Hi there. I'm Stephen Adecker, and I'm head of the neurology service at the Royal Vetic College. And next webinar I'm going to discuss with you one of the most challenging neurological syndromes that we can imagine, and that's cervical spondylomante Wobblers syndrome.
Now Wobbler's syndrome, it's kind of chronic, chronic spinal disorders. It's a neck problem. It's what we refer to as a multi-factorial, is a little bit more about that later, but it's associated with a few challenges and although, in the last 10 to 20 years, a lot of papers have been published on this syndrome.
It's still confusing in variable terminology. We are not that sure about the about the physiology, this controversy about the treatments, and this is probably I don't think there's any condition in the world with more surgical, more surgical techniques have been developed. So to illustrate the difficulty of this syndrome or the fact that we still have a lot of questions, is the fact that we have more than 10 synonyms for only one condition.
I think it's quite unique in veterinary medicine that we have so many names to refer to just one condition. It's probably a reflection. Of a, of a kind of incomplete understanding of this syndrome.
And some of these names are like cervicalspoullomyopathy, guard of cervical spoullomyopathy, Wagler syndrome, malarticulation, malformation syndrome, stenotic cervical myelopathy, and now more and more names. So, Cervicalspondent is what what I often call like this complex and complex and poorly understood neurological syndrome, but it is definitely possible that the terminology of cervical spondullo maps is just an umbrella term. And that it contains multiple, more or less separate conditions.
So all of these conditions will cause a chronic and progressive cervical vertebral can stenosis, and it typically affects more commonly theal part of the cervical vertebral column. Now there are variable clinical presentations ranging from just neck pain to non-numb the tetraparesis. One of the more common clinical presentations that we see is what we call the the two engine gate, and the two engine git.
Consists of kind of a wide-based ataxia and paresis of the pelvic limbs. But on the front climbs have this short strided climbs, short and stiff. So it looks like the drachi limbs and the pelvic climbs are walking at a completely different speed.
So that's what we call it two engine gait. And this is from, a video during my PhD when I was still working in Ghent, so in Belgium. So it's quite an old video but it illustrates quite well this to engine gate.
So when the dog walks away from us, you see this wide-based ataxia with Paris of the high limbs, but then when he takes a turn, you will see the short strided, the short strided tragic limb gate, as you can see here. You also can see the low head carriage. So it looks like two bad cars put together, and that's what the two engine gates.
Now, although this is quite a clinic, like a typical clinical presentation. It can be a little bit more challenging and sometimes it's even kind of challenging. To recognise, to recognise the clinical presentation.
And, and that happens more so what we can also see is, and that's also kind of a classic presentation of all the, or, or kind of large breed dogs with chronic chronic card or cervical spinal problems. It's where the pelvic limbs show quite obvious. Signs, but only limited clinical signs in the thoracic glimpse.
So the pelvic climbs have this wide-based ataxia, while the thoracic limbs only have limited abnormalities. And when you see this young Great Dane walking through the corridor of a hospital, you will see obviously the abnormal pelvic limb gait. It's a white-based ataxia with paresis.
But then when the dog comes back, It might be very challenging to see any abnormalities of the tragic claims, so in a talk like this. It's very challenging to recognise that this dog has a neck problem instead of, for example, a Toro Colombo spinal problem because the Tarachi climbs look quite normal. To make it even more challenging, dogs with chronic spinal problems don't always read neurology textbooks, so they often don't have any neurological deficits.
So for example, when you test pro perception, like in this talk, Properception will be will be unaffected. So it's not only difficult to recognise that the dog has a neck problem, it might even be difficult to recognise that the dog has a neurological problem because the neuro exam, besides the clinical sciences, is often completely normal and also in the terrachi claims. You will see that his you will see that his perception is completely normal.
So like I said, it can be very challenging to identify and that these dogs have a neck problem. And that's even more challenging because these dogs often don't show obvious neck pain. So when you do neck manipulation, they often don't scream or yelp, but what you often see, that one specific neck motion or two specific neck motions will be severely limited.
So for example, in this talk, we will see that when we do flexion, he doesn't mind, but when we do extension he freezes completely and he does everything possible to resist. And when we do lateral bending from the left to the right, he doesn't mind bending to the left, but to the right again, he freezes completely. And when you see that, in my interpretation, that's an indication of, of, of discomfort in the neck, so flexion is fine.
But then when you do dorsal extension, you see he freezes completely, it's very difficult to extend his neck. Now when you do lateral bending to the left. That's fine.
But then again, to the right. He freezes completely and in my opinion, that can be, it's an indication for cervical discomfort and that can be your strongest evidence that this dog has indeed a neck problem. So now the question is, if you have a neck problem, you would expect gait abnormalities in all four, but why is it so common for these dogs with chronic neck problems to only have obvious abnormalities in the In the pelvic limbs, and that's, that's anatomy.
So what we do see in the cervical spinal cords is that the nerve tracts that go to the pelvic limbs are typically in the periphery, while the nerve tracts that go to thoracic limbs are more centrally located in the cervical spinal cord. So when you have a chronic condition that slowly compresses the spinal cord, You first get compression of those tracts come to the pelvic limbs and only later compression of those tracts that go to the tatic limbs. So that really explains why dogs with chronic neck problems like dogs with wobbler syndrome often have obvious clinical signs in the pelvic, but not in a tatic glimpse.
So this is also one of these conditions where until now still don't know the underlying aetiology of pathophysiology. So historically these conditions are acid with specific breeds, unlike the Doberman and the Great Dane. So historically there's been suggested to be heredary or genetic components.
