Continuum Audio features conversations with the guest editors and authors of Continuum: Lifelong Learning in Neurology, the premier topic-based neurology clinical review and CME journal from the American Academy of Neurology. AAN members can earn CME for listening to interviews for review articles and completing the evaluation on the AAN's Online Learning Center.
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Muscle Channelopathies and Rhabdomyolysis with Dr. Hani Kushlaf
mercredi 12 novembre 2025 • Durée 24:21
Genetic variants that underlie skeletal muscle channelopathies and rhabdomyolysis can also cause persistent and progressive muscle weakness. The availability and expanded use of genetic testing allows for the identification of new genes causing periodic paralysis and rhabdomyolysis.
In this episode, Teshamae Monteith, MD, FAAN speaks with Hani Kushlaf, MD, MS, FAAN, author of the article "Muscle Channelopathies and Rhabdomyolysis" in the Continuum® October 2025 Muscle and Neuromuscular Junction Disorders issue.
Dr. Monteith is the associate editor of Continuum® Audio and an associate professor of clinical neurology at the University of Miami Miller School of Medicine in Miami, Florida.
Dr. Kushlaf is a professor of neurology and pathology as well as the director of the Neuromuscular Division, director of Neuromuscular Research, and director of the Neuromuscular Medicine Fellowship in the Department of Neurology and Rehabilitation Medicine and the Department of Pathology and Laboratory Medicine at the University of Cincinnati College of Medicine in Cincinnati, Ohio.
Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum. Thank you for listening to Continuum Audio. Be sure to visit the links in the episode notes for information about earning CME, subscribing to the journal, and exclusive access to interviews not featured on the podcast.
Dr Monteith: This is Dr Teshamae Monteith. Today I'm interviewing Dr Hani Kushlaf about his article on muscle channelopathies and rhabdomyolysis, which appears in the October 2025 Continuum issue on muscle and neuromuscular junction disorders. Hi, Hani. How are you?
Dr Kushlaf: Good. How are you doing? Thank you for having me.
Dr Monteith: Well, thank you for coming on our podcast. So why don't you introduce yourself?
Dr Kushlaf: So, I'm Hani Kushlaf. I'm a professor of Neurology and Pathology in the Department of Neurology and Rehabilitation Medicine at the University of Cincinnati in Cincinnati, Ohio.
Dr Monteith: And what got you interested in muscle disorders?
Dr Kushlaf: So, this is a long story. At first in residency, I was interested in epilepsy, but the moment I started doing a rotation in neuromuscular, I became enamored with neuromuscular disorders. I remember seeing the first patient in the rotation who had myofibrillar myopathy, and I found out that there is very little known about muscle disease at the time. So, I became very interested and I immediately changed direction as I started doing nerve conduction studies and EMGs and having that procedure base, I just decided that I want to pursue neuromuscular disorders.
Dr Monteith: Well, that doesn't sound like a long story. It sounds like love at first sight.
Dr Kushlaf: Yes, I think part of it is not very far from neuromuscular disorders and that it does have some electrophysiology involved. But muscle disease and nerve disorders, they need that detailed neurologic examination, which I love in terms of doing the localization exercise.
Dr Monteith: Great. So why don't we talk about the objectives of your article?
Dr Kushlaf: This article was written to review muscle channelopathies that include myotonic disorders and periodic paralysis, and also rhabdomyolysis, with emphasis on genetic causes of rhabdomyolysis more than acquired causes.
Dr Monteith: So, why was this update so important?
Dr Kushlaf: I think this area of muscle disorders hasn't seen a lot of progress in recent years, but there are interesting findings that we're learning that spark, hopefully, more research into the area, because we do have significant gaps that are related to understanding pathophysiology of some of these disorders. For example, in patients with periodic paralysis, it's clearly known now that these patients over time develop muscle weakness, and the muscle weakness is unrelated to how many episodes of weakness they have---basically, the episodic paralysis part of the disease. So, this is an important finding that I think we need to look more into it and understand that these disorders actually progress, even though that they may not have episodes of paralysis. In addition, there are genetic therapies that have been introduced into most of neuromuscular medicine at this time, including muscle disorders, while this specific part of muscle diseases has not had that luxury yet. And I'm hoping over time that there will be an introduction of gene therapies for these diseases.
Dr Monteith: Great. So, it sounds like there's some clinical advances, then, as well as genetic advances. Now, you also spoke about rhabdomyolysis and that there's newer ways of thinking about that from perhaps when I was in residency. So why don't you update me on these newer approaches?
Dr Kushlaf: The rhabdomyolysis… first, the definition of it is changing. We used to use a cut off, a CK of about a thousand, to call it rhabdomyolysis. And very recently it's clear that that level of CK is not sufficient to call it rhabdomyolysis. So, now the level went up in terms of exertion of rhabdomyolysis, up to ten thousand, has to be more than ten thousand. And in patients who haven't had exercise, the level is up to five thousand. So, it's no longer actually one thousand. And that refinement in the definition is important because there are some patients who exercise all the time and they may exercise at an athletic level and they have very high CK's. And those patients should not be labeled as having rhabdomyolysis. Basically, they are doing strenuous physiologic exercise. In addition, not only the definition of rhabdomyolysis is changing, it is our approach to which disorders to consider first and how we should work up patients with rhabdomyolysis. So, acquired rhabdomyolysis remains the most important etiology to be ruled out first. So, I always tell my fellows and residents that, think about acquired rhabdomyolysis first before you think about the genetic disorder. After you rule out the fact that it is not a toxic or metabolic or medication-induced rhabdomyolysis, then think about a genetic etiology. But when you get that consultation from the hospital that the patient has rhabdomyolysis and we want you to figure it out, always look at the medication list and make sure that there isn't anything on it that causes, actually, a rhabdomyolysis. And in many instances, you find out that it's actually a toxic or metabolic etiology for the rhabdomyolysis.
And as part of this article, there's also an acronym that's now being used to identify those patients who would benefit from genetic testing. The acronym is called RHABDO. It's as is the word, RHABDO. R refers to Recurrent exertion of rhabdomyolysis. So, it's not just one episode. And the H refers to HyperCKemia, and the hyperCKemia should persist more than eight weeks after the episodes of rhabdomyolysis. And if it is exertional, then the person has not done an unaccustomed exercise. So, they have changed the way that they do exercise and now they are exercising for two hours instead of one hour or they have introduced a new way of exercise into their exercise regimen. Then that should not be considered. It's not considered necessary to test these patients for a genetic cause. Also, the muscle enzyme typically, in genetic causes of rhabdomyolysis, goes more than fifty times above the upper limit of normal, which is more than a thousand. So that has to be taken into account. And then for the D it's Drugs and medications. This has to be ruled out before you say yes, we need to find the genetic cause of rhabdomyolysis. And then the O, it's basically family history. If you find that there is other family members who are affected or they have a high CK, then of course that would point you toward doing genetic testing.
Dr Monteith: Great. So, it sounds like there's some advances there in how we approach these patients. In what way is this practice changing? You mentioned, you know, really important to rule out these potentially reversible causes first.
Dr Kushlaf: Yeah. So, once you identify the theology, it becomes easier to manage the patient. So, if it is a statin-induced rhabdomyolysis, you know that you want to stop the statin and you are not going to have this problem again. So, that's quite important. The statins, of course, will have to not be reintroduced in the future for that specific patient who developed statin-induced rhabdomyolysis. But for the genetic causes of rhabdomyolysis, if you go down the path of genetic rhabdomyolysis, of course we have no cures for these disorders. We may have treatments. One of the conditions that I have alluded to as one of the case presentations in the article is a patient who has riboflavin responsive multiple acid CoA dehydrogenase deficiency, and I wanted to highlight this disorder because it's a disorder not to be missed. It does have a treatment, which is riboflavin, and that comes from the name riboflavin-responsive. So that's why I put there in the article as part of the manuscript. However, some of these disorders, once you find the genetic etiology, there may be a way of preventing it in the future generation. Family planning, reproductive medicine technologies, can help in this instance and prevent this disease from occurring in the future generations.
Dr Monteith: So, why don't we move on to episodic skeletal disorders? What is your general approach for these types of diseases?
Dr Kushlaf: Muscle channelopathies, skeletal muscle channelopathies, are ultra-rare disorders. And part of the issue is not giving them a high index of suspicion in the diagnostic process. So, these patients typically come to us in clinics with very vague symptoms, and they may have lived with these symptoms for a very long time. So, they may have muscle pain, they may have fatigue, they may have muscle stiffness. Even though in most instances they do not tell you that they have muscle stiffness, they will tell you that when I wake up in the morning, I feel like I walk like a robot. My legs feel rigid, something like that. The word stiffness is not usually in the vocabulary of patients. When they come to see you and you examine them and you find out that the muscle strength is normal, you may not think much about the myotonic disorder. And that's where the issue is. You always have to keep these disorders in your differential diagnosis. So, you elicit for myotonia and for paramyotonia on examination, look at the muscle size, see if there is any muscle hypertrophy that happens in fluoride channelopathies, and that will typically guide you toward the diagnosis.
And also ask about whether their symptoms get worse in a cold environment. So, sometimes they tell you they don't like winter because during winter everything is not doing well. They may report that they even feel like they cannot move their face because of facial stiffness in wintertime, especially in states where it snows outside and patients will be walking outside. So, these are things, typically, that give you clues about the diagnosis. But in patients who are affected minimally with the disease, sometimes you do not catch them, really, till they come to the EMG lab because of another reason. If they develop a neck pain and someone thinks that they may have a cervical radiculopathy and they want to do an EMG on them, or if they develop carpal tunnel symptoms, they send them to the EMG lab for carpal tunnel. And the moment we see them in the EMG lab, we start doing the needle examination and we find out that there is myotonic discharges in every muscle that we stick with the needle. And we're like, well, this person must have a myotonic disorder. And you ask them more about their symptoms. They may have symptoms, but they will tell you that they have ignored them for too long because it's something that they live with throughout their lives since childhood. They thought this is what is normal for them and this is what normal people might have. They may have aches and pains here and there and that is normal. So, these are clues, typically, for the diagnosis. Once you find the myotonia, your next bet to identify the exact genetic abnormalities to do genetic testing. And nowadays I think the field has benefited from the availability of free genetic testing so we can find out which channel is affected and then move on toward freezing that disorder.
Dr Monteith: So, you spoke about nondystrophic myotonia. What are some bedside tips to try and really get at the diagnosis?
Dr Kushlaf: So as I said, first is, look at the muscle build of the patient. So, these disorders, chloride channelopathies---so, the autosomal dominant and autosomal recessive chloride channelopathies---can cause muscle hypertrophy. So, these patients can have an athletic appearance even though when you ask them, do you exercise? I don't exercise at all. Do you lift weights? I don't lift weights at all. And they look like bodybuilders, so that's something to think about. Also eliciting the myotonia and typically we elicit the myotonia by using, of course, the reflex hammer. You can either tap on the phenol eminence and notice the myotonia in the thumb as it moves inward and stays in that position for some time. Depending on the severity of the myotonia, you can tap on the extensor digitorum in the forearm and notice the middle finger as it gets up and gets stuck for some time before it goes down. You can also ask patients to squeeze your fingers and then release quickly. Squeeze forcefully, of course, and find out how long does it take them to release their fingers, and that way you can identify the myotonia.
Also, you may need to repeat the elicitation of myotonia several times because it can be not myotonia but paramyotonia, which is the opposite of myotonia. It's basically worsening of the myotonia as you keep doing the eliciting activity. So, the more they squeeze your fingers, the more difficult it is for them to improve. While the warm up phenomenon, which is the opposite of paradoxical myotonia, is, for them, as they repeat squeezing, they are able to do it better and better. They would be able to release more quickly with each attempt. In some patients, you can also ask them to close their eyes if they have facial myotonia, to close their eyes forcefully and see how quickly does it take for them to open their eyes. You may see that they do not open their eyes quickly. Or if you repeat in patients with paramyotonia, if you ask them to close and open, close and open, close and open, there will come a point where they really cannot open their eyes anymore, and that tells you there is paramyotonia. Of course, if you find paramyotonia, then you know that this is a sodium channel abnormality, that the genetic testing would just confirm that.
Dr Monteith: And what about for periodic paralysis? Is there anything new in the field?
Dr Kushlaf: Periodic paralysis… if I can say one thing about periodic paralysis, it's to talk about Andersen Tawil syndrome. It's an ultra-rare disorder also, but the episodes of paralysis that happens in patients with Andersen Tawil syndrome, they occur either with hypokalemia, so it can be hypokalemic---like, exactly hypokalemic periodic paralysis---or with hyperkalemia. So, it's hyperkalemic periodic paralysis. It doesn't really matter whether it's hyperkalemic or hypokalemic. These patients they typically have dysmorphic features. And the most common dysmorphic feature, and I chose a picture for the article, is a patient who has a small mandible. That is the most common dysmorphic feature. There are other dysmorphic features which include short stature, hypertelorism---which is the distance between eyes, the eyes become widened. Also, scoliosis and low-set ears. So, the ears are lower than the level of the eyes. So, these are dysmorphic features one can look for, but they do not exist in every patient with Andersen Tawil syndrome.
The problem with Andersen Tawil syndrome is that these patients, as opposed to hyperkalemic and hypokalemic periodic paralysis, they have cardiac involvement. And the cardiac involvement can be deadly. So, it's very important that these patients are identified quickly. And anyone who has episodic weakness should have an EKG and should have halter monitoring to recognize if there are any arrhythmias or EKG abnormalities. So, one can identify anything that needs to be corrected from the cardiac standpoint. I think that is the most important point about periodic paralysis. Overall, these disorders… I mean, they are disabling and they can have huge effect on patient's life in terms of productivity and employment. And the diagnosis can be very difficult, especially that we do not know all the genes that are associated with periodic paralysis. Right now, the genetic testing that's available to us includes five genes that are associated with periodic paralysis. But I think we need to know more. There's a proportion of patients who do not have an identifiable abnormality at this time. So, I think as time goes on, we'll recognize more causes for periodic paralysis.
