Lec #1 Hearing Disorders: Part 2 PDF

Created with Coconote - https://coconote.app Lec # 1 Hearing Disorders: Part 2 Hey, class. Can you guys hear me back there? Is is the microphone working back there? Yeah. Is that better? Yeah. Okay. K. So the next part we need to consider how we evaluate our patients. So most of you will see clie...

Created with Coconote - https://coconote.app Lec # 1 Hearing Disorders: Part 2 Hey, class. Can you guys hear me back there? Is is the microphone working back there? Yeah. Is that better? Yeah. Okay. K. So the next part we need to consider how we evaluate our patients. So most of you will see clients or patients. Some of you may go on to do other things or, work for a hearing aid company or become a faculty member, member, but most of you end up seeing patients. So when we see somebody in our practice, there's a general order in terms of how we sort of assess them or see. So the first thing we do is we talk to them. We take a history of what's been going on with that person. Right? So 2 year, 3 year old preschool kid who has unintelligible speech. Right? So you're gonna ask the mom, you know, if they have any hearing concerns or have other problems or what kind of sounds do they make, for instance. Right? So you talk about their presenting problem. So that's history. Right? See somebody who says they can't hear, you're gonna ask, well, how long has this been going on? Is it getting worse? Do you have tinnitus, other stuff? Right? So that's history. Arguably, that's the most important part of health care professionals interaction. K? If you do a good, careful history, that really gives you a lot of information. And a lot of the time, you can come up with possible diagnosis good history. Next is we typically most of us will do some type of a physical examination. Right? So for your audios students, you'll look in the ears, but there's more to it than just looking in the ears. But otoscopy is certainly something you'll do for you speech people. You may need to, again, assess other things going on in their head and neck area. And then after that, you have to think about, well, what tests do we need to order to figure out what's going on. Right? So, obviously, audiograms are gonna be key for us. But for you SLPs, you may think, well, this 3 year old, may need we need may need to do, like, a Goldman Fristo articulation test, for instance, to figure out what sounds they're having problems with, for instance. Right? So those are specific tests based on the history in your exam findings. K? And then after that, sort of you have an idea And it may not be your job to make the definitive diagnosis, but you should have some type of an idea, so you may need to refer to the right people to make that diagnosis. Right? And then after that, those clients do get some type of a treatment or some type of a follow-up plan. So if you find somebody with bad hearing loss, then you may need to the intervention or treatment, maybe hearing aids, or could be speech therapy. And then, obviously, follow-up referrals are important as well. But that's sort of the general step in how we deal with, patients, as health care professionals. Now, again, for us, we're really gonna be focused on the oral logic history, hearing or ear related history, as well as speech history. The other things to consider, though, are listed there. Right? Things like past medical history or what surgeries have they had. Right? So if you have somebody so if you see somebody with a hearing loss and they tell you they had a stroke a few months ago, then, I mean, that's important for you to know. Right? Even though that happened in the past. Medication allergies, we're gonna have a class part of the class on ototoxicity. Right? Ototoxic substances. So some medications, for instance, can cause hearing loss. So that's important there. Family history, if you see somebody with some type of a syndrome, then obviously, you need to know the family history. Is this something passed down, or is it a brand new genetic mutation for that individual you're seeing? If you're seeing a child, like a brand new baby with year in loss, then obviously, the pregnancy, labor, delivery, birth history is important as well. Right? So if the baby had low oxygen levels, for instance, during delivery for some reason, then that in itself is a risk factor for congenital hair. Right? So history is very important, but it can be somewhat targeted. Now in terms of of oral logic history, again, these are the things you need to ask about. Basically, this is what we ask about, and anybody presenting will hear complaints, you know, when when I see them. So do they have pain or talsia? Do they have hearing loss? Maybe subjective hearing loss, but that's important to know. Some people will state their ears will feel very full or feels like it's underwater, so that's called oral oral fullness. So