Genetic Myelopathies with Dr. Kara Stavros

While collectively uncommon, the clinical presentation of genetically-mediated spinal cord disorders frequently overlaps with other neurologic conditions. Our understanding of these disorders has grown considerably.

In this episode, Kait Nevel, MD, speaks with Kara Stavros, MD, FAAN, author of the article “Genetic Myelopathies,” in the Continuum February 2024 Spinal Cord Disorders issue.

Dr. Nevel is a Continuum® Audio interviewer and a neurologist and neuro-oncologist at Indiana University School of Medicine in Indianapolis, Indiana.

Dr. Stavros is an associate professor of neurology and clinician educator at Warren Alpert Medical School of Brown University in Providence, Rhode Island.

Additional Resources

Read the article: Genetic Myelopathies

Subscribe to Continuum: shop.lww.com/Continuum

Earn CME (available only to AAN members): continpub.com/AudioCME

Continuum® Aloud (verbatim audio-book style recordings of articles available only to Continuum® subscribers): continpub.com/Aloud

More about the American Academy of Neurology: aan.com

Social Media

facebook.com/continuumcme

@ContinuumAAN

Host: @IUneurodocmom

Guest: @StavrosKara

Transcript

 Full transcript available on Libsyn

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 Nevel: This is Dr Kait Nevel. Today, I'm interviewing Dr Kara Stavros on genetic myelopathies, which is part of the February 2024 Continuum issue on spinal cord disorders. Dr Stavros is an Associate Professor of Neurology and Clinician Educator at Warren Alpert Medical School at Brown University in Providence, Rhode Island. Welcome to the podcast. What is the biggest takeaway from your article that you'd like the neurologists listening to this to know?

Dr Stavros: I would have to say that there's maybe two big takeaways that I would want to highlight. One would be that, generally speaking, in a nutshell, the genetic myelopathies can present with chronic and progressive symptoms, oftentimes (but not always) a family history of similar symptoms, and involvement of other structures outside of the spinal cord. Exclusion of the more treatable causes of myelopathy is a really key and important step in the diagnostic process. And because there are many different causes of genetic myelopathies, in some cases, the symptoms can overlap. I think this really underscores the utility of doing genetic testing to really confirm the precise underlying neurologic condition. The second takeaway that I would want to highlight is that, while treatment for most of these conditions is typically supportive, there have been a number of recent therapeutic breakthroughs for treatments in ALS, spinal muscular atrophy, adrenal myeloneuropathy, and Friedreich ataxia. While these aren't cures, it's really exciting and gratifying to see new therapeutics emerge via different mechanisms for patients with conditions that we've had very little treatment options for in the past.

Dr Nevel: Yeah, I really enjoyed reading that in your article - about these treatments that have been coming out over the past several years. The one with Friedreich’s ataxia, too - that looked like it was really just recently approved this year.

Dr Stavros: Yes.

Dr Nevel: And so, kind of jumping off of that topic - there have been these exciting treatments that have been coming through. What do you think is going to be the next big thing? Or what do you think is the next thing that might come through? Or what's going on in research in genetic myelopathies that might help our patients?

Dr Stavros: That's a really great question. I think that, as far as the future in this area, genetic testing has definitely grown in terms of being able to identify more genes now that are implicated in these disorders than ever before. But this is still an area where our knowledge is continuing to evolve. So, I think the future holds further advancements in our ability to successfully diagnose patients who have these conditions and provide them with the sense of closure that having a definitive diagnosis brings, as well as opening the door to potentially targeted treatment options once a specific diagnosis is made. Another thing I think the future holds is continued development of expanded treatment options for patients with these conditions, both in terms of advancing our supportive care capabilities and then also providing more disease-modifying therapies. Again, as I mentioned, in recent years, new disease-modifying treatments have actually become available for several of these conditions. And I think that's just the beginning. There's going to be more to come, for sure.

Dr. Nevel: Yeah, that would be great. Going back to the genetic testing and how things are - we're finding more and more and more genes. When you decide that genetic testing is indicated, how do you counsel your patients about genetic testing and walk them through that process?