Dr Monteith: I'm just reading your really great article, and it sounds like there's a lot of variability in presentation from I'm not feeling that well or I'm not feeling my best for mild disease, and then very severe disease where the whole body can be weak without alteration in consciousness.
Dr Kushlaf: That's correct. So, my patients tell me that you never know when you're going to develop episodes of weakness. And sometimes they can recognize the precipitant, sometimes they cannot. Stress, sometimes, is a precipitant. At times, they really cannot tell what happened. And the weakness can be affecting one limb or more than one limb. It can be isolated to an arm or isolated to one leg. And that is the issue with the diagnosis, is that for those who do not suspect periodic paralysis, they are labeled as a functional neurologic disorder and they do not get the care that they need. I'm hoping that this article will shed a light on how to think about these disorders and how to diagnose them because treating them can have a significant impact on patient's life.
Dr Monteith: How useful are these laboratory tests?
Dr Kushlaf: So, in any patients where I suspect periodic paralysis, I would always do thyroid function testing to rule out hyperthyroidism because it can cause episodes of paralysis similar to hyperkalemic and hypokalemic paralysis. And I also do EKG and halter monitoring to make sure that I'm not missing the cardiac manifestations of Andersen Tawil syndrome. On top of that, then I would do genetic testing. And the genetic testing, as I said, at this time includes five genes. So, we will recognize any genetic abnormality that comes on that genetic testing. And if it is negative and I still have a high suspicion for the disease, I will do a long exercise test. The long exercise testing is, we record from a muscle in the hand---it's called the productive digit minimi---and stimulate the unknown nerve. We record, typically, baseline responses and then exercise the muscle for five minutes and keep recording after five minutes of exercise for up to forty minutes after. We're looking for a change in the amplitude of the motor response that typically happens over time.
Dr Monteith: Great. Well, thank you so much for being on our podcast.
Dr Kushlaf: I appreciate it. Thank you very much.
Dr Monteith: Again, today I've been interviewing Dr Hani Kushlaf, whose article on episodic skeletal muscle disorders, muscle channelopathies, and rhabdomyolysis appears in the most recent issue of Continuum on muscle disease. Be sure to check out 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, you'll love the journal, which is full of in-depth and clinically relevant information important for neurology practitioners. Use the link in the episode notes to learn more and subscribe. AAN members, you can get CME for listening to this interview by completing the evaluation at continpub.com/audioCME. Thank you for listening to Continuum Audio.
Idiopathic Inflammatory Myopathies With Dr. Anthony Amato
mercredi 5 novembre 2025 • Durée 20:08
Inflammatory myopathies are a large group of disorders associated with an inflammatory response targeting skeletal muscle. Treatment hinges on the use of evolving immunotherapies and diagnostic tools to quickly identify inflammatory myopathy, initiate appropriate therapy, and exclude underlying malignancy or infection of other organs.
In this episode, Katie Grouse, MD, FAAN speaks with Anthony A. Amato, MD, an author of the article "Idiopathic Inflammatory Myopathies" in the Continuum® October 2025 Muscle and Neuromuscular Junction Disorders issue.
Dr. Grouse is a Continuum® Audio interviewer and a clinical assistant professor at the University of California San Francisco in San Francisco, California.
Dr. Amato is the Brigham and Women's Hospital Distinguished Chair in Neurology and the director of neuromuscular research at Mass General Brigham, and is a professor of neurology at Harvard Medical School in Boston, Massachusetts.
Continuum® Aloud(verbatim audio-book style recordings of articles available only to Continuum® subscribers): continpub.com/Aloud
More about the American Academy of Neurology:
Huntington Disease and Chorea with Dr. Kathryn Moore
mercredi 3 septembre 2025 • Durée 22:30
Chorea describes involuntary movements that are random, abrupt, and unpredictable, flowing from one body part to another. The most common cause of genetic chorea in adults is Huntington disease, which requires comprehensive, multidisciplinary care as well as support for care partners, who may themselves be diagnosed with the disease.
In this episode, Aaron Berkowitz, MD, PhD FAAN speaks with Kathryn P. L. Moore, MD, MSc, author of the article "Huntington Disease and Chorea" in the Continuum® August 2025 Movement Disorders issue.
Dr. Berkowitz is a Continuum® Audio interviewer and a professor of neurology at the University of California San Francisco in the Department of Neurology in San Francisco, California.
Dr. Moore is an assistant professor and director of the Parkinson's Disease and Movement Disorders Fellowship in the department of neurology at Duke University in Durham, North Carolina.
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
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Progressive Supranuclear Palsy and Corticobasal Syndrome With Dr. Nikolaus McFarland
mercredi 27 août 2025 • Durée 23:51
Progressive supranuclear palsy and corticobasal syndrome are closely related neurodegenerative disorders that present with progressive parkinsonism and multiple other features that overlap clinically and neuropathologically. Early recognition is critical to provide appropriate treatment and supportive care.
In this episode, Teshamae Monteith, MD, FAAN speaks with Nikolaus R. McFarland, MD, PhD, FAAN, author of the article "Progressive Supranuclear Palsy and Corticobasal Syndrome" in the Continuum® August 2025 Movement Disorders issue.
Dr. Monteith is the associate editor of Continuum® Audio and an associate professor of clinical neurology at the University of Miami Miller School of Medicine in Miami, Florida.
Dr. McFarland is an associate professor of neurology at the University of Florida College of Medicine at the Norman Fixel Institute for Neurological Diseases in Gainesville, Florida.
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
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Multiple System Atrophy With Dr. Tao Xie
mercredi 20 août 2025 • Durée 22:25
Multiple system atrophy is a rare, sporadic, adult-onset, progressive, and fatal neurodegenerative disease. Accurate and early diagnosis remains challenging because it presents with a variable combination of symptoms across the autonomic, extrapyramidal, cerebellar, and pyramidal systems. Advances in brain imaging, molecular biomarker research, and efforts to develop disease-modifying agents have shown promise to improve diagnosis and treatment.
In this episode, Casey Albin, MD speaks with Tao Xie, MD, PhD, author of the article "Multiple System Atrophy" in the Continuum® August 2025 Movement Disorders issue.
Dr. Albin is a Continuum® Audio interviewer, associate editor of media engagement, and an assistant professor of neurology and neurosurgery at Emory University School of Medicine in Atlanta, Georgia.
Dr. Xie is director of the Movement Disorder Program, chief of the Neurodegenerative Disease Section in the department of neurology at the University of Chicago Medicine in Chicago, Illinois.
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
Essential Tremor With Dr. Ludy Shih
mercredi 13 août 2025 • Durée 21:38
Essential tremor is the most common movement disorder, although it is often misdiagnosed. A careful history and clinical examination for other neurologic findings, such as bradykinesia, dystonia, or evidence of peripheral neuropathy, can reveal potential alternative etiologies. Knowledge about epidemiology and associated health outcomes is important for counseling and monitoring for physical impairment and disability.
In this episode, Lyell Jones, MD, FAAN, speaks with Ludy C. Shih, MD, MMSc, FAAN, author of the article "Essential Tremor" in the Continuum® August 2025 Movement 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. Shih is clinical director of the Parkinson's Disease and Movement Disorders Center at Beth Israel Deaconess Medical Center in Boston, Massachusetts.
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
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Parkinson Disease With Dr. Ashley Rawls
mercredi 6 août 2025 • Durée 25:26
Parkinson disease is a neurodegenerative movement disorder that is increasing in prevalence as the population ages. The symptoms and rate of progression are clinically heterogenous, and medical management is focused on the individual needs of the patient.
In this episode, Kait Nevel MD, speaks with Ashley Rawls, MD, MS, author of the article "Parkinson Disease" in the Continuum® August 2025 Movement 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. Rawls is an assistant professor at the University of Florida Health, Department of Neurology at the Norman Fixel Institute for Neurological Diseases in Gainesville, Florida
August 2025 Movement Disorders Issue With Dr. Michael Okun
mercredi 30 juillet 2025 • Durée 22:42
In this episode, Lyell K. Jones Jr, MD, FAAN, speaks with Michael S. Okun, MD, FAAN, who served as the guest editor of the August 2025 Movement Disorders issue. They provide a preview of the issue, which publishes on August 1, 2025.
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. Okun is the director at Norman Fixel Institute for Neurological Diseases and distinguished professor of neurology at University of Florida in Gainesville, Florida.
BONUS EPISODE: Bridging the Gap Between Brain Health Guidelines and Real-world Implementation With Drs. Daniel Correa and Rana Said
samedi 26 juillet 2025 • Durée 23:45
With the increase in the public's attention to all aspects of brain health, neurologists need to understand their role in raising awareness, advocating for preventive strategies, and promoting brain health for all. To achieve brain health equity, neurologists must integrate culturally sensitive care approaches, develop adapted assessment tools, improve professional and public educational materials, and continually innovate interventions to meet the diverse needs of our communities.
In this BONUS episode, Casey Albin, MD, speaks with Daniel José Correa, MD, MSc, FAAN and Rana R. Said, MD, FAAN, coauthors of the article "Bridging the Gap Between Brain Health Guidelines and Real-world Implementation" in the Continuum® June 2025 Disorders of CSF Dynamics issue.
Dr. Albin is a Continuum® Audio interviewer, associate editor of media engagement, and an assistant professor of neurology and neurosurgery at Emory University School of Medicine in Atlanta, Georgia.
Dr. Correa is the associate dean for community engagement and outreach and an associate professor of neurology at the Albert Einstein College of Medicine Division of Clinical Neurophysiology in the Saul Korey Department of Neurology at the Montefiore Medical Center, New York, New York.
Dr. Said is a professor of pediatrics and neurology, the director of education, and an associate clinical chief in the division of pediatric neurology at the University of Texas Southwest Medical Center in Dallas, Texas.
Childhood-onset Hydrocephalus With Dr. Shenandoah Robinson
mercredi 23 juillet 2025 • Durée 27:41
Childhood-onset hydrocephalus encompasses a wide range of disorders with varying clinical implications. There are numerous causes of symptomatic hydrocephalus in neonates, infants, and children, and each predicts the typical clinical course across the lifespan. Etiology and age of onset impact the lifelong management of individuals living with childhood-onset hydrocephalus.
In this episode, Casey Albin, MD, speaks with Shenandoah Robinson, MD, FAANS, FAAP, FACS, author of the article "Childhood-onset Hydrocephalus" in the Continuum® June 2025 Disorders of CSF Dynamics issue.
Dr. Albin is a Continuum® Audio interviewer, associate editor of media engagement, and an assistant professor of neurology and neurosurgery at Emory University School of Medicine in Atlanta, Georgia.
Dr. Robinson is a professor of neurosurgery, neurology, and pediatrics at Johns Hopkins University School of Medicine in Baltimore, Maryland.
Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum. Thank you for listening to Continuum Audio. Be sure to visit the links in the episode notes for information about earning CME, subscribing to the journal, and exclusive access to interviews not featured on the podcast.
Dr Grouse: This is Dr Katie Grouse. Today I'm interviewing Dr Anthony Amato about his article on idiopathic inflammatory myopathies, which he wrote with Dr Kian Salajegheh. This article appears in the October 2025 Continuum issue on muscle and neuromuscular junction disorders. Welcome to the podcast, and please introduce yourself to our audience.
Dr Amato: Thank you. And I am Tony Amato. I'm in Boston at Mass General Brigham.
Dr Grouse: It is a distinct pleasure to have you here with us today, and I'm really excited to talk with you about your article. I thought it was a fantastic overview of the subject. And I'd like to start by asking what you hope will be the key takeaway for those who are reading this article.
Dr Amato: I think it's kind of basic: how to make a diagnosis, describe about the inflammatory myopathy as approach to, again, diagnosis, and then a little bit on pathogenesis, which… and kind of leading to the treatments, and hopefully we'll have more treatments based on the distinct pathogenesis in the future.
Dr Grouse: Can you give a brief overview of the categories of inflammatory myopathies you reviewed in your article?
Dr Amato: So, I mean, the major inflammatory myopathies, radiopathic inflammatory myopathies, are dermatomyositis, antisynthetase syndrome, immune-mediated necrotizing myopathy, inclusion body myositis, and polymyositis. Now, that's been a big change, as you know. I mean it used to be, you know, we all started off it was dermato or poly. But I've kind of made a name for myself- a bad name for myself in the early 2000s saying, I'm not sure there's much of a thing called polymyositis. I think it's a hodgepodge and it's not distinct. And that's come to be, now most of those cases are- now we find out having antisynthetase syndrome or necrotizing myositis or IBM.
Dr Grouse: Could you walk us through your diagnostic approach with a patient in your clinic presenting with symptoms that are suspicious for inflammatory myopathy?
Dr Amato: So, you want to really make sure that they have inflammatory myopathy as opposed to some other kind of myopathy, a muscular dystrophy, for example. Taking family history first is going to be important, clueing in are they really weak or what they're complaining of is fatigue or muscle pain? Are they feel weak but what they really are complaining of is stiffness and rigidity from parkinsonism, or they have a sensory ataxia so they can't modulate? I want to know about other organ system involvement. Do they have a rash? Do they have joint swelling and pain that you might see with arthritis? Do they have shortness of breath that you might see with interstitial lung disease or ventilatory muscle weakness? Or do they have a cardiomyopathy? What kind of weakness do they have? Is it proximal weakness in the arms or legs? Getting out of a chair, climbing stairs. Do they have problems lifting their arms over their head---so, proximal weakness---or do they have more problems with grip, finger flexion, holding a pen, tripping? Do they have swallowing problems? Do they have ocular problems? So that's the big history on the exam. Again, I'm looking for pattern of involvement. So, on my exam, is there atrophy or weakness in muscles---you know, fasciculations---which would take it out of the motor? Is it mainly proximal? Is it distal? Again, is there ocular bulbar involvement? Is it symmetric, particularly in, like, the IBM? Most of the other inflammatory myopathies are going to be mainly and proximal and mainly symmetric. IBM is different, and that the- at least in the hands it's more distal, and it's finger flexors. So, you're looking at flexing the tips of the fingers, you're looking at the forearms, best looked at in a semipronated position to see if it's atrophied. And that leads you to an IBM if you see that. So that's the main things on exam.