oral means ear as well. Tinnitus, we'll cover in detail later on. Vertigo, we'll cover in detail later on, but remember the inner ear, there's the balanced organ part as well. Right? So if you have an inner ear disorder, you may get vertigo or balance problems with or without hearing problems. Odorrhoea, that denotes some type of an infectious process. Now we put ear tugging in brackets because, like, a 8 month old is gonna tell you, ouch. My right ear hurts. Right? So they may just pull out their ears a lot. But it's a bit of a soft sign, so we'll cover that. That's why it's a practice. But you may need to ask the mom, for instance, about your tongue, or the mom will tell your mom. So you do a history. You, do a careful history regarding the presenting complaint or presenting issue. And the next thing you're gonna do is you're gonna do the exam. Right? So, again, for us, it's the ear exam. Now ear exam doesn't automatically mean we're gonna jump into this, right, apostrophe. We're actually gonna do an inspection first. And that's what we do in all areas of health care. When you see somebody, when you examine them, you inspect them first. Right? Meaning, you just look at them. Right? There are things you can pick up, like maybe masses or skin changes. Ear may look very asymmetric, for instance. Positioning of the ear may be off, or some of those parts we're gonna know about, maybe absent or missing. You can just get that just by looking at the person. The inspection is the first thing we do. Then comes the otoscopy. Now otoscopy is an extremely difficult skill to learn and master. And there's been there's been numerous studies that show very poor diagnostic accuracies of otoscopies, even in experienced clinicians or pediatricians or whatever. K? So, again, you don't have to memorize these numbers by any means. I just want you to get the idea that otoscopy is a challenging skill, so you may not it may take you a long time for you to get even decent at it. Especially when you look at some art clinic here, to look in the ears. Right? So you're looking at the ear canal as well as the eardrum. So you're not just looking at the eardrum. Okay? But this is a hand a handheld otoscope. Right? Now there are different ways to hold it. Some people tell you to hold it like a pencil, but, honestly, you can hold it whatever way you want. Just become comfortable with it. And hold it using the handle, not up here. Right? The handle's down here. There's the battery part. You can see it is important to steady yourself with the patients. So the reason why is because if that person moves, then you move with them. Right? If you're stationary and they move, you may nick the ear canal and cause discomfort and pain. So when you do autoscopy, this piece is called the speculum, ear speculum. Okay? And they come in different sizes. So different sizes means different openings here, different aperture. Okay? So the important thing when you pick speculum is just pick the widest one possible that will fit into the person. Why? Well, because there's more light going on. Right? If you're shining a light through a tiny hole, it's not as bright as if you're shining it through a bigger hole. So typically speaking, you can use 4 to 5 millimeter in pretty much everyone. Adults, it should be 5. Kids, it may be 4 millimeters. Sometimes there are conditions like trisomy 21 where you may have to downsize a bit, but just use the widest or the biggest speculum possible that will fit into the ear canal because it just delivers more light. Now when you do examine kids, you have to be at their level. So you're usually sitting down. So we have these rolly sort of chairs in our clinic and the audiology clinic as well. And older kids, again, you sort of get down on their level and you do your regular laposcopy. Younger kids, we usually get the caregivers or the parents to help. So we usually get the kids to sit on their mom, dad, or caregiver's lap, and usually get them to sort of hold them hold their body and arm with one of mom's arm and hold the head against the mom with the other arm. So, usually, one of these arms is holding the head, raised against the parent. That sort of is the easiest way to kid looking kids first. Because, again, the most kids don't, like, have barriers like that. They may be, scared or upset. The other thing to know when you do otoscopy is you always see people sort of pulling out the ears. And the main reason is because the ear canal is not a straight structure, And I'll show you some CT scan images of that. The ear canal is actually a very tortuous structure, meaning that it's not a it's not a straight cylinder going in like this. Okay? But light travels in a straight line. Right? So you do need to straighten out the ear canal by pulling it back a little bit so that the light can travel on straight and hit the eardrum so you can see the