 Last but not least is Jonathan Scoville. He's a neurosurgery resident that will be presenting on Dwayne syndrome. So we've already kind of had a preface for that with Dr. Byrds, and so we'll go a little bit further into that. Please just be aware that next week, we have our UBitis presentation by Dr. Big Halling. Yeah, so this actually works out because this is a great segue into a later talk. So we're going to kind of go on the other end of the spectrum from a patient who presented with a six-nerve palsy that had DIPG to the other end, which I think is kind of interesting that we're going to have these back to back. OK, so interestingly, another six-year-old female who presented to Dr. Katz's clinic last Monday, she had no significant past medical history, but her mother was concerned. She was actually concerned because she thought her right eye turned in and was kind of a lazy eye and that she could do it at will, but then sometimes it would just do it on its own. And then the patient herself complained of some double vision with leftward gaze. On examination, her ocular examination was unremarkable. Visual acuity was 20-20 in both eyes. The only thing that was abnormal was that in her left eye, she was unable to abduct. And then she had narrowing of the palpipal frissure with adduction, but no up-shooter, down-shoot, and then some contraction, I guess, of the globe. And her up gaze and down gaze were normal. And then as I said before, she did have some diplopia with leftward gaze. So here are some images of the patients. You can see on the far left, that's her leftward gaze, and that left eye is unable to abduct really at all. So when thinking of when you see a patient with horizontal gaze, abnormality, especially in the pediatric population, I think that the differential diagnosis was include Dwayne syndrome. You could also think of a cranial nerve 6-policy, which the case of the other patient had. And that's commonly seen in hydrocephalus, which is common in the pediatric population, due to the unbraced nature of the sixth nerve as it transverses to the cavernous sinus. The pressure affects that significantly. And then also other neurosurgical pathologies like a DIPG or other tumors. You can think of Brown syndrome as well. However, that's more seen in vertical gaze. And then you could also have a simple esotropia or exotropia of infancy. So this patient did indeed have Dwayne syndrome. And we'll talk about some of the Dwayne syndrome as a clinical diagnosis. We'll talk about some of the characteristics in a minute. But it's named for Alexander Dwayne, who is an American ophthalmologist who practiced in the early 1900s on the east coast and studied extracular movements of the eye. And actually wrote a book on it from which Dwayne's retraction syndrome, as it was originally called, was named for. It's a congenital limitation of abduction or adduction of the eyes due to mouth development of the motor nucleus or motor fibers of the sixth nerve. And in many cases, it's an absence of the motor nucleus of the sixth nerve. And it can be unilateral or bilateral. It's also characterized by co-contraction of the medial rectus and lateral rectus muscles as the third nerve will inervate the inferior portion of the lateral rectus muscle. And so when they adduct their eye, we'll actually pull both muscles and contract the globe and then narrow that to help people fissure as well. And then amblyopia is present about 10 cases of Dwayne syndrome. So the minority, but it should be noted that they have a higher than normal percentage of or risk of developing amblyopia and should be followed. So here is a pathology slide from the patient. You can see all the premium nerves are marked out. But sixth is the sixth premium nerve is completely absent. So it's broken down into three types. And although the pathophysiology is the same for all three types, it's more of a clinical distinction. So type one is the most common type. It's characterized by abduction abnormalities, which is absent or limited. And then can have normal to limited adduction, but more classically abduction of vulnerable thighs. Can have up-shooting and down-shooting of the affected globe on adduction and then esotropia in primary gaze is common, but not always present. Type two is the least common. It's characterized by adduction of the affected globe with norm with limited adduction as well. Can be bilateral or unilateral again with up-shooting, down-shooting of the affected globe on adduction and exotropia in primary gaze. And then type three is the second most common type. And it's abduction or adduction of vulnerable thighs, up-shoots and down-shoots are against seen. But these are more common in type three than the other types. And then you can have esotropia or exotropia in primary gaze. So the pathophysiology, most cases are sporadic. So there's mutation of a gene that is unknown, as you add to that causes disinnovation of the sixth nerve on vulnerable sides. However, it has been found to be associated with this DURS-2 locus on chromosome two. And they are more commonly seen in type one or three. It is also associated with Ocahiro syndrome, which is also called Dwayne radial ray syndrome, which is characterized by Dwayne syndrome and the dysplasia of the radial bone, artery, and thumb. So you have the thenar eminence is this plastic. And then it's associated with this mutation of SAL4, which is the zinc finger transcription vector. It's also associated with Goldenhar syndrome, which is also called ocular acoustic vertebral syndrome, characterized by craniofacial ocular cardiac vertebral and central nervous defects. So it's consistent with maldevelopment of the first and second brachial arches, which is usually associated with cranial nerve five and seven. However, that great slide that was presented showed that house seven kind of loops around sixth. And so you can have disinnovation syndrome of the sixth nerve as well. So on the left, this is a patient with Ocahiro syndrome. You can see the dysplastic thenar evidence on the left and then also the inability to abduct the right eye on rightward gaze in the patient. And then on the left is a patient with Goldenhar syndrome. And you can see the dysplastic of the right side of her face with the ear and jaw being misformed. This is actually a milder case of Goldenhar syndrome. So the treatment, once the clinical diagnosis of the joint syndrome is made, and most cases can be managed with observation, especially if they have minimal isoerexotropia. And if they do have ambiopia, you can occlude the better-seeing eye to try and prevent loss of vision in the affected eye. And then you can also, for extreme forms of isotropia, isotropia prisms or a corrective surgery can be used to improve compulsory head posture, which can cause pain in cervical algea, and to improve alignment in primary position or to improve up-shooter downshoots. So in conclusion, this is a clinical diagnosis. Should not be confused with cranial nerve 6 palsy. If there are other worsening symptoms or signs of ischemia or progressive symptoms, then obviously more serious pathology should be expected. And further evaluation should be done to provide a good diagnosis. Most patients still have a good alignment and can be managed expectantly. And like I said about ambiopia, they have a higher risk for this, and so should be monitored throughout childhood. And surgery can be used in extreme cases. Thank you very much. I'd like to thank Dr. Katz and the Neurophthalmology Department for allowing me to follow them around and teaching me how to use a slip of the land this month. So thank you very much.