Evaluation of Risks and Benefits of Anti-Platelet and Anti-Coagulation Therapy in Traumatic Vascular Injury

Traumatic spinal cord injury is a potentially devastating disorder. Best practices in clinical care for these patients has evolved, with implications for long term outcomes.

In this episode, Aaron Berkowitz, MD, PhD, FAAN, speaks with Saef Izzy, MD, author of the article “Traumatic Spinal Cord Injury,” in the Continuum February 2024 Spinal Cord Disorders issue.

Dr. Berkowitz is a Continuum® Audio interviewer and a professor of clinical neurology at the University of California, San Francisco

Dr. Izzy is an assistant professor of neurology at Harvard Medical School and an associate neurologist in the Department of Neurology, Divisions of Neurocritical Care and Cerebrovascular Diseases at Brigham and Women’s Hospital in Boston, Massachusetts.

Additional Resources

Read the article: Traumatic Spinal Cord Injury

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Host: @AaronLBerkowitz

Guest: @SaefIzzy

Full transcript available here

Dr Jones: This is Dr. Lyell Jones, editor-in-chief of Continuum, the premier topic-based neurology clinical review and CME journal from the American Academy of Neurology. Thank you for joining us on Continuum Audio, a companion podcast of the journal. Continuum Audio features conversations with the guest editors and authors of Continuum, who are the leading experts in their fields. Subscribers to the Continuum journal can read the full article or listen to verbatim recordings of the article by clicking on the link in the show notes. Subscribers also have access to exclusive audio content not featured on the podcast. As an ad-free journal entirely supported by subscriptions, if you're not already a subscriber, we encourage you to become one. For more information on subscribing, please visit the link in the episode notes. AAN members, stay tuned after the episode to hear how you can get CME for listening.

Dr Berkowitz: This is Dr. Aaron Berkowitz. Today, I'm interviewing Dr. Saef Izzy about his article on traumatic spinal cord disorders from the February 2024 Continuum issue on spinal cord disorders. Dr. Izzy is an Assistant Professor of Neurology at Harvard Medical School and an associate neurologist at Brigham and Women's Hospital in Boston, Massachusetts. Welcome to the podcast, Dr. Izzy. So, let's say a patient comes to the emergency room with an acute spinal cord injury due to a car accident. Walk us through your approach. What's going through your mind when you hear this pager go off and you're walking down to the emergency room; what are you thinking?

Dr Izzy: Yeah, great question. So, one of the first question is, what's the medical status of the patient? And, starting from, “How sick is the patient? (looking at the ABCD - basically, airway, breathing, circulation), make sure the patient is stable from that perspective, with the specific focus then going to be the injury level and the injury severity. And with that, once the patient is clinically stable, we try to pay very close attention to that aspect, especially since we know the patient is coming with a spinal cord injury from the prefield assessment. So, having a very close assessment to the spinal cord using a standardized tool (such as the ASIA, which is the American Spinal Injury Association Impairment Scale) will be very helpful to communicate the level of injury to the rest of the team, which usually is going to be a multidisciplinary team approach from the emergency room into neurosurgery, neurology and other disciplines where we'll be involved. So, having a standardized tool will be a key. ASIA, as a scale - it starts with a letter “A” - and to be A when there is a complete injury, with loss of motor and sensory, and E is basically normal exam (a neuro exam with normal motor and sensory examination). And between B to D, they have some preserved voluntary anal contraction and some of the reflexes, such as the bulbocavernosus reflexes, with a various degree of motor and sensory. Having an early introduction into this scale will be super helpful to communicate with other services. Then will be the decision about who I should image, and also, whether I should clear the C-collar or not. And this is also another sort of decision making, comes into the patient mental status, the injury severity, the level of injury, as well as ability to perform a reliable neurological examination - all plays a role into this decision. In this article, we have elaborated on the clinical decision making - an approach in the acute setting - and we provided, in Figure 1, a comprehensive approach about patient we should think about imaging and what modality of imaging, as well.

Dr Berkowitz: Perfect, that's so helpful. So, you're thinking through the ABCDs, as you mentioned. And then a detailed neurologic exam to get a sense of the degree of injury. And then you mentioned the decisions about imaging. Tell us a little bit about how you think about who to image, what to image, how to image, after you've done your neurologic exam.

Dr Izzy: So, the imaging in general, as we know, that previously used to be an x-ray. But the recent literature really focus on utilizing the utility of high-quality CAT scans as it's provide more comprehensive characterization of vertebral fractures. And that will be very helpful to identify the level and severity of radiographic injury. However, MRI will always be superior, as it also provides the extent of the cord compression, signs of cord injury, as well as could help us rule out ligamentous injury within, especially, the first 48 hours post the event. In addition to that, we have to pay attention to a patient at risk of having vascular injuries, as many spinal cord, especially the cervical and skull-based injuries, can associate with blunt cerebrovascular injuries, which often missed in the emergency room, and even in the acute stay, as no one would have thought about that aspect. That's why, in this article, we have highlighted the role of Memphis criteria, which is a very valuable tool to identify patients at risk to be scanned. And also the Biffl Scale, which used to be known at the Denver, and modified Denver Scale, to assist classifying the level of vascular injury.

Dr Berkowitz: Great. So, I want to pick up on a number of the things you mentioned there. So, let's talk about injury to the bony structures that could result in impingement on neurologic structures, such as the nerve roots or cord or cauda equina. So, Often, neurology and neurosurgery are consulted together in these patients, right? And both arrive at the bedside in the emergency room. Tell us a little bit about working with our neurosurgical colleagues to figure out who should go for surgery, what type of surgery they should go for, and the neurologist’s role in helping in that decision making.

Dr Izzy: I believe the neurologists have a significant role in the acute setting, especially with performing a very thorough, refined neurological examination when it comes into assessing the cranial nerve, because often traumatic spinal cord injury could associate with traumatic head injury. In addition to that, perform a very thorough motor and sensory exam, with a specific look into reflexes, as well as anal reflexes. And documenting that, in conjuncture with the neurosurgery colleague, will be super helpful. We have to know that doing neurological assessment, or also relying on them, the ASIA scale is a key, but also could be confounded in the acute setting with other multisystemic events, including respiratory failure, using some pain medication, traumatic brain injury, hypotension, which all could confound the initial exam. That's why having a repeated exam for this patient throughout the hospital stay will be a key, especially when we are using some of these examination in the acute setting to guide our prognostication. Also, when it comes into the neurological assessment, looking into, not only the level of injury, but paying attention into the levels below. And documenting this exam is also a very critical aspect of assessment. One of the early decisions we share - many times when we, as neurologists, get consulted on these patients who should go to surgery, and that's a whole topic by itself discussed thoroughly in this article about the literature on a patient who should basically pursue surgery. And, one of the main highlight of the literature that, pursuing surgery in less than 24 hours has been associated with improved outcomes. Yet the literature on that still need further evaluation, especially now the most common practice that patients with worsening exam, mass effect, and epidural mass takes priority. But further studies on this area definitely require further exploration.

Dr Berkowitz: Another aspect you mentioned is blunt cerebrovascular injury - so, injury to the carotid or vertebral arteries in the neck or in the skull base. So, are CT angiograms part of the standard neuroimaging now for patients with spine injury, or on a case-by-case basis, or perhaps should they be?

Dr Izzy: Great question. It's not. That's why paying specific attention for a patient at risk, and that's where the Memphis screening protocol takes place. And we encourage our colleagues from neurology and neurosurgery, as well as emergency department, to try to keep this sort of screening, helpful protocol handy when approach traumatic spinal cord injury. More specifically patients, who have basilar skull fracture with involvement of the carotid canal; the one with a basilar fracture with involvement of the petrous bone; the cervical spine fracture with neurological exam that doesn't necessarily explained by imaging; having a Horner syndrome on neurological exam; fractures pattern involve LeFort II or III fractures; as well as neck soft injury; the seatbelt sign - these are all signs that could really raise the red flag that there is a possible underlying vascular injury that require evaluation by CT angiogram in the emergency room to further identify. Once we identify the vascular injury, there is another helpful and valuable score, which is the Biffl Scale, or the - what also well known to be Denver or the modified Denver. And that one will further characterize the injury from level 1 to 5, 1 involving the luminal irregularity and dissection with less than 25% luminal narrowing - that's the 1. And 2, more than 25% narrowing. The 1 and 2 carries different prognostication and management, because these two we can always think about starting antiplatelet or anticoagulation on the first two, while 3 is aneurysm or pseudoaneurysm in the artery, while 4 is occlusion or thrombosis, and 5, usually transection of the vessel, the free extravasation. Grade 3 and above, usually, medical treatment has not much of a big role and discussion with the vascular neurosurgery or neuroendovascular colleague will be super helpful.

Dr Berkowitz: You started alluding to the next question I was going to ask you related to these. As neurologists are often consulted when there's vascular injury, traumatic vascular injury, about the questions of the risks and benefits of starting antiplatelets or anticoagulation. You mentioned that, in extreme cases - obviously if the vessel is transected or there's extravasation - there'll probably be great danger in starting those types of agents. But often we're consulted for the lower grades, such as a dissection or a luminal irregularity. And the question comes up, what is the extent of the benefit of antiplatelet and anticoagulation when balanced with the risk? – that these are often patients with polytrauma, not just affecting the nervous system, but often systemic organs as well. How do you balance the risk and benefit of treating these traumatic vascular injuries with antiplatelets or anticoagulation, to wanting to reduce the stroke risk related to these, on the one hand, and taking into account the extensive injuries that often accompany these?

Dr Izzy: Yeah, absolutely. Very clinical relevant question. The short answer: there is no randomized clinical trials that compared antiplatelet therapy with anticoagulation, whether it's unfractionated or low-molecular-weight heparin, for the treatment of blunt cerebrovascular injury- not even compare the timing to start. That's why it comes into the clinical judgment when it comes to answer this question. As far as level of injury defined by Biffl Scale, Grade 1 and 2, when there is a dissection less than or more than 25%, it's reasonable to start either or. And that comes into the context of the patient. In general, most of these patient comes with other multisystemic event. Could be having a traumatic brain injury with contusion, and the size of the contusion maybe also play a role in this decision where there is risk of contusion expansion or bleeding in other parts of the body, which makes anticoagulation very critical and dangerous with these patients. Maybe starting aspirin could be reasonable and safe, as that comes into a multidisciplinary discussion with our colleague from neurosurgery, ortho (if they are involved), as well as the primary ICU team. Having a thorough discussion about the pros and cons of this decision is a key. Most specifically, it's about balancing the risks and benefits in management. When it comes into high grade (3 and above) involving pseudoaneurysm, we know that antiplatelet or anticoagulation might play a lesser role; might be beneficial to some extent (not very well studied in this cohort of patients). But having a discussion when it comes into vascular malformation involving arteriovenous fistula or near occlusion of a vessel with our neuroendovascular colleague and vascular neurosurgeon will be always a key. Just one more point to make - that if it's too risky to start in the acute setting because of other multisystemic involvement, having a repeat imaging in a few days might be also helpful in assessing the progression of the vascular injury - could also be helpful from that setting. If the patient start developing new neurological symptoms, rather than just blaming it on the cervical or thoracic spine, thinking about new-onset strokes that happen would be a key to elaborate there, as we know the duration - for how long. If we end up starting patients on anticoagulation, or antiplatelets such as aspirin, for how long we should keep it for? It's still controversial, but the common approach is to start when it's safe from clinical standpoint and consider keeping it for three to six months. And repeat follow up imaging in the outpatient setting to assess that vascular injury and determine the duration of treatment will also be a key.

Dr Berkowitz: Shifting gears again here - you're involved in the acute setting here, diagnosing and managing these patients, often otherwise healthy patients who've suffered a devastating accident. How do you begin the conversation about communicating the prognosis, often probably the first question from the patient's family, “Are they going to walk again?” Obviously, a lot of factors go into this and it can be hard to prognosticate from the first moments of injury. But how do you begin to have that conversation when that question is asked for the first time, often in the emergency room?

Dr Izzy: As a neural intensivist, commonly involved in the acute management of traumatic spinal cord injury patients, we try to focus on the acute management of patient, try to inform families that it’s too early to provide an accurate prognostication of the long-term outcome. Especially, that the acute course of the disease could associate with so many other clinically relevant variables that could have an impact on the long-term outcome, such as respiratory failure, hypotension, in terms of neurogenic or spinal shock, in addition to rate of infections. In such acute, early, or superacute stage of the disease, there's still not much known about the correlation with the very-long-term outcomes. As I mentioned earlier, even the very first ASIA scale, the first neurological assessment could be easily confounded by many of these factors. Once we address the hypotension, treat the infection, or even try to control the respiratory failure, we have seen that might improve the neurological assessment - could be in the acute setting. That's why we try to provide the families with the clinical status of the patient and postpone any discussion on neuroprognostication until the patient in a stable clinical state and when we have a better assessment of the neurological and hemodynamic state.

Dr Berkowitz: Tell us now, in closing, what does the future hold for the treatment of these patients with acute spinal cord injury?

Dr Izzy: Despite all the unknowns about the course of the disease, when it comes into the long-term outcomes and the increasing rate of early and delayed mortality in this disease and poor outcome, there are many ongoing attempts to test various pharmacological and nonpharmacological interventions to achieve neuroprotection and enhanced functional outcome after traumatic spinal cord injury. There are many promising attempts for transplantation of neuronal embryonic mesenteric stem cells, as well as oligodendrocyte precursor cells. Two or three clinical trials now ongoing, trying to assess the benefit for long-term outcome. The future is still optimistic that some of these initiatives might eventually transition to the bedside application and potentially leading to significant improvement in the long-term outcomes of our patient. However, many of these initiatives are still investigational but carries the hope. Our role as a clinical team - always satisfying taking care of traumatic spinal cord injury patients and their family and guide them through the journey to recovery.

Dr Berkowitz: Dr. Izzy, thanks so much for taking the time to speak with us today. I encourage all of our listeners to read your phenomenal article. We could only scratch the surface today in our discussion on this very complicated, challenging area of neurologic practice, but your article lays out a lot of very helpful, practical clinical elements in the diagnosis, treatment, and prognostication in patients with spinal cord injury.

Dr Izzy: Absolutely. My pleasure.

Dr Berkowitz:  Again, for our listeners, I've been interviewing Dr. Saef Izzy, whose article on traumatic spinal cord disorders appears in the most recent issue of Continuum on spinal cord disorders. Be sure to check out other Continuum Audio episodes from this and other issues. And thank you to our listeners for joining today.

Dr Monteith: This is Dr. Teshamae Monteith, Associate Editor of Continuum Audio. If you've enjoyed this episode, please consider subscribing to the journal. There's a link in the episode notes. We'd also appreciate you following the podcast and rating or reviewing it. AAN members, go to the link in the episode notes and  complete the evaluation to get CME for this article. Thank you for listening to Continuum Audio.