Dr Grouse: That's a really helpful overview. I was wondering, in earlier training days, the convention was you- once you've suspected myopathy, you get your CK, you get your EMG, then that may give you the information you need for your diagnosis. It seems that things have been turned a little on their head. We're often skipping those things to go straight to the antibody testing. When should we be going for the myositis-specific antibodies before considering other things like EMG or muscle biopsy?
Dr Amato: I would always get a CK first. You know, in somebody who's weak. You know, the EMG, I don't need an EMG if the CK is two or three thousand. I mean, EMG is- localize it to, is it muscle, nerve, neuromuscular junction. If it's very elevated CK, it really doesn't help me there. Sometimes if I have myotonic discharges or something that might make me think of a myotonic dystrophy or something else like that. But you can see that with the inflammatory myopathy. So, if I'm pretty sure of a myositis, I don't always do an EMG, or- unless I really need it to help guide what muscle biopsies I do. if I'm suspicious then on my exam and I see the CK---or they come to me already with the CK, which often happens, and it's very elevated---that's when I'll do the myositis-specific antibody panels if I'm really thinking that. And the important thing to know from that is, you have antibodies for dermatomyositis and antisynthetase that are on the panel that are available, and even signal recognition particle, which is a necrotizing myositis. But what's not on the panel is HMGCR antibodies, which is important because that's 70% of the necrotizing myocidites are HMGCR, and then the IBM antibody and T5-C1A is not on that. So, you need to order those separately. If somebody doesn't know, they order a myositis-specific antibody and think that it's all-inclusive, but it doesn't have IBM or the HMGCR antibody. And the other test that I sometimes will do is a skeletal-muscle MRI to help in the evaluation. Sometimes, not all the time, but I'm not sure it's a dystrophy, is it a myositis when I see a lot of STIR signal, which is edema. And you can still see STIR signal in a dystrophy and toxic. But sometimes I'll do it depending on whether I need a biopsy or not.
Dr Grouse: What is the benefit of an open biopsy versus a needle biopsy, and when should we be considering using one over the other?
Dr Amato: So, it really is not our decision. It's the pass lab. So, it's the technicians and the pathologists who read the biopsies need to be able to process a needle biopsy, which might be much smaller. Needle biopsies show to be fairly accurate in a lot of the hereditary disorders where you might just look for central nuclear core, and they might be- so, mainly in kids, but in the inflammatory myopathies, it's really patchy. So, if I'm thinking of an inflammatory, I like an open biopsy. I think it's hit and miss. And so, I like open biopsies for the adults that I'm thinking of inflammatory.
Dr Grouse: Do you have any other tips or tricks in the diagnosis of inflammatory myopathies that you could share with our listeners?
Dr Amato: I would say first, in terms of what muscle to biopsy, you're not doing them yourself, but you're referring to a surgeon. You have to tell them what to do with the biopsy. And you want to pick a muscle that's about an MRC grade 4 because if it's a normal muscle, the muscle strength, the biopsy, is likely to be normal. If it's less than a 4, you might just have end-stage muscle. And saying you can't tell end-stage muscle from a bad myositis, from a dystrophy, from a severe end-stage neurogenic. If I don't have a muscle that I would typically biopsy that's an MRC grade 4---for example, somebody with an early weakness and they're only weak, say, in their in their hip girdle. So hip flexors, abductors, extensors, and we're usually not biopsying the iliopsoas or the gluteal muscles. Then what do you pick? That's when I like to do an EMG on one side of the body and look at proximal and distal muscles and select one that's irritable, you know, some fibs and positive sharp waves that I might biopsy. And then maybe consider doing a skeletal muscle MRI to go from muscle that's abnormal, that has a lot of edema in it, to increase the yield.
Dr Grouse: That's really helpful. And then, I think, jumping from that, what are pitfalls that you've seen neurologists fall into in this diagnosis or other challenging aspects of the diagnosis that you could review with us?
Dr Amato: Some of the things that we see are hard to pick up. It might be hard to pick up a rim vacuole. They're very rare, too. And so, you might miss it, particularly if you don't see a lot. Sometimes, like looking at the dermato and that's the, on the exam question, perifascicular atrophy, but that's a late stage, usually. And so, if you're really attuned and you're a good clinician, you make that diagnosis really quick. You do a biopsy, you might not see that paraphysical atrophy. So, they don't know that in a necrotizing myopathy, the pathologists often think of what they see in a toxic myopathy or a metabolic where there's a lot of necrotic fibers. But in most of the autoimmune necrotizing, it's not. It's actually what you see is more regenerating fibers, a few necrotic fibers. It's because it's usually been smoldering along for a while, and so you have many more regenerating fibers than ones that are actively, and that can fool a lot of people. So, that's a pitfall from that end of things. Some of these myositis specific antibodies aren't specific and at a low titer, particularly if you have more than one antibody being positive, that would be a red flag that it could be false. That's another pitfall. I think a lot of people don't, when they're examining people, really look at the finger flexors and stuff. And again, if I have somebody over the age of fifty, the most common muscle disease is IBM. Number two is IBM, number three is IBM. If you don't- and you have to think about that, and you need to examine the distal finger flexors because it doesn't get better with immunotherapy. You don't want to put people at the risk of immunotherapy when they're not going to get better. I talked a lot about the biopsies, and biopsy, biopsy, biopsy. But you know, sometimes you can make the diagnosis without a biopsy. So, if somebody's like a classic dermato rash and they have a dermato antibody, do they need a biopsy? No. If they have, you know, CKs of ten thousand proximal weakness, they're on a statin and they have HMGCR antibody, do they need us have a biopsy to confirm? Probably not.
Dr Grouse: Those are some really great pearls that you've shared with us, and I think will be very helpful to many of our listeners. Now, you mentioned earlier about the diminishing category of polymyositis as other types of myosidites have been discovered and better described. Do you think that is the most controversial aspect of this field currently, or are there other controversial areas or areas of ongoing debate that exist?
Dr Amato: It was very controversial twenty years ago, or maybe ten years ago. So, the rheumatology guidelines, they're the ones that are often saying, oh yeah, we were right.Polymyositis, it's just hodgepodge, and it's ever-shrinking. So that's not so controversial anymore. I mean, the controversies that we have, what's the pathogenesis of dermato? It's still a little debated, some- the old theory was that it was a complement-mediated microangiopathy and the damage was caused by ischemia. That's probably not the case. It looks more and more like it's a type 1 interferonopathy, and that's toxic to the vessels in the muscle. There's still a little bit of a debate about that or, you know, you have complement might be on it, but how much that might be damaging, or it's just a secondary phenomenon. I think in the antisynthetase things, I think there's some interesting things also with that these antibodies. We used to think of that they're just diagnostic biomarkers. But there's some recent studies suggesting that these antibodies which are directed against intracellular targets, which is interesting and applies to other autoimmune diseases and that are in the brain too. And we would think that, oh, if it's a intracellular target, it it's secondary. But there's suggestion now that- again, it did demonstrate that the antibodies actually get into muscle fibers. And they bind to these targets. So maybe they're just not epiphenomenon, but they might be binding to a target and causing pathology. And that's what there's some preliminary studies that are impressed, I will say, that have antibodies, anti-HMGCR, that actually go into the cell and they inhibit the enzyme. And that might be causing the pathology. And so that's interesting. And then IBM is a big field. Is this a primary autoimmune disease that has these other kinds of degenerative features like REM vacuoles, or is it a primary degenerative that has secondary inflammation, or is it a combination of both? So, that's probably the biggest controversy these days. It is probably with IBM. What the heck is causing it?
Dr Grouse: Sounds like a lot that we still have to understand about these diseases. This does lead me to wonder, though, have some of these new discoveries and ideas led to or will lead to any new breakthroughs, either in diagnostics or in therapeutics?
Dr Amato: So, certainly in therapeutics. So, the discovery of dermato being an interferonopathy, probably a beta-interferonopathy, has led to development of monoclonal antibodies that target interferon, and there's trials underway. And in phase 2 studies, I can tell you from talking to colleagues that participate just melted away the rash of dermato. So, I think that's going to be a very, very good drug in the future for dermato. There's others, like JAK. JAK inhibitors work on that interferon pathway too. So, I think we'll be going towards, like, less broad-spectrum steroids, IVIG, to going, let's go to the target. Certainly, in dermato, I mean, IBM, we don't know. There is an inflammatory cell that we see in IBM that has a receptor, KCRRN receptor, and there's a monoclonal antibody that targets that in IBM, and that's a phase 3 trial right now. Hopefully that study should be ending in December, and so early next year we'll have results about that. The fact that these antibodies might be pathogenic of themselves is other ways to get rid of the antibodies. So, getting rid of plasma cells and B cells, and FCRN receptors which have been approved or antagonists that are approved for myasthenia. Now CIDP might work in some of the inflammatory myopathies where we think the antibodies might be pathogenic. So, FCRN receptor antagonist and they're in trial now as well. And there's CAR-T therapies to knock out the antibody-producing lymphocytes and plasma cell. So, I think we're going to move into the field of individualized therapies as we find the distinct pathogenesis of these disorders.
Dr Grouse: That's really exciting to hear and I can't wait to see what's coming down the pipeline as more of these discoveries are made and the clinical trials advance. It has been such a pleasure. I've learned so much. So much is packed into the article. So again, I can't stress enough, please take the time to check out this article. I think you'll learn a lot, and it'll really help you fine-tune your diagnostic pathway in relation to myopathies.
Dr Amato: Oh, my pleasure. Thank you. Anybody has questions, please feel free to send me an email.
Dr Grouse: We may just take you up on that. Again, today I've been interviewing Dr Anthony Amato about his article on idiopathic inflammatory myopathies, which he wrote with Dr Kian Salajegheh. This article appears in the October 2025 Continuum issue on muscle and neuromuscular junction disorders. Be sure to check out Continuum Audio episodes from this and other issues, and thank you to our listeners for joining today.
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Dr Berkowitz: This is Dr Aaron Berkowitz with Continuum Audio, and today I'm interviewing Dr Kathryn Moore about her article on diagnosis and management of Huntington disease and chorea, which appears in the August 2025 Continuum issue on movement disorders. Welcome to the podcast, Dr Moore. Could you please introduce yourself to our audience?
Dr Moore: Yeah, thank you so much. I'm so excited to be here. I'm Dr Moore. I'm an assistant professor of neurology at Duke University, where I work as a movement disorder specialist. I run our fellowship there and help with our residency program as well. So, I'm excited to speak with our listeners about chorea today.
Dr Berkowitz: Fantastic. And we're excited to talk to you about chorea. So, as a general neurologist myself, I only see chorea pretty rarely compared to other movement disorders like tremor, myoclonus, maybe the occasional tic disorder. And like anything I don't see very often, I always have to look up the differential diagnosis and how to evaluate a patient with chorea. So, I was so glad to read your article. And next time I see a patient with chorea, I know I'll be referring to your article as a great reference to have a framework for how to approach it. I hope our readers will look at all these helpful tables on differential diagnosis based on distribution of chorea in the body, potential etiologies, time course of onset and evolution, associated drug-induced causes, what tests to send. So, I highly recommend our listeners read the article. Keep those tables handy for when a patient comes in with chorea. I'm excited to pick your brain about some of these topics today. First, how do you go about distinguishing chorea from other hyperkinetic movement disorders when you see a patient that you think might have chorea?
Dr Moore: One of the wonderful things about being a movement disorder specialist is we spend a lot of time looking at movements and training our brain to make these distinctions. The things that I would be looking out for chorea is involuntary, uncontrolled movements that appear to be brief and flowing from one part of the body to another. So, if you can watch a patient and predict what movements they're going to do, this probably isn't chorea. And it should be flowing from one part of the body to another. So, not staying just in one part of the body or having sustained movements. It can be difficult to distinguish between a tic or dystonia or myoclonus. Those things tend to be more predictable and repetitive than the chorea, which tends to be really random and can look like dancing.
Dr Berkowitz: That's very helpful. So, once you've decided the patient has chorea, what's your framework for thinking about the differential diagnosis of the cause of the patient's chorea?
Dr Moore: Well, that could be really challenging. The differential for chorea is very broad, and so the two things that I tend to use are age of the patient and acuity of onset. And so, if you're thinking about acute onset of chorea, you're really looking at a structural lesion like a stroke or a systemic issue like infection, hyperglycemia, etc. Where a gradually progressive chorea tends to be genetic in nature. When you're thinking about the difference between a child and an adult, the most common cause of chorea in a child is Sydenham's chorea. And actually, the most common cause of chorea that I tend to see is Parkinson's disease medication. So, if anybody's seen dyskinesia in Parkinson's disease, you've seen chorea. But it's those two things that I'm using, the age of the patient and the acuity. Somewhere in the middle, though---so, if you have subacute onset of chorea---it's important to remember to think about autoimmune conditions or paraneoplastic conditions because these are treatable.
Dr Berkowitz: That's very helpful. So, like in any chief concern in neurology, we're using the context like the age and then the time course. And then a number of other helpful points in your article about the distribution of chorea in the body. Any comments you'd like to make about- we have this very helpful table that I thought was very interesting. So, you really get deep into the nuances of chorea and the movement disorder specialist expert level. Are there any aspects of parts of the body affected by chorea or distribution of chorea across the body that help you hone your differential diagnosis?