But the studies so far have not been able to identify this, and it's important that we say here the studies so far, because the studies I have evaluated were kind of all the studies evaluating pedigree analysis, but since the discovery of the canine genome and that we have much more modern. DNA sequencing techniques. So far there have been no studies into a possible genetic link or genetic predisposing factors for cervical spondylomyopathy.
So although it's not proven now, maybe future studies will answer the question if or if not, there's an underlying genetic factor being involved. A very important, a very kind of not important, but a very kind of popular theory is instability, but . Especially with orthopaedic surgery, but until now, there's absolutely no indication that vertebral instability plays a role in the pathophysiology of cervicalspoullomyopathy.
There have not even been any studies that have tried to evaluate instability. So at this point, although it's a very popular term, there's absolutely no evidence that vertebral instability plays a role in the pathophysiology of cervical spondullomyopathy. The body confirmation has been suggested, but there have been multiple studies in Great Danes and Dobermans that have evaluated if the if the dimensions of the neck or the head or the thorax would play a role in the pathophysiology of cervical.
Also no evidence there, use of a slip chain, no evidence, and also what has been, A popular theory, I think a few decades ago, was that they said, oh, if you have these giant breeds like a Great Dane and you feed them, too excessively and they grow too quickly, they can develop a bit similar to osteochondrosis in horses, but again there's absolutely no evidence that feeding an excessive high calorie diet would play a role in the athophysiology of cervicalspondylomyopathy. So when you read a textbook, About cervicalspolomati Waler syndrome, you'll often find something that cervicalspondullomyopathy is a chronic neck problem, and it typically occurs in large giant breed dogs, such as the Doberman pinscher and the creatan, but, Over years, that's maybe one of the bigger developments in the last few decades, we start to realise there are more or less two separate clinical syndromes, and there's two separate clinical syndromes that are associated with a different signalment, different abnormalities. On, imaging studies, different, treatments, suggestions, different complications associated, and maybe, even a different outcome in these talks.
So those two more or less different, syndromes that we start to recognise is disc associated cervicalspondullomyopathy and also associated cervicalspoullomyopathy. So disc associated cervical spondedlomopathy is what we typically see in dopamine pinches. So these are typically older dogs, older than 7 years old, so typically 89 years old.
And as the name suggests, the predominant cause of chronic card or cervical invertible disc compression is one or more in type 2 intervertebral disc protrusions. If there are any other abnormalities, it's typical of some ligament and flare from hypertrophy and very mild vert vertebral anomalies. So, Typically the cardal cervical vertible column C6, C7, sometimes also C5, C6, and up to 50% of dogs have already two sites of spinal cord compression at the time of diagnosis.
So the other form is ulcers associated cervical spondent, and like that's a very different signalment because these are much younger dogs, typically 18 months, 36 months old, or sometimes even 48 months old. But these are not large breeds, they are giant breeds such as, the Great Dane, Bullmastiffs, Do the Bordeauxs, . And as the name suggests, spinal cord compression is caused by bony abnormalities.
So it's now dorsolateral compression caused by hypertrophy of the articular processes. When you see other abnormalities, it's typically again hypertrophy, the ligament or flavour, and hypertrophy, the roof of the vertebra can on the dorsal lamina. This is often a more generalised condition, so the cardal cervical vertical column is most often affected, but in 85% of cases, it's, it's more generalised, so 23, and even 4 sides are affected at the same time.
So that sounds like I said, not two separate clinical syndromes, but unfortunately, It's never as easy as it seems, because it's illustrated, by this recent paper, from the group of, Ronaldo da Costa. He's, he's one of the kind of the, probably the world authority in cervicalspondyloopathy. And he recently published his paper with dogs that had an imaging characteristics of both disc associated and also associated cervicalspoelloopathy.
So it's probably not as black and white, and there might be some overlap in these syndromes. So what we're going to discuss now separately is the diagnosis and treatments and clinical presentation of talks with disc associated and then separately OS associated cervical spondylomyopathy. So like I said, disc associated.
I said it's a quite a common cause of chronic. And progressive cervical spinal problems in older large breed dogs such as the Doberman, Dalmatians, Wemoanas, and when we say older, typically older than 7 years old. So I mentioned a few times that it's a multifactorial condition.
So what do we mean with multi-factors that that there can be multiple anatomical abnormalities that kind of work together or or contribute to progressive card or cervical vertebral canal stenosis. And like I said, the predominant cause of spinal cord compression is one or more type 2 intervertebral disc protrusions. But if you see other abnormalities, it's, ligament and flavour hypertrophy, that's quite common.
And in cervical spoullomyopathy, there's kind of this popular opinion that it's associated with vertebral abnormalities. When you see vertebral abnormalities that's often relatively mild. And if you don't know exactly how they should look like, it's easily missed because, what you often see is kind of an, a flattening of the cranio ventral border of the 7th cervical vertebra or sometimes a cranio dorsal tilting, a crani dorsal tilting of the C6 cervical vertebral body.
But you can also see sometimes is is spondylosis a performance or new bone formation and a funnel-shaped vertebral canal. So, This is kind of a typical one, where you have a type 2 intervertebral disc protrusion over here and then here, that's what we call that ligament and flavour hypertrophy, so you get kind of an . Ventral and dorsal compression and sometimes this is also referred to as the hourglass compression, because the spinal cord goes into a kind of an hourglass shape.
