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OK. So, hello everyone. Welcome to New Anatomy Collaborative. My name is my, I'm the chair of the Collaborative this year. I'm delighted to present our 14 part series this year starting with our first talk today and section one talk, one of our series. And I will now hand over to Paul who will provide just a brief overview of our talks and also who introduce our first speaker. Right? Hi. Uh uh too. This year, we decided to structure our talk starting uh first I spine and brains then and the talks with that and we decided to have Oscar um Mr M join us to present this first one on spinal anatomy. He correct me if I'm wrong, but he's a phd student at Kings. He, he's currently in his training in the London Deanery for neurosurgery. And research interests include, I interest include, oh yeah, see I and integrating imaging techniques, surgical work like to improve tissue differentiation and I'll hand it over to him. Just the great. Uh Thank you very much. First of all, can everyone see there's a presentation on your screen? Yep. Great. Excellent. That's a good start. So, er thank you. For the kind introduction. I said brand name Oscar um Neurosurgery Registrar, I'm ST four. but I'm on and out of program for research doing a phd at Kings. Um, as you rightly said in, er, interoperative imaging, er, to help surgeons differentiate more clearly between tumor and healthy brain tissue and also to look at real time, er, brain oxygenation information to help prevent surgical complications. Um So that's the side, let's get straight into it. We're going to go into spinal anatomy today, er, for all of those that didn't hear at the beginning, I do apologize. I'm not on webcam, but that's probably better for you guys to be honest. Um the area that is just broken. Um So learning objectives today. Um we're gonna do a broad overview and we've got less than an hour. So this is not gonna be super detailed. There's a lot to cover um anatomy of the vertebral column. Um We're gonna look into how to lumbar puncture and we're gonna have a quick look at the autonomic nervous system. Uh There's not a, again a huge amount of time to go into this um anatomy of the chord. Look at some of the tracks which I know is a particularly er in theory complex thing which is to get your head around. Um So we're going to try and simplify that as much as we can. Sorry to interrupt my name's Jing Jing. I'm from the med, a team your slides aren't moving for us. Yeah, I think you need to share slides, not window. Ok, fine. So let's have a look. Mm. Um Sure. Sharing touch screen maybe let's try that. Yeah, I think and then if I go to sorry about this. Um how about now? Can you see? Yep, we can see. Yeah, thank you. Does it move? Yup. It does. Excellent, good. All right, fine. Um So then we're gonna apply this to you some clinical scenarios if we have time to do that. Um So without further ado it is probably worthwhile just familiarizing ourselves with the bony structure of the vertebral column. Um It will help us overall in the anatomy, particularly when looking at er, lumbar punctures where we want to go, et cetera. Um So let's start this off as nice and easy. Um Can anyone er, in the, I don't like the sound of my own voice particularly much. So I try and make this relatively interactive, er, can anyone, er, shout out some names, er, of parts of the vertebral of the vertebral that they're aware of? Yes. Right pointer. Anyone. The yeah, virtual body. Excellent. So vertebra body is here. Very good. That's the first one anyone else. So we've got from the chart, gray and white matter, body, pedicle and OK, good. So gray and white matter remember is the cord. So we're talking about the bones here, the actual vertebra itself. Um So the cord will lie elsewhere and but you are right gram white matter of the cord, um some other bits as well to talk about a transverse process pedicle as we've got outlined here by this red line. So someone's had that it's very good inferior facet. So this is the joining part of the vertebra. Remember they're all connected uh spinus process lamina as we've got here, superior facet. Again, the other joining part, the articulation between the, the vertebra above and below is the superior and inferior facet. Um And of course, the spinal canal I've also added on something here. Can anyone say what this might be? These structures always tend to be represented as bluey whitish in textbooks. So I've tried to follow the same thing. So this is one of the ligaments. Er So it's the posterior longitudinal ligament um and the anterior longitudinal ligament which travel all the way up and down the spinal spinal column. Er These are important as we will come into a little bit later on in this talk if we've got time. So it's important as well to distinguish between different bones of the vertebral column. So remember that we have cervical bones, we have uh thoracic vertebra and we have um a lumbar vertebra as well. The sacrum is separate and fused. Uh but these are the three main bones, er main vertebra er that you will come across and it's not uncommon in exams including in the MRC S. Um to be asked to differentiate between, uh, between the two, between the three. Sorry. So, er, first of all, what is, there are obviously exceptions, which we'll go into in a second. But, um, what is, er, this likely to be Lumbar Thoracic or Cervical? I can't see the chat as well. So, if anyone's typing and if someone could chat out, that'd be great. Uh, Thoracic. Ok. So we've got a vote for Thoracic, so not thoracic and I'll explain why in a second. Um someone said lumber. Ok, good. So, er this is indeed a lumbar vertebra. I hope you can all still see my laser pointer. Um but this is a lumbar vertebra because it has a really, really chunky vertebral body. OK. Very, very strong, very thick, um thick pedicles as well. Um and relatively narrow vertebral foramen. If you think about why that is, it's at the bottom of your spine, this has to carry a huge amount of load through it compared to bones