Dr Moore: Certainly. I think where the chorea is located in the body can be helpful, but not as helpful as other conditions where you're localizing a lesion or that sort of thing. Because you can have a systemic cause of chorea that causes a hemichorea; that you can have hyperglycemia causing a hemichorea, or even Sydenham's chorea being a hemichorea. But things that we think about, if the forehead is involved, I would think about Huntington's disease, although this is not pathognomonic. And if it's involving the face or the mouth, you can think about neuroacanthocytosis or, more commonly, tardive dyskinesia. Hemichorea would make me think about some of those systemic issues like hyperglycemia, Sydenham's chorea, those sorts of things, but I would rely more on the historical context and the acuity of presentation than the distribution itself.
Dr Berkowitz: Got it. That's very helpful. So those can be helpful features, but not sort of specific for any particular condition.
Dr Moore: Exactly.
Dr Berkowitz: Yeah, I often see forehead chorea mentioned as sort of specific to Huntington's disease. Since I don't see much Huntington's disease myself, what does forehead chorea look like? What is the forehead doing? How do you recognize that there is chorea of the forehead? It's just sort of hard for me to imagine what it would look like.
Dr Moore: It's really tricky. I think seeing the eyebrows go up and down or the brows furrow in an unpredictable way is really what we're looking for. And that can be hard if you're having a conversation. My forehead is certainly animated as we're talking about one of my favorite topics here. One of the tricks that I use with the fellows is to observe the forehead from the side, and there you can see the undulation of the forehead muscles. And that can be helpful as you're looking for these things. I think where it's most helpful to use the forehead is if you're trying to determine if someone with a psychiatric history has tardive dyskinesia or Huntington's disease, because there can be quite a lot of overlap there. And unfortunately, patients can have both conditions. And so, using the forehead movement can be helpful to maybe direct further testing for Huntington's disease.
Dr Berkowitz: Oh, wow, that's a very helpful pearl. So, if you see, sort of, diffuse chorea throughout the body and the forehead is involved, to my understanding it may be less specific. But in the context of wondering, is the neuropsychiatric condition and movement disorder related by an underlying cause in the case of seeing orofacial dyskinesias, is the relationship a drug having caused a tardive dyskinesia or is the whole underlying process Huntington's, the absence of forehead might push you a little more towards tardive dyskinesia, presuming there is an appropriate implicated drug and the presence of forehead chorea would really clue you in more to Huntington's. Did I understand that pearl?
Dr Moore: That's exactly right, and I'm glad you brought up the point about making sure, if you're considering tardive dyskinesia, that there has been an appropriate drug exposure. Because without that you can't make that diagnosis.
Dr Berkowitz: That's a very helpful and interesting pearl, looking at the forehead from the side. That is a movement disorders pearl for sure. Sort of not just looking at the forehead from one angle and trying to figure out what it's doing, but going to look at the patient in profile and trying to sort it out. I love that. Okay. So, based on the differential diagnosis you would have crafted based on whether this is sort of acute, subacute, chronic, the age of the patient, whether it's unilateral, bilateral, which parts of the body. How do you go about the initial evaluation in terms of laboratory testing, imaging, etc.?
Dr Moore: Well, certainly in an acute-onset patient, you're going to get a number of labs---and that's listed out for you in the paper---and consider imaging as well, looking for an infarct. One thing our learners will know is that sort of the typical answer to what's the infarct causing hemichorea would be the subthalamic nucleus. But really, those infarcts can be almost anywhere. There are case reports for infarcts in a wide variety of places in the brain leading to hemichorea. So, I think some general blood work and an MRI of the brain is a good place to start. For someone who has a more chronic course of the development of chorea, there are certain labs that I would get---and an MRI, because if you get an MRI and there's heavy metal deposition or other disease, structurally, that indicates a certain condition, that can help you pretty considerably. But otherwise, I'm looking for inflammatory markers, heavy metals, HIV, some general other things that are outlined, to help make sure that I'm not missing something that's treatable before I go down the route of genetic testing. And we may talk about this in a little bit, but if you start out with genetic testing and then you sort of have to back up and do more systemic testing, that can be very disjointed when it comes to good patient care.
Dr Berkowitz: That's very helpful. So yeah, if it's acute, obviously this is the most straightforward scenario, acute and unilateral. We're imagining something lesional, as you said, either a stroke or---not sort of sudden, but fast, but not sudden---you might think of another structural lesion. Toxoplasmosis, right, has an affinity for the basal ganglia if you were seeing this in a patient who is immunocompromised. But in a case that, probably as you alluded to, sort of what we would see most commonly in practice, those still relatively rare, sort of subacute to chronic symmetric chorea. There's a long list of tests that are recommended. In your article and in other texts, I've read lupus testing, anti-phospholipid antibodies… but the list is long. I'll refer readers to your article. Out of curiosity as a specialist, how often do you see any of these labs come back revealing any underlying diagnosis in a patient who's otherwise healthy and just has developed chorea and comes to you with that chief concern? I feel like I've sent that mega-workup a few times; I'm obviously a general neurologist, but not nearly as many times as you have been. It's- I can't remember a time where something has come up, maybe an ANA one to forty or something like this that we don't think is relevant. But in your practice, how often do you end up finding a reversible cause in the laboratory testing versus ending up starting to go down the genetic testing route, which we'll talk about in a moment?
Dr Moore: It's not common, but it is important that we capture these things. Because for a lot of those laboratory tests, there are treatments that are available, or other health implications if those come back positive. So, the case I think of is a polycythemia vera patient who had diffused subacute onset chorea and was able to be treated, was temporarily managed with medication for her chorea, and as her PV improved, she was able to come off those medications. As I was alluding to before---and I'm sure we'll talk about genetic testing---if you test for HD and it's negative, do you go down the route of additional expensive genetic testing, or do you then circle back and go, oops, I missed this treatable condition? As we talk about genetic testing as well, getting HD testing is a pretty involved process. And so, we want to make sure we are checking all those boxes before we move forward. So, it's not common, but we do catch some treatable conditions, and that's really important not to miss.
Dr Berkowitz: That's very interesting. So, you diagnosed that polycythemia vera by blood smear, is that how you make the diagnosis?
Dr Moore: Yes.
Dr Berkowitz: And is that a once-in-a-career-so-far type of thing, or does that happen time to time?
Dr Moore: For me, that's a once-so-far, but I don't doubt that I'll see it again.
Dr Berkowitz: Great. And how about lupus and some of these other things we look for in the absence of other systemic features? Have you picked up any of these or heard of colleagues picking up something on laboratory testing? They said, oh, this patient came in for a referral for genetic testing, negative Huntington's disease. And good news, we found polycythemia vera; good news, we found undiagnosed lupus and we reversed it. I'm just curious, epidemiologically, seeing these long lists and not having the subspecialty practice that you do, how often you find a reversible cause like we do for neuropathy all the time, right? Oh, it's diabetes, it's B12---maybe not reversible, but preventing progression---or reversible dementia work up. You get so excited when you find low B12 and you replete the patient's B12, and they get better when they had been concerned they were developing an irreversible condition. How often does one in your subspecialty find a reversible cause on that initial mega-lab screen?
Dr Moore: I think it's really uncommon, and maybe the folks that do are caught by someone else that never make it to Huntington's clinic, but I don't tend to see those cases. There are, of course, case reports and well-described in the literature about lupus and movement disorders and things of that nature, but that doesn't come to our clinic on a regular basis for sure.
Dr Berkowitz: Got it. That's helpful to hear. Well, we've alluded to genetic testing a number of times now, so let's go ahead and talk about it. A lot of your article focuses on Huntington disease, and I was thinking about---in the course of our medical training in medical school, and then neurology residency, for those of us who don't become movement disorder experts like yourself---we learn a lot about Huntington disease. That's sort of the disease that causes chorea, until we later learned there are a whole number of diseases, not just the reversible causes we've been talking about, but a number of genetic diseases which you expertly reviewing your article. So, what are some of the red flags that suggest to you that a patient with chronically progressive chorea---and whom you're concerned for Huntington's or another genetic cause---what are some things you notice about the history, about the exam, the symptoms, the signs, the syndrome, that suggest to you that, actually, this one looks like it might not turn out to be HD. I think this patient might have something else. And as you have alluded to, how do you approach this? Do you send HD testing, wait for it to come back, and then go forward? Are there genetic panels for certain genetic causes of chorea? Do you skip just a whole exome sequencing, or will you miss some of the trinucleotide repeat conditions? How do you approach this in practice?
Dr Moore: I'll try to tackle all that. One thing I will say is that a lot of patients with chorea, regardless of the cause, can look very similar to one another. So, if you're looking at chronic onset chorea, perhaps with some neuropsychiatric features, I'm going to most often think about HD because that's the most common cause. Certainly, as we mentioned before, if there's a lot of tongue protrusion, I would think about the acanthocytic conditions, neurocanthocytosis and McCloud syndrome. But generally in those conditions, we're looking at HD as the most likely cause. Certainly, if there is epilepsy or some other syndromic types of things going on, I may think more broadly. But it's important to know that while HD, as you mentioned, is the cause of chorea, many of our patients will have parkinsonism, tics, dystonia, a whole host of other movement phenomenologies. So, that wouldn't dissuade me from thinking about HD. When we think about the kind of patients that you're describing, upwards of 95% of those people will have Huntington's disease. And the process for genetic testing is fairly involved. The Huntington's Disease Society of America has organized a set of recommendations for providers to go about the process of genetic testing in a safe and supportive way for patients and their families. And so that's referred to in the article because it really is important and was devised by patients and families that are affected by this disease.
And so, when we're thinking about genetic testing for HD, if I reveal that you have HD, this potentially affects your children and your parents and your siblings. You can have a lot of implications for the lives and health and finances of your family members. We also know that there is high suicidality in patients with HD, in patients who are at risk for HD; and there's even a higher risk of suicidality in patients who are at risk but test negative for HD. So, we do recommend a supportive environment for these patients and their families. And so, for presymptomatic patients or patients who are at risk and don't have chorea, this involves making sure we have, sort of, our ducks in a row, as it were, when we think about life insurance, and, do you have somebody supportive to be with you through this journey of genetic testing, no matter what the results are? So, oftentimes I'll say to folks, you know, there's this 20-page policy that I encourage you to look at, but there are Huntington's Disease Centers of Excellence across the country that are happy to help you with that process, to make sure that the patients are well supported. This is an individual genetic test because, as you mentioned, it is a CAG repeat disorder. And unfortunately, there is no chorea panel.
So, if an HD test comes back negative, what we'll do then is think about what's called the HD phenocopies. As I mentioned before, some of these patients who look like they have HD will have a negative HD test. And so, what do you do then? Well, there's a handful of phenocopies---so, other genetic mutations that cause a very similar presentation. And so, we try to be smart, since there's not a panel, we try to be smart about how we choose which test to do next. So, for instance, there's a condition called DRPLA that is present in an African-American family here in my area, in North Carolina, as well as in Japan. And so, if someone comes from those backgrounds, we may decide that that's the next test that we're going to do. If they are white European descent, we may consider a different genetic test; or if they're sub-Saharan African, we may choose a different one from that. However, even if you do a really thorough job, all those blood tests, all those genetic tests, you will occasionally get patients that you can't find a diagnosis for. And so, it's important to know even when you do a good job, you may still not find the answer. And so, I think trying to do things with this complex of the presentation in a systematic way for yourself so you're not missing something. So, going back to our answer about, how do I look at lupus and polycythemia vera and all of that, to think about it in a systematic way. That when you get to the end and you say, well, I don't have an answer, you know you've tried.
Dr Berkowitz: That's very helpful to hear your approach to these challenging scenarios, and also how to approach the potential challenging diagnosis for patients and their families getting this diagnosis, particularly in the presymptomatic phase. And your article touches on this with a lot of nuance and thoughtfulness. So, I encourage our listeners to have a read of that section as well. So, last here, just briefly in our final moments, you discuss in your article the various symptomatic treatments for chorea. We won't have time to go into all the details of all the many treatments you discussed, but just briefly, how do you decide which medication to start in an individual patient with chorea for symptomatic management? What are some of the considerations related to the underlying condition, potential side effect profiles of the particular medications, or any other considerations just broadly, generally, as you think about choosing one of the many medications that can be used to treat chorea?
Dr Moore: Certainly. So, there is a group of FDA-approved medications, VMAT2 inhibitors, that we can choose from, or the off-label use of neuroleptics. And so, there's a lot of things that go into that. Some of that is insurance and cost and that sort of thing, and that can play a role. Others are side effects. So, for the VMAT2 inhibitors, they all do have a black box warning from the FDA about suicidality. And so, if a patient does struggle with mental health, has a history of suicidality, psychiatric admissions for that sort of thing, then I would be more cautious about using that medication. All patients are counseled about that, as are their families, to help us give them good support. So, the neuroleptics do not tend to have that side effect and can help with mood as well as the chorea and can be helpful in that way. And some of them, of course, will have beneficial side effects. So, olanzapine may help with appetite, which can be important in this disease. So, the big considerations would be the black box warning and suicidality, as well as, are we trying to just treat chorea or are we treating chorea and neuropsychiatric issues?
Dr Berkowitz: Fantastic. Thank you for that overview. And again, for our listeners, there's a lot more detail about all of these medications, how they work, how they're used in different patient populations, their side effects, etc, to be reviewed in your excellent article. Again, today, I've been interviewing Dr Kathryn Moore about her article on diagnosis and management of Huntington's disease in chorea, which appears in the August 2025 Continuum issue on movement disorders. Be sure to check out Continuum Audio episodes from this and other issues. And thank you so much to our listeners for joining today. And thank you again, Dr Moore.
Dr Moore: Thanks for having me.
Dr Monteith: This is Dr Teshamae Monteith, associate editor of Continuum Audio. If you've enjoyed this episode, you'll love the journal, which is full of in-depth and clinically relevant information important for neurology practitioners. Use the link in the episode notes to learn more and subscribe. AAN members, you can get CME for listening to this interview by completing the evaluation at continpub.com/audioCME. Thank you for listening to Continuum Audio.
Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum. Thank you for listening to Continuum Audio. Be sure to visit the links in the episode notes for information about earning CME, subscribing to the journal, and exclusive access to interviews not featured on the podcast.
Dr Monteith: Hi, this is Dr Teshamae Monteith. Today I'm interviewing Dr Nikolaus McFarland about his article on progressive supranuclear palsy and cortical basilar syndrome, which appears in the August 2025 Continuum issue on movement disorders. Welcome, how are you?
Dr Farland: I'm great. Thank you for inviting me to do this. This is a great opportunity. I had fun putting this article together, and it's part of my passion.
Dr Monteith: Yes, I know that. You sit on the board with me in the Florida Society of Neurology and I've seen your lectures. You're very passionate about this. And so why don't you first start off with introducing yourself, and then tell us just a little bit about what got you interested in this field.
Dr Farland: I'm Dr Nicholas McFarlane. I'm an associate professor at the University of Florida, and I work at the Norman Fixel Institute for Neurological Diseases. I am a director of a number of different centers. So, I actually direct the cure PSP Center of Care and the MSA Center of Excellence at the University of Florida; I also direct the Huntington's clinic there as well. But for many years my focus has been on atypical parkinsonisms. And, you know, I've treated these patients for years, and one of my focuses is actually these patients who suffer from progressive supranuclear palsy and corticobasal syndrome. So that's kind of what this review is all about.
Dr Monteith: You probably were born excited, but I want to know what got you interested in this in particular?
Dr Farland: So, what got me interested in this in particular was really the disease and the challenges that's involved in it. So, Parkinson's disease is pretty common, and we see a lot of that in our clinic. Yet many times, roughly about 10 to 15% of my patients present with these atypical disorders. And they're quite fascinating. They present in different ways. They're fairly uncommon. They're complex disorders that progress fairly rapidly, and they have multiple different features. They're sort of exciting to see clinically as a neurologist. I think they're really interesting from an academic standpoint, but also in the standpoint of really trying to bring together sort of a team. We have built a multidisciplinary team here at the University of Florida to take care of these patients. They require a number of folks on that team to take care of them. And so, what's exciting, really, is the challenge of treating these patients. There are very limited numbers of therapies that are available, and the current therapies that we have often really aren't great and over time they fail. And so, part of the challenge is actually doing research. And so, there's actually a lot of new research that's been going on in this field. Recently, there's been some revisions to the clinical criteria to help diagnose these disorders. So, that's really what's exciting. The field is really moving forward fairly rapidly with a number of new diagnostics, therapeutics coming out. And hopefully we can make a real difference for these patients. And so that's what really got me into this field, the challenge of trying to treat these patients, help them, advocate for them and make them better.
Dr Monteith: And so, tell me what the essential points of this article.
Dr Farland: So, the essential points, really, of this article is: number one, you know, just to recognize the new clinical criteria for both PSP and corticobasal syndrome, the diagnosis for these disorders or the phenotypic spectrum has really expanded over the years. So, we now recognize many different phenotypes of these disorders, and the diagnosis has gotten fairly complicated. And so, one of the goals of this article was to review those new diagnostic criteria and the different phenotypic ways these diseases present. I wanted to discuss, also, some of the neuropathology and clinicopathological overlap that's occurred in these diseases as well as some of the new diagnostic tests that are available. That's definitely growing. Some of the new studies that are out, in terms of research and clinical trials. And then wanted to review some of the approaches for treatment for neurologists. Particularly, we're hoping that, you know, this article educates folks. If you're a general neurologist, we're hoping that recognizing these diseases early on will prompt you to refer these patients to specialty clinics or movement disorder specialists early on so they can get appropriate care, confirm your diagnosis, as well as get them involved in trials if they are available.
Dr Monteith: And how has the clinical criteria for PSP and cortical basilar syndrome changed?
Dr Farland: I think I already mentioned there's been an evolution of the clinical criteria for PSP. There's new diagnostic criteria that were recently published, and it recognizes the multiple clinical phenotypes and the spectrum of the disease that's out there, which is much broader than we thought about. Corticobasal clinical criteria are the Dr Armstrong criteria from 2013. They have not been updated, but they are in the works of being updated. But it does recognize the classic presentation of corticobasal syndrome, plus a frontal executive predominant and then a variant that actually overlaps with PSP. So, there's a lot more overlap in these two diseases than we originally recognized.
Dr Monteith: And so, you spoke a bit about FTD spectrum. So why don't you tell us a little bit about what that is? I know you mentioned multiple phenotypes.
Dr Farland: What I really want to say is that both PSP and corticobasal syndrome, they're relatively rare, and what- sort of as to common features, they both are progressive Parkinson disorders, but they have variable features. While they're commonly associated with Parkinson's, they also fit within this frontotemporal lobar spectrum, having features that overlap both clinically and neuropathologically. I just want folks to understand that overlap. One of this pathological overlap here is the predominant Tau pathology in the brain, an increasing recognology- recognition of sort of the pathological heterogeneity within these disorders. So, there's an initial description, a classic of PSP, as Richardson syndrome. But now we recognize there are lots of different features to it and there are different ways it presents, and there's definitely a lot of clinical pathological overlap.
Dr Monteith: Why don't we just talk about some red flags for PSP?
Dr Farland: Yeah, sure. So, some of the red flags for PSP and even corticobasal syndrome are: number one is rapid progression with early onset of falls, gait difficulty, falling typically backwards, early speech and swallow problems that are more prominent than you see in Parkinson's disease, as well as eye gaze issues. So, ocular motor features, particularly vertical gaze palsy. In particular what we talk about is the supranuclear gaze palsy, and one of the most sensitive features that we've seen with these is downgaze limitation or slowed downgaze, and eventually a full vertical gaze palsy and followed supranuclear gaze palsy. So, there's some of the red flags that we see. So, while we think about the lack of response to levodopa frequently as something that's a red flag for Parkinson's, there are many times that we see Parkinson's patients, and about a quarter of them don't really respond. There's some features that don't respond to levodopa that may not be so specific, but also can be helpful in this disease.
Dr Monteith: And what about the red flags for cortical basilar syndrome?
Dr Farland: So, for cortical basilar syndrome, some of the red flags again are this rapidly depressive syndrome tends to be, at least in its classical present presentation, more asymmetric in its presentation of parkinsonism, with features including things like dystonic features, okay? For limb dystonia and apraxias---so, inability to do a learned behavior. One of those red flags is a patient who comes in and says, my hand doesn't work anymore, which is something extremely uncommon that you hear in Parkinson's disease. Most of those patients will present, say, I might have a tremor, but they very rarely will tell you that I can't use my hand. So look out for that sign.
Dr Monteith: And let's talk a little bit about some of the advances in the fields you mentioned, evolving biomarker and imaging capacities. So, how are these advances useful in helping us understand these conditions, especially when there's so much heterogeneity?
Dr Farland: I might start by talking a little bit about some of the clinical criteria that have advanced. Why don't we start there and just discuss some of the advances? I think in PSP, I think, originally we had both probable and possible diagnoses of PSP, and the diagnostic criteria were basically focused on what was what's called "classical PSP" or "Richardson syndrome". But now we recognize that there are multiple phenotypes. There's an overlap with Parkinsonism that's slower in progression and morphs into PSP, the classical form. There's a frontal behavioral variant where patients present with that frontal behavioral kind of thing. There's a speech-language variant that can overlap with PSP. So they have prominent speech language, potentially even apraxia speech. So, recognition of these different phenotypes is sort of a new thing in this field. There's even overlap with cortical basal syndrome and PSP, and we note that the pathology can overlap as well. So, I think that's one of the things that have changed over time. And these were- recently came out in 2017 in a new publication in the Movement Disorders Society. So, in terms of diagnostic tests as well---and there's been quite a bit of evolution---really still to date, our best diagnostic test is imaging. MRI is really one of our best tests currently. Currently blood tests, spinal fluid, there's new biomarkers in terms of skin… they're still in the research phase and not necessarily very specific yet. So, we rely heavily on imaging still; and for PSP, what we're looking for largely are changes in the brain stem, and particularly focused on the midbrain. So disproportionate midbrain atrophy compared to the pons and the rest of the midbrain is a fairly specific intensive sign for PSP. Whereas in MSA we see more of a pontine atrophy compared to the midbrain. So that can be really helpful, and there are lots of different new measurements that can be done.
PET scans are also being used as well. And there are new PET markers, but they still remain kind of research-based, but are becoming more and more prevalent and may be available soon for potential use. Although there's some overlap with PET tracers with Alzheimer's disease and different Tau isoforms. So, something to be wary about, but we will be seeing some of these soon coming out as well. More kind of up-to-date things include things like the spinal fluid as well as even some of the skin biopsies. And I think we've heard some word of recent studies that have come out that potentially in the very near future we might actually have some Tau protein tests that we can look at Tau either in spinal fluid or even in a skin biopsy. But again, still remains research-based and, we still need more information as to whether these tests can be reproducible and how sensitive or specific they are.
Dr Monteith: It sounds like, when really approaching these patients, still, it's a lot of back to the history, back to the clinical and some basic imaging that we should be able to identify to distinguish these types of patients, and we're not quite where we need to be yet for biomarker.
Dr Farland: I totally agree with you. I think it starts, really, with the clinical exam and that's our main focus here; and understanding some of the new clinical criteria which are more sensitive, but also specific, too. And they're really useful to look at. So, I think reviewing those; patients do progress, following them over time can be really useful. And then for diagnosis, getting imaging if you suspect a patient has an atypical presentation of parkinsonism, to look for signs or features that might be specific for these different disorders.
Dr Monteith: Why don't we take a typical case, a typical patient that you would see in clinic, and walk us through the thought process---especially, maybe they presented somewhat early---and the different treatment approaches to helping the patient, and of course their family.
Dr Farland: Yeah, sure. So, a typical patient might be someone who comes in with, like, a three year history of progressive gait problems and falling. And let's say the patient says, I'm falling backwards frequently. They may have had, like, a rib fracture, or they hit their head once, and they're describing some speech issues as well. Now they're relying on a walker and family members saying they rarely let them be by themselves. And there may be some slowing of their cognitive function and maybe a bit of withdrawal. So that's a typical patient. So, the approach here is really, what are some of the red flags? I think already you hear a red flag of a rapidly progressive disease. So, Parkinson's disease patients rarely have frequent falls within the first five years. So, this is within three years or less. You're already hearing early onset of gait problems and falling, and particularly falling backwards rather than forwards as often Parkinson's disease patients do. You're hearing early speech problems and maybe a subtle hint of cognitive slowing and some withdrawal. So, a lot of things that sort of are red flags. So, our approach really would be examining this patient really closely. Okay? We'd be listening to the history, looking at the patient. One thing is that some of these patients come in, they may be in a wheelchair already. That's a red flag for us. If they're wearing sunglasses---sometimes we see that patients, they have photosensitivity and they're in a chair and they're wearing sunglasses---you take the glasses off and you look at their face and they have that sort of a facial stare to them---not just the masked face, but the stare---and their eyes really aren't moving. So, another kind of clue, maybe this is probably something atypical, particularly PSP is what I'm thinking about.
So, the approach is really, do a thorough exam. I always recommend looking at eye movements and starting with volitional saccades, not giving them a target necessarily, but asking them to look up and then look down. And then particularly look at the speed of downgaze and whether they actually have full versions down, are able to do that. That's probably your most sensitive test for a patient who has PSP. Not the upgaze, which can be- upgaze impairment in older patients can be nonspecific. So, look for that down gaze. So, if I can get out one message, that's one thing that can be easily done and examined fairly quickly for diagnosis of these patients. And then just look for signs of rigidity, bradykinesia, maybe even some myelopraxia, and then look at their gait carefully so that there's a high suspicion. Again, if there's some atypical features, imaging is really important. So, my next step would be probably getting an MRI to evaluate whether- do they have brain somatrophy or other widespread atrophy or other signs? You need to think about your differential diagnosis for some of these patients as well. So, common things are common; vascular disease, you can't have vascular parkinsonism or even signs of NPH. Both of those can present with progressive gait difficulty and falls. So, the gait may look more like Parkinson's rather than ataxic gait that we see in classic PSP, but still they have early gait issues, and that can be a mimicker of PSP, So looking for both of those things in your imaging. Think about sort of autoimmune potentially causes. So, if they have a really rapid progressive cause, there are some rare autoimmune things. There have been recent reports of things like IgLON5, although there's limited cases, but we're doing more screening for some of those autoimmune causes. And then even some infectious causes like Whipples, that are rarely present like this. Okay? And have other signs and features.
Dr Monteith: So, let's say you diagnose this patient with PSP and you're assessing the patients to see how you can improve their quality of life. So, what are some potential symptomatic managements that will help our patient?
Dr Farland: I recommend for most all of these patients… while the literature indicates that many patients with PSP, and especially corticobasal syndrome, don't respond well to levodopa. So, the classic treatment for parkinsonism. However, we all recommend a trial of levodopa. These patients may respond partially to doses of levodopa, and we try to push the doses a bit higher. So, the recommended trial is usually a dose up to roughly 1000 milligrams of levodopa per day. And give it some time, at least two, if not actually three months of a trial. If not well-tolerated, you can back off. If there's no response at all or no improvement, then slowly back off and taper patients off and ask them to tell you whether they feel like they're actually worsening. So, many patients, sometimes, don't recognize the improvements, or family members don't recognize it until we actually taper them back off. And they may end up saying there are some other things that even recognize. Even some nonmotor benefits can be seen with levodopa. In some cases, we do keep them on levodopa, but levodopa's our best therapy for this. Dopamine agonists, MAO inhibitors, have all been sort of tried and they've been studied, but often don't really help or fail to help benefit these patients and could be fraught with some other side effects.