So on radiographs, what can you see? . Typically collapsed into vertebral disc space, maybe some sclerosis of the end plates in the vertebral bodies, and here are some Some spondylosis deformance.
Like I said, if there is a vertible anomaly, it's often mild, and, and this is the typical one here. So it's just this flattening of the cranio ventral border of C7. Sometimes, and that's typically what you see here, this kind of a little, not a perfectly shaped, it's kind of a flattening of the vertical body.
Sometimes you can hear here that kind of cranial dorsal tilting of C6 into the vertebral canal. And quite surprisingly, the spinal cord compression is not often here. It's typically here at the car the length of that tilting.
You might have heard of this kind of terminology of funnel shaped vertable can. Now what does it mean? It's that normally the vertebral canon is kind of cylindric shaped, but you see here, it's kind of funnel shaped.
So the goal orifice or opening is larger than the cranial part. So in this cranial parts, and again at C6, C7 is a predisposed for spinal cord compression. So, .
What is important is that radiographic abnormalities do not always correspond to the site of spinal cord compression as the main limitation of radiographs. Sometimes you have these dramatic radiographic abnormalities, but no spinal cord compression, and then sometimes you have no no radiographic abnormalities but a big spinal cord compression. And all of these days we don't do myelograms anymore, I find the old myelograms I have, they illustrate quite well the problem of cervical sppoullar myelopathy, but also to make this point because here you see like an obvious abnormality on the radiographs.
But then when you look at the corresponding myelogram, you see here, this is the spinal cord. The contrast has delineated the spinal cord, it's beautifully cylindrical, but then here. Is an obvious spinal cord compression, while the there's only milder spinal cord compression at the site of those obvious radiographic abnormalities.
Now, In a disc associated cervicalpondullomyopathy, there can be kind of this range of diagnostic abnormalities. Also you, like I said, you have multiple sites of spinal cord compression in 20 to 50% of cases, . Those myelograms are quite easy for interpretation.
That's why I still use them in the lectures, although we don't use them anymore in the UK in clinical practise. But also what is very popular with with conditions like cervical spondylomyopathy or Warbler syndrome are these dynamic studies where you first do imaging studies in a neutral position. And then you repeat imaging with applying a distraction or traction on the on the vertical column or doing it inflexion and extension.
It's a little bit controversial, . It's a little bit controversial, because not everybody does it. I, for example, I don't do it routinely, these dynamic studies.
What is important, the reason why we do, Traction, flexion extension is to see how the how the degree of spinal cord compression changes. So there's, so that will illustrate a dynamic component of the spinal cord compression, but it has nothing to do with instability. The the concept of a dynamic spinal cord compression and vertible instability is something completely different, and I should not be confused.
So also for that reason, you know that on radiographs you can't see the spinal cord, so there's absolutely zero value, no value at all in performing plain radiographs, with the neck inflexion, extension, or traction, and I still see that quite commonly that when we get cases referred. That for some reason, radiographs have been repeated with flexion extensions are absolutely not necessary, absolutely no additional value. So like I said, I still like, like, to explain the abnormalities based on, myelograms, because here you see that you see multiple spinal cord compressions.
You see here one between, C6, C7, C5, C6, and even C3, C4. But it's not just a ventral compression, it's associated with disc protrusion, but also here you see this beautiful dorsal compression and this is also causing this kind of Hourglass shape of the spinal cord. And this is what we call the traction responsive studies.
So the upper myelogram is neutral, but then we're going to apply traction, linear traction on, on, on the vertebral column, typically by pulling on the head. And then you see actually that compression completely disappears. Now again there's some controversy because of course applying traction is not always standardised, and there's some definition of what is a traction responsive lesion.
Does it mean that the compression gets better, or does it have to resolve completely, as we don't know which factors are kind of influence, if it's traction responsive or not, . And also it's not really standardised because all you have to apply manual traction, but of course if if a strong person does it, then it's maybe different than when a when a weaker person does it. So it's a little bit controversial but that saying.
The concept or the discovery of the fact that a lot of compressions associated with this associated cervicalpoullomyopathy. Improve by applying traction. Comes back to our treatment because one of the surgical approaches is to during surgery apply traction and then stabilise the vertebral column into the distracted position.
So that's why I said, so the traction studies or the results of traction studies have historically been used to suggest which surgical technique, so you should perform. So it has been suggested if the compression improves after applying traction, maybe you can then stabilise those vertebral column or those vertebrae in that distracted position. So you can also do flexion extension, I don't do that standardly, but that's my personal opinion.
So what typically happens with cervical spondylomyopathy, and as you remember from the video, the dog didn't mind flexion. But really resistance extension because what you will see that with, this is neutron and then when we do flexion here. The compression gets much better.
And then when we do an extension, the compression gets much worse. So and that is what we call a dynamic lesion. And it means that .
And that means that . The spinal cord compression kind of gets worse or better with physiological movements, of the head. So every time when the torque extends, the compression gets worse.
When the dog does flexion, the compression gets better. So with, cervical spondylomyopathy, the spinal cord compression has a dynamic component. Now, again, I really have to highlight because there's so much confusion about this, that this whole concept of a dynamic spinal cord compression.
And vertebral instability, it's completely, completely separate. So the fact that the spinal cord compression gets worse or better with different positions of the head does not mean that there's vertebral instability. It's a completely different concept.
