[Music] well um thank you again for that information that introduction we're going to talk about spinal cord injury from sort of basic science to clinical management to clinical syndromes um and um i think you know one of the the scariest things uh when you're a resident especially a junior resident taking care of patients that come through the er is being tasked with figuring out if someone has an injury if they have a fracture is it an unstable fracture does it need surgery do i need to talk call my attending or can i wait till the morning those kind of things so this chart just basically uh tells you sort of my personal experience with the surgical management a spinal cord injury and you can see that there's sort of peaks and valleys uh to the levels for which people get spinal cord injuries and and the most common areas to see injuries are in the mid cervical spine and at the thoracolumbar junction and that just has a bit to do where uh people are susceptible to fracture dislocations in these areas and we're not going to go into the details of fractured dislocations that's a really another talk but just to be cognizant about that in terms of incidents it's about 10 000 cases per year in the us actually slightly going down over time fortunately because of preventative measures and educational measures we see if for for example in florida much less diving accidents than we did before um the prevalence obviously is the uh incidence times the years that these people survive and as survival has increased the prevalence has increased and it's an incredibly costly disease not only to manage initially but also to um take care of the patients after after their injury and the cost is proportional to their level of injury so obviously someone who's para is much more much less costly than someone who's quadriplegic which is much less costly than someone who is quadriplegic and on a ventilator in terms of um mechanisms of injuries uh most common motor vehicle accident and these statistics are a little bit old the the motor vehicle accident as an etiology is declining and that has to do with the fact that cars are much safer with air bags and and seat belts and we're seeing uh still see lots of assaults uh guns and knives but we also seeing more and more falls as cause for spinal cord injury and particularly in the elderly with pre-existing stenosis a relatively light injury can result in a significant uh injury to the cord because of the pre-existing stenosis we're actually going to talk a little bit about that specifically when you look at the pathophysiology of acute spinal cord injury there are primary injury mechanisms and secondary injury mechanism primary injury mechanism is what happens at the time of the injury and secondary injury mechanisms are the biochemical events that occur subsequently that can result in further injury and neurological deterioration so the primary injury mechanism acute compression if like for example a fracture dislocation all the way to shear missile injury for a penetrating trauma and when you look at a microscopic level the secondary injury mechanisms are listed above i'm not going to list every single one of them but edema formation vascular changes are important electrolyte shifts free radicals and some of the secondary injury treatments or neuroprotective strategies sort of target these secondary injury mechanisms when you look at the spinal cord grossly after injury interestingly that most cases the spinal cord is in continuity in some way either attached by axonal remnants or astrocytic remnants scar tissue or intact axons that are just simply non-functionally non-functionally possibly demyelinated so even in someone who's so-called complete may still have uh neurological elements bridging the area of injury and so that's an important point in terms of trying to identify possible treatments the most common pathology is that that of an area of central cystic necrosis or cystic degeneration and that usually evolves from an area of central hemorrhage and there may be a preservation of peripheral rim of white matter or pia this is a autopsy specimen and you can see here that there's a fractured dislocation there's a central area of hemorrhage within the cord but the cord is still in continuity uh and this is sort of the most common thing that you see after spinal cord injury you can also see cord maceration in more severe injuries or cord laceration for example in a knife or a gunshot wound and in the some of the more minor injuries like we'll be talking about the central court injury you'll just see some central softening with axonal disruption but not necessarily anything more than that and those are for some of the lighter injuries if you look under the microscope you'll see central hemorrhage especially in the gray matter necrosis necrosis edema you'll see axonal injury with retraction of the axonal ends with and if the axons are transected you'll see organelle accumulation and swelling you'll see myelin sheath injury including demyelination and inflammation also very important again as a secondary injury target a secondary injury sort of target for drugs for example the next important thing is the in spinal cord injury neurological examination and this is particularly important when you're trying to transmit a picture of how the patient is doing to your colleagues and it also has a very important prognostic element to it so there's a used to be called the frankel scale then it became the asia impairment scale now it's