I think many people do also turn to Amantadine as a treatment for Parkinson's, gait problems, freezing, if you see it in these disorders. Yet Amantadine is fraught with issues of side effects, including cognitive issues, and I think is not well-tolerated. But there are the rare patient who actually does respond to this or claims they respond to this. By and large, these patients relentlessly progress, unfortunately. So, beside treatment of other symptoms, I think it's really important to recognize that they require supportive cares and therapy. So, starting those early on and getting your allied healthcares kind of involved. So that includes people like physical, occupational therapy for the gait issues, the falls, occupational therapy for doing daily activities. Speech language pathology can be really a critical player for these because of the early speech and language issues, as well as swallow difficulties. Swallow is compared quickly in these patients. And so, we do recommend the screening evaluation, then often following patients either every six- or even annually, at least, with a swallow evaluation. And we recommend the fluoroscopic-guided kind of modified barium swallow for these patients.
Dr Monteith: And how does that differ if, let's say, the patient had cortical basilar syndrome? What are some of the symptomatic treatments that would be high on your consideration?
Dr Farland: So actually, these patients also have a very similar approach, and they often have some overlapping features. Maybe a little bit of difference in terms of the level of apraxia and some dystonic features that you see in corticobasal syndrome. So, as I mentioned earlier that these patients have a more typ- when they present, typically have a more asymmetric presentation. And one of the biggest issues is this limb apraxia. They may have abnormal movements as well as, like, the alien limb-type phenomena as well. So, the focus of therapy, while similar in the sense we focus on the parkinsonism, I do always try levodopa and try to ramp up the doses to see if it benefits. It does often fail, but it's definitely worth trying. The other focus of these patients is trying to treat symptoms. Dystonia, those features… in some cases, we can help; if it's painful or uncomfortable, muscle relaxants can be used. If it's vocal, things like Botox can be really helpful. Often times it is more palliative than actually restorative in terms of function, but still can be really helpful for patients who ask about pain and discomfort and trying to treat. And then of course, again, the focus on our supportive care. We need to build that network and build that team of folks, the therapists, the physical, occupational, and the speech therapist to help them. If they have language problems---like either in PSP or corticobasal---I'll also include my request to a speech language pathologist to work on cognitive function. That's a special, additional thing you have to ask for and then specifically request when you make a referral to a speech language pathologist.
Dr Monteith: That is so important. I think keeping the simulation, keeping the social support, and I would probably guess that you would also include screening for sleep and mood disorder.
Dr Farland: Absolutely. Mood disorders are really big in these diseases. Patients are suffering terribly. You do hear about labile mood in both of these diseases, particularly PSP; and even what's called pseudobulbar palsy, where the mood is not always congruent with the affect. So they may laugh or cry inappropriately, and particularly the crying can be very disturbing to family and caregivers to see that. And so, treating those things can be really important. So always asking about the mood issues. Depression in particular is something that we're very sensitive about, and there is a higher incidence of suicidal ideations. Asking about that and feeling and making sure that they are in a safe environment can be really important.
Dr Monteith: Thank you so much.
Dr Farland: Thank you.
Dr Monteith: Today I've been interviewing Dr Nikolaus McFarland about his article on progressive supranuclear palsy and cortical basilar syndrome, which appears in the August 2025 Continuum issue on movement disorders. Be sure to check out 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, you'll love the journal, which is full of in-depth and clinically relevant information important for neurology practitioners. Use the link in the episode notes to learn more and subscribe. AAN members, you can get CME for listening to this interview by completing the evaluation at continpub.com/audioCME. Thank you for listening to Continuum Audio.
Dr. Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum. Thank you for listening to Continuum Audio. Be sure to visit the links in the episode notes for information about earning CME, subscribing to the journal, and exclusive access to interviews not featured on the podcast.
Dr Albin: Hello everyone, this is Dr Casey Albin. Today I'm interviewing Dr Tao Xie about his article on diagnosis and management of multiple system atrophy, which appears in the August 2025 Continuum issue on movement disorders. Welcome to the podcast, and please introduce yourself to our audience.
Dr Xie: Thank you so much, Dr Albin. My name is Tao Xie, and sometimes people also call me Tao Z. I'm a mood disorder neurologist, professor of neurology at the University of Chicago. I'm also in charge of the mood disorder program here, and I'm the section chief in the neurodegenerative disease in the Department of Neurology at the University of Chicago Medicine. Thank you for having me, Dr Albin and Dr Okun and the American Academy of Neurology. This is a great honor and pleasure to be involved in this education session.
Dr Albin: We are delighted to have you, and thank you so much for the thoughtful approach to the diagnosis and management. I really want to encourage our listeners to check out this article. You know, one of the things that you emphasize is multiple system atrophy is a fairly rare condition. And I suspect that clinicians and trainees who even have a fair amount of exposure to movement disorders may not have encountered that many cases. And so, I was hoping that you could just start us off and walk us through what defines multiple system atrophy, and then maybe a little bit about how it's different from some of the more commonly encountered movement disorders.
Dr Xie: This is a really good question, Dr Albin. Indeed, MSA---multisystem atrophy----is a rare disease. It is sporadic, adult-onset, progressive, fatal neurodegenerative disease. By the name MSA, multisystem atrophy. Clinically, it will present with multiple symptoms and signs involving multiple systems, including symptoms of autonomic dysfunction and symptoms of parkinsonism, which is polyresponsive to the levodopa treatment; and the symptom of cerebellar ataxia, and symptom of spasticity and other motor and nonmotor symptoms. And you may be wondering, what is the cause- underlying cause of these symptoms? Anatomically, we can find the area in the basal ganglia striatonigral system, particularly in the putamen and also in the cerebellar pontine inferior, all of the nuclear area and the specific area involved in the autonomic system in the brain stem and spinal cord: all become smaller. We call it atrophy. Because of the atrophy in this area, they are responsible for the symptom of parkinsonism if it is involved in the putamen and the cerebral ataxia, if it's involved in the pons and cerebral peduncle and the cerebellum. And all other area, if it's involved in the autonomic system can cause autonomic symptoms as well.
So that's why we call it multisystem atrophy. And then what's the underlying cellular and subcellular pathological, a hallmark that is in fact caused by misfolded alpha-synuclein aggregate in the oligodontia site known as GCI---glial cytoplasmic increasing bodies---in the cells, and sometimes it can also be found in the neuronal cell as well in those areas, as mentioned, which causes the symptom. But clinically, the patient may not present all the symptoms at the same time. So, based on the predominant clinical symptom, if it's mainly levodopa, polyresponsive parkinsonism, then we call it MSAP. If it's mainly cerebellar ataxia, then we call it MSAC. But whether we call it MSP or MSC, they all got to have autonomic dysfunction. And also as the disease progresses, they can also present both phenotypes together. We call that mixed cerebellar ataxia and parkinsonism in the advanced stage of the disease. So, it is really a complicated disease. The complexity and the similarity to other mood disorders, including parkinsonism and the cerebellar ataxia, make it really difficult sometimes, particularly at the early stages of disease, to differentiate one from the other. So, that was challenging not only for other professionals, general neurologists and even for some movement disorder specialists, that could be difficult particularly if you aim to make an accurate and early diagnosis.
Dr Albin: Absolutely. That is such a wealth of knowledge here. And I'm going to distill it just a little bit just to make sure that I understand this right. There is alpha-synuclein depositions, and it's really more widespread than one would see maybe in just Parkinson's disease. And with this, you are having patients present with maybe one of two subtypes of their clinical manifestations, either with a Parkinson's-predominant movement disorder pattern or a cerebellar ataxia type movement disorder pattern. Or maybe even mixed, which really, you know, we have to make things quite complicated, but they are all unified and having this shared importance of autonomic features to the diagnosis. Have I got that all sort of correct?
Dr Xie: Correct. You really summarize well.
Dr Albin: Fantastic. I mean, this is quite a complicated disease. I would pose to you sort of a case, and I imagine this is quite common to what you see in your clinic. And let's say, you know, a seventy-year-old woman comes to your clinic because she has had rigidity and poor balance. And she's had several falls already, almost always from ground level. And her family tells you she's quite woozy whenever she gets up from the chair and she tends to kind of fall over. But they noticed that she's been stiff,and they've actually brought her to their primary care doctor and he thought that she had Parkinson's disease. So, she started levodopa, but they're coming to you because they think that she probably needs a higher dose. It's just not working out very well for her. So how would you sort of take that history and sort of comb through some of the features that might make you more concerned that the patient actually has undiagnosed multiple systems atrophy?
Dr Xie: This is a great case, because we oftentimes can encounter similar cases like this in the clinic. First of all, based on the history you described, it sounds like an atypical parkinsonism based on the slowness, rigidity, stiffness; and particularly the early onset of falls, which is very unusual for typical Parkinson disease. It occurs too early. If its loss of balance, postural instability, and fall occurred within three years of disease onset---usually the motor symptom onset---then it raises a red flag to suspect this must be some atypical Parkinson disorders, including multiple system atrophy. Particularly, pou also mentioned that the patient is poorly responsive to their levodopa therapy, which is very unusual because for Parkinson disease, idiopathic Parkinson disease, we typically expect patients would have a great response to the levodopa, particularly in the first 5 to 7 years. So to put it all together, this could be atypical parkinsonism, and I could not rule out the possibility of MSA. Then I need to check more about other symptoms including autonomic dysfunction, such as orthostatic hypertension, which is a blood pressure drop when the patient stands up from a lying-down position, or other autonomic dysfunctions such as urinary incontinence or severe urinary retention. So, in the meantime, I also have to put the other atypical Parkinson disorder on the differential diagnosis, such as PSP---progressive supranuclear palsy---and the DLBD---dementia with Lewy body disease.---Bear this in mind. So, I want to get more history and more thorough bedside assessment to rule in or rule out my diagnosis and differential diagnosis.
Dr Albin: That's super helpful. So, looking for early falls, the prominence of autonomic dysfunction, and then that poor levodopa responsiveness while continuing to sort of keep a very broad differential diagnosis?
Dr Xie: Correct.
Dr Albin: One of the things that I just have to ask, because I so taken by this, is that you say in the article that some of these patients actually have preservation of smell. In medical school, we always learn that our Parkinson's disease patients kind of had that early loss of smell. Do you find that to be clinically relevant? Is that- does that anecdotally help?
Dr Xie: This is a very interesting point because we know that the loss of smelling function is a risk effect, a prodromal effect, for the future development of Parkinson disease. But it is not the case for MSA. Strange enough, based on the literature and the studies, it is not common for the patient with MSA to present with anosmia. Some of the patients may have mild to moderate hyposmia, but not to the degree of anosmia. So, this is why even in the more recent diagnosis criteria, the MDS criteria published 2022, it even put the presence of anosmia in the exclusion criteria. So, highlight the importance of the smell function, which is well-preserved for the majority in MSA, into that category. So, this is a really interesting point and very important for us, particularly clinicians, to know the difference in the hyposmia, anosmia between the- we call it the PD, and the dementia Lewy bodies versus MSA.
Dr Albin: Fascinating. And just such a cool little tidbit to take with us. So, the family, you know, you're talking to them and they say, oh yes, she has had several fainting episodes and we keep taking her to the primary care doctor because she's had urinary incontinence, and they thought maybe she had urinary tract infections. We've been dealing with that. And you're sort of thinking, hm, this is all kind of coming together, but I imagine it is still quite difficult to make this diagnosis based on history and physical alone. Walk our listeners through sort of how you're using MRI and DAT scan and maybe even some other biomarkers to help sort of solidify that diagnosis.
Dr Xie: Yeah, that's a wonderful question. Yeah. First of all, UTI is very common for patients with MSA because of urinary retention, which puts them into a high risk of developing frequent UTI. That, for some patients, could be the very initial presentation of symptoms. In this case, if we check, we say UTI is not present or UTI is present but we treat it, then we check the blood pressure and we do find also hypertension---according to new diagnosis criteria, starting drop is 20mm mercury, but that's- the blood pressure drop is ten within three minutes. And also, in the meantime the patients present persistent urinary incontinence even after UTI was treated. And then the suspicion for MS is really high right at this point. But if you want increased certainty and a comfortable level on your diagnosis, then we also need to look at the brain MRI mark. This is a required according to the most recent MDS diagnosis criteria. The presence of the MRI marker typical for MSA is needed for the diagnosis of clinically established MSA, which holds the highest specificity in the clinical diagnosis. So then, we have- we're back to your question. We do need to look at the brain MRI to see whether evidence suggestive of atrophy around the putamen area, around the cerebellar pontine inferior olive area, is present or not.
Dr Albin: Absolutely. That's super helpful. And I think clinicians will really take that to sort of helping to build a case and maybe recognizing some of this atypical Parkinson's disease as a different disease entity. Are there any other biomarkers in the pipeline that you're excited about that may give us even more clarity on this diagnosis?
Dr Xie: Oh, yeah. This is a very exciting area. In terms of biomarker for the brain imaging, particularly brain MRI, in fact, today there's a landmark paper just published in the Java Neurology using AI, artificial intelligence or machine learning aid, diagnoses a patient with parkinsonism including Parkinson's disease, MSA, and PSP, with very high diagnostic accuracy ranging from 96% to 98%. And some of the cases even were standard for autopsy, with pathological verification at a very high accurate rate of 93.9%. This is quite amazing and can really open new diagnosis tools for us to diagnose this difficult disease; not only in an area with a bunch of mood disorder experts, but also in the rural area, in the area really in need of mood disorder experts. They can provide tremendous help to provide accurate, early diagnosis.
Dr Albin: That's fantastic and I love that, increasing the access to this accurate diagnosis. What can't artificial intelligence do for us? That's just incredible.
Dr Xie: And also, you know, this is just one example of how the brain biomarker can help us. Theres other---a fluid biomarker, molecular diagnostic tools, is also available. Just to give you an example, one thing we know over the past couple years is skin biopsy. Through the immunofluorescent reaction, we can detect whether the hallmark of abnormally folded, misfolded, and the phosphorate, the alpha-synuclein aggregate can be found just by this little pinch of skin biopsy. Even more advanced, there's another diagnosis tool we call the SAA, we call the seizure amplification assay, that can even help us to differentiate MSA from other alpha-synucleinopathy, including Parkinson disease and dementia with Lewy bodies. If we get a little sample from CSF, spinal cerebral fluids, even though this is probably still at the early stage, a lot of developments still ongoing, but this, this really shows you how exciting this area is now. We're really in a fast forward-moving path now.