And again, at this point, maybe in a few years, I have a different opinion, but at this point there's absolutely no evidence that vertebral instability plays a role in the pathophysiology of cervical spondylo myopathy. So, Again, it's highlighted here just because it's such a common mistake. So instability has historically been very popular, to, to explain the pathophysiology of cervicalspoullo yopathy.
But no single study so far has evaluated instability. We also don't really know what would be the definition of instability based on imaging studies. So and that worsening of spinal cord compression means that there's a dynamic compression.
It doesn't say anything about instability, and again, At this point, there's no evidence that instability plays a role in the part of physiology of cervical spondylomyopathy. So I showed you a few myelograms because I think they still illustrate quite well. But also I mentioned that actually we don't use myelograms anymore in the UK.
In the UK and in other parts of the world, myelogram has been completely replaced by more advanced diagnostic techniques, especially, MRI. And the limitations of myelogram is, of course, you don't have transverse imaging, so I only have the sagittal view. The spinal cord cannot be evaluated, you can't see if there are additional amounts in the spinal cord, but probably the most important reason why we don't do it anymore because it's an invasive technique, .
And so after myelogram, complications can occur, and we see that complications can especially occur in large breed dogs with a neck problem. And of course, dogs with cervical spondylomyopathy are large breed dogs with neck problems. And the most common complication we see are seizures, so that you do a myelogram, but then when the dog recovers, during the recovery from the anaesthesia, they get a seizure.
And then the other one is trans worsening. For example, a dog comes in walking, you do a myelogram, but the dog recovers it can't walk anymore. Fortunately, this is typically transient and they improve again, but still, it illustrates that this should be considered an invasive, diagnostic modality.
And this is quite well illustrated in another paper from, from Doctor Da Costa, where he found that in large breed dogs, you see more than 35 times more likely to have complications. The location of the contrast injection, so if it's in the neck, more likely complication, neck problems, and the total volume of the contrast. So that illustrates that kind of large breed dogs with neck problems, tick all these boxes to have complications with, Myelograms.
So then the next step would be CT. But the problem with, so the, the amazing thing with CT it gives excellent bone detail. So you see those vertebrae, you can see quite beautifully, but the challenge is on this normal CT.
You don't see, you don't see the spinal cord, so we know the spinal cord will be here somewhere in the vertebral canon, but you cannot see it, so normal CT. Cannot be used to cannot be used to confirm a diagnosis of cervical spondylomyelopathy, and again traction, flexion, extension during normal CT is of absolutely no diagnostic value. So if you want to make a diagnosis of Cervical spondylomyopathy with the CT you have to again inject the contrast dye.
This is what you get. This is the contrast dye in a superachnoid space. It delineates the spinal cord, and then when there's a spinal cord compression, you see the spinal cord gets distorted, it gets compressed, it gets a different shape.
And also on CT that is quite nice and big advantage is that after the CT you can do the reconstruction of the images. And you can get a sagittal view and even a dorsal view. So here again you see that this vertebral body is a little bit abnormal, you have a collapse of the disc space, a mild compression, but the big compression is actually at C5, C6.
And because you have to inject a contrast dye, there's the same or similar safety questions compared to a myelogram. So, CT myelogram is something that we try to avoid if we don't have to do it. So just to highlight, with native CT or plain CT you cannot confirm a diagnosis of cervical spondylomyopathy.
And the reason is you know the spinal cord runs somewhere here, but you cannot see it on the CT. So the diagnostic method of choice is an MRI. And an MRI is a little bit more difficult, to interpret.
You have to get a little bit more experience, a little bit more training. So here you see the brain. This is the cervical spinal cord.
Here you see the spinous processes of the thoracic vertebral column. This is the big spinous process of C2. Here you have, this is the spinal cord here, this grey structure.
And here you have the vertible bodies. In between each vertebral body is this kind of intervertebral disc, and then you see again here. And here that introvertible disc space has collapsed this.
C7 vertebral body has an abnormal shape. You see here the spinal cord compression and there's even what we would call a hyperintensity in the spinal cord parma. So, it just illustrates everything you want to see, you can see an MRI.
MRI is a diagnostic modality of choice, but unfortunately, MRI requires interpret requires experience, requires training, it's not that straightforward, and these are some paper, one paper from my PhD, one paper again from Doctor Da Costa, and it just shows that there's a lot of overlap between imaging characteristics of clinically normal dogs and dogs with with disc associated cervical spondylomyopathy. And for example, in, in my study, I found a very high prevalence of, intervertebral disc degeneration, intervertebral disc, Invertebral disc protrusion, even spinal cord compression in the car of cervical region of clinically normal large breed dogs. What we would see if it was age related.
So it's very common in older dogs to see some sort of chronic spinal cord compression without any clinical relevance. And it's very similar in people. If you would scan, like, like 7, like group of people from 65 years or older.
It's very likely you will see intervertebral disc degeneration, invertible disc protrusion, even degrees of spinal cord compression without any clinical relevance. And that's probably the biggest challenge with MRI is that you see that it's so sensitive, is that you will always see abnormalities, and that's a challenge sometimes to correlate the imaging abnormalities with the clinical picture of the dog. So there is a realistic chance of overinterpretation.
Of over interpretation of imaging findings now. I mentioned a few times that cervicalspondulloyopin, especially this disc associated form of cervicalspond, is very controversial. Now there's only one statement that's not controversial.
And that's that treatment is controversial, so there's especially a lot of challenges about this treatment and. I don't think there's any other condition in veterinary medicine, where there are so many surgical techniques for reported currently more than 30 surgical techniques have been reported for just one condition, and every year, more surgical techniques are added to this list. At least 1 or 2 new surgical techniques are reported every year.
So it's clear there's no consensus on what is the most, what is the best surgical technique. There's not even a consensus on what is the best surgical approach, because all those surgical techniques seem to be associated with similar outcomes and especially similar complications. So, All those 30 surgical techniques, we can actually group them in 3 kind of approaches or tree philosophies.
One is what we call a direct decompressive surgery, so that's a ventral slot surgery. It's the same surgery as we do for type 1 acute intervertebral disc protrusion. And then I said, that compression often improves when you apply linear traction to the neck.
So, most of those surgical techniques are what we call distraction stabilisation. So you have here distraction, and then with some sort, so you apply the distraction of it, with implants, or in the vertible bodies or between the, or in the invertible disc space, you keep that traction and you stabilise it in a position. And more recently, There is what we call the the Adamo disc because the the inventor Filippo Adamo, .
Or arthroplasty, it's, it's another name for it, or artificial discs, and that's kind of a disc that is placed, an artificially invertible disc that's placed in the invertible disc, kind of a ball and joint, and the idea is that it should maintain normal motion. So those are the three surgical techniques or the three surgical approaches that we do now. But what in the classic literature, And still in some papers that we find now, what is very interesting, I think especially if they're written by surgeons, they will, the conclusion will always be.
Oh, this surgical technique gives a successful outcome in 75 to 85% of the cases, so this surgical technique can be considered a good alternative for treatment of cervical spondyloy, but the question is if everybody has 75 or 85% success, why do we keep searching for new surgical techniques? Why are we not not happy? It's probably because at 75 to 85% is maybe an overestimation, and actually it's absolutely no clear evidence that any of those surgical techniques is better than the other.
And what we start to realise now is that maybe there's no fit for all. You know, we discussed that, this is a multifactorial disorder, so in some dogs it's just one type 2 intervertebral disc protrusion. In other dogs are multiple intervertebral disc protrusions.
In other dogs, again, then there's also a dorsal compression because of the ligament and flare from hypertrophy. So it's maybe that even if you are, very familiar with one surgical technique that for different cases of cervical spondylomas, you have to apply a different surgical approach, and that's something that we start to consider right now, . And just to illustrates that none of these surgical techniques is superior.
There are not a lot of studies that, there are not a lot of studies that compare multiple surgical techniques, but this group from Italy, from this babe from Christian Falzoni, very experienced spinal surgeon, he compared this prosthetic disc with what we call a distraction stabilisation. And during this technique they applied during the surgery traction, then they placed an intervertebr spacer in the disc space, and then they stabilised that position with the plates and screws, and also dorsally with screws through the articular processes. So, Again, they did not find like strong evidence that one technique was superior over the other, but what he did found that especially in the dogs with a prosthetic disc, that there were some complications, and also he found that of the Of the of the 12 dogs, most dogs had improved, had distraction stabilisation, and most of dogs that got worse or had complications had prosthetic discs.
So maybe that new concept of the prosthetic disc was very popular a few years ago, but I think a lot of surgeons are stepping away from it. Also in human medicine, the prosthetic disc is not used that commonly anymore, so maybe you are stepping away from that category. Already.
And then a very interesting, complication that is reported more recently is what we call subsidence. And I think one of the reasons why only more recent papers, subsidence is reported, because especially in the last decades, it has become a little bit the norm. If you want to report outcome and you want to follow up this case, you have to do follow up imaging.
So what is subsides is it's when you place an implant in into vertical disc space, so it makes contact with the vertible end plate that you actually, it doesn't just sit there. You you can get some sort of remodelling process around the implant and the end and the end plate, you get kind of absorption and remodelling of that end plate and often what happens is that it starts like this. So this is just after surgery, but then later you will see that actually there's kind of a collapse of that disc space because of the remodelling of the end plate around the implant and you get then loss of distraction and that can be most of the time.
The subsides is just radiographic, it's not clinically relevant, but you can get lots of distraction, so they also reported due to subsidence, you have an you have kind of a recurrence of clinical signs. So, like I said, all of these surgical techniques are associated with similar complications. And it can be, implant failure, like here where we lose the implants, subsidence, like this remodelling of the vertible end plate around the implant with loss of or collapse of the intervertebral disc space.
Of course, when you place implants in around the vertebr you can get infection such as discospondylitis. But the most common Complic long term complication. Is what we call adjacent segment disease, and what is adjacent segment disease, it is that you treat the dog successfully, so you do the surgery, they recover, they're doing fine.
So you do the surgery, for example, at C67, but then maybe a year later or 18 months later it comes back to you with similar clinical signs when you do imaging, they have the same disease but one disc space next to it. So now, for example, C5, C6, and that used to be called a domino lesion, but now, because also to have consistency with human literature we call this adjacent segment disease. And this is the most common or the most important long-term complication that we see in disc associated cervical spondylomyopathy.
And with all those surgical techniques, we see that the That the, the kind of the prevalence of this is quite similar and there are actually two theories about this adjacent segment disease, and it's, they are not mutually exclusive, so it's very possible, at least in my opinion, that those two theories contribute to the development of adjacent segment disease. One says, Or if you fuse or stabilise one, invertible disc space, you put in, abnormal load on the adjacent disc space, and that's why you get this adjacent segment disease. And the other one says, Oh no, we know already that 2.
5 to 50% of dogs has compression at multiple sites, so maybe adjacent segment disease is just a natural progression of the disease, and maybe it's a combination, it's a natural progression, but it goes a little bit quicker because you kind of intervened with placing implants into the vertebral column. So then, of course, that doesn't sound very optimistic. So then if you would ask me, so what are the advances in the surgical treatments of disc associated cervical spondylomatia, I would, I would say that, you know what, the typical advances or developments that we made in spinal sur in veterinary spinal surgery, they also reflected in these challenging conditions like cervical spondylomyopathy.
And that's typically that instead of using bicortical systems, so normally when you place a peal screw it has to go to one cortex and then to the other cortex, but the problem in spinal surgery, if you go too deep, you go into the spinal cord or into blood vessels. That also now more, we, we stepped away from stainless steel implants and go to titanium implants. A big advantage of titanium is that you, that they are MRI safe, so you can follow them up with an MRI scanner.
Also, like I said, sometimes we place implants, in the intervertebral disc space, so between two vertebral bodies. Now there are more, different kind of, surfaces like porous structures, so that bone can grow through these surfaces. And also what we use much more now in vet medicine is kind of 3D printed drill guides, individualised 3D printed implants, and I think most of these, Advances are kind of demonstrated in this very recent paper from Colin Driver, in in the UK where Victor Lopez, who's a PhD student, he actually has an engineering background.
He developed this, this implant and you see this porous structure, so that kind of stimulates fusion of two adjacent vertebrae. This is 3D printed, so individualised for the dog, so it has perfectly the shape of the vertebral end plates, and also they used then as . Titanium screws, monocortical systems.
So, this is quite a high tech paper and I, I think maybe this, especially this 3D printing of the sort of get individualised implants, maybe that will improve outcomes in this case, but. What I, from the beginning found very interesting about this condition was, you know, there are 30 surgical techniques. Every year, more surgical techniques are added to this list.
It really illustrates that one, it's a very challenging condition to treat surgically, and maybe we don't know the ideal surgical techniques. So what I wonder always like, like, why don't we know what happens with medical management? Because before you.
You you discuss with the owner, oh we're going to do this super expensive, invasive, difficult surgery. I think the owner should know what the alternative is. So I, I think even if there's consensus that surgery is the most appropriate treatment, not all owners will elect for surgery because like I said, it can be very expensive.
So I think we should know what happens with medical management, but what is interesting is that. They're absolutely not dirty papers that discuss medical management. Only a handful of papers.
Actually 3 papers discuss the results of medical management. And the first was again from Ronaldo da Costa. He did not divide between disc associated and also associated cervical spondullomyopathy, but here in Illustrated actually some dogs do quite well with medical management, so, .
So that he treated the dogs medically. What is important, because it's important to discuss with the other babes and medical management, is that dogs have to be available for at least 6 months. So if they were put to sleep or were euthanized or went for surgery in the 1st 6 months after diagnosis, they could not be included anymore in this study.
And he actually found that with surgery, 81% improved and 3% stays the same, so maybe mild clinical size. While with medical management, actually 54% improved, and 27 remained unchanged. So actually for in this paper, it was just that maybe there's not much of a difference between medical management and surgery.
There's also not much difference in survival time, . What did happen that no matter which treatment you had, half of the dogs, if they died, it was because of complications or due to progression of clinical signs of cervical spondylomyopathy. So in the beginning of my PhD, so that's not quite, quite a while ago, I started with a retrospective study on the medical management of disc associate cervical spondylomyopathy.
But quite surprisingly, only found that 45% of these dogs had a successful outcome. And you might remember that I said, that actually, . In the previous study, dogs had to be available for at least 6 months because I found that half of the dogs that were euthanized because of cervical spondylomati were so in the 1st 6 months after diagnosis.
So after that I started my PhD. And then the prospective study, where dogs where I followed them up after 1 month, 3 months, 6 months, 24 months, 12 months, they, they got everything they wanted, so I was really expecting the results would be much better. But unfortunately not.
We found that only 38% of dogs medically did quite well. And again, if they did not respond to medical management, they deteriorated quite quickly. So typically they became non-ambulatory and were euthanized in the 1st 6 or the 1st 12 months after making a diagnosis.
So what I now often Feel Is that, you know, even if only 1 in 3 can be treated medically. In the ideal world, we should not, we should identify those 1 in 3 and don't consider them for surgery. So what I often do is that I start medical management and then if any deterioration occurs after 1 month or sooner, we consider surgery.
Also, it was an eye opener for me in that study. Historically we would use a lot of steroids to treat them medically, but I was completely shocked by all the side effects these these dogs had. And in some dogs that I followed up, I really questioned if the quality of life was.
Most affected by the chronic steroids or by the disease itself. So that's also something I stepped away from, like doing chronic long-term steroid use for this type of conditions. So that's a bit of a summary for disc associated cervicalspoulloying.
So now we go to O's associate cervical Spolomyopathy. And for me, that's a very different story. And, and I also feel that here in the UK I personally see much more dogs with os associated cervicalspondullomopathy.
So like, like a completely different dogs. Young giant breeds like Great Danes, bull mastiffs, talked about those much younger, between 12 months, 48 months of age, typically young adults. And the compression is not ventral anymore from a disc.
It's now dorsolateral because of hypertrophy and degeneration of articular processes, . If you have other abnormalities, you can get also hypertrophy of the roof, the dorsal lamina, and ligament and flavour hypertrophy. On radiographs, you can see some abnormalities.
So this is the radiograph, this side here, cranial cervical is completely normal. You see here's an articular process, here's an articular process, and the lining between is a facet joint, you can recognise it beautifully here. But then you see here and here.
Is that it becomes much more blurry, you don't see that line anymore. And even more you start to see here. Kind of these radio round radio big structures, you also see it here.
And you also see it here this round radio big structures in the invertible form and and those are those hypertrophic articular processes. And also this condition cannot be diagnosed by CT because you don't see spinal cord compression. I often use CT for surgical planning because you can see the abnormality quite well.
This is normal. And you see the two articular processes with The facet joint, and this is, you see beautifully wide vertebral canal. And this is abnormal, you see the articular processes are much bigger, the hypertrophic.
You see that this lamina, if you compare with the, this case in here where you almost don't see it, the lamina is much thicker and you see how narrowed this vertebral canon is compared to this side. And again, MRI is a diagnostic modality of choice, because this is normal, so here's the kind of the intervertebral disc. This is the spinal cord.
These are the end plates, no, I mean, these are the articular processes. And here you see the nerves. That exits the vertebral canal through the intervertebral foramen.
And it's an affected dog. Again, you see the intervertebral disc. You see this much bigger, really hypertrophic articular processes here and here.
Causing kind of lateral compression of the spinal cord. And then this lamina is also much thicker than in a normal dog. So this, it's quite clear that the, abnormalities that we see here are very different than what we see in disc associated cervical spondullomyopathy.
So again, here, so when you look at the sagittal MRI, see this is the spinal cord, and you see this disc is quite normal, but you see the compression really comes from dorsally and laterally. So you see this flat spinal cord is completely flattened and squeezed, from, lateral. Now, This is also a very challenging condition to treat.
And similar to disc associated cervical spondylomyopathy, it's very little known about what happens if you don't perform surgery. But in contrast to the disc associated form of cervical sponylomati, there's no big discussion here about the treatments or the most preferred surgical treatments, because most spinal surgeons will agree that for now. The surgical technique of choice will be a dorsal cervical laminectomy, which is very invasive, often over multiple signs.
Now, the long term outcome is typically good, but what is the biggest problem or the biggest complication in these talks is what we call early postoperative neurological deterioration. And that happens in 70 to 80% of talks. So what typically happens, a Great Dane walks into your consult room.
You, you examine him, you diagnose him with also as he had cervical spondylomyopopathy. You take them to surgeries. Those are surgeries that take hours and hours and hours, even for experienced spinal surgeons.
Surgical's brilliant, technically perfect. You call the owner and say, you know, it's amazing, it went as good as it could go, but the next day you come in and the dog can't walk anymore. It's non-ambulatory tetraporetic, even tetraplegic, and of course it's a Great Dane, so it's a bit of a nursing nightmare.
And that's the most common challenge with surgical treatment of this is this postoperative neurological deterioration. Fortunately, it's typically transient, so it's something that we counsel the owners that we're going to do the surgery, even if surgery goes brilliantly, they can be much worse after the surgery and then typically they start improving again. So, Because we see that it's such an invasive surgery.
There is an interest in alternative surgical approaches, but until now, we are still doing the continuous dorsal cervical laminectomies. And like I said, And there's not much, not much information about medical management or surgery compared to medical, but this is a paper from the United States where they said surgical treatment is typically associated with neurological improvement and good long term outcomes, a very different story than the disc associated, . And then medical management is a neurological deterioration, but it's typically slow and can even go over multiple years.
Now, in a paper that we published a few years ago, We found actually that. The the cases are relatively mild, we treat surg we treat medically and the more severely affected cases we treat surgically and we see that For medical treatment, 15% only improves, 40% remains the same, and that can be good because they only mildly affected, so maybe 55% we see that actually it's a good outcome, but in surgery we see that the long term improvement is much higher, I think in 67% of the cases we see an improvement, 29% stays the same, so actually successful outcome. In 1990 to 95% of cases are very high long term success rates, but this is the problem.
We see that more than 70% of cases is much worse immediately after surgery, so it illustrated here and this is kind of a typical clinical recovery after successful surgery, so this is the dog one day before surgery. And this surgery went perfectly, but this is to talk immediately after surgery. So that looks like a drama, but there was no reason to panic because we were expecting this.
We also told the owner to expect it so the owner could accept it. But this is when the dog came back after 4 to 6 weeks, and it just illustrates that although that deterioration is quite dramatic, typically it's transient, so, if you can look after these dogs, it's worthwhile, taking them to to surgery, . So what happens until quite a few years ago, if we have to do this dorsal cervical approach, we would discuss with the owners how invasive it was, so that the dog might be much worse, but then we would see that in some dogs they would be doing really well.
In other dogs, they would be much worse. And we really question why is it that some dogs are so much worse after dorsal cervical laminectomy, while other dogs don't show any deterioration. And the most important factor is the underlying diagnosis for which disease you do it.
So, also in this study we found that for ulcers associated cervical spondylomyopathy, 78% was much worse. While if we do it for an acute condition like an intervertebral disc extrusion, only 23% is worse after surgery. So we typically have to consider this transient surgical surgical deterioration.
Or this transient neurological deterioration after surgery in chronic spinal conditions such as cervical spondylomyopathy. And, and we get these cases quite often referred, and of course I would like to think that it's because we, we are so great in spinal surgery. But actually the reason I think why we get these cases referred even from other referral centres is because we have a big group of neurology nurses, and I think that's something very important is that when you're going to consider surgery in these talks, you have to realise that the inhospitals in hospitals post-operative care might be very intense, but it might be very worthwhile.
So this is also a young great thing. He saw at Christmas, he, he has ataxia, he has tetraparesis, but then he deteriorated relatively quick. And you see here at the 6th of January, he could barely walk.
So now the owner called me and said, Can we please do the surgery, as soon as possible? Because you see, he can only take a few steps. So we did the surgery the 8th of January.
It took a whole day, but it went technically brilliant, but then 48 hours after surgery, and you see, we need, we even need two hoists. And the dog can't do anything. And again, the owner was expecting this.
The owner was not too surprised by this. But, so what is necessary if you're going to do surgery in these cases, you have to be able to look after them. And I'm very fortunate because, you know, I work with a big group of nurses.
They provided for him daily. Physiotherapy, daily hydrotherapy, we also have all this kind of equipment to look after these dogs, and this was on the dog a couple of weeks later. He made a recovery, he made a long term improvement without relapses, without deterioration.
Like his long term outcome was fantastic of this talk, so. We were going to summarise a little bit then after this, at the end of this lecture, the diagnosis and treatment of cervical spondylomyopathy. It can be questions, like I said, it's not black and white, but it can be questions if this disc associated and it's also associated should be considered different clinical syndromes, like different signalment.
Different abnormalities on imaging, different treatments, different complications, maybe a different outcome. For all of these syndromes, radiographs can be suggestive, but MRI is a diagnostic modality of choice, especially also because MRI is a non-invasive imaging modality, but, This for these conditions, controversy about treatment, little known about medical management. Difficult to compare surgery and medical treatment, and difficult to compare surgical techniques.
Now with all the data I've shown you. It seemed that medical management was associated with relatively poor outcome while surgery was associated with much better outcomes. So that can be really good news for the hardcore surgeons, because it can mean that maybe it is an inherent surgical disorder, and we should discuss with the owners that we should do surgery as soon as possible, but.
I think one is definitely possible, because I have a strong academic interest in chronic spinal disease. These are often quite challenging conditions. I've published multiple papers on medical management, always with poor outcomes.
But what is maybe important is the cases that I see at a specialist referral hospital. They are maybe already referred because they are so bad, because medical management already failed in the primary care setting, and that's why they are referred to us, and also maybe they were bad enough to justify that we do an expensive MRI scan, so it's definitely possible that, The papers that we publish do not reflect the overall dog population but are kind of a snapshot of kind of a bias to what's more severely affected cases. And it's also possible that what we consider medical management is is becoming a little bit outdated and that we should maybe consider a more proactive approach, such as a visa.
Therapy, hydrotherapy, multimodal analgesia and stuff like that. So, and maybe it's a bit of a combination like this, is that indeed we see the most severe cases. Indeed, maybe we can step up on medical management, but maybe we also have to admit that surgery inherently is associated with a better outcome.
So there remains this difficulty that It, that we don't know for sure if surgery should be considered superior of a medical management. So what you will always hear when when people start digging into this is that, oh, ideally you should do kind of a randomised, a randomised, like a prospective randomised blinded placebo controlled study. But I really don't like this type of comments because it's, with clinical condition, almost impossible to organise this, this randomised treatments.
And we always like to think that in human medicine, they, they have much more knowledge in human medicine, they don't have these questions. But when I, when I discuss this, this, this, this, this, condition with human spinal surgeons, they tell me, oh, in a human, In human, in human spin we have a similar condition. It used to be called cervical spondylotic myelopathy, but similar to and we change terminology all the time.
So now it's called degenerative cervical myelopathy. And the question is, do we have randomised studies comparing medical and surgical treatment, . It seems, yes, but then when you read the paper further, there's only randomised treatment for mildly affected cases.
So when, when a case becomes more severely affected, they don't consider, they don't consider medical management, anymore. So, Also then when you look at this, this is a paper where like all the world authorities in degenerative cervical myelopathy, so this is the new name of cervical stenotic myopathy, which is kind of a counterpart of warbler syndrome in human medicine, especially the first out of micro failings, it's kind of the gods in this condition. Where they're trying to recommend evidence-based treatments, and they say we recommend surgical intervention for patients with moderate and severe disease and offering surgical intervention or supervised trial of rehabilitation for patients with mild disease.
So that sounds very similar to what we do. But again, when you read further, is that to say, you know what, actually there's no evidence for this because we don't find in the literature, more severely affected cases are treated medically. So also in human medicine, there's absolutely no randomised studies where they, compare medical versus surgical treatments.
Depending and when we look at the conclusions of this paper in human medicine, they actually are very similar controversies and problems as, as we have, like, like here they have limited understanding of the natural progression of the disease, controversy surrounding the comparative effectiveness between medical and surgical treatment. And a lack of research on structured therapies that's typically physiotherapy, hydrotherapy, it's not much evidence if it if it works or not, . And this is very important, we also in human medicine, they say, .
There are no large controlled randomised trials, and actually this is this is unfeasible, not only because it's unpractical, but it's also unethical. You know, if you know that it's kind of a difficult, difficult to treat, difficult to treat condition. And there's absolutely no evidence that medical management would be successful.
It's maybe not not ethical to try medical management just for the sake of, of science. So just to kind of summarise that although we have all these problems and controversies and remaining questions, it's not much better in human medicine because they have very similar questions. So I hope I, I am.
Did not discourage you to kind of treat these cases, and they are very challenging cases, but sometimes also very rewarding, and I thank you for your attention.