higher up. Uh hence having the thick pedicles and thick vertebral body. And in terms of nerves as they're coming away from the spinal cord and spinal column, um it has far fewer at this point because all of the cervical nerves have come off at their respective levels, er, as have the thoracic. Er, and so we have far fewer needed in this canal. So big thick vertebral body, um narrower canal, chunky pedicles again to take that axial load. Ok. So this one and there are characteristic features of this one that really give it away. This should be the easiest one to identify any classic. That's good. That's a thoracic verte, right? Um So, er, does anyone know what the sort of giveaway features are on this? I will point to them in a second. It's supposed to be like a long spinus process. Uh So the, you, you are, right, you do have relatively long spinous process. But the actual, the key giveaway that this is a thoracic vertebra is we've got our facet joints here. But if you look here and here, there is an additional joint, what joints, the thoracic vertebrae that doesn't happen in any of the other vertebra, the reps. Exactly. So these are the joints for the ribs. So if you see these, you've got long transverse process joint for the rib joint for the rib, er, costotransverse joint, costovertebral joint, er, and that's where they happen here. So if you see this, um this is always going to be a er thoracic vertebra, other features, they say heart shaped vertebral body, smaller than that of the lumbar wider canal because we've got more um sort of nerve roots within the cord. Um So, nev within the cord coming off here um and er sort of m smaller overall structure because less actual load required. And then finally, this is obviously, I'm not gonna get anyone to say it, this is a cervical vertebra. Um so slightly different structure overall, again, small vertebral body because not a lot of axial load coming through. Um and we have some er typical features here. This is not always the case, but the spinal process tends to be bifid. So if you see a bifid spinus process, er that is a good indicator that er this is a cervical vertebra really wide vertebral foramen because hardly any of those nerves have come off of the cord yet. And then we have some additional features. So does anyone know what this is here? What we call this, the the superior articular a it is not the severe articular f it would sit above that. So I will give you that. But the sort of overall chunky um wide structure is what's called the lateral mass. So we've got very narrow pedicles here where my laser pointer is but actually very thick chunky lateral masses. And so when we're doing spinal fixations, for example, the pedicles are what we go for in the lumbar. Um and the thoracic vertebra and you can put screws into these nicely into the vertebral body. We actually go through aim for the lateral masses here um because they're sort of much chunkier than these sort of weedy pedicles and allows good strong fixation. Um So lateral masses is one. And then what about these here? Mhm. Trans Yeah, exactly. So the trans Fermin transmits what vertebral arteries, the arteries. Yes, correct. Yeah. So the vertebral arteries travel through these, so key features. If you see this, there are lots of identifying features for a cervical vertebrae. You shouldn't get too confused with this, if asked to differentiate between them. Um, what level does the vertebral artery enter? Just bonus points for anyone? I mean, there are no prizes but you can keep score yourself. C six, C six. Exactly. Right. Good. Um, and fine. So obviously we have some special er things. I would try and do my own pictures, but there's not any point. Um some other people have done it much better. So we obviously have C one and C two. C two is er the sort of dens as well. It was referred to as the Odonto of the peg um has er different components to it. So vertical body articulating point with the um er with C one er and obviously er posterior facet as well. Er And this is where the um transverse band would sit as you'll see er on this in a second. Um So this is to allow er it to slot nicely into er C one and allows movements such as rotation, nodding the head, et cetera, increased flexion extension. Um uh And this is where all of that movement comes from. So it is relatively critical in terms of overall stability. However, you can get fractures through if they're just through the base of the peg provided ligamentous structures are intact. Um spinal stability is actually often preserved and we just put them in a collar for healing purposes to allow the bone to heal. There are actually trials ongoing to see whether we even need to do that at the moment. So, um this is the axis. Um and the atlas obviously, it's called that because it carries the weight of the head. So see one here, um the C two is obviously identifiable for you because you've got the clear odontoid peg C one very, very wide um vertebral foramen. And because you've got er obviously a huge amount of cord coming through this, um nothing's come off at this point, pretty much. You have the Foramen transversarium, albeit at C one, the vertebral arteries have actually come out at this point um and are traveling over here. So they don't really carry anything. Um Anterior, we could talk about the arches. So the anterior arch of C one posterior arch here and then this is the articulating point with the occipital condyles um of the skull, the top of the peg sitting in nicely here. These are the alar ligaments which uh don't contribute hugely er to stability, but to a degree and this is the most important structure here. So if you have a significant fracture, um significant trauma here, this is a very, very strong band, it will rupture and then you have free movement of the peg which can easily slide into the canal here. Um That is obviously a huge problem. Um As if you have injury to the cord at the level of C one, you will lose things like it's not only paralysis but respiratory function. Um and it will probably be terminal for ac one injury. Um So, um yeah, very important structure to keep this in place. Um The other is this is just sort of different views, essentially the same thing. Um But yeah, so how many chord levels are there? Does anyone want to say where does the chord travel from? So if you said the spinal cord sits between C one, we've obviously already mentioned, that's where it starts and talent. Um So, C 1 to L1 2, this is where the Conus med iis sits. Um It's the corda quina nerve roots thereafter. So you have to remember this, this is not cord, this is not upper motion, urine beyond the level of L2 beneath the Conus. Uh it becomes a cord quina. Um So survival. Er so for vertebrae, we've got seven CV. So two axial that's C one and C two and five subaxial 12 thoracic five lumbar five sacral fused. Er and we also have the coccyx. Um I put fuse usually in there for the sacrum. They're not always you can have what's called lumbarized er sacrum where it does appear to be a a dispace in between and there's eight cervial 12 thoracic five sacral and obviously one coccygeal, which doesn't really count. So, just looking at, er, this picture on the right of the screen, we've got to keep in mind where, er, this often confuses people up here. It's the, the survival side of things because where does the C eight nerve root come from? And that's very simply because, er, c one comes, well, the first C, 1 to 7 come above the pedicle. Um, and so they're sort of higher than the vertebral body of their labeled um region if you like. And as you can actually see, so see one above here, see two here, C 34567. But as we transition into the thoracic spine, uh we actually get it sort of coming underneath instead. So that's why we have room for C eight and then from T one onwards, it starts to come from underneath the vertebral body underneath the pedicle at those levels. And that's the er explanation for just having that. It's just that transition point. So remember seven cervical vertebrae, but eight spinal nerves in the cervical spine. Um So just keep that in mind as I'm sure most of you already know, um we really don't have time for detail on this. Um But just remember the sympathetic and parasympathetic. So your sympathetic is thoraco lumbar, parasympathetic chain is craniosacral. Uh So, um however, that doesn't mean you can't injure the um sympathetic chain at other levels. Um as you'll see on the image on the left of the image, uh even though the nerves come off at the thoraco lumbar region, they enter the synthetic chain and enter ganglia above and below. So you can get um sort of cervical and lumbar um autonomic ganglia as well, really important to keep that in mind. Um So lumbar puncture, um I've been asked to just briefly interclude this. So we are going to just reorientate ourselves a little bit. So this is a sagittal view. So we're looking from the side through the body of the patient, we have vertebral body here. What does this represent? Just so everyone, we're all on the same page. I've not actually discussed it yet. Anyone we have intervert disc. Yeah. Good inter disc. Exactly. So the squash absorbent pads in between er, the er vertebral bodies um that are essentially shock absorbers. So that's good. Um And so talking through a lumbar puncture in principle, obviously, the layers here, we have skin, we have subcutaneous fat, we have the supraspinous ligament in er interspinous ligament here, ligamentum flavum, some bit of epidural fat, which isn't really there. Um And then some er, you know, the epid dura mater. So which levels, well, which of these structures do you think you'll feel the pop through? Obviously the skin? But you'll see that. So it doesn't count. What's the sort of haptic feedback that you're looking for? Where will you feel the pops? So you're looking at the passing through the ligamentum f, yeah. So ligamentum flavum is one. All right, I'll give you, then. How many pops do you expect to feel? It's probably an easier question and then we can talk about where? Ok. So you, you actually expect to feel three pops. Um, and when you first start doing these, you'll sort of think. Mm. I can maybe feel one as you get used to them. Er, you, you will start to differentiate so obviously through the skin that doesn't count into the subcutaneous fat doesn't count big funky, er, chunky supraspinous ligament, you'll feel a pop as you go through that. Then if you're in the right plane, sort of interspinous ligament feels kind of uh odd and crunchy, but there's not a specific pop there. So pop number one through the er supraspinous ligament crunch you through the infraspinous and then you're correct. There is another pop at the ligamentum flavum. You will feel that finally there is a small give as you go through the dura mater and then you're in the CSF space. Just remember that the er, level that you want to do this. Um So this is obviously um 5145, this is 34. I would tend to go in er L4 5 is the, the goal and the reason for that is just to be objectively as far away as you possibly can be from the Conus metal, which is obviously cord um, if you injure that, er, that's, it's not going to look great for you. Um, and the way to identify that is uh two face lines. So essentially you have the patient line in um left lateral decubitus, um, you have their knees squeezed up to their chest, their head bent to their chin, you have the spine as straight as you possibly can. So sh shoulders and hips should be in line. And if you position the patient like this, this procedure becomes infinitely easier. If you don't, it becomes almost impossible. Um So spending a bit of time getting him in the right position is really useful. Um and er, once you've done that, you feel the peak of the iliac crest, so the highest point of the iliac crest and you do a straight line down, you can often do it with one hand, straight line down from that point. And the first um space that you feel in between the spinus processes that usually represents um, er, L4 5. So that's two piers line good. Um So now we're gonna go a little bit, I'm afraid into coronectomy. Um It is slightly trickier um but not the, er, it, it's not as complex as sort of textbooks, make it actually, you can make it as complex as you like, but I'm, I'm trying to simplify it a little bit um to make this one clinically relevant. We've got some clinical scenarios at the end er, and to sort of what you need to know, um, as the bare bones is, er, clinician, obviously, um, we'll just go through, you've got some highlighted, this is taken from letters just so no one accuses me of stealing stuff. Um, but you've got some highlighted reasons here. These are gonna be the tracks, we'll talk about those in a second. It is just, I'd like to make it very clear throughout this, that even though these tracks are represented in blue on the left of the screen and these are in red on the right of the screen. Please remember that these are duplicated either side, we've just removed, essentially sensory and motor from one side just to make it easier to get your head around and not lost in all of the the tract anatomy. But they are replicated on both sides. This butterfly here, this represents the gray matter of the cord. Ok. Um So this is where the cell body sits. Remember gray matter everywhere. It's the opposite in the spine to the brain. So, gray matter in the brain is located peripherally in the cortical region. Um and white matter is located more medially. Uh gray matter in the spine is medial, white matter tracts, lateral cell bodies in gray matter and dendrites tracts are the white matter, the axons um that are traveling um to where they need to go. Um So just keep that in mind as well. Um Ventral remis this is where motor function tends to come in. Dorsal ramus is where uh the sensory function tends to come in. Um And outside of this, you have your dorsal root ganglion and the ventral, ventral aspect of your nerve root as well, which we'll see in another slide. So just keep those basics in uh in mind, so called anatomy. First of all, so, motor or efferent or descending, they all mean the same thing. So what that is is that it is coming from the brain to the muscle? Ok. That's the way it's traveling. Um It sounds obvious it's really easy to forget in time, particularly if your questions or uh someone's asking you and using terms such as efferent, that's what it means. It is traveling away from, they are descending which tracks primarily and we're not gonna go into all of them. There is one main tracks that we talk about when we talk about motor function in terms of gross motor function. Can anyone name it? Uh corticospinal? Yeah. Absolutely. So that's good. So the corticospinal tract um and we can see that represented here. So it has two components. It has an anterior component and it has a lateral component. OK. The lateral component is the main body of function for the corticospinal fracture. We don't really consider the anterior component other than anatomically when we talk about decussation or crossing over fibers, it's the slightly interesting in the fact that it does not cross over, which is why in some injuries, in some um pathologies, you can still have a very small amount of preserved motor function on the affected side. Um And that's due to the fact that the anterior corticospinal tract does not cross over, whereas the lateral corticospinal tract carries the main body um of your motor function, it does cross over as we'll talk about in a sec. Um since what we mentioned, So these are the perimeter tracks. Um There are obviously er extra per perimeter tracts as well. Um We're not gonna go into those a lot today or go into those at all today. Um but they, they have a, a smaller role in sort of fine control and autonomic control of motor function. Um So this is your gross motor um and we've talked about as well. Um extra per but not really relevant here. Um So when we look at the cord anatomy, we look at the motor. So we think about the um motor hamus, which is located over here. This is obviously the precentral gyrus. Um And uh we have our motor fiber traveling down into the er corticospinal tracts. So, er into the basis peduncular, as you can see here in the mid brain really needs to know that in the pons and then in the medulla, er, is where we start to get. So this is all the same region broadly is where you start to get crossover as you can see the anterior corticospinal tract does not devastate at any point, it just carries on. Um whereas at the pyramids within the medulla, um you do indeed get uh a crossover of the um er of the lateral corticospinal tract. Er and as it starts to travel down, and this is why obviously this happened to the medulla, this is still in theory, brainstem. Uh and what you're talking about here, that's what you're looking at when you have a cord injury, this is why you will get ipsilateral. So the same side um motor injury, if you have a spinal cord injury or a hemi cord injury. Um uh The reason for that is because it's crossed over already at this point. Ok. So sensory a little bit trickier because they do lots of strange things. Um So we'll start with the most simple. Um So what are these at the back here? Mhm One dorsal column back. Yeah, exactly. So the dorsal columns are located at the back of the posterior. These are the easiest ones to remember. Um And anyone know what function they transmit pro perception, vibration. Yeah, so deep touch. Er so yeah, vibration, er fine touch generally and proprioception as well. Um spinothalamic we've got here. Um So that's pain and temperature, crude touch, er spinothalamic. Um And uh you remember there's anterior and posterior components as well. I don't really used to know that they are all essentially one tracked from our point of view. Um and then spina cerebellar as well. Um, anterior, that's primarily your appropriate se. Ok. So. Oh yeah. So, um just quickly as well. So dorsal columns are further divided into the fasciculus cuneatus and fasciculus gracilis. So, cuneatus is above T six, gracilis is below T six. Just remember that those are the easiest way to remember if you can remember the two names. I'm sure you've been told this before, but gracile gra gravity is lower down. Er So it's below er two, it's below T six if that helps any of you remember it did me when I was in med school. Um So the sensory relay here. So let's start with the er dorsal column. So just remember our first order neurons, these are our sensory neurons um er located with our body. Um They travel through to the dorsal root ganglia here. They synapse here um entered the tract. So synapse in the dorsal wood ganglia and in the dorsal ramus as we've entered through here, er come out into the er tracks. So either the gra cell or the um cunia um and then we'll travel upwards here as our second order neurons um and then up into the medulla, er that is where they will decorate at that point. So again, like the lateral corticospinal, they cross over in the medulla, but remember that these are afferent ascending fibers, so they're going the other way. Um and then er coming up into thalamus and then third auto neuron um transmit to um the post central gyrus, which is where we're um thinking about our primary sensory cortex. So the dorsal columns are essentially in the broadest sense of it, the reverse of the lateral corticospinal tract. So they're just doing the same thing but going the other way, spinothalamic, um I'm sure you will know this is uh a little bit of a pain. So it will devastate either at the level of or one or two levels above um the level that, that, that the ro 10. So say this is coming in at T six. it will either cross over here or it will stay on the side of the um ventral ramus of the, of the gray matter will travel at one or two levels and then we will cross over to the other side at say T five or T four. So what you actually get is a contralateral er representation at this point which is why in certain spinal syndromes that we may or may not talk about later on, you get a an atypical sensory pattern. So if you had a hemi section of the cord, you would get ipsilateral loss of um the er sort of um fine touch um dorsal dorsal columns, you would get ipsilateral motor loss of motor function, but you can potentially get, well, you will get contralateral pain and temperature function below because you've had this crossing over within the spinal cord as opposed to much higher up. So just keep that in mind. Um the other slightly confusing one, which there wasn't a nice er image of on the internet. So I had to try and do a terrible version myself is the spinal cerebellar tract. Um So the spinal cerebellar is a little fy um it has er anterior and posterior um cracks and they er the posterior is essentially very straightforward and it just stays where it's meant to on the same side because you will remember that cerebellar lesions will er typically present with ipsilateral symptoms. The anterior um is a little bit trickier. So the anterior will start by again, all of our sensory tracts, dorsal root ganglion er come into the dorsal MS um and then sign up in the gray matter here. However, the second ordinary will do the similar thing to the spinothalamic. So with the anterior spinal cerebella, it will cross at the level of or one or two levels above um where it enters and then will travel up in that tract. Now, you're thinking probably hang on a second, but you've just said cerebellum represents ipsilateral um symptoms. So, if it's crossed over, how can that possibly be? It's a very good question. So, er sorry, posterior, as we said, just stays the same side. The reason for that is that the anterior represented in red um is the sort of do what we call the double crosser. So the in the posterior comes into the inferior cerebellum, uncle stays on the same side and er goes to the ipsilateral side of the cerebellum. The um anterior spinocerebellar tract enters and crosses over within the cerebellum um to the contralateral side. So essentially, it has crossed again. Uh therefore, representing itself, no one knows why it does this. Um But just remember anterior spinal cerebellar or if you're just asked a question on spinal cerebellar, uh I would take that all as one and just say um this is known as typically the double crossing tract which gives it ipsilateral representation. It just has crossed twice along its pathway. So just try to keep that in mind for spinal cerebellar is a little trickier to remember, but actually, in the broad sense of things very straightforward, I think. Um so blood supply, we have two anterior spinal arteries, er sorry, two posterior spinal arteries and one anterior spinal artery. Um where is the biggest um supply coming from? Is it anterior or posterior? It's a 5050 guess. Someone say something anterior. Very good. Yeah, absolutely. So controversially, er well, not controversially but counterintuitively rather. Um it has two posterior spinal arteries and one anterior. However, the anterior supplies by far and away the most significant portion to two thirds of the spinal cord. And that is important when we think about some um clinical cases, we go into a bit later. So, um the anterior spinal artery. So it just orange originates directly from the vertebra. Um The supplies the anterior two thirds of the core that we said um, posterior, there's two, they usually arise from the piker um and supplies there posterior third. So essentially just the dorsal columns. Um just a brief note on venous drainage. So, er blood drains from the spinal cord into the anterior posterior, called radicular medullary drains. Um They drain into the paravertebral and intervert black eye um and also into these associated segmental veins. Um So, speaking of segmental veins, we need to remember that all of this blood supply is backed up by multiple segmental arteries from varying locations along the vertebral course, often from the thoracic arteries. So, uh arteries coming uh some somewhere along the ribs, um and and off of the aorta as well and they er contribute a large amount at each level to just bolster this blood supply because obviously purely coming from the vertebrals wouldn't be enough. Again, the anterior, um this particular reference there is one, very significant segmental artery, er, the artery of Adamowicz. Um So it is um it's the longest anterior segmental artery if you like. Um, it's usually made up from er, thoracic arteries from the ninth to the 12th ribs, um, and will enter at the level of L2, but then the hairpins back on itself and travels up to supply a large really back up of the anterior spinal artery in the thoracic cord. Um, it is a really important artery because it is subject to injury uh in surgery particularly. Um, so anterior spinal surgery, it can be injured in um, but also um uh descending aorta surgery as well. Um which again will be important for you to remember when we discuss some clinical cases, which I hope will put these into perspective a little bit. Um, so let's talk about some, just some clinical scenarios. Now, I know this is a sort of a very broad overview um of spinal anatomy. But, er, it helps when you, I think anyway, when you try and apply the anatomy to the situation and nothing in these scenarios will be particularly foreign to you. So a 24 year old male stabbed to the left of the back, just left or to the midline, approximately a level of T 11 is hemodynamically stable, marked, reduced power to the left lower limb. Um, and, er, he's complaining of an unusual pattern of numbness in the lower limbs. So, uh, what syndrome are we talking about here? What condition does it bounce the card? Yeah, absolutely. Er, so Brown Sicard is a really useful, er, syndrome for teaching anatomy. It is a really useless syndrome to know. Er, I've seen it in my career, I think once, um, from exactly this mechanism, er, it is vanishingly rare to see through, er, brown a card. So you get the opportunity you do go and see the patient provide a bit well, obviously, um but vanishingly rare but really useful to try and teach anatomy. Um So yeah, we've talked about this knife not in situ, this is just basic ABCD S are done for the patient. Um No other injuries CT S unremarkable. So, yes, we're talking about. So guard and what is it physically? So we've talked about it already. What is physically happening in brax of cards? The big red line helping. Yeah, you have in the chart half of the cord is damaged. Yeah, exactly. So half of the cord is damaged. Um So we would call that a cord hemisection. All right. Um So what is it clinically? So we have lost half of the cord here. So we know that as I've mentioned at the beginning that even though we've left the senty on this side and the motor on this side, these are all replicated over here. So dorsal columns on. So we'll call this uh the left side. Um So dorsal columns have gone, we know that. So we will get, we know that they cross over, they decussate in the medulla. So at this level, we're gonna have ipsilateral um uh fine touch er loss. So we know it's the left side, we're going to have ipsilateral, fine touch loss, lateral corticospinal is here. We know that on the left side, this is all gone. So we will have lost er ipsilateral gross motor function, spinothalamic. On the other hand, which will be represented here as well. So the spinothalamic tract crosses over one or two levels above. So we will get contralateral from a point contralateral pain and temperature loss. Ok. Uh And that's really, really important just to sort of highlight the, the points of where they c er cross over. So dorsal columns cross over at the medulla, lateral corticospinal crosses over at the medulla. So ipsilateral symptoms, spinothalamic represented here, obviously on this side. But spinothalamic here um is like I say it's at the level of the injury and therefore you get contralateral pain and temperature loss. Um So the easy way to remember that is that the spinothalamic is the con man contralateral. Uh So, yeah, essential what he says. So going scenario 2, 68 year old male post AAA develops sudden onset lower limb paralysis, noted to have lost pinprick sensation from t 12 downwards, bilaterally fine touch and proprioception intact. So, first of all, think about this anatomically, what is, which tracts are preserved? The dorsal columns are preserved? Ok. Um So if we've only got dorsal columns preserved, what is the likely? Um Yeah, where, where is the injury essentially? What have we lost? But if we go back to this slide, so this is what's preserved and it's all messed up. The anterior two sides of the cord have gone. Ok. So remember two posterior spinal arteries, but they really don't contribute much. One, anterior spinal artery contributes a huge amount, anterior two thirds. The reason why in aortic surgery, as we've already mentioned earlier on is that you can injure this special artery. It's something called the artery of Adam itch as well as other segmental arteries coming off of the aorta as well. Um and that will reduce the blood supply to the um anterior spinal artery and can cause a cord infarction. This results in something called anterior cord syndrome, paralysis, loss of pain and temperature, preservation of the function of the dorsal columns only. Ok. Good. Um And then finally, it would be impossible to do a spinal anatomy talk. Um This is not specifically cord but without talking about this particular syndrome um because it comes up all the time in everything and it is the bane of my life. Certainly. Um, so 45 year old obese call center adviser stood up from a chair and felt a pop. There's all of your er, pre red flags, er, tried heat and simple analgesia but as well as back pain, noticed stabbing pain in both of the legs, buttocks, er, from the buttocks down to the soles of the feet of one episode of urinary incontinence that evening. Er, and that was noticed by his partner from a patch on the trousers. What are we talking about here called equina syndrome? Yeah, absolutely. So we're talking about ca quina syndrome. Um, the red flags in this are that the episode of urine incontinence, but particularly that it was noticed by his partner from a patch on the trousers. That's really important because, er, that means that they probably haven't felt themselves be incontinent. Ok. So that suggests saddle anesthesia. One red flag insensate urinary retention. Ok. Er, as well. Um, bilateral lower limb radiculopathy, um, as well as another, er, red flag as well. Ok. So what is called equina syndrome? We've mentioned these er terrible drawings for me before. I've not put them in blue this time they're in purple. Um So, anterior longitudinal ligament, posterior longitudinal ligament, vertebral body, vertebral body disc, OK. Posterior longitudinal ligament really weedy, anterior longitudinal ligament very thick. So if there's going to be a disc injury, it all pretty much always will go backwards. Ok, unless it's seriously high trauma. So it's gonna come out backwards. Unfortunately, it's a bit of a design floor as this is where all of our important structures are. So our cord equina or obviously higher up our spinal cord co um parts of a disc. So the annulus fibrosis, very thick and tough nucleus, pulposus, this tears, this is what comes out. Um so just a normal MRI to orientate you as to what it looks like. So, vertebral body is a sagittal view. So looking from the side, front, back, vertebral body, vertebral body, disc disc disc disc. Ok, bright white. This is at two sequence. So CSF is bright white and then you can start to see the actual why it's called the corner, the horse's tail, the strands coming down from the Conus here. And if you go 54321, look at that, the Conus is nicely ending at L1, like we said, it probably should um a your view now, um hopefully through this line, so your vertebral body just could be just above um you can see the pedicles here lamina that we've looked at before spinus process, um facet joint, facet joint and then the vertebral um canal is here, the right white fluid and these little dots represent uh the nicely not compressed chro and nerve root swimming in CSF er very, very happy. So the normal level. So what happens in most disc prolapses is that a helpful diagram, the nucleus pulposus will herniate laterally and that will give unilateral radiculopathy. Um So sciatica, essentially, it is painful, it is annoying, it will most of the time go away without intervention. And some physiotherapy activity is the best treatment for this a gentle activity. Um and the vast majority will resolve without intervention called requip. So this is what that looks like on MRI. So you can see you always look at two planes. So we've got the s view again, the actual view and here we can see what looks like quite a big scary disc. But actually, when we look at it er on the side, we can see, it's just come laterally and actually the nerve roots of our cord equina are still mostly visible here on this side. So we're just compressing this, it will give them a sore right sided um sciatica. So what happens in cord equina is that very rarely, that band fails completely in the posterior ligament and we get total occupation of the spine of the VL canal at this level, compressing all of those nerve roots. So the lumbar and tac nerve roots and that's what it looks like here. So again, scary looking disc prolapse at this point, but also similar, similarly scary on the actual view. And we've lost all of that lovely bright white. We can't see those nerve roots, they're compressed. This is now a neurosurgical emergency. So, features that we've mentioned are sad anesthesia. So you say called dermatomes um in sensor urinary incontinence and painless retention. Um So we have to remember that the urinary incontinence occurs due to reduced parasympathetics. So what happens is that you have got uh stretching of the detrusa, but you don't have any input from the spinal nerves anymore because you've compressed the autonomic. So they're no longer functioning. The detrusa doesn't know how to empty it is not because you have loss of sphincter function at that point. Um It is just because the bladder becomes so full that it overpowers the sphincters uh and you get leaking of urine um which is often small volumes which is why when one of the things that we used to look for still do to a degree is, um, post void urinary retention. Um So they've gone, they've peed, they've not peed very much or they've been incontinent and there's still a huge amount left in the bladder. It's because the trees, muscle of the bladder is being stretched, but there's no response, no signal back from the autonomic to relax the sphincters, um, reduced angle tone. Um I understand how to assess this here. It is not asking them to squeeze just so, you know, it is the resistance that you feel when you insert your finger. So asking them to squeeze is voluntary, anal contraction. That's a different thing. Um We actually tend not to assess um anal tone anymore is one of the last things to go. It is very ambiguous. Uh older population tend to have laxity there. Anyway, no one really knows what normal and inverted commas, anal tone feels like. And so it's not particularly useful. We've stopped doing it. Um The sacral dermatomes are really important. And then obviously, we've talked about bilateral radiculopathies and in men, don't forget uh loss of erections as well. A management of surgical decompression within 24 to 48 hours. So, yeah, sorry for that brief segue. But I can't really talk about spinal anatomy and obviously, the nerve roots coming off of the spinal cord without talking about cord equina syndrome because it's really important within that vertical column structure. So hopefully that helps you understand the anatomy of the problem a little bit more. Um, and that's it. So a bit of a whistle stop tour. Um, I think I've overrun slightly. I do apologize. Um, but I hope that's been of some use and please do, er, give me any questions that you may have. Uh, thank you, Miss, er, thank you Mr mccormack for that really, uh really kind of insightful talk on spinal anatomy. Um I mean the floor, the floor as always is open for questions now and in regards in regard, I just want to kind of ok, we do have a question in the chat uh is, is the surface anatomy relevant to lumbar spinal levels? Um not hugely. So I yeah, not, not massively. There are certain things that can point me in the right direction as we talked about trying to get to the L4 5, we talked about twos line as well. So the peak of the ace when they're in lateral, left, lateral, dub the disposition um that will and then straight line down the first er space that you will come to is um the L4 5 that traditionally has actually been shown to be relatively inaccurate. Um So I think it's about 70% sensitivity or something like that. So it's not um so broadly. No, I think if you uh assessing the spine and if you things are fractures as long as you know that it is in the upper or lower lumbar spine or thoracic, lower thoracic spine. I think that's fine. That's enough for you to get the imaging that is gonna tell you exactly where it is. Anyway, thank you. I just wanna remind everyone in the audience to, if you want to get your certificates, please do fill out the feedback form. Uh That's how we know that, uh that's essentially how we know that you attended the session. Um We do have, we do have a couple of questions from before. Is that ok? If I for my, someone did ask, what are the functional differences between the anterior and posterior spinal cerebellar tracts? Considering that one exactly the same. So consider them all as one tract. It's just to be complete where we were talking about that tract, that it does have a variation. But the functional and it's the same with the anterior and lateral corticospinal tract. There is no functional difference. It is just the majority um is carried with the um lateral cord of the spinal spinal cerebellar equal, but broadly, just because it crosses over the anterior crosses, posterior, doesn't it still? Great? Thank you. And in regards, we have, we have one more question from, from the newsletter in regards to the in how do you clinically rehabilitate a patient when they have a dual, sympathetic and parasympathetic uh injury typically in, in high thoracic spinal injuries and see in what, in terms of what rehabilitation, it's not so much rehabilitation, if there is an injury to the, to the trunk and the ganglia, which you have to bear in mind because high thoracic don't necessarily give you parasympathetic direct injury. Um, but it's the, it's the ganglia that they feed into. So, if there is an injury there, then it's not about rehabilitation. It's unfortunately about symptom management. Um, predominantly is, um, er, it's sympathetic syndrome is what we're most worried about. So, um, regular intermittent self catheterization or permanent catheterization, um, is sometimes required. Um, we need to manage BP, monitor BP really, really carefully and educate the patient in terms of signs and symptoms of that. So they will get um, uh, of sweating, um, high BP, high heart rate will feel really normal, normal. Um, and it's purely symptom management at that point. Um, regular bowel evacuation as well. Um, is really important too, um, because they can all stimulate this. Thank you. I believe, I believe that's all the questions I have. Yeah, thanks. Thanks Tara. Um, yeah, thank you so much for the talk. I have one more question if that's ok. Of course. I was just wondering, um, I guess looking into the future are there ways that we can use like A I or engineering and things like that to prevent spinal cord injuries or vertebral column injuries? Um, kind of going forward. Er, II don't think to prevent so much. Um I think once it's happened, it's happened, there's not much you can do about it. The only thing that these source of coming up in terms of prevention is you have an injury and obviously you, you'll probably be aware of the Asia classification of spinal injuries from A to E so, e is no loss of function. A is the worst possible outcome. You've completely lost function below that level. And then there are varying degrees in between depending on where your sensory function is. Um And the difficulty sometimes is differentiating between Asia A and Asia B because of spinal shock, which occurs in the first sort of 24 to 48 hours where you have a total flaccid paralysis. Anyway, it doesn't necessarily represent your actual spinal function at that point. And so what we're looking at some studies are looking at is looking at we can do MRI scans that show tractography in the brain. So where different tracts are in the brain, we're looking at applying that to the spinal column to see if we can see the tracks which we can and to see whether there is a correlation and improvement between um if there is preservation of some of the tracks during that DTI that tractography, imaging, whether that could lead to early surgery, which could lead to better outcomes because what happens. And when you have a classic as a is the surgery is actually non emergency. At that point, we do things to stabilize um and facilitate any degree of rehabilitation and reduce pain. Um But actually, in terms of function, there's nothing that we can do. But if there's evidence that there is preserved tracks, then that would certainly spare us as surgeons onwards to um decompressing early in order to try and maintain that um that track function in terms of rehabilitation, there's obviously a lot going on. Um So in terms of stem cell research, um spinal cord stimulators, um there is a lot going on um from that side at the moment, but with fairly limited results at the moment. Thank you. I think we're out of time. Dara. Uh Yeah. No, that, that concludes, that concludes the time that we have. So again, I want to say thank you on behalf of us on the as the kind of new anatomy collaborative team. Um Mr mccormack for coming, giving us this really wonderful talk on spinal anatomy. Thank you to all our attendees and there is another talk happening next week on cranial nerves. Please do stay tuned for that and our other talks. Um More information is on our other platforms regarding that and metal and Jeff. Once again. Thank you. Thanks very much. Thank you so much.