Introduction

Regardless of the underlying cause of spinal cord disease, we have many tools at our disposal to improve symptoms and function in these patients. Even better, technology in this area is advancing rapidly.

In this episode, Lyell Jones, MD, FAAN, speaks with Kathy Chuang, MD, author of the article “Symptomatic Treatment of Myelopathy,” in the Continuum February 2024 Spinal Cord Disorders issue.

Dr. Jones is the editor-in-chief of Continuum: Lifelong Learning in Neurology® and is a professor of neurology at Mayo Clinic in Rochester, Minnesota.

Dr. Chuang is an instructor in neurology at Harvard Medical School and assistant in neurology co-director at Paralysis Center, Massachusetts General Hospital and Spaulding Rehabilitation Hospital in Boston, Massachusetts.

Additional Resources

Read the article: Symptomatic Treatment of Myelopathy

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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

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@ContinuumAAN

Host: @LyellJ

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 to 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 visiting the link in the show notes. Subscribers also have access 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 show notes. AAN members, stay tuned after the episode to hear how you can get CME for listening.

Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum Lifelong Learning in Neurology. Today, I'm interviewing Dr Kathy Chuang, who has recently authored an article on symptomatic management of myelopathy in the latest issue of Continuum, on spinal cord disorders. Dr. Chuang is a neurologist and physical medicine and rehabilitation specialist at Mass General, where she serves as Co-Director of the MGH Paralysis Program and Chief of the Neuromuscular Rehabilitation Program. Dr Chuang, welcome, and thank you for joining us today. Would you introduce yourself to our listeners?

Dr Chuang: Hi, my name is Kathy Chuang. As you said, I'm a neurologist at Mass General Hospital specializing in neuromuscular medicine, also physiatry, physical medicine, and rehab. And I'm glad to be here.

Dr Jones: Thank you for joining us. Basically, if we want to know more about managing spinal cord disorders, we have come to the right person, right?

Dr Chuang: I try to do my best with all patients - yep.

Dr Jones: For our listeners who are new to Continuum, Continuum is a journal dedicated to helping clinicians deliver the highest quality neurologic care to their patients, and we do this with high-quality and current clinical reviews. For our long-time Continuum Audio listeners, you'll notice a few different things with our latest issue and series of author interviews. For many years, Continuum Audio has been a great way to learn about our Continuum articles. Starting with our issue on spinal cord disorders (this issue), I'm happy to announce that our Continuum Audio interviews will now be available to all on your favorite open podcast platform, with some exciting new content in our interviews. Dr. Chuang, your article is absolutely full of extremely helpful and clinically relevant recommendations for the treatment of myelopathy, regardless of the cause. If there were one single most important practice-changing recommendation that you'd like our listeners to take away, what would that be?

Dr Chuang: I think the most important thing to take away is that spinal cord injury of any type spans so many organ systems, it is good to get people - or multidisciplinary care - involved early on. There's eighteen model systems for spinal cord injuries scattered across the US. Those can be great avenues of resources for patients and for practitioners, for people around. Physical medicine and rehab specialists (our physiatrists or spinal cord injury specialists) can be very useful. And then, also for each individual organ system, there are specialists involved. And so, having that multidisciplinary care is probably the most important thing for a patient that's suffering from myelopathy because every patient is different and coordinating that care is so important to them.

Dr Jones: So, teamwork is probably the most important thing, and I think most of our listeners who have taken care of patients with spinal cord disorders realize that that's really key. Your article - it leads off with such a great review of one of the big problems with myelopathy, which is spasticity management. From a medication perspective, I think many of us struggle with the balance between controlling the spasticity and some of the side effects of those medications, like sedation. How do you walk that fine line, Dr. Chuang?

Dr Chuang: Spasticity management, like everything else, is patient directed. It depends on what the patient is most complaining of. If a patient has spasticity but they're not actually having any complaints from it, we don't need to treat, because of fear of side effects. I tend to try to use focal procedures (like botulinum toxin injections) earlier on, in order to try and spare side effects of antispasticity medications. Use of other conservative therapies, like bracing, stretching, is very essential. Another thing to consider is that dantrolene doesn't usually have side effects - cognitive side effects, at least - and actually can be monitored pretty closely for hepatotoxicity, which is its major side effect. Other possibilities are the baclofen pumps, which can be very useful in patients with spinal cord injury because their spasticity is often more in their lower limbs than in their upper limbs. By using multimodality approaches, we can definitely limit the amount of cognitive side effects of medications.