Dr Albin: It's really incredible. So, lots coming down the track in, sort of, MRI, but also with CSF diagnosis and skin biopsies. Really hoping that we can hone in some of those tools as they become more and more validated to make this diagnosis. Is that right?
Dr Xie: Correct.
Dr Albin: Amazing. We can talk all day about how you manage these in the clinic, and I really am going to direct our listeners to go and read your fantastic article, because you do such an elegant job talking about how this takes place in a multidisciplinary setting, if at all possible. But as a neurointensivist, I was telling you, we have so much trouble in the hospital. We have A-lines, and we have the ability to get rapid KUBs to look at Ilias, and we can have many people as lots of diagnosis, and we still have a lot of trouble treating autonomiclike symptoms. Really, really difficult. And so, I just wanted to kind of pick your brain, and I'll start with just the one of orthostatic hypotension. What are some of the tips that you have for, you know, clinicians that are dealing with this? Because I imagine that this is quite difficult to do without patients.
Dr Xie: Exactly. This is indeed a very difficult symptom to deal with, particularly at an outpatient setting. But nowadays with the availability of more medication---to give an example, to treat patients with orthostatic hypertension, we have not only midodrine for the cortisol, we also have droxidopa and several others as well. And so, we have more tools at hand to treat the patient with orthostatic hypertension. But I think the key thing here, particularly for us to the patient at the outpatient setting: we need to educate the patient's family well about the natural history of the disease course. And we also need to tell them what's the indication and the potential side effect profile of any medication we prescribe to them so that they can understand what to expect and what to watch for. And in the meantime, we also need to keep really effective and timely communication channels, make sure that the treating physician and our team can be reached at any time when the patient and family need us so that we can be closely monitoring, their response, and also monitoring potential side effects as well to keep up the quality of care in that way.
Dr Albin: Yeah, I imagine that that open communication plays a huge role in just making sure that patients are adapting to their symptoms, understanding that they can reach out if they have refractory symptoms, and that- I imagine this takes a lot of fine tuning over time.
Dr Xie: Correct.
Dr Albin: Well, this has just been such a delight to get to talk to you. I really feel like we could dive even deeper, but I know for the sake of time we have to kind of close out. Are there any final points that you wanted to share with our listeners before we end the interview?
Dr Xie: I think for the patients, I want them to know that nowadays with advances in science and technology, particularly given a sample of rapid development in the diagnostic tools and the multidisciplinary and multisystemic approach to treatment, nowadays we can make an early and accurate diagnosis of the MSA, and also, we can provide better treatment. Even though so far it is still symptomatically, mainly, but in the near future we hope we can also discover disease-modifying treatment which can slow down, even pause or prevent the disease from happening. And for the treating physician and care team professionals, I just want them to know that you can make a difference and greatly help the patient and the family through your dedicated care and also through your active learning and innovative research. You can make a difference.
Dr Albin: That's amazing and lots of hope for these patients. Right now, you can provide really great care to take care of them, make an early and accurate diagnosis; but on the horizon, there are really several things that are going to move the field forward, which is just so exciting. Again today, I've been really greatly honored and privileged to be able to talk to Dr Tao Xie about his article on diagnosis and management of multiple system atrophy, which appears in the August 2025 Continuum issue on movement disorders. Be sure to check out Continuum Audio episodes for this and other issues. And thank you again to our listeners for joining us today.
Dr Xie: Thank you so much for having me.
Dr Monteith: This is Dr Teshamae Monteith, Associate Editor of Continuum Audio. If you've enjoyed this episode, you'll love the journal, which is full of in-depth and clinically relevant information important for neurology practitioners. Use the link in the episode notes to learn more and subscribe. AAN members, you can get CME for listening to this interview by completing the evaluation at continpub.com/audioCME. Thank you for listening to Continuum Audio.
Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum. Thank you for listening to Continuum Audio. Be sure to visit the links in the episode notes for information about earning CME, subscribing to the journal, and exclusive access to interviews not featured on the podcast.
Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum: Lifelong Learning in Neurology. Today, I'm interviewing Dr Ludy Shih, who recently authored an article on essential tremor for our latest issue of Continuum on movement disorders. Dr Shih is an associate professor of neurology at Harvard Medical School and the clinical director of the Parkinson's Disease and Movement Disorder Center at Beth Israel Deaconess Medical Center in Boston. Dr Shih, welcome, and thank you for joining us today. Why don't you introduce yourself to our listeners?
Dr Shih: Thank you, Dr Jones, for having me. It's a real pleasure to be here on the podcast with you. I'm a neurologist, I trained in movement disorders fellowship, and I currently see patients and conduct clinical research. We offer a variety of treatments and diagnostic tests for our patients with movement disorders. And I have developed this interest, a clinical research interest in essential tremor.
Dr Jones: And so, as an expert in essential tremor, the perfect person to write such a really spectacular article. And I can't wait for our listeners to hear more about it and our subscribers to read it. And let's get right to it. If you had, Dr Shih, a single most important message for our listeners about caring for patients with essential tremor, what would that message be?
Dr Shih: Yeah, I think the takeaway that I've learned over the years is that people with essential tremor do develop quite a few other symptoms. And although we propose that essential tremor is this pure tremor disorder, they can experience a lot of different comorbidities. Now, there is some debate as to whether that is expected for essential tremor or is this some part of another syndrome, which we may talk about later in the interview. But the fact of the matter is, it's not a benign condition and people do experience some disability from it.
Dr Jones: And I think that speaks to how the name of this disorder has evolved over time. right? You point out in your article, it used to be called benign essential tremor or benign familial tremor. But it's really not so straightforward as it. And fairly frequently these symptoms, the patient's tremor, can be functionally limiting, correct?
Dr Shih: That is correct. In fact, the reason I probably started getting interested in essential tremor was because our center had been doing a lot of deep brain stimulation for essential tremor, which is remarkably effective, especially for tremor that reaches an amplitude that really no oral medication is going to satisfyingly treat. And if you have enough upper limb disability from this very large-amplitude tremor, a surgical option may make a lot of sense for a lot of patients. And yet, how did they get to that point? Do they continue to progress? These were the sort of interesting questions that got raised in my mind as I started to treat these folks.
Dr Jones: We'll come back to treatment in just a minute here, because there are many options, and it sounds like the options are expanding. To start with the diagnosis- I mean, this is an extraordinarily common disorder. As you point out, it is the most common movement disorder in the US and maybe the world, and yet it seems to be underrecognized and frequently misdiagnosed. Why do you think that is?
Dr Shih: Great question. It's been pretty consistent, with several case series over the decades showing a fairly high rate of quote/unquote "misdiagnosis." And I think it speaks to two things, probably. One is that once someone sees a postural and kinetic tremor of the arms, immediately they think of essential tremor because it is quite common. But there's a whole host of things that it could actually be. And the biggest one that we also have to factor in is also the heterogeneity of the presentation of Parkinson's disease. Many people, and I think increasingly now these days, can present with not a whole lot of the other symptoms, but may present with an atypical tremor. And it becomes actually a little hard to sort out, well, do they have enough of these other symptoms for me to suspect Parkinson's, or is the nature of their tremor suspicious enough that it would just be so unusual that this stays essential tremor and doesn't eventually develop into Parkinson's disease? And I think those are the questions that we all still grapple with from time to time in some of our clinics.
Dr Jones: Probably some other things related to it with, you know, our understanding of the pathophysiology and the availability of tests. And I do want to come back to those questions here in just a minute, but, you know, just the nomenclature of this disorder… I think our clinical listeners are familiar with our tendency in medicine to use words like essential or idiopathic to describe disorders or phenomena where we don't understand the precise underlying mechanism. When I'm working with our trainees, I call these "job-security terms" because it sounds less humbling than "you have a tremor and we don't know what causes it," right? So, your article does a really nice job outlining the absence of a clear monogenic or Mendelian mechanism for essential tremor. Do you think we'll ever have a eureka moment in neurology for this disorder and maybe give it a different name?
Dr Shih: It's a great question. I think as we're learning with a lot of our neurologic diseases---and including, I would even say, Parkinson's disease, to which ET gets compared to a lot---there's already now so much more known complexity to something that has a very specific idea and concept in people's minds. So, I tend to think we'll still be in an area where we'll have a lot of different causes of tremor, but I'm hopeful that we'll uncover some new mechanisms for which treating or addressing that mechanism would take care of the tremor in a way that we haven't been able to make as much progress on in the last few decades as maybe we would have thought given all the advances in in technology.
Dr Jones: That's very helpful, and we'll be hopeful for that series of discoveries that lead us to that point. I think many of our listeners will be familiar with the utility---and, I think, even for most insurance companies, approval---for DAT scans to discriminate between essential tremor and Parkinsonian disorders. What about lab work? Are there any other disorders that you commonly screen for in patients who you suspect may have essential tremor?
Dr Shih: Yeah, it's a great question. And I think, you know, I'm always mindful that what I'm seeing in my clinic may not always be representative of what's seen in the community or out in practice. I'll give an example. You know, most of the time when people come to the academic Medical Center, they're thinking, gosh, I've tried this or that. I've been on these medicines for the last ten years. But I've had essential tremor for twenty years. We get to benefit a little bit from all that history that's been laid down. And so, it's not as likely you're going to misdiagnose it. But once in a while, you'll get someone with tremor that just started a month ago or just started, you know, 2 or 3 months ago. And you have to still be thinking, well, I've got to get out of the specialist clinic mindset, and think, well, what else really could this be? And so, while it's true for everybody, moreso in those cases, in those recent onset cases, you really got to be looking for things like medications, electrolyte abnormalities, and new-onset thyroid disorder, for example, thyroid toxicosis.
Dr Jones: Very helpful. And your article has a wonderful list of the conditions to consider, including the medications that might be used for those conditions that might result or unmask a tremor of a different cause. And I think being open-minded and not anchoring on essential tremor just because it's common, I think is a is a key point here. And another feature in your article that I really enjoyed was your step-by-step approach to tremor. What are those steps?
Dr Shih: Well, I think you know first of all, tremor is such common terminology that even lay people, patients, nonclinicians will use the word "tremor." And so, it can be tempting when the notes on your schedule says referred for tremor to sort of immediately jump to that. I think the first step is, is it tremor? And that's really something that the clinician first has to decide. And I think that's a really important step. A lot of things can look superficially like tremor, and you shouldn't even assume that another clinician knows what tremor looks like as opposed to, say, myoclonus. Or for example a tremor of the mouth; well, it actually could be orolingual or orobuccal dyskinesia, as in tardive dyskinesia. And another one that tremor can look like is ataxia. And so, I think- while they sound obvious to most neurologists, perhaps, I think that---especially in the area of myoclonus, where it can be quite repetitive, quite small amplitude in some conditions---it can really resemble a tremor. And so, there are examples of these where making that first decision of whether it's a tremor or not can really be a good sort of time-out to make sure you're going down the right path to begin with. And I think what's helpful is to think about some of the clinical definitions of a tremor. And tremor is really rhythmic, it's oscillatory. You should see an agonist and antagonist muscle group moving back and forth, to and fro. And then it's involuntary. And so, I think these descriptors can really help; and to help isolate, if you can describe it in your note, you can probably be more convinced that you're dealing with the tremor.
The second step that I would encourage people to really consider: you've established it's a tremor. The most important part exam now becomes, really, the nontremor part of the exam. And it should be really comprehensive to think of what else could be accompanying this, because that's really how we make diagnosis of other things besides essential tremor. There really should be a minimum of evidence of parkinsonism, dystonia, neuropathy, ataxia- and the ataxia could be either from a peripheral or central nervous system etiology. Those are the big four or five things that, you know, I'm very keen to look for and will look pretty much in the head, neck, the axial sort of musculature, as well as the limbs. And I think this is very helpful in terms of identifying cases which turn out to have either, say, well, Parkinson's or even a typical Parkinson disorder; or even a genetic disorder, maybe even something like a fragile X tremor ataxia syndrome; or even a spinal cerebellar ataxia. These cases are rare, but I think if you uncover just enough ataxia, for example, that really shouldn't be there in a person, let's say, who's younger and also doesn't have a long history of tremor; you should be more suspicious that this is not essential tremor that you're dealing with.
And then the last thing is, once you've identified the tremor and you're trying to establish, well, what should be done about the tremor, you really have to say what kind of tremor it is so that you can follow it, so you can convey to other people really what the disability is coming from the tremor and how severe the tremor is. So, I think an example of this is, often in the clinic, people will have their patients extend their arms and hands and kind of say, oh, it's an essential tremor, and that's kind of the end of the exam. But it doesn't give you the flavor. Sometimes you'll have a patient come in and have a fairly minimal postural tremor, but then you go out, take those extra few seconds to go grab a cup of water or two cups of water and have them pour or drink. And now all of a sudden you see this tremor is quite large-amplitude and very disabling. Now you have a better appreciation of what you really need to do for this patient, and it might not be present with just these very simple maneuvers that you have at bedside without props and items. And then the severity of it; you know, we're so used to saying mild, moderate, severe. I think what we've done in the Tremor Research Group to use and develop the Essential Tremor Rating Assessment Scale is to get people used to trying to estimate what size the tremor is. And you can do that by taking a ruler or developing a sense of what 1 centimeter, 2 centimeters, 3 centimeters looks like. I think it'd be tremendously helpful too, it's very easy and quick to convey severity in a given patient.
Dr Jones: I appreciate you, you know, having a patient-centered approach to the- how this is affecting them and being quantitative in the assessment of the tremor. And that's a great segue to a key question that I run into and I think others run into, which is when to initiate therapy? You know, if you see a patient who, let's say they have a mild tremor or, you know, something that quantitatively is on the mild end of the spectrum, and you have, you know, a series of options… from a medication perspective, you have to say, well, when does this across that threshold of being more likely to benefit the patient than to harm the patient? How do you approach that question? What's your threshold for starting medication?