often referred to as the inski they're all very similar but they basically divide injuries into five types those that are complete with no motor or sensory function below the level of injury b is incomplete with complete loss of motor function but sensory preservation including again examination of the perianal area to see if there's any preserved sacral function that would be in b a c is sensory incomplete and motor incomplete but the motor function is less than three on five d is obviously a lesser form of injury sensory incomplete motor incomplete but the motor function is greater than four on five and then e is normal so that's the asian impairment scale with regards to a b c d or e but then there's also levels that you can define and this is um based on key motor groups that you examine and so if i'll give you an example you can read the table here but if somebody has no motor function in their hands and legs but they have deltoid biceps and wrist extension that is greater than three on five then they would be asia a c6 and then if they had wrist extension but also had triceps that was greater than three on five they would be a c7 and so and the difference between a c6 and a c7 level is enormous a c6 would be able to navigate a electric wheelchair while a c7 could navigate a self-powered wheelchair so you can see just one level one muscle group can make an enormous difference in mobility there's another term two terms that you need to be aware of one of them is spinal shock and the other is neurogenic shock spinal shock refers to the motor sensory and reflex changes that happen early on after spinal cord injury so for example this is the easiest example and most uh impressive is that when a patient comes in with a serious spinal cord injury and you examine their reflexes they're often a reflexic so that you know reflex hammer to the knee illicits no response but if you see them in rehab three weeks later they've recovered from the spinal reflex shock and they're hyperreflexic have clonus spasticity so that's an example of the early phases of spinal cord injury where the neurological exam may not be completely accurate and it has to be distinguished from neurogenic shock which is the cardiovascular effects of a spinal cord injury of blood above t6 and essentially you knock out the sympathetic system and you have parasympathetic overdrive so you have decreased blood pressure which is the shock part but you also have a decreased heart rate as opposed to an increased heart rate where you might which might be seen in anemic shocks septic shock cardiogenic shock so if you see someone with no movement and has a level above t6 and has hypotension and um a bradycardia that that's that's a manifestation of neurogenic shock and then there's a bunch of different spinal cord syndromes that you need to be aware of anterior cord syndrome central cord system and brown sacard syndrome and we'll talk a little bit about each of them in terms of trauma anterior cord syndrome is very rare almost never seen it's most common in disciples where you get infarction of the anterior spinal artery and you have no motor sensory function below the level of injury but you have retained dorsal column function unusual in trauma central cord syndrome like i said is super common probably the the most common spinal cord injury that we see and it's and we'll we'll talk specifically about how those patients present in a second and then brown cycad syndrome is more common in penetrating trauma like knife injuries or gunshot wounds where you get a hemisection of the cord you'll have ipsilateral motor paralysis and contralateral loss of pinprick and that's that's a brown cicada syndrome ipsilateral loss of dorsal column function so ipsilateral loss of proprioception um and so we again we've talked about all this anterior spinal cord syndrome is rare acute traumatic syndrome spinal cord syndrome super common and what defines it is basically patients who present with severe hand weakness greater than arm weakness or leg weakness so they they're paralyzed in their hands but their leg leg uh power is pretty normal it's pretty classic elderly patients hyperextension injury with inbuckling of lincamentum flavum in an area of pre-existing stenosis the sensory loss is typically incomplete and patients tend to improve over time so this this picture is probably 65 years old it was drawn by netter and almost everything in it is correct except for the bottom left figure but again older patient hyper extension of the neck has in-buckling of the ligamentum flavum compression of the cord weak hands uh and strong legs and the the reason why was called central cord syndrome it was always thought because there's an area of central damage to the cord that the cortical spinal tract is somatotopically organized and you're preferentially picking off the upper limb fibers while the lower limb fibers remain intact and if you look at any textbook grey's anatomy greenberg you know the neurology textbooks harrison's internal medicine all of them have this figure which always drove me uh crazy and i'll and i'll tell you why uh so there's a bunch of uh syndromes in addition to uh central court syndrome bell's cruciate paralysis is basically central cord syndrome with a patient who has an upper cervical cord injury and it was described by pell but they present similarly with weakened strong legs and it was also felt that the reason for this differential you know presentation of arms and legs is that there was a decussation