Dr Jones: That's fantastic. Do you start with that multimodal at the beginning, or do you step into it with one, then the other, then the other?

Dr Chuang: I usually start off with a low-dose baclofen because they usually have generalized tone - first, in order to see if they have cognitive side effects with it and if so, at what dose. Also, so that insurers have a trial of some medication before we proceed to something as expensive as botulinum toxin injection. But yes, if there's significant focal spasticity, especially, I try to bring in botulinum toxin injections as early as possible, just because of the possibility of minimizing the effect.

Dr Jones: That's a great point - that you can start these from multiple angles and start them early. And great point about dantrolene - I think the hepatotoxicity makes many of us nervous. But it’s a key point there - that it can spare some of the cognitive side effects.

Dr Chuang: Yes, and actually, it can be monitored pretty closely. As long as a patient has access to labs, we can check liver function tests weekly or every two weeks until you're on a stable dose, and after that, only at intervals. And it can be weaned off just as quickly.

Dr Jones: Fantastic. Another issue that you cover really nicely in the article, that I think is an underrecognized complication of spinal cord diseases - neuropathic pain. What's your approach to that problem, Dr. Chuang?

Dr Chuang: Neuropathic pain is very, very tough to treat a lot of times. I usually give the chance of gabapentin, pregabalin, and duloxetine early, just to see if we can start managing their pain early and to try to prevent potentiation of pain. But I also tend to try to get pain management specialists on early, and also keep in mind that there can be other causes of pain other than just the actual spinal cord injury itself. Because of deafferentation and reafferentation, patients may think of neuropathic pain, and it could be something as simple as appendicitis. If there's a change in pain, there always needs to be a workup for acute causes. Again, multidisciplinary treatment, especially with pain specialists, can be really helpful.

Dr Jones: Great point about thinking of other causes, including appendicitis or the musculoskeletal things that I'm sure can be pain generators in this pain population, right?

Dr Chuang: Yeah, it's very common. Patients can often fracture themselves just with a simple transfer and that can cause a huge flare-up of pain. So, not all pain should be just dismissed as being neuropathic or just from the spinal cord injury itself.

Dr Jones: Great point - thank you. Another topic that you cover - that I think is mystifying to many of us - is the neurogenic bladder problems that occur in patients with myelopathy. You talk about the different types - how do you tell them apart?

Dr Chuang: It's hard to tell them apart from a patient perspective because a patient will just say that they have difficulty with urination. With a spastic bladder or detrusor sphincter dyssynergia, oftentimes, patients will complain of a short stream and having to force things out. And with an atonic bladder or flaccid bladder, they have difficulty initiating a stream. What can be useful are postvoid residuals - where, if a patient is in the hospital, or if you have access to an ultrasound, or if they see a urologist - after they void, you measure the amount of urine left in their bladder. You can see whether it's a smaller amount, which is suggestive of a spastic bladder, versus a large amount, or an atonic or flaccid bladder. The standard procedure that's done to measure these are also urodynamic studies that are done, oftentimes, by urologists, where they can actually measure pressure volumes and oftentimes get EMG recordings of the actual bladder - the sphincters.

Dr Jones: Perfect. When you do those postvoid residuals (easiest done with ultrasound), what's the general cutoff you use to say - that's a small amount that might be suggestive of a spastic bladder?

Dr Chuang: I would say, probably less than a hundred. And then, if it was flaccid, more than five hundred. If there's in between, it may fall into either category.

Dr Jones: Got it. When you think about neurogenic bladder, what are the treatment options? How do they vary between the different types that patients may have?

Dr Chuang: If you have an atonic or flaccid bladder, the main possibilities for patients just are, oftentimes, Credé maneuvers (or pressure on the bladder) in order to try and help with the bladder to squeeze urine out. But a lot of times they need clean intermittent catheterization or maybe placement of a suprapubic catheter long term. For patients who have a spastic bladder or detrusor sphincter dyssynergia, we can use anticholinergic medications, like bethanechol, tolterodine - those medications - in order to try to relax the sphincter a little bit and then allow the urine to pass through. You can also have BOTOX injections to these sphincters of the bladder as well, which can be useful to relax them so that they can allow the urine to pass through. But a lot of times, a mainstay of treatment is intermittent catheterization, also for patients with severe detrusor sphincter dyssynergia, so that we can maintain small bladder volumes and not develop hydronephrosis, urinary tract infections, and complications of holding urine in the bladder.