Dr Stavros: Okay - I would say that it usually starts with having a conversation with the patient about whether they want to pursue genetic testing or not for the particular condition or conditions that are suspected. Genetic testing is really helpful to, again, confirm the diagnosis once the initial diagnostic workup perhaps has given you some clues as to what the underlying condition might be. Again, because sometimes the clinical symptoms can overlap in different genetic myelopathies in particular, the genetic diagnosis can be really important as far as getting a definitive, final diagnosis. Usually testing is pretty carefully considered and the risks versus the benefits are explored with the patient. Oftentimes, this is done in conjunction with a genetic counselor or with genetics clinic. So, there's a lot of teamwork there in working with the genetics department, at least in my experience. There's a lot of options that might include testing a panel of genes for the suspected condition, to up to whole-exome sequencing. Again, this is really like an evolving landscape. So, we have a current understanding of the genes that are implicated in some of the genetic myelopathies, but there's still so much that we don't know. So, a lot of times, testing can result inconclusive or may be falsely negative, and it can be tough because a negative test doesn't necessarily exclude a potential genetic etiology. It becomes a very nuanced, I think, conversation and journey with the patient.

Dr Nevel: Yeah, and in your article you mentioned some of the health care disparities that exist around genetic testing and access to genetic testing, specifically. How do we, as clinicians, try to mitigate inequities in regard to access, or in regards to being able to offer our patients genetic testing - is there anything that we can do?

Dr Stavros: I do think there are some resources available, where free or sponsored testing can be utilized from nonprofit organizations or pharmaceutical companies. But you're right that this is a real area for potential health care disparities. And making sure that we have equitable access to genetic testing is really important. Some of the issues that come up are: limited access due to location; due to socioeconomic factors; a lack of awareness on the part of the patient or sometimes the provider about testing that's available; cost, of course, being a big issue, oftentimes; and sometimes, distrust of how the medical information, the genetic information, might be used or protected.

Dr Nevel: What do you think is one of the most challenging things about managing patients with genetic myelopathies?

Dr Stavros: I think one of the more challenging aspects of the care is the diagnostic journey. I think that some of these conditions - most of them are not terribly common – and they may not always be at the top of our differential diagnosis in the course of a workup for myelopathy. The first step, I think, is really continuing to be aware of these conditions and not letting them become a “blind spot” when we're formulating a differential diagnosis for a patient with myelopathic symptoms. I think it can really take some time to reach the ultimate diagnosis for most of these conditions. Another challenging aspect, which I alluded to earlier, is sometimes when genetic testing might come back inconclusive or nonrevealing, and there remains some diagnostic uncertainty despite best efforts and a thorough workup -that can be frustrating as well, sometimes. Again, our knowledge of these genetics and the genetic mutations underlying these disorders is still really evolving. But on the flip side, there's a lot of rewarding aspects as well. I think one of the most rewarding aspects is trying to help patients identify interventions that improve their quality of life, and working with the patients and their families (who oftentimes become very expert in their own rare conditions in their own right), and working amongst the interdisciplinary teams. So many of these conditions are associated with extraneurologic manifestations, and so patients need coordination of care with other specialists. Hereditary spastic paraplegia is a great example, as well as Friedreich ataxia, where you often work closely with the cardiologist and of course, ALS, where there are a lot of multidisciplinary needs.

Dr Nevel: Yeah, I'm so glad that you mentioned that because, in neurology in general (and specifically in this area), I can imagine the benefit to patients when there are multiple specialists involved in their care who are experts in the various aspects that are impacted from their underlying condition. Shifting gears a little bit - but going back to something that you've mentioned a few times, about making sure that we don't have a blind spot to genetic myelopathies, and that we consider this in part of our differential diagnosis when we're evaluating patients - in the patient who doesn't have an extensive family history of the exact same neurological symptoms, when should we consider genetic testing for patients that we're seeing in clinic? Like, at what point should we say, “Okay, we've done the other tests and now is the time to consider genetic testing.” Because I think, unless somebody has that really strong family history, it's probably not on the top of your list to do it right away, for a variety of reasons.

Dr Stavros: I think you make a great point. Family history is tricky because, typically, we use that as a really strong clue of an inherited disorder of any type. But it can be tricky because, for a variety of reasons, it might be negative. Sometimes there is a de novo mutation, or there's variable phenotypes within the family, variable penetrance within the same family. Autosomal recessive inheritance can actually be, sometimes, hard to pick out. Or sometimes, patients don't have knowledge of their family members’ medical histories. For all of these reasons, there may be information lacking in the family history. But I would say one of the most important things to exclude when you're working up patients initially is, of course, acquired causes of myelopathy, because you wouldn't want to miss a more treatable cause. And so, things like structural causes, nutritional, vascular or demyelinating causes (things that are explored more deeply in some of the other articles in this issue) are important. But if you've excluded acquired causes despite lacking a strong family history, I think, at that point, it's worth broadening your differential diagnosis to consider whether you might have reason to suspect a genetic myelopathy, particularly if you have some extraneurologic manifestations, some systemic symptoms that might be a clue towards a more systemic process. In genetic myelopathy, sometimes imaging can actually be quite helpful. It helps you exclude - MRI of the spine can help you exclude acquired causes, but it also helps you sometimes get clues toward a genetic cause. Typically, the finding might be either normal or show some spinal cord atrophy (but typically without signal change, so that can sometimes be a clue).

Dr Nevel: What's one mistake that is made in managing patients with genetic myelopathies? Maybe “mistake” is too strong a word; maybe “misconception” about treating patients with genetic myelopathies.

Dr Stavros: That’s a great question. I think that one of the, maybe, misconceptions might be that these are homogeneous entities, these different diseases. But one of the things that surprised me anew in going back to research this topic and prepare this article was a reminder of just how variable both the genotypes and the phenotypes are within what we consider sometimes just one diagnosis, like hereditary spastic paraplegia, for example, spinocerebellar ataxia. There's so many different presentations and genotypes associated with these. It's really a family of different conditions. You could say the same thing about ALS as well. So, the spectrum of disease, I think, is important to recognize.

Dr Nevel: Yeah, and I can imagine because of that spectrum of disease, just having an open mind in considering genetic testing and not excluding a potential genetic cause because it doesn't fit into what we think is the most typical presentation of that genetic condition.

Dr Stavros: Yes - I'm in total agreement.

Dr Nevel: I've asked you about what some of the misconceptions are and what some of the challenges are, but what's the most rewarding part about taking care of patients with genetic myelopathies for you?

Dr Stavros: I think one of the most rewarding parts has to be working with the patients and the families. Like I mentioned earlier, sometimes they become so expert in their own conditions - it's amazing. And, working with them, working with the interdisciplinary teams, is a really rewarding process. I think that the more I've encountered patients with some of these rare conditions, the more I've learned from their stories and experiences, and so, that's, I think, been the most rewarding aspect to me.

Dr Nevel: You've mentioned the multidisciplinary team a couple of times that we've talked about this, but who specifically do you usually include or contributes to the care of these patients?

Dr Stavros: It may depend on the condition in question. So, for example, for Friedreich ataxia, there's always going to be a cardiologist involved in the patient's care. For ALS, there's going to be a larger team. For those who are familiar with ALS multidisciplinary clinics, this often includes physical therapy, speech therapy, nursing, pulmonary, and many others. And so, it really depends. I think in most cases though, genetics evaluation and genetic counseling is a really important piece.

Dr Nevel: How do you work with the genetic counselors in counseling families about testing other family members? Because that's something that's really challenging in genetic conditions, especially for people with children that may be underage, and this is a really complicated topic. But how do you approach that?

Dr Stavros: I think that it may depend on your particular institution. Where I'm at, typically, that's something that our genetics department will take the lead on and they will meet with the patient first and then also meet with and bring in any interested family members who are hoping to pursue the possibility of testing themselves. There's a bit of controversy or differing opinions around genetic testing, specifically for presymptomatic individuals for inherited ALS, because - certainly, there's pros and cons for being tested for any condition, but some special considerations come into play when someone is presymptomatic. There's actually been studies done, in particular, on patients who have a family history of ALS who are presymptomatic, and generally, the studies have shown that those patients are usually - the majority - in favor of being tested. But it does certainly bring up some ethical implications. Of course, any discussion is going to be undertaken with the goal of informing the patient and discussing the risks versus the benefits in detail. There's actually recommendations on the principles and the practice of presymptomatic testing for ALS, which is available and referenced in the article.

Dr Nevel: Do you think as - hopefully, in the future, as more treatments become available - that presymptomatic genetic testing could play a role in how we manage patients?

Dr Stavros: I think that's a great thought. I think it may, especially as more treatments become available, I think there may be a greater interest in demand for finding out early whether you might have a likelihood of developing a certain condition so that you can plan accordingly and perhaps even pursue treatments early on.

Dr Nevel: You know, you mentioned this (and this isn't maybe quite exactly the same thing), but in SMA - you mentioned newborn screening for SMA and new treatment for SMA, and that newborn screening is not always a standard, and that there's controversy around that, now that we have treatment for it.

Dr Stavros: Yes. That's another area where some controversy comes up as well, as far as cost and treatment, for sure.

Dr Nevel: Thank you, Dr Stavros, for joining me on Continuum Audio. Again, today we've been interviewing Dr Kara Stavros, whose article on genetic myelopathies appears in the most recent issue of Continuum on spinal cord disorders. Be sure to check out Continuum Audio podcasts 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 episode. Thank you for listening to Continuum Audio.