Dr Shih: Yeah. You know, sometimes I will ask, because---and I know this sounds like a strange question---because I feel like my patients will come for a couple of different reasons. Sometimes it's usually one over the other. I think people can get concerned about a symptom of a tremor. So, I actually will ask them, was your goal to just get a sense for what this tremor is caused by? I understand that many people who develop tremor might be concerned it might be something like Parkinson's disease. Or is this also a tremor that is bothering you in day-to-day life? And often you will hear the former. No, I just wanted to get checked out and make sure you don't think it's Parkinson's. It doesn't bother me enough that I want to take medication. They're quite happy with that. And then the second scenario is more the, yeah, no, it bothers me and it's embarrassing. And that's a very common answer you may hear, may be embarrassing, people are noticing. It's funny in that many people with essential tremor don't come to see a doctor or even the neurologist for many years. And they will put up with it for a very long time. And they've adopted all sorts of compensatory strategies, and they've just been able to handle themselves very admirably with this, in some cases, very severe tremor. So, for some of them, it'll take a lot to come to the doctor, and then it becomes clear. They said, I think I'm at the point where I need to do something about this tremor. And so, I think those three buckets are often sort of where my patients fall into. And I think asking them directly will give you a sense of that. But you know, it can be a nice time to try some as-needed doses of something like Propranolol, or if it's something that you know that they're going to need something on day-to-day to get control of the tremor over time, there are other options for that as well.
Dr Jones: Seems like a perfect scenario for shared decision-making. Is it bothersome enough to the patient to try the therapy? And I like that suggestion. That's a nice pearl that you could start with an a- needed beta blocker, right, with Propranolol. And this is a question that I think many of us struggle with as well. If you've followed a patient with essential tremor for some time and you've tried different medications and they've either lost effectiveness or have intolerable adverse effects, what is your threshold for referring a patient for at least considering a surgical neurostimulator therapy for their essential tremor?
Dr Shih: Yeah, so surgical therapies for tremor have been around for a long time now, since 1997, which was when it was approved by the FDA for essential tremor and Parkinson tremor. And then obviously since then, we have a couple more options in the focus ultrasound thalamotomy, which is a lesioning technique. When you have been on several tremor medications, the list gets smaller and smaller. It- and then chance of likely satisfying benefit from some of these medications can be small and small as you pass through the first and second line agents and these would be the Propranolol and the primidone. And as you say, quite a few patients- it's estimated between 30 to 50% of these patients end up not tolerating these first two medications and end up discontinuing them. Some portion of that might also be due to the fact that some of our patients who have been living with essential tremor for decades now, to the point that their tremor is getting worse, are also getting older. And so, polypharmacy and/or some of the potential side effects of beta blockers and anticonvulsants like primidone may be harder to bear in an older adult. And then as you talk about in the article, there's some level of evidence for topiramate, and then from there a number of anticonvulsants or benzos, which have even weaker evidence for them. It's a personal decision. As I tell folks, look, this is not going to likely extend your life or save your life, but it's a quality of life issue. And of course, if there are other things going on in life that need to be taken care of and they need that kind of care and attention, then, you know, you don't need to be adding this to your plate. But if you are in the position where those other things are actually okay, but quality of life is really affected by your being unable to use your upper limbs in the way that you would like to… A lot of people's hobbies and applications are upper limb-based, and enjoying those things is really important. Then I think that this is something- a conversation that we begin and we begin by talking about yes, there are some risks involved, but fortunately this is the data we have on it, which is a fairly extensive experience in terms of this is the risk of, you know, surgery-related side effects. This is the risk of if you're having stimulation from DBS stimulation-related side effects, which can be adjustable. It's interesting, I was talking with colleagues, you know, after focused ultrasound thalamotomy was approved. That really led more people to come to the clinic and start having these discussions, because that seemed like a very the different sort of approach where hardware wasn't needed, but it was still a surgery. And so, it began that conversation again for a bunch of people to say, you know, what could I do? What could I tolerate? What would I accept in terms of risk and potential benefit?
Dr Jones: Well, I think that's a great overview of a disorder where, you know, I think the neurologist's role is really indispensable. Right? I mean, you have to have this conversation not just once, this is a conversation that you have over time. And again, I really want to refer our listeners to this article. It's just a fantastic overview of a common disorder, but one where I think there are probably gaps where we can improve care. And Dr Shih, I want to thank you for joining us, and thank you for such a great discussion on essential tremor. I learned a lot from your article, and I learned even more from the interview today. I suspect our readers and listeners will too.
Dr Shih: Well, thank you again for the invitation and the opportunity to kind of spread the word on this really common condition.
Dr Jones: Again, we've been speaking with Dr Ludy Shih, author of a fantastic article on essential tremor in Continuum's latest issue on movement disorders. 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, you'll love the journal, which is full of in-depth and clinically relevant information important for neurology practitioners. Use the link in the episode notes to learn more and subscribe. AAN members, you can get CME for listening to this interview by completing the evaluation at continpub.com/audioCME. Thank you for listening to Continuum Audio.
Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum. Thank you for listening to Continuum Audio. Be sure to visit the links in the episode notes for information about earning CME, subscribing to the journal, and exclusive access to interviews not featured on the podcast.
Dr Nevel: Hello, this is Dr Kait Nevel. Today I'm interviewing Dr Ashley Rawls about her article on Parkinson disease, which appears in the August 2025 Continuum issue on movement disorders. Ashley, welcome to the podcast, and please introduce yourself to the audience.
Dr Rawls: Thank you, Kait. Hello everyone, my name is Dr Ashley Rawls. I am a movement disorder specialist at the University of Florida Fixel Institute for Neurologic Diseases in Gainesville, Florida. It's a pleasure to be here.
Dr Nevel: Awesome. To start us off talking about your article, can you share what you think is the most important takeaway for the practicing neurologist?
Dr Rawls: Yes. I would say that my most important takeaway for this article is that Parkinson disease remains a clinical diagnosis. I think the field has really been advancing and trying to find a biomarker to help with diagnosis through ancillary testing. For example, with the dopamine transporter, the DAT scan, an alpha-synuclein skin biopsy, an alpha-synuclein amplification assay that can happen in blood and CSF. However, I think it's so critical to make sure that you have a very strong history and a very thorough physical exam and use those biomarkers or other testing to help with, kind of, bolstering your thoughts on what's going on with the patient.
Dr Nevel: Great. And I can't wait to talk a little bit more about the ancillary testing and how you use that. Before we get to that, can you review with us some of the components of the clinical diagnosis of Parkinson disease?
Dr Rawls: Yes. So, when I think about a person that comes in that might have a neurodegenerative disease, I think about two different features, mainly: both motor and Manon motor. So, for my motor features, I'm thinking about resting tremor, bradykinesia---which is fullness of movement with decrement over time---rigidity, and then a specific gait disturbance, a Parkinsonian gait, involving stooped posture, decreased arm swing. They can also have reemergent tremor while walking if they do have tremor as part of their disease process, and also in-block turning as they are walking down the hallway. So, those are my motor features that I look for. So now, when we're talking about a specific diagnosis of Parkinson disease, the one motor feature that you need to have is bradykinesia. The reason why I make sure to speak about bradykinesia, which is slowness of movement with decrement over time, is because people can still have Parkinson disease without having tremor, a resting tremor. So even though that's one of the core cardinal features that most of us will be able to notice very readily, you don't have to necessarily have a resting tremor to be diagnosed with Parkinson' disease. When I talk about nonmotor features, those are going to be the three, particularly the prodromal features that can occur even ten years before people have motor features, can be very prominent early on in the disease process. For example, hyposmia or anosmia for decrease or lack of sense of smell. Another one that we really look for is going to be RBD, or rapid eye movement behavior disorder; or REM behavior disorder, the person acting out their dreams, calling out, flailing their limbs, hitting their bed partner. And then the other one is going to be severe constipation. So those three prodromal nonmotor symptoms of hyposmia/anosmia, RBD or REM behavior disorder, and severe constipation can also make me concerned as a red flag that there is a sort of neurodegenerative issue like a Parkinson disease that may be going on with the patient.
Dr Nevel: Great, thank you so much for that overview. While we're talking about the diagnosis, do you mind kind of going back to what you mentioned in the beginning and talking about the ancillary tests that sometimes are used to kind of help, again, bolster that diagnosis of Parkinson disease? You know, like the DAT or the alpha-synuclein skin biopsy. When should we be using those? Should we be getting these on everyone? And what scenarios should we really consider doing one of those tests?
Dr Rawls: The scenario in which I would order one of the ancillary testing, particularly like a DAT scan or a skin biopsy, looking for alpha-synuclein is going to be when there are potential red flags or a little bit of confusion in regard to the history and physical that I need to have a little bit more clarification on. For example, if I have a patient that has a history of using dopamine blocking agents, for example, for severe depression; or they have a history of cancer diagnosis and they've been on a dopamine agent like metoclopramide; those I want to be mindful because if they're coming in to see me and they're having the symptoms of Parkinsonism---which is going to be resting tremor, bradykinesia rigidity, or gait disturbance---I need to try to figure out is it potentially due to a medication effect, particularly if they're still on the dopamine blockade medication, or is it something where they're actually having a neurodegenerative illness underneath it, like a Parkinson disease?
The other situation that would make me order a DAT skin or a skin biopsy is going to be someone who is coming in that maybe has elements of essential tremor, they have more of a postural or an intention tremor that's very flapping and larger amplitude, and maybe have some mild symptoms and Parkinsonism that might be difficult to distinguish between other musculoskeletal things like arthritis, other imbalance issues from, you know, hip problems or knee problems and what have you. Then I might say, okay, let's see if there is some sort of neurodegeneration underneath this; that may be- that there could be, you know, potentially two elements like a central tremor and Parkinson disease going on. Or is this someone who actually really has Parkinson disease, but there's other factors that are kind of playing into that.
Dr Nevel: Great, thank you for that. Gosh, things have really changed over the past fifteen years or so where we have this ancillary testing that we're able to use more, because what you read in the textbook isn't always what you see in clinic. And as you described, there are patients who… it's not as clear cut, and these tests can be helpful. Could you tell us more about the levodopa challenge test? How is this useful in clinical practice? And what are some key points that we should know about when utilizing this strategy for patients who we think have Parkinson disease?
Dr Rawls: So, before we had all this ancillary testing with the DAT scan, the skin biopsy, the alpha-synuclein amplification assay, many times if you had a suspicion that a person that had Parkinson disease, but you weren't entirely sure, you would say, hey, listen, let us give you back the dopamine that your body may be missing and see if you have an improvement, in particular in your motor symptom. So, when I talk with my patients, I say, listen, I might have a strong suspicion that you have Parkinson disease. Doing a levodopa trial can not only be diagnostic, but also can be therapeutic as well. So, with this levodopa trial, what I end up doing is saying, okay, we're going to start the medication at a low dose because we are looking to see if you have improvement in three of the main cardinal motor symptoms. Obviously, tremor is much easier for us to see if it gets better. It's very obvious on exam, and the patients are more readily able to see it. Whereas stiffness and slowness is much harder to quantify and try to figure out. Am I stiff and slow because of potential muscle tightness from Parkinson disease, or is it something that's more of a musculoskeletal issue? So, I will tell persons, okay, we're looking for improvement in these three cardinal motor symptoms, and things that we're looking for is getting into and out of a car, into and out of a chair, turning over in bed, seeing how do we navigate ourselves in our daily lives? I give people the example of going through the grocery store, going through a busy airport. Are we able to move better and respond better to different changes in our environment which can give us a better clue of if our stiffness and slowness in particular are being improved with the medication?
The other part of this is talking about potential side effects of the carbidopa- of the levodopa in particular. One big thing that I think limits people initially is going to be the nausea, vomiting, potential GI upset when starting this medication initially. So, oftentimes I will find people coming in, oh, you know,my outside doctor started me immediately on one tab of carbidopa/levodopa three times per day. I got nauseous, I threw up, and I never took the medication again. So often times I will start low and go slow because once someone throws up my medication, they are not going to want to take it again---with good reason. So, often times I will ask the patient, hey listen, are you very sensitive to medications? If you are very sensitive, we might start one tablet per day for a week, one tablet twice a day, and then go up until we get to two tablets three times a day if we're talking about carbidopa/levodopa. If someone is not as sensitive then I might go up a little bit quicker. What do we mean when we talk about 600 milligrams per day? So usually, the amount that I use is carbidopa/levodopa, 25/100; so, 100 milligrams being the levodopa portion. Many people just start off at 1 tab 3 times a day, which gives you 300 milligrams of levodopa, and they say, oh, it didn't work, I must not have Parkinson or something else. Well, it just may have been that we did not give an adequate trial and adequate dose to the person. Now if they're not able to tolerate the medication because of the side effects, that's something different. But if they don't have side effects and don't notice a difference, there is room to increase the carbidopa/levodopa or the levodopa replacement that you are using so that you can give it, you know, a very good try to see, is it actually improving resting tremor, bradykinesia and rigidity?
Dr Nevel: Yeah, great. Thanks for that. When you diagnose a patient with Parkinson disease, how do you counsel that patient? How do you break that difficult news? And how do you counsel them on what to expect in the future and goals of treatment? I know that's a lot in that question, but it also is a lot that you do in one visit, oftentimes, or at least introduce these kind of concepts to patients in a single visit.
Dr Rawls: One thing that I think is helpful for me is trying to understand where the patients and their families are when they come in. Because some of the patients come in and have no prior inkling that they may have a neurodegenerative illness like Parkinson disease. Some of my patients come in and say, I'm here for a second opinion for Parkinson disease. So, then I have an idea of where we are in regard to potential understanding of how to start the conversation going forward. If it is someone who is coming in and has not heