 So I guess I'll start talking about Griffin, even though I think he's tanking up on breakfast over there. You want to make sure he has the fuel to continue and give us his really important talk, which is anomalous head positions, force nerve palsies, and the three-step Bill Kowski test. I just want to thank Dr. Jardine for volunteering to take on many positions, being responsible for our wellness and being our assistant program director. I don't know if any of you know this, but he got tapped to be the assistant program director even before he arrived in Utah. So thank you. All right. Before I begin, I just want to say how actually how grateful I am to be here. I, in medical school, was a, I've told the story a couple of times, but I was kind of a wandering through your student, not having picked a career. And Jeff Petty pulled me inside and said, you should look at ophthalmology. And that's essentially what led me to choose to feel that I did. And my dream job was to come back here. So I really couldn't be more grateful to be here. Felt so supported and just loved the collaborative collegial environment of the Moran. So I'm sure you were all just dying to get here when you saw the topics. It's business today. It's arguably the sexiest stuff in ophthalmology, right? So the, hopefully, though, this talk is really targeted towards just the fundamentals of the three-step test, fourth nerve call season, and, you know, approaching the pediatric eye exam. So I may not get into a lot of the nuances, but I hope this, at the very least, will be helpful to residents for OCAS and give everybody just a really basic and appropriate knowledge of when these tests are appropriate and how to evaluate these children. I've no financial disclosures. A lot of these pictures were taken from my fellowship in Indiana. So I just want to acknowledge that. So as you can see, just like the boring title stated, we're going to go through novel side positions, three-step test, and then talk about the general versus acquired causes of the fourth nerve policies with some surgical considerations. So the case that I saw about midway through my fellowship, which I thought was quite interesting, is a five-year-old boy who came in with a diagnosis of torticollis and was scheduled by orthopedics for a sternoclindomastoid release because of the torticollis. The insurance delayed or rejected the, you know, didn't get pre-approved essentially. And so the family came to see us in the interim. And this is actually my son. This is an actor, not the actual patient. We came in with this big head tilt. We're kind of a Weasley family. So the patient comes in with this head tilt and he was a lot younger, a lot less cooperative than my 70-year-old son. But the, as he came in, it was really a tough exam to really figure out what was driving his head tilt. But in moving his neck and the neck was really mobile. I feel like there's any really tightness in the neck muscles. So we did one of my favorite strobe business or anomalous head position tests. And that is the patch test. So I got this kid's mom to put a patch over one eye and the head straight right out. So we're gonna come back and try to explain why that happens in these ophthalmologic driven anomalous head positions. But and forgive me, I hope this isn't inappropriate to be interactive in grand rounds. I just can't talk for 20 minutes straight. I'll start boring myself. So can I ask what is the differential for anomalous head positions that we see that ophthalmology causes? Classic way to catch the little, grab the little hanging fruit. Fourth nerve palsies. What else? Oh, nice. Yeah. Anything else? Nice daggers? Great one. Yeah, the no point in my staggers. Exactly. Anything else come to mind? Yeah, doing yes. So yeah, I'll form the strobe business like doings and more some of the more. So six nerve palsies we often see a head a head turn away from the the eye that can't add depth. The last time to no point. Do you think in strobe business causes of anomalous head positions is more common with combatant or incompetent strobe business? Incompetent, definitely. I know Bob's going to talk about A and B patterns. We see it with patterns for business as well, like an easter trope of the V pattern will often put their chin down to bring the use the V pattern to their advantage to actually try to potentially obtain fusion. Tosis and interestingly, we see it even in such an incident last week, about a five month old with unilateral congenital ptosis that have a dramatic head up position just to get know that one I looked just fine, but just to get the other I engaged and have to allow fusion this child as soon as they have control of their neck muscles was putting their head up to try to get that find that head position where they can use both eyes. Interestingly, we see it sometimes with refractive errors. And then congenital ET, you know, they have the cross fixation, but these patients are at high risk of developing amblyopia. So if they develop fixation preference, though, they often have limited abduction, and you see a head turned towards that using the eye that they're preferring. So this is an interesting case. Just to point out the differential of case in Indiana, a girl who once put in glasses, the anomalous head position went away. So it's not always true business or some of these nice daggers and more