difference in the arm and leg fibers at the cervical medullary junction we know that the corticospinal tract decasates at the medullary pyramids and he hypothesized based on some old literature that they decided at different levels that you picked up the picked off the arm fibers and that's why you got weak legs so this leads to this here and it's very timely because we just uh published this literally this weekend it came out in journal nurse surgery um as the front cover and it is it's basically entitled uh a critical reappraisal of corticospinal tract somatotopic and and and the gist of the paper is and you'd have to read the paper to really sort of understand the reasons behind it and we don't have enough time to go into the details but but it basically says that you know these pictures from grey's anatomy greenberg and from the atoms and victor which is the principle neurology text is incorrect there is no somatic topic organization in the cortical spinal tract even though there is for cement for the spinal thalamic and the dorsal columns and that really that the basis for the problems with hand function is that the corticospinal tract which is uniquely human and we need you know that there's major evolutionary differences in the corticospinal tract between a rat and a human is predominantly important for hand function and if you get a diffuse injury to the corticospinal crack it it will be manifest with weak hands so that that's basically the the gist of the paper and this figure is actually on on the front cover of the journal neurosurgery april uh issue so the the brown sacard syndrome we've already talked about there's also conus medullaris syndrome which is involving the conus of the spinal cord where you get prominent autonomic dysfunction because of injury to the conus so loss of bowel bladder dis function and usually a combination of upper and lower motor neuron findings that's a conus syndrome as opposed to a cot aquinas syndrome which is typically below l1 l2 and it's a pure peripheral nerve injury so no hyperreflexia only hyporeflexia tends to be asymmetric tends to have prominent autonomic dysfunction and has a slightly better potential for recovery than a conus syndrome so that's really pathology pathophysiology presentations clinical presentation syndromes we're going to go now into the treatment strategies which you can just you can divide into medical surgical and experimental and we'll start with medical and so the the the the pre the premise for medical management is basically abc's airway breathing circulation if you're some have someone who's hypotensive or hypoxic you know in addition to their spinal cord injury or their brain injury for that matter things are going to go badly you're going to you're going to promote secondary injury we're going to talk about pharmacotherapy mobilization nutrition dbt prophylaxis and rehabilitation and just keeping in mind that all of these treatments may or may have not undergone either phase 1 phase 2 or phase 3 studies to to prove their efficacy and we'll try to distinguish between those different types of studies in terms of the evidence for its use so you know it was in 1990 so it's now 32 years since this paper was published and it was a very impactful paper in the new england journal of medicine that was and it was it was impactful because it was a randomized controlled trial looking at methylprednisolone for acute spinal cord injury you can see all of these luminaries in neurosurgery who were involved in the study in particularly you know wise young um and others who were who did a lot of the basic science work beforehand and essentially if you look at the study was a large study spinal cord injury multi-center and it looked at methyl presence alone versus naloxone versus control and found essentially that there was improvement with methylprednisolone at the doses listed here but you know there are a lot of questions about the study particularly things like the subgroup analysis uh that that was showing efficacy and i can go on and on of all the criticism so we went through a phase where we gave methylprednisolone to everyone and now we're in a phase where we give it to very few and the um we do have guidelines and the guidelines currently and it could change state that it's not recommended and the reason why it's not recommended is that the evidence for uh complications is higher than the evidence for benefit one of the real challenges in any spinal cord injury research is that patients without any treatment tend to improve and this is a combination of a number of studies looking that if you're asia a that there's at least a three to five percent chance that you could change to an asia d without any treatment so the reason why that becomes difficult is that any treatment that you plan you you've got to understand that there'll be a maybe a natural history of some recovery so any drug or treatment that you suggest has to be better than the natural history and again this is a natural history chart showing how many people who are asia a are ambulating after a year how many with a b and and as you become less and less injured and more and more young the chances of you recovering become higher so if you're asia c less than 50 years of age there's a 91 chance you'll be ambulating at the end of the year so this is just again some comments about natural history this is the a table from that methylprednisolone study showing that it was a very small subgroup that showed benefit not not the entire uh group and one of the big criticisms is that they the eight hours uh effect so if they looked at the entire group of patients who were enrolled there was no effect they had to do a sub-group analysis of those who got treated less than eight hours um and then these are the complications which when you look grossly or not insignificant such things like wound infection gi bleed not significant but you can see there seem to be considerably highly higher in the methylpredicilone group than in the controls so this was uh the the results of the nascus ii study uh but as i said in the current 2013 guidelines and i'm sure that 2023 they'll come up with another one it's currently uh not recommended with level one uh evidence something that we've been working on in miami for literally 15 years is cooling after spinal cord injury and we we have done a single center study for safety and then extended the inclusion criteria and for the last four years we've been doing a multi-center study with jefferson grady barrows maryland shock trauma looking at cooling for spinal cord injury compared to control and again without getting into too much detail we've published a num a number of articles in this area there's a lot of different ways of cooling we use a transvenous catheter that has a balloon at the end of it which basically cools the blood as it rushes by and that's a mechanism how we uh cool people to 33 degrees for 40 uh out 48 hours after their injury uh and you can do mris with it you can give iv fluids with it and it's the the that we use a basically a cool guard uh catheter um and so we you this is like a typical patient who's been cooled there's a three-hour cooling period we cool them for 48 hours and then we slowly rewarm them and essentially this was an original study for safety on the first 14 patients the asia conversion rates were certainly favorable compared to natural history like i said we increased our people with cervical injuries to include asia a's and b's and now even more recently c's and have published uh essentially um 60 of our own patients who have been treated and we're now up to about 60 patients who have been randomized in our in our larger uh prospective uh study so again we continue to work on that uh there are other neuroprotective strategies that people are working on including really azoll and others in terms of surgical strategies you know the purpose of surgery is numerous one is to reduce the fracture to decompress the spinal cord and to stabilize the fracture with rods and screws typically if it's an unstable fracture and reason for decompression it's been known for a long time in experimental animals that if that the injury severity is equal to the force of impact and the duration of compression you can't control the force of impact but you can control the duration of compression so the the shorter or quicker you decompress the cord the pot the better potential outcomes and these are some of the animal studies that have been done over time showing that reduction or quicker decompression results and better outcomes in multiple animal models unfortunately there's no prospective randomized studies looking at surgical decompression but there is the stascus study which was conducted by failings and vacaro and that basically looked at a multi-center uh study without randomization and looking at the outcomes of patients who got decompressed in less than 24 hours versus patients that got decompressed in greater than 24 hours and this is how the study was conducted this was the screen these are the enrolled 313 182 went to early surgery 130 what one went to surgery late surgery and then they looked at the outcome of these 131 versus 91 patients again remembering that this is non-randomized and basically what they found is that patients who got treated early or less than 24 hours and when you looked at six-month asia-grade improvement those that were decompressed early had significantly more uh impr too great improvement in asia score so more patients went from a to c or b to d in the early group than in the in the late group and that it that's shown here in one of the tables from the paper so i would just say in general uh based on these results and mother multiple other studies that we tend to do early surgery on these patients which means if someone comes in with a c6 c7 dislocation in the middle of the night they usually have surgery in the middle of the night even though you can criticize certain aspects of this study but that's basically how we take care of things in miami and then the last part of the talk is really talking about how spinal cord injury really affects every single body system from the heart to the lungs to the urinary tract to the gi tract and we're just going to go over the various systems and the impacts of spinal cord injury on those systems we talked a little bit already regarding cardiovascular that patients can have neurogenic shock they can have bradycardia they may need atropine or a pacemaker to increase their heart rate very commonly they come in hypotensive and we often have to give them fluids or pressers and you know we have level two evidence to suggest that keeping the blood pressure map at 80 or greater greater can result in beneficial effects so we often give them pressers for the first five to seven days post injury to improve outcomes we do dvt prophylaxis in fact it is a requirement in patients with spinal cord injury because they're at such high risk of dvts or pes and that's usually in the term in in our center lovenox with anti-embolic stockings some people or and compression boots and early mobilizations we tend not to do ivc filters and we tend not to do heparin that the respiratory system can be severely affected because you can imagine if you're paralyzed and you can't use your intercostal muscles to help you breathe and certainly if you have a very high cervical spinal cord injury that involves c234 i'm sorry c345 that you would infect your phrenic nerve function so they often have pneumonia atelectasis ventilatory failure trach that's not uncommon and respiratory therapy is important part and suctioning for mucous plugs is an important part to prevent them from getting on a ventilator or ultimately requiring a trait if they're a high injury like c1 c2 and their phrenic nerve is not working they'll often need a pacemaker and this is showing a patient on a road arrest bed which we used to use more often than we do now but it's a mechanism to improve pulmonary function and reduce pressure source the genital urinary system's not working they have no spontaneous or they have no voluntary contraction of their bladder so they often require a foley catheter initially that's often changed to intermittent catheterizations when they're stable they're suspect to urinary tract infections and they can later on get autonomic dysreflexia which is manifest by hypertension sweating headache particularly when they get catheterized they can have gi bleeds uh something often referred to as a cushing ulcer from the stress of the spinal cord injury they often get h2 blockers and they can't have problems with elementation occasionally they'll need a ng tube or even peripheral or central out hyper elementation but they do need to start a bottle program which is often consists of laxatives and stool softeners again because their gi system is not working they're prone to contractures pressure sores heterotopic ossification which is a bony formation in their muscles that can be a source of fever early on again preventing pressure sores is critical and both the teacher both the patient and the caretaker are important in that and of course this is psychologically devastating to the patient and the family so we have psychology and psychiatry involved early for counseling often the patients will require antidepressants the last thing i was going to talk about before i answered any questions was post-traumatic syringomyelia which is something that we occasionally see after spinal cord injury but it's important to recognize as a cause for secondary neurological deterioration and so it happens in about two to three percent of cases uh and so you can see because spinal cord injury is relatively uncommon syringomyelia or post-traumatic stronger myelia is under is not common but again if it happens it's very important that you be aware of it and i think there's a heightened awareness of it and it's certainly easier to diagnose in the mri era and and the pathophysiology is is relatively simple it's basically an injury to the cord with cis formation there's arachnoid isoditis around the cord there's impaired csf flow that happens and because of that csf is driven into this to the cyst and the cyst can expand and the csf often flows into the cyst through the virgo rob and spaces as i said mr is the uh diagnostic modality of choice and we often do sin amr which can detect flow around the spinal cord using uh special sequences the syrinx may go anywhere from three to twenty levels this is evidence of a csf flow study i don't think the video will play but you can actually look at the flow of fluid around the spinal cord with the alternating black and white lines and that helps you detect where the blockage is you can see here the syrinx is the white thing in the middle of the of the cord and so how do we treat it sometimes we do shunting but shunts no matter which area that they empty to can block they can tether they can become infected so there's lots of potential problems with any type of shunting procedure this is an example of a shunt autopsy specimen where there are literally three different shunts that have been placed within the spinal cord and so the shunt failure rate depending on who you read is about 50 um and again due to blockage of these of these shunts they can tether the court this is an example of a tethered cord so uh one potential way of treating it if it's focal blockage is basically untethering the spinal cord and this was described by the late bernard williams and that's simply untethering the cord and then often doing a duraplasty and this is again a an example of someone with a cyst of the cord where it was untethered and the csf flow was reestablished and that's shown in these sagittal and axial views pre and post-op [Music] this is another example of someone who developed a serine 30 years after their initial injury you can see a large cyst within the conus this is an ultrasound that was done during surgery this is opening the dura and seeing a lot of scar tissue around the cot equina and the conus the scar tissue can be removed you can see the syringe in the cord and you can you can fenestrate that cyst and also sometimes do a duroplasty so that's all i got that's about a 40 minute talk on spinal cord injury and i am be delighted to answer any questions that people might have [Music] hey everyone ryan rad here from neurosurgerytraining.org if you like that video subscribe and donate to keep our content available for medical students across the world