eardrum itself. Now you'll read in some textbooks, you know, for adults, you pull up or kids, you pull down. That's all that's all BS, actually. I know. Just from looking at 1,000 of years. You just have to sort of bypass the entrance, pull it back to straighten out the ear canal. That's all you need to do. The key most of the time when medical students, you guys, residents, when when you look in the ears, you tend to really pinch hard and then pull really hard. Again, that that's not necessary. You just gently pull the ear back. That's all you need to do. The other thing to note is the ear canal, not only is it sort of almost like a horizontal s shape, it doesn't usually go in straight like this. It may go anterosuperior, in post or inferior, antero inferior. So it's not what I'm trying to say is you shouldn't just go in straight and hold it there. Right? You may need to move this around to find the eardrum. K? Now this is a monocular viewer. Right? It's not a it's not a, binocular. You don't get binocular vision. Right? So if you use microscope or binoculars and you set it to your correct interpupillary distance, what do you get? You get one image. Right? You get one circle of the image. You don't get 2 2 images like at best. Here, you need to use 1 your usually, your dominant eye to look. So you need to know you need to close your nondominant eye and then have a look. Now how do you know the shy your dominant? Well, just Google it. There's very simple ways to know. You can look at an image and, you know, if you close out one eye, close the other, one moves more and stuff like that. But, again, it's not it's best used when you close your non dominant eye and look at the viewer. When you look in with the handheld otoscope, I'm gonna show you lots of images of the eartron like shown here. Right? Look at this beautiful view. Right? You may not get a perfectly holistic view like that with a handheld otoscope, which is what you're gonna have access to. Right? Meaning, you may just see part of the eardrum when you look in. So what is why am I showing you this? Well, if you see something like this, you need to point up to look at the entire eardrum. K? So, again, it's very important when you go in the ear, you don't stay stationary. You may need to move this around to get a whole view of the eardrum. Okay? Now there are other things we can do, like in, in our clinic, we have this thing called pneumatical autoscopy, where there's a it's literally a bulb where you can I can push the bulb and it pushes air in, which moves the eardrum, cover that more, as well as you can use oval microscopy, meaning we use binocular microscope to look in the ear, which gives us 3 d perception and much better view as well? But, typically, all we have access is this. Okay? In pneumatical otoscopy, we'll cover in more detail, but you do have to form a seal with the ear canal. Otherwise, if you put in that puff of air, it may just escape out rather than go in and hit the eardrum, which is what you want it to do. Now when you do autoscopy, what are you looking for? Well, again, you're looking at the ear canal first. Right? And we have half a lecture, ear canal disorders. So you're not just looking for the ear drum right away. You're gonna look at the ear canal and describe any acromatosis. After you look at the ear canal, you look at the eardrum. Right? So the majority ear majority of the eardrum is called the pars tensa, and most of the time, we divide it up into quadrants, k, as shown here. So if I say there so this is in this is the right ear, and I'll show I'll tell you why I know it's the right ear, but it's the right ear. So meaning this is anterior, this is posterior, this is superior, this is inferior. K? So if I tell you, okay, we're we're working together at the other meeting. So this kid there's a I'm seeing a kid who perforated his ears wrong. Right? So I tell you I'm gonna tell you, can you please check his earring? I see a perforation in the postero inferior part of the eardrum. Right? And you know where you know where that is. So that's why we divide it up into quadrants because we can say anterosuperior, postural superior, antero inferior. You know which quadrant I'm talking about when we're covering abnormal pathology. What else are you looking at? Well, there's this thin area called pars flaccida. It's called the attic. Attic is on top. Right? So that's the pars flaccida, and we'll talk about the importance of that. But there's a disease that can occur in that area that can have some consequences. It should describe the way the eardrum appears. Right? Color, consistency, how thick you think it is, whether you can see through it or not, whether it's translucent or old paper. That's important. And then anatomic structures. Some of them shown here. K? So if you can make some of these if you can make out some of these, then you're sitting