Dr Jones: Thanks for that, Dr. Chuang. Another part of your article that I thought was really fascinating, and probably will cover some new ground for our readers and listeners, is the use of nerve transfers or surgical treatment of weakness, basically. Tell us about that and how it's used in patients with myelopathy.

Dr Chuang: For patients with myelopathy, it's used often in the upper extremities. If a patient has voluntary control of either elbow flexion or elbow extension (usually, elbow flexion), you can oftentimes have the ability to transfer nerves into the finger flexors and allow voluntary hand closure. If there's supination or wrist extension, you can oftentimes allow transfers of branches of the nerve - for example, from the supinator, or from the branch to the extensor carpi radialis brevis, into the finger extensor - so that, over a period of nine to twelve months, we'll be able to slowly regrow the nerve back in and allow the denervated muscle to become reinnervated with a voluntary controlled muscle and then restore voluntary finger extension, which can be extremely beneficial - just being able to voluntarily open and close their hands.

Dr Jones: Right. And it sounds like the goal is really that functional use of grip and use of the upper limb. Not really so much for transfers, I imagine - is that not so much the goal?

Dr Chuang: If there's less than antigravity strength of elbow extension and reasonable external rotation strength, you may be able to get elbow extension strong enough antigravity, and at that point a patient may be able to transfer independently - with a lot of training.

Dr Jones: Wow, that's fantastic - thank you. There's lots of therapeutic options, really, for many of these complications, which I think is an important point for our readers and our listeners to take home. When you look into the future, Dr. Chuang, what do you see on the horizon as the next generation of care for patients with spinal cord disorders?

Dr Chuang: I see a huge, expanding field, both of therapeutics - there are stem cell trials all over the world; there are neurorestorative hormones that are being tried. I'm very excited about the advent of robotics, with motors being basically shrunk down to the size of millimeters, and exoskeletons becoming lighter and lighter. I suspect that, long term, we’ll be able to have robotic exoskeletons to be able to help patients walk and move their limbs normally. I know there are clinical trials right now involving orthoses that are controlled with brain interfaces that will hopefully help restore function in patients who need it.

Dr Jones: It sounds like science fiction, but a lot of that technology exists now, right?

Dr Chuang: Yes, it does. We definitely have prototypes of multigear hands with multiple directions. Now, the problem is trying to find the way to control these motors and to control these robotic hands and legs.

Dr Jones: Caring for patients with myelopathy I imagine can be challenging, but I imagine it can also be quite rewarding. Tell us, Dr. Chuang, what drew you to this work specifically, and what do you find most exciting about it?

Dr Chuang: I want to help people move better. I'm a physiatrist by training, and our job as physiatrist is to try to get people back to their activities of daily living as soon as possible; to try to remove any barriers to becoming active, independent people in their society. And so, I think that spinal patients that suffer from myelopathies or other spinal cord injuries have a lot of potential in the amount of activities that they can do and the way that they can contribute. I've seen patients who have been paralyzed and unable to move their hands at all develop tenodesis scripts, initially in order to just pick up things and then later obtain voluntary control of opening and closing their fingers. And it's huge in terms of what they can do in their everyday lives. Just being able to see that is just really rewarding. And even being able to help patients navigate society around them is just a hugely rewarding experience.

Dr Jones: I imagine that must be really fantastic to see folks regain those milestones.

Dr Chuang: Yes.

Dr Jones: It's pretty unusual for someone to have done a neurology and a physiatry residency. So, between me and you and all of our listeners, which residency was better?

Dr Chuang: Wouldn't trade one without the other. Probably wouldn't have done the one without the other, either!

Dr Jones: What a great, diplomatic answer. Okay, good.

Dr Chuang: It's true.

Dr Jones: Yeah. You avoided offending all the neurologists and physiatrists out there. And really fascinating discussion, Dr. Chuang. It's an outstanding article. I think it's a must-read for anyone who takes care of patients with spinal cord disorders. I want to thank you Dr. Wang for joining us and for such a thoughtful, fascinating discussion on symptomatic management of spinal cord disorders.

Dr Chuang: Thank you, Dr. Jones for having me today.

Dr Jones: Again, we've been speaking with Dr. Kathy Chuang, author of an article on symptomatic treatment of myelopathy in Continuum's most recent issue on spinal cord disease - please check it out. 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.