened, um, by 1 month of age. We wanna make sure that if they have hearing loss, that we've diagnosed it by 3 months of age, and we wanna make sure that we've moved on to early intervention services and the rehab, um, side of this by the time they hit 6 months of age. So, how do we time this? Um, if the child has been born via vaginal delivery, generally we'd like to do it in the 1st 24 hours. Um, if they've had a cesarean section, we often wait a little longer, um, just, um, particularly with their possible exposure to sedating medications and, um, with the physiological stress of a cesarean, they're very often harder to test early on, so we often wait up to 48 hours. Um, and then children that go into the NICU, you'll see they have special conditions for testing. We try to get to them right before discharge if possible. Um, occasionally we'll sneak in if they're stable and appropriate earlier on, um, but they even have special, um, um, difference in differences in the way we screen them. So, um, in the well children, the way we're screening them is we usually do uh auto acoustic emission testing. All right, um, if, um, that's normal, that's often considered a pass. Um, if it's abnormal, you move on to an automated acoustic brain stem response testing, um, and you have to try and do this while the child's asleep, which fortunately most neonates are pretty sleepy. Um, you don't use the OAE step in children in the NICU. Um, children at the NICU are considered high risk of having a hearing loss, um, and so we like to do the more specific test in children that are in the NICU, um, we just skip the, the OAE. All right. Um, and then when they come to the clinic, there's a couple of things that we do. I'm sure you guys are all used to doing otoscopy too. We do the same thing here. Um, the only difference is very often I have the luxury of having a binocular operating microscope and in my clinic, so sometimes I'm able, if I have any doubt about my otoscopy findings, I just bring the kid in to my microscope room and use 40 times magnification to try and figure out what's going on. Um, I do still fairly regular use tuning fork tests. Um, I find that a tuning fork is a quick way just to really reinforce what's going on. Um, and occasionally a tuning fork is a very good specific test for certain things, um, like if you're trying to determine if somebody hastay foot plate fixation and whether or not you should operate on them. They better have flipped their forks um on a a Renee's test. Um, so, um, I still very regularly do tuning fork testing. I also do tuning fork testing on just about every kid that I, um, operate on when they wake up. Um, we often do fiber optic examination in the clinic, mostly to look at the nasopharynx, um, you know, kids with effusions, they very often have adenoid problems. Um, even some kids who are going for their second set of ear tubes, I often consider taking their adenoids out at the time, so, but I like to confirm before I'm asleep on an operating table whether or not they have. Um, adenoid hypertrophy, um, which sometimes it can be a struggle to do a fiber optic exam in a, a two year old, but, um, I think most kids surprise you. All right. Um, and then I often will, um, look at all the rest of the cranial nerves cause I think otolaryngologists are First and foremost looking after cranial nerves on their day to day basis. Um, as far as the imaging tests we often get, Um, as a general rule of thumb, CT is a very good test if you've got a conductive hearing loss that you don't fully understand or want to characterize, and also a CT is something that is necessary if you have a child with a choplasatoma. MRI is really a good test for um looking at the shape of the labyrinth itself and the 7th and 8th cranial nerves. So it's more of a test for um some forms of mixed hearing loss and for sensory neural hearing loss. And just about every child with profound sensory neural hearing loss or with asymmetric sensory neural hearing loss, we would consider getting an MRI of their internal auditory canals. All right. So let's take a break for a second before we start talking about management. Does anyone have any questions so far? All right. Well, I'll move on to talking about how we manage a couple of different things, um, and then, um, at the end, we'll talk about some future directions as well. OK? Um, so, uh, this is one of those things that can sometimes be the bane of our residents' existence. Um, but it is one of the most common things that I get asked questions about, and it is what to do with serumin. Impacted serumin, too much serumin, seruminous discharge. I think far and away the number one thing parents ask me about when I'm in clinic is what to do about their child's earwax. Um, there are a lot of commercially available wax removal kits and all sorts of devices that are available on the internet now. You can go on Amazon and buy these endoscopic curettes, um, and, um, we see no end of problems with those. Um, people also often put put Q-tips into their ears and cause injuries to the tympanic membrane, injuries to the external auditory canal, impact their wax further, um. As far as what we are happy with people doing, um, you know, I would often consider trying a serum lytic agent. Um, Debrox drops are very popular. They're um available at most pharmacies. These contain uh a form of peroxide. And the mechanism by which they work is they generate oxygen bubbles which then break up the wax and allow it to come out. Um, the disadvantage of deox drops is if they get through a perforation in the tomatic membrane or through a tube, they can be pretty uncomfortable. They're unlikely to, um, exert any sort of major odotoxic effect, um, and They are more expensive than what I most commonly advise, um, patients and their parents to use, and I often ask them just to use, um, at night, right before they go to bed, a couple of drops of either mineral oil or olive oil every night for 2 or 3 weeks. And what that does is it just gets into the wax, it softens it, it solubilizes it and allows it to slowly come out over time. It's not as fast, but it is very gentle and it's very unlikely to injure the skin of the external auditory canal or cause any sort of major ill effects if you've got um tympanic membrane perforation you're not aware of. Um, there are a lot of places that will still wash out the ear canal, um, and that's fine, provided you're not using a lot of pressure or force. Um, you do occasionally see um a traumatic injury. Um, and if you happen to be using something that's either very warm or very cold, you can exert a caloric effect on the patient, and they will be very vertiginous for a few seconds. Um, in the clinic, what I generally do is use the microscope and then either curette out. Um, the, um, serumen or use micro suction, we've got all sorts of different sizes of microsuction that can take out soft wax, right? Um, so that was our external auditory canal pathology that's the most common. Um, far and away the most common thing that we end up seeing on a day to day basis in the ENT clinic would be middle ear effusions. Um, and, um, we get asked by a lot of parents. I also have a lot of pediatricians who ask me, well, what do I do about the fluid? Um, you know, cause you have lots of kids that have chronic otitis media, um, with effusion that aren't actively infected where you don't need antibiotics, um, uh, very often as a, a step that you could consider, um, you know, Sometimes instructing kids on how to do a Valsalva and try to inflate their balloons or inflate balloons works in an older patient, um, you probably won't be able to get um the peak ages for chronic otitis media with effusion to do that. The other thing I also often would consider, um, if the parents want to try something medically. While they're waiting would be a nasal nasal corticosteroid spray, something like Flonase or Nasonex. Um, I know in a very early age groups, um, it's not FDA approved, but, um, we often use it off label even in infants, um, when there's a strong indication, right? Um, if you've got conductive hearing loss that's 25 decibels or worse at 3 frequencies, and it's present for at least 3 months, or if you get 3 episodes of acute otitis media in 6 months or 4 in a year, then that's when we start talking about putting in ear tubes, um, which does require general anesthetic, but I would say I probably do. Around 10 to 20 sets of ear tubes a week, so it is far and away the most common thing I do. Um, And then one of the other things that I like to make sure everybody is very careful about looking for cause catching these early makes everyone's life much more straightforward as cholesteatoma. Um, so I would be wary of any child that has a, a painless discharging ear that doesn't respond to antibiotics. Um, and, you know, there are some kids that will have an acute otitis media, they'll perforate, they'll discharge for a few days and they'll stop. But, you know, if you've got a child that's been discharging for 2 or 3 weeks, they're not in pain. Um, you can't get a good look at the eardrum. I would let us know, um, and I think we should see most of the kids that don't respond to antibiotic therapy cause there could be something going on. The images that I've put up here, um, one thing just to be aware of, um, occasionally a cholesteatoma can be very sneaky, um, and you may be presented with the image that's on the left. So, um, this is an endoscopic image of, uh, a left eardrum, and you can see this crust that's forming over the posterior superior aspect of the eardrum here. Um, if you go in and and lift off this crust, you'll find a bunch of keratin underneath. So, um, this is the other thing that I watch out for. If you get a good look at an eardrum and you see the attic, the top part of the eardrum is covered in an adherent crust. That would be something that could be hiding a cholesteatoma and, you know, would be something that I would like to see. Um, the other thing is occasionally you'll find behind a closed eardrum, a little white pearl. Um, and so you can have what we call congenital cholesteatomas, which forms in utero. Um, by squamous epithelium getting trapped in the middle ear space, um, and they can occur in a child who has never had an acute otitis media, never had ear surgery, never had a perforation, and never had a history of Eustachian tube dysfunction. So, um, if you've got a kid that's got, um, a gradual onset subjective hearing loss in one ear and you look in their ear and you see. You're not sure um if it's meryngosclerosis or maybe it just looks sort of like there's something underneath the drum, that would be another something that we would normally want to review, um, and just have a look at it, right? Um, for cholesteatoma, um, the treatments for these nowadays is all still surgical. Um, we have a lot of research going on in the ENT community trying to identify better ways of treating cholesteatoma. Um, our, our surgical treatment, um, you know, even in the best of hands, you can sometimes have recidivism rates for cholesteatoma of up to 60, 70%. Um, so, um, truly it can be a chronic disease state, um, and it's an extremely challenging disease to look after, um, and, um, the average patient. Who has a cholesteatoma requires a minimum of 2 and sometimes even 3 or 4 operations over the course of their lifetime. Um, One of the other things that we do a lot of in pediatrics is we talk about different types of hearing rehab implants and um hearing rehab options. I specifically put up bone anchored hearing aids here, um, because, um, we've had a recent shift with the OSCA implant that's produced by the, the Cochlear America Corporation. So this is a, um, totally um subcutaneous implant that um transmits sound, um, it's based on their old cochlear implant um processor system. Um, but this is for, um, unilateral profound hearing loss or for, um, a severe conductive hearing loss where they can't wear um a conventional hearing aid, like say you have a child with a microtia, no ear canal, um, but, um, the old bone anchored hearing aid system, some of them had a percutaneous component that came out through the scalp of the skin, and in a child, those were. Fairly challenging to maintain because they were constantly forming granulation tissue. The skin was constantly trying to close over, but now there's this generation of totally subcutaneous implants, um, and so you don't have to deal with any of the skin complications. Um, OCI put up because it's now approved in children 5 and up, um, whereas before it was children 12 and up, so there were a lot of children that were having to use soft band conduction, um, headband hearing aids for years and years and years before they were suitable to get implanted. But now this OC implant, we've got a backlog of kids that we're working through, and so we're doing quite a few of these. Um, because the 5 to 12 year olds are all able to get these now, so fewer skin complications, really good access to sound, um, the soft bands, bone conduction hearing aids are quite prone to making a lot of whistling and feedback, um, and you don't get any of that with, um, this particular system. Um, Cochlear implants then. Um, this is sort of the next echelon for children who are born with bilateral profound hearing loss. Um, I put up the referral candidacy here, the referral criteria, just so that it's something you're familiar with, but if you ever see a child who um has worse than 70 decibels hearing loss in one or both ears. We should probably see them. Um, if they've got hearing aids on, but they are doing worse than 50% on standard speech recognition testing, they're a cochlear implant candidate. And the other thing that I always want people to keep in mind is, if you've got a kid that's using their hearing aids, but struggling with it and not doing well and having poor quality of life, that's another thing for us to see and assess. Um, because occasionally we find children do not do as well as we're expecting them to with their conventional hearing aids, and that bears further investigation and conversation. Um, but, um, this is, um, the cochlear implant has probably been the single greatest technological advancement in um profound hearing loss that has been developed in the last century. Um, and this is really revolutionized. There are children who now integrate into mainstream school, um, and are able to communicate verbally, whereas before, um, they would have been communicating with sign only. So this is, um, really one of the, the greatest joys I have in my um working life is to be able to put in a cochlear implant for a child born with with little to no hearing. Um, Then Are there any options if you don't have a cochlea or you don't have cochlear nerves, cause you have to have both of those in order to be a candidate for a cochlear implant. Um, yes, there is. Um, right now the FDA has approved an acoustic brain stem response implant, um, so on the photo on the right, we can see an endoscopic view of the cerebral pontine angle. Um, uh, this is where the lower cranial nerves insert into the brain stem. There's a little foramen, which is right next to the cochlear nucleus, um, and in particularly in children who have neurofibromatosis type 2, who lose both of their 8th cranial nerves, this is sometimes an option. The problem with um an acoustic brain stem implant is the speech discrimination is nowhere near as good as you get with a cochlear implant. Um, and having an intracranial implant, um, has a higher risk of meningitis, also has a slightly increased, um, risk of, um, seizures, um, but it is an option, um, for when there's No cochlea or nerve available. Um, other things that are coming down the pipeline, um, so one of the things that we're working on, and there are a bunch of companies that are competing to try and get to market with this, is a totally implanted cochlear implant. Um, so right now with a cochlear implant, there's an external processor that you have to wear, and the problem with that is if you're not wearing it, you don't have any access to sound. Um, so one company, um, is Envoy Medical, that's based out of White Bear Lake in Minnesota. They've actually engineered a system where the microphone for their cochlear implant is actually a little transducer that's clipped onto the um incus and uses the eardrum and incus as a natural microphone, um, and then that's connected to a processor that's connected to sort of a traditional cochlear implant. It's all connected to a battery pack that's implanted underneath the anterior, um, chest wall skin. So, um, and this is chargeable via transcutaneous device. Um, this is just in the very early phases of, of testing right now, um, but I would say within the next decade we'll start to see the big companies like Cochlear, ME, and Advanced bionics start coming to market with totally implantable, um, uh, cochlear implant devices. Um, and then. One last thing in future directions before I start letting you get to your questions. Um, Recently, there's been sort of a tidal shift in how we work up kids in the clinic. Um, it used to be that we were very slow to recommend genetic testing. Um, however, I don't know if anyone's seen, um, this, but there is, um, at least there's been several, um, cases reported of successful gene therapy for one particular type of sensory neural hearing loss. So, um, initially this group in China produced an adenovirus factor. Um, that was able to treat odourin associated hearing loss, um, which is a cause of bilateral, um, congenital profound non-syndromic sensory neural hearing loss, and they were able to completely reverse the hearing loss in 9 children in this, um, Nature Medicine article. Um, this is being duplicated by a couple of different groups around the world right now. Um, and so while this is the first time we've had successful gene therapy for sensory neural hearing loss, there are groups right now that are actively looking at different genes and developing further um genetic treatments. So, um, we have entered the age of gene therapy when it comes to treating profound sensory neural hearing loss. All right? Um, and with that, I'd like to thank everyone. Um, I put any my email up here in case anyone wants to get in touch. Created by Presenters Benjamin Speaker, MBBCh Pediatric Otolaryngology, Ear, Nose & Throat (Otolaryngology) View full profile