pretty deep. So the most obvious one is the malleus because that's the one most close to you when you do the the otoscopy. And don't worry too much about the cone of light. Lots of textbooks describe cone of light as means that the eardrum is normal, but that's actually not true. And we'll show you I'll show you examples of that. Monoplait is only useful for identifying the eardrum. Incus is coming down here. So So the valleus is actually you're just seeing the bottom part of it. There's a big top part connected to the incus here, and then it's coming down, and then the state piece is going in. And, again, you can see again, there's no real redness. You can clearly see through the eardrum. It's not opaque. So this is a very normal looking eardrum. Now the way the ossicles are arranged, again, if you see this little bump here, that's called a that's part of the amylase here. This part. So that part corresponds to this bump here. Okay? So that's the lateral process of the malleus. But you can see again the top part of the malleus and bulk of the incus, the body of the incus is actually hidden at the top here. It's up here. So you can't really see it because it's covered by part of the temporal bone. You just sort of see this part when you look in the yoga screen. So again, you see the Malleus, the lower part, the long process of the ingress, it's called, and then state based going in. The reason why I know this is a left here, I mean, other than the fact that I labeled it, is the orientation of the ossicles here. So you see how the incus coming down is posterior to the Malleus. So I know that's the way the obstacles are arranged. So I know this is the left chair. So if you look at this chair, for instance, this one's harder to see, but see, Alias is here. And where is the Incas? Well, it's coming down here. So this is the right ear. It's just the way the all skills are oriented. That's how I can tell whether it's a left or right ear. Now this is a picture this is a picture, of an eardrum with a large perforation. So it's called a subtotal perforation. And the reason why I showed it is because you can see some of the middle ear floor and middle ear anatomy. Right? So here's the malleus. Right? Again, top part is hidden up here. This is actually the chord of timpani nerve, but we'll talk about that later. But if you remove this part of the eardrum, you can see the ink is coming down, and the staypiece is going in. The staypiece footplate is here, which means this is the cochlear, the basal turn of the cochlear. Right? In here, and that's the round window niche. So and on top of the state B's foot plate, up here is the facial nerve, So you can see how both things can be effective. Now look at this picture of an otoscopic image of the eardrum. Right? You can see this eardrum looks I mean, there's some redness and stuff, obviously, but look at you can't see through here at all. Right? It's very white. It's opaque. It's it's not translucent. You can't see through I mean, you can see the Malleus here, but you can't see anything else. There's some error there, so you can see the difference there. But you can see there's this is fluid. K? That's all Titus media. On this picture, what do you see? Well, you can see there's a perforation. Right? There's a hole. Not as big as the previous picture, but previous line. You can see there's a perforated drum. How did that happen? Don't know. Maybe it's q tip trauma or something, but something perforated eardrum. Now mouth and throat exam came for you SLPs. A lot of you will have light, hemlite, or some other light with you. You do have to have a good look in the mouth. Right? Look at the palate, tongue movement, and stuff if needed for, again, oral neck exam. And we'll cover some of this later on. For us and sometimes in some areas, SLPs will do endoscopic examinations as well. Sometimes you need to put a camera into the nose to look at how the palate is moving, for instance, for patients with, cleft palate or call it the filofaryngeal, insufficiency. And sometimes you put a rigid scope to look at how the larynx moves, call that stroboscopy. Right? You guys help us with voice clinics for patients with voice disorders. So this is how we assess the larynx, vocal cord, palate, other speech related structures as well, which we'll cover in more detail later. Alright. So the last bit here is, the tuning fork exam. So tuning fork, it's a screening measure, so it doesn't give you it doesn't give you sort of a specific accurate diagnosis of anything, but it points you towards what you need to be thinking about. So, again, screening exam, like, you know, PSA testing for prostate. PSA doesn't mean if you have elevated PSA, it doesn't mean you have prostate cancer. Right? But there's a chance you're made for instance. So there actually, more than 2 may 2 types of tuning fork tests, but we're gonna talk about the 2 major ones. Weber or Weber and Renee testing. K? It's usually done with a, 512 hertz tuning fork, which I brought to here, there is one 28 hertz tuning forks as well. But, usually, we tend to use 5 12 hertz. May I can I get you this in here? It's probably easiest to demonstrate. Okay. You just okay. So can you satellite really bright? You're okay. Okay. So we're gonna do the Weber testing first. So this is the way you do the Weber testing. You hold the bottom part, right, not the top part, because the top part is vibrating. Right? It's the vibratory energy. You don't wanna dampen it by holding it up there. So I usually use my elbow. So you don't want it to be too loud, but you do want it to be, again, obviously, vibrating enough for there to be energy transmission. K? So I think that's pretty good. Okay. And the Weber test is you actually put it in the vertex, forehead or vertex, or some people even use, like, central incisor upper teeth. But the key is you have to be down the middle. Okay? Because you're looking for a lateralization. Alright. You're gonna try it? Okay. So you just hold it, and I have the head brace back here because I'm pushing on it pretty firm. And you may leave a little skin mark because if you don't really push it firm enough, then you're not transmitting energy. Right? Because this energy has to go through skin, bone to your ear. Right? And then you ask the person, can you hear it better on the right, left, or sort of down the middle? What do you think? Okay. Yeah. So that's sort of what you expect with someone normal hearing. Okay? Alright. Thank you. I I did all the work, so I hope you're clapping for me. Oh, good job. Okay. So Weber testing is when it's normal, when the person has normal hearing, you expect them to say you don't expect them to say, oh, I hear better on my right or left. You expect what we just saw. You're sort of down here, down the middle. Right? So that's no lateralization. However, if you if the person says, oh, I hear it better on the right, that means it's lateralizing to that side. Okay? So what does that mean? Well, that means either the person has a conductive hearing loss on that side or a sensory neural hearing loss on the contralateral side. That's you don't know which one, but it's either of these two scenarios. K? So you can see why this is a screening measure. It sort of points you towards the right direction, but you're gonna have to do a formal audiogram to know exactly what's going on. Now the occlusion effect is what what that means is and you can try this during the next break. That's why I brought, several several tuning forks and otoscopes as well. So if you do the lever testing and then if you actually occlude the ear by pushing on tragus or putting your finger, it will lateralize to that side because you're causing conductive urine loss. Right? So you you can try that. But if you, again, plug your ear canal and do the Weber testing, it will lateralize to that side. Okay. Renee testing. Okay. So Renee testing is there are 2 parts to the Renee testing. You're gonna test air conduction and then bone conduction. So bone conduction air conduction is just through the air, just in front of the ear. Bone conduction is through the mastoid process here. So I usually do it like this. Again, you get the tuning for phoneword, and you say this is number 1, and this is number 2. So 12. And then you ask what's lower? 1. Yeah. That's right. Wow. I'm nervous. So Yeah. She could well, actually No. Maybe not. Okay. So that's sort of the result to expect. You want air Maybe not. Okay. So that's sort of the result to expect. You want air conduction to be greater than bone conduction. Right? So that's what you expect for someone with normal hearing. Now so we call that Renee positive result. K? If you get conductive hearing loss, bone conduction is louder than air conduction. So number 2 is greater than or louder than number 1. So we call that running negative testing. Now the only scenario where the test result we just saw could be an abnormal situation is when the person has has sensory neural hearing loss. K? So the person can still have sensory neural hearing loss, then they have Renee positive test, meaning air conduction is greater than bone conduction. K? So they may have sensory neural hearing loss. You can't really pick that up with relay test. Right? Because it's just testing air conduction versus bone conduction. So it just picks up conductive hearing loss for you. So, again, that's tuning fork So I did bring some tuning fork test or tuning forks, and some otoscopes here. There's 3 otoscopes with different different earpieces. So you're welcome to try it during the next break, and I'll help you with both if needed. Just again, when you use the tip, I'll give you another bag to put it in so you don't, you know, contaminate, but don't throw don't throw them out. But we can try it on each other. You can practice on each other. Okay. So we'll do imaging, CT scan, and MRIs, and then we'll take another break, and then finish up the last little bit. So we're gonna cover CT scans and MRIs briefly. And this is just another way to understand the the anatomy, three-dimensional structure of the ear, mainly. K? Obviously, you're not radiologists, so I'm not gonna ask you stuff about CT scans or MRI and the exam, but it's just another way for you to understand the anatomy and some abnormalities. CT scan may be the only way to pick up certain hearing disorders, for instance. So, again, this is why we have to know a little bit about imaging. So CT scan, some people call it CAT scan. Right? But there's no real a or cats involved. It's CT stands for computed tomography, and CT is good for bony anatomy. Okay? So if you break a bone, they're gonna do x-ray blood. They'll usually do a CT scan. MRI is good for soft tissue anatomy. So if you have a stroke or if you wanna see something inside the brain, you're gonna do an MRI. So that's the major difference between CT scan and MRI, bone and soft tissue. So what are you really looking for? And on a CT scan, we discover or we describe density, like, is it hyperdense, hypodense? So dense means it's white. So white is, again, bone. Gray is sort of soft tissue, things like muscle, nerve, fluid, blood, and black is air. And you can use contrast as well. Contrast is when you inject dye into the blood screen to see where your blood vessels are going. Now when you look at a CT scan, the one we're gonna mainly focus is, the plane, that we're focused on will be the axial or transverse images. K? Meaning that you're think about somebody lying down. Let's say there's a bed here, and I'm lying down. And my feet are there, and my head is up here. Okay? So you're looking at someone from that way. So what does that mean? Well, this side is my right, and this side is left. Right? So you're looking at someone from feet down, and then you're slicing this way. So we're gonna go from top to bottom. Look at the ear structures. Okay? Okay. So we're looking at the top part here. You can see the brain. Look at this brain. Like, it's all gray. There's no gyri or anything. You can't make out any soft tissue. Right? It's just sort of one gray issue. So this is CT. But you can see the bony anatomy coming in here. You're gonna see beautiful bony anatomy. That's top of the orbit, eyeballs. That's your frontal sinus here. Sinuses usually have air vent. So we're about here. Now we're gonna be going down. K? These are just sort of pillows to stabilize your head in the scanner. Okay. So we've gone down a little bit. What do we see? Well, we see, again, eyeballs. Your your ethmoid sinuses, trichome. But we're gonna start seeing the sort of honeycomb like structures. That's your mastoid bone. K? So that's part of your temporal bone here. So that's mastoid bone, mastoid. It has some air inside, as well as here. So the first important structure you're gonna see is this. It's the superior semicircular canal. Okay? So this is a 2 dimensional image, obviously, but you have to think in 3 dimensions. Okay? So this is a superior semicircular canal, which semicircular canals are like like c shaped. Right? This is going like this. Right? So that's the top part of it. That's looking at the top part. That's why it's sliced out like that. So what is this gonna look like when we go down further? Right? So if we're looking at something like this here, the top part, and if we go down further, we're gonna see like, snake eyes. Right? Almost like 2 eyes because we're going down further. Right? So let's see what happens. There they are. Right? You see about that. So semi circle will come out like this. Top part, and you're going down, and you see the 2 separate circles. So that's superior semi circle for now. That's so that's the first thing, the superior most part of the inner ear. Next thing you're gonna see is back here. It's called the it's the posterior semicircular canal. Right? The semicircular canals, there's there are 3 of them, and they're orthogonal to each other. Other. Right? They're 90 degrees to each other. Right? So superior one here, posterior one is like this. Okay? So let's go down further and find it. And there it is here. It's a little bit more of a slit here. That's all it is. So again, superior canal, posterior canal. And then the next one is gonna be lateral canal, it's gonna be like this. And they're all sort of 90 degrees to each other, which is shown here. Right? Now it's flat. Now it's flat. You're looking at it on this way, not from this way. So that's the lateral semicircular canal here. This little structure behind the lateral semicircular canal is the vestibular aqueduct. That's part of your inner ear. K? K. There's a condition called enlarged vestibular aqueduct that causes