common things just even a refractive error can cause a head position. What was that? No, the rest of these are actual patients. So now after your causes, we do see so a lot of the pathology is generally kind of mastoid muscle driving toward a callus. Spinal deformity, injuries, C spine fractures, you know, so you get some acquired causes of toward a cost or anomalous head positions, dystonias, your unilateral hearing loss, they'll turn their good ear towards you. And so I can be, you know, easily mistaken for, you know, an ocular driven head turn medications like phenolthiasis can induce a dystonia, moving disorders. There's a lot a large differential, but but ophthalmology causes are a common cause of these. So most patients deserve an evaluation by an ophthalmologist if they present this way. So my question to you is what drives this position? A lot of these look pretty uncomfortable. At least let's let's talk about the fourth nerve palsy. Why would you know, we see kids suppress one eye all the time, develop amblyopia. I mean, this brilliant neuro adaptation that we have to avoid Diplopia, right is our brain just suppress one eye and that we just use one eye. Why would the patients go to uncomfortable lengths to obtain fusion? Any thoughts? Simply said, perfect, actually. I would even say they strongly prefer it's a powerful drive that the brain has instinctually from, you know, time to the child's four months old that can control their neck muscles. You know, binocular fusion is far and away. Plan a suppression or squinting or all those other things are backup plans that if it's unattainable, you know, occasionally, you will see patients who can't get fusion will maximally displaced images to what the head had her, but more commonly they'll suppress one eye. I like this quote from Bill Chowsky, the patient chooses the least inconvenient position of the head by which the peretic muscle sufficiently relieved so that binocular single vision can be obtained. So we'll we'll talk about that. And going back to that original case that I was with a patch test, when you break fusion, that drive is no longer there because there's only they're now monocular. So the patch test is a great way to test if it's an ophthalmology cause for the anomalous head position, because all of a sudden they have one eye and they'll just straighten right up or give her that turn. So long as it's not the nice average no point that obviously is by an ocular or monocular. Do you assume in some cases it matters which eye you're catching? Yeah, if there is an ability, a lot of these cases that have the anomalous head position, they've been able to avoid amblyopia. So so it's a great point, like in a six nerve palsy, if you know, the right eye can't abduct, you'll get rid of that head turn way covering that eye up, but maybe not by covering the other eye, they'll still have that decreased abduction. So the three step Park Spilchowsky test, I didn't fully understand this until probably at least at least fellowship, when it's appropriate. So could any guesses? When is this test used? I'm just saying, what was that? Yep. Yeah, I would even say only vertical misalignments. And only in only in cases of isolated, but my husband, Bob's excited, you can barely hold my hands. Yeah. So it's isolated vertical peretic muscles. So one muscle is out. And that's it. If there's multiple muscles that are not working, or if they're postop or restrictive, it doesn't apply. So it's a pretty narrow patient population that you can apply this test to. So step is step 123. Step first step, which eye is is higher in primary gaze? Is it worse than left to right gaze, worse than left to right head tilt? So I want to talk just for a second about motility exam. So I feel like I feel like a lot of us memorize this pattern. And we probably everyone here probably understands it pretty, pretty well. But I find it extraordinarily helpful to overlay the anatomy and just think about how these muscles work in abduction versus adduction. We spent a lot of time and for OCAPs memorizing the primary, secondary, tertiary actions of the extractive muscles. But I find that actually almost just not unhelpful memorization. If you just look at the anatomy, when the eye is abducting, so the eyes looking out here, all of a sudden the vertical muscles are in alignment to just they're isolated in elevating or you know, in abducting the eye. So in abduction, you are essentially isolating the vertical muscles in their, or the suit, the rectus muscles. And I remember Dr. Christensen, a piece of my residency in Oregon, used to say, the motility exam is designated to get the muscles in the field of gaze where they sing their solo. And I thought that was just really catch you if you remember this. So in an abduction in elevation, the right superior rectus is really doing almost all the elevation by itself. Contrarily, when the eye is adducting, all of a sudden you see now if this eye is turning in towards the nose, this muscle is now the rectus is becoming more of a encyclotortor than an elevator and the superior oblique is now in position to move the eye. Now, since it's a oblique angle, it actually moves the eye down and the inferior oblique moves it up. So it's that that always to me is just really helpful and understanding motility. So we used to call these the dreaded nine pictures for OCAPs. We have to figure out what's going on here. So walking through this three step Otowski test, again, I often thought as a resident, you had to have a prison bar to sort this out. But that's not true because it's often evident just by looking at the motility. So any guesses which eye is up here, it's pretty subtle. The other guess, left, really hard to tell, but it is left. Now that one, you would be able to much more easily decipher with the alternate cover test. So so you've got a left hypertropia. That's step one. Is it worse than right or left gaze? Yeah, you see how much higher that eye is in that eye was over here. That looks pretty ortho. So let me walk you. So I'm going to walk you as one by one. So if the left eye is up, which muscles in the left eye are potentially not working? Now, we're thinking peretic muscles, right? Not restrictive. So would the peretic muscles be the elevators or the infraductors? If the left is up, it's the it's the it's the downplaying muscles that are that are one of the two are not working. You always have to remember that it could be that this could this patient could be having a right hypo, in which case the elevators aren't working. So that's step one, you've isolated. Now, you've cut you've cut down the muscles in half. We decided that it was worse than right gaze. So now now you know some muscles involved in right gaze. So you've limited now to two muscles and shorting out which which one is peretic. And then you can see that this much worse and left head tilt. So conveniently, when you when you diagram this out, you just circle the muscles in the same alignment as the head tilt. So if it's if it's worse than left head tilt, then you circle the muscles in kind of a tilt to the left. Yeah, and I often thought that third step always is throw me off as a resident. And then and also why it worsens so much in head tilt. Let me read this quote. So preferably, one should remember that there is a head position in which the peretic muscle receives a minimum of impulses to contract. This is the position in which a patient with a paralyzed muscle habitually holds the head. So, so again, thinking about the superior bleak, it's, it's a big intorter. So our eyes are incredible to maintain our horizon when we tilt left or right. I mean, they're they're really almost like those toys where the eyes stay still regardless of how you move the move the dollar the toy. And what we want to what the patient is trying to do is they're trying to find the position where they're minimally using a superior bleak. So in left head tilt, this patient has a left superior bleak palsy. And left head tilt that left eye is trying to in tort and the right eye x cycle tort. And in cycle torsion involves, obviously, the majority of which is the superior bleak. Does anybody remember what other muscle is responsible for in torsion? Synrad? Superior rectus. Yeah, perfect. So you think about this. So the superior rectus has in torsion is one of its secondary function and then the superior bleak. But if the superior bleak is firing is not firing or at least in balance and compared to superior rectus, what's going to happen to that eyes that tries to in tort. It's going to it's going to get pulled up because the superior bleak, when it's functioning kind of keeps it from pulling up and just they both in tort together, but you tilt the head the wrong way and then also in this in balance cause that superior rectus to pull that I out. So as you see this so conveniently, when you circle, when this patient is turned to the left, you circle the two superior muscles, both involved in in torsion. Now the three step test. Now, if you think about an isolated vertical peretic muscle, the superior rectus inferior bleak and inferior rectus are all innervated by the third nerve. So they they're just not commonly, um, peretic in isolation. So this test is far and away most useful with the superior bleak palsy. We actually do see it. We do see isolated peretic muscles of those three. But as you can imagine from kind of a neuro anatomical basis, it's less common. So so the the acronym for memorizing the three step test for fourth nurse is SOS. If it's a right superior bleak palsy, you get a right hyper worse than left gaze and a right head tilt. So same opposite same. So just just to do some quick practices to put this into practice. If you had to guess if you knew this was a fourth nerve palsy, which which side is the palsy on? Right? Yeah. So so they come in. So they come in with a compensatory head position. So they have a left tilt because this would be worse in right head tilt. And it's same opposite same that third step. So we this is so whenever I see a child with a knowledge head position, the first thing I do you're limited in how much the kid is going to participate in the exam. So almost always that a knowledge head position I try to get their head and I try to move them whatever head position they're avoiding. Because you almost always will see ice play or you'll you'll see my staggers come out. So you grab this child you turn the head the other way and they get this huge deviation. So it's a right superior bleak palsy with a compensatory left head tilt. So where would this one be? Left and a side. What was that two rudimentary left? So it would be worse and right or left gaze. So yep, it's ours. And that left eye is trying to x cycle. So here that left eye is palsy. But in right head tilt, remember that left eye is now is being x cycle toward it. And that's the opposite function of the superior bleak. So that superior bleak is maximally relaxed in that tilt that's allowing for fusion. Do you guys see which one it is here? Which which side the palsy's on? Right? Yeah. So so part of the stock is hoping to and make everybody feel a little bit more able to identify for their policies without a prison bar not feeling like they have to have all the tools that we are using regularly in the pizza clinic. This is subtle. Can you tell which which way this man is tilting his head? It's a real subtle right tilt. So it's going to be worse and right or left gaze. So we assume it's a if it's a right tilt, what's what size the palsy on left. So it'd be worse than right gaze. Now you can see that inferior bleak overaction coming up as he looks up as he looks off to the right. So again, what do you think what gave what's worse than left to right gaze? What would you guess? So what head tilt is he going to be worse at? So so this is the compensatory head position. That's that that's what always threw me off, right? So you gotta make sure that you're not when you think about same opposite same, it's it's where the deviation is worse for the three step test. So it's a left head tilt, it's a compensatory head tilt, be worse than right tilt and left gaze. There is a left gaze again, not not over the obvious. But you look at the bottom of the limbus of the right eye versus the inferior border of the limbus of the left eye, you can tell that is actually higher. So just another kind of interesting trend, an interesting point about Forthner palsy says the majorities are congenital. Interestingly, a lot of people will have it come out later in life as their ability to fuse the eyes decreases or breaks. So can you tell which way this gentleman is tilting his head? Left. Interestingly, just by looking at him, you can you can tell if this is congenital or acquired. The way you tell is a congenital Forthner palsy actually will develop midface hypoplasia on the side that they're tilting. The way that you diagnose that is you draw a line from their kind of from there through their eyes, and then through either edge of their mouth, and you'll see that these are not parallel. You actually is developed from a chronic left head tilt, a unilateral midface hypoplasia. So it was one of the reasons that we try to fix these early is it actually does affect the way that your, your facial anatomy develops. So we tilt so again, you see a left head tilt, you just tilt them the other way. And then that there that hyper deviation comes out in a really big inferior leak overaction. Here again, you can see right head tilt. Now can you appreciate the midface hypoplasia there? The distance from the corner of his mouth to the lateral campus is shorter on this side than it is on that side. You draw the lines and you can see just just subtle. So this is a case from a textbook in 1967. This is a lifelong head tilt that drove that caused that amount of midface hypoplasia and deviation from Von Norton's text in 1967. I thought that was just a really striking picture. So I don't know if you can see these numbers. Can you see these numbers at all here is too small? That's probably too small. So this is a case that I saw just a week ago. I just want to try this is a three step test that a patient that seemed a little unusual because they had superior leak overaction in the left eye. So there's a right hyper in primary gaze. So what muscles should we circle for the step one? Let's start with the right eye. What what muscle if it's a right hyper what muscles on the right do we think are not working? Perfect and then the left eye the opposite, right? So step two is it worse in right or left gaze? Well, in right gaze, there's a right intermittent hyper of 14 and then ortho and left gaze. So what muscles are going to circle for the step two? On the right eye, right superior rectus and right inferior rectus and the left eye. Left inferior left superior. Yep, perfect. And then if you look away over here, the comparison is but it's worse in right head tilt. As good a left head tilt. So I dropped to the right. So this patient actually had an isolated left inferior leak palsy. Which is you think it'd be extraordinarily well, extraordinarily rare again based on that kind of neuro anatomical basis but the it turns out you actually do see a fair amount of these, you know, in the literature. And so this patient had not had surgery, had not had any trauma in this, in which case this test was appropriate. So just review isolated credit muscles only doesn't work in postoper restrictive cases. So you yeah, this is a bad question, but you of course never use this in a six nerve palsy. It's not it's not vertical. And you wouldn't use it in a thyroid eye disease patient or myosinia patient because it's not an isolated parotid muscle. We see we see bilateral cases where they they sometimes will have a hyper but then you'll see alternating if you leak over actually look left to right and they'll have a lot of xyplotorchic and large v pattern. So not to be missed. So just wrapping up here, let me go through a couple of things to distinguish congenital from acquired. The in congenital fourth nerve palsy, which again, are even in adults that will present with the fourth nerve palsy, you can pick out some of these features that suggested it was a congenital palsy that decompensated with just with time. You'll see that facial asymmetry like we talked about in this patient. They have much larger vertical fusional amplitudes. So you'll see as you as you break them down, like that one patient had a vertical intermittent hyper of 10, you know, patients without this would never be able to fuse a hyper deviation of 10 prison doctors, with exception to these cases. congenital cases have less xyplotorchic and more vertical, whereas acquired are just the opposite. And a big where I trained any other really big advocates of traction testing to distinguish these. So let me let me kind of start lasting the photo album, tomography scan, you go back to pictures of where their child that you'll see a head till in congenital cases. So so go through just surgical decision making. There's a lot of different schools of thought about how to approach this. Where I was trained a big probably the most prominent way to kind of think about these was traction testing in the OR. And what that was is that it came from the theory that congenital superior belief policy actually may be less neurologic and maybe more anatomic in that when you compare the superior belief tendon and traction testing, you'll find that these patients with the policy will have a very asymmetric laxity. And the tendon will feel like you can just tell that it's almost too long, and thus enabling the muscle to kind of optimally work. So before we do every case, we do traction testing and compare between the two eyes. And often that would drive treatment. If you felt an asymmetry in that laxity, you would tuck one of the eyes to match the superior belief laxity to the other eye. And interestingly, we would see a handful of cases where there would be bilateral laxity, in which case, you would just go after the inferior oblique, but warn the family that this your child probably has a bilateral superior oblique palsy, even though they're it's a little asymmetric is why they're still a head tilt. You would you would do the inferior oblique might be your recession on one side and then a year later, you come out and they have a head tilt the other direction. And so you have to go after the other the other inferior oblique. Another way to approach it is you can think about how large the prism that deviation is. So if it's if it's less than 15, you could probably get away doing one muscle and then you just based on their if your leak is overacting you address that if the there's restriction superior rectus on the same side, or you can always recessed it, recessed the yolk muscle on the other eye. Here's the inferior oblique and then here's the superior oblique. Large deviations you often need to do more than one muscle. And then the other way to think about this is just identify which gaze it's a problem. So I know it's kind of a busy slide. Let me just jump to a picture. So here's a patient. Can you tell which I if you had to guess which which is the superior oblique palsy and in this patient, I can contain myself. That was so enthusiastic. So the. So left hyper worse than right gaze and left head tilt. So here if you're thinking about surgery, if you when you when you see this, that's that's a good sign that it's not working the end. You could go after the left eyes inferior obliques. You can clearly see it's overacting. But then if they look down into the right, you often see you also see there's a lot of superior bleak underaction. So again, as you're watching this patient move their eyes, you find out what do you think is more useful the down and right or up and right down right. So this would argue me on this patient, they actually doing during this again, kind of overlaying the majority exam here, you can see that this patient has an underacting left superior bleak. And we also left inferior bleak overaction. This patient had superior bleak laxity in that left eye and was tucked. So the inferior bleak is now a little bit underacting. But you can see that with that tucked superior bleak, you really improved that down to the right gaze. So my references. Thank you. Any questions before I turn the time over to Bob? It's a great, it's a great question. You'll see it still work in patients who have fourth nerve policies that don't really come out into their 80s. So what happens though with the fourth nerve policies, you get a spread of competence. So although you'll see a much more dramatic hyper in, you know, like a left superior bleak policy will look much worse than right gaze. Over time, for reasons that aren't totally clear, your, your, your brain or your eyes will spread that competence and make it less of an incombinant deviation. And it can be much harder to tell over time as well. If you've had a chronic left hypertropia, your superior erectus on that same eye can get tight, because it's just been shortened. And so when you start throwing those things in there, if you've got a tight superior erectus or a spread of competence, it's no longer an isolated peretic muscle. But so to your point, it does longer you wait, maybe the less valid it can be, but we do see it working at all ages quite, quite effectively if, if it's used the right, right patient. Any other questions? All right, thanks.