hearing loss, which we'll cover later on. But again, this is the importance of knowing CT scan for people who make the diagnosis. Right? That's the only way we can diagnose that condition, for instance. Other thing to note here is this structure here. That's a, remember, whitest bone, which there's an opening in the bone in the skull base here, which is not this yellow. So that's the that's the opening in the bone where cranial nerve number 7 and 8 run from the brain stem. K? It's so the cranial nerve, facial nerve, and the cochlear vestibular nerve are running side by side in here and innervating the air and coming out, innervating the face. So that area is called the internal auditory canal or the IAC. Not the external auditory canal. Right? That's the ear canal, but the IAC is the internal auditory canal. And there's a tumor that can occur there that's relatively common in in the elderly. That's showing you the course of the facial nerve. So it comes out from the brainstem. It sort of makes this weird term for the 1st Janu or the 1st knee bend, and then it comes out underneath, the stapes footplate, and goes into the mastoid bone, and then comes up through the face, and interates our face. But that's the facial part. Now if you go down further, you start seeing the structure here green. These are the ossicles. And you start seeing the cochlea. Right? So you see how low the cochlea is compared to the semicircular canals and other interior structures. Right? So it's actually located very anterior and low. So if you get a sort of a comparative picture with model anatomic model and a bone real bone drilled out. This is all showing you the same thing. So here are the your, semicircular canals drilled out in the cadaver. Right? There's a lateral one there. Here's the cochlea drilled out, basal term, apical tendering. Here's the facial nerve. Remember, it's going like this, and then it comes out. That's the first name. And then these are the ossicles. That's what this is sort of showing you the same thing. Same here. Marrow canal, facial nerve, ossicles coming in. Right? So look at all the important structures in that tiny little area. Right? So let's say you have something let's say you have an infection there or a tumor, or you can have vertigo, you can have hearing loss, you can have conductive hearing loss, you can have ruptured eardrum, you can have facial nerve weakness. Right? So that's a very sort of, an important area in the ear and the temporal bone where things go wrong, all of those structures can cause bad effects. So we're gonna blow up that part, to show you the ossicles. And ossicles actually they kinda look like ice cream cones. Right? Right? So the cone part is the body of the incus, and the ice cream part is the head of the malleus. They're connected there. Yeah. It looks like an ice cream cone. Right? But that's why that's the way that's the, way the ossicles appear on that side. And the facial nerve is running right there. That's what the yellow is showing. And the cochlea, again, remember it's, there's a basal term and apical turn. It's almost like stacked points on top of each other like here. Right? And you're cutting through on different planes. That's why you see the basal turn and the apical turn here. But that's the cochlea coming in. So that's the bottom turn and the apron turn. And then if you go down further, you can see that the split is here, ausal turn and the apron turn. If you go down further, you're gonna start seeing the eustachian tube opening there. Now this picture is showing you the very tortuous course of the ear canal. Right? Look at the ear canal. If you shine your light in like this, you're gonna see not the eardrum, which is way down here. Right? So that's why you need to straighten out the ear canal, and that's the back of the antenna. So that's a normal CT scan of the temporal. Abnormal CT scan, look at this normal side, it's not it's an older scan, not the best quality, but you can see the cochlea coming here, basal turn, apical turn. But this here, on this right side, it's all bone. So there's a condition called Michelle aplasia that you're born with that you don't have a cochlear. So obviously, this person cannot hear at all. It's not like we can do cochlear implant to improve that because there is no cochlear. And the only way to know is to do imaging CT scan. This is another condition down here called Mondini Malformation, which we'll cover later on, one of the inner ear malformations. You can see it's supposed to have a nice partition. You can see again there's a basal turn, apical turn by separated by thin white line bone, but but they're all sort of it's like a big blob here. So, again, these are some of the conditions where we have to do CT scan to diagnose. Okay. So let's take another 10 minute break. 422, come back at 4:32, and then, we'll finish. So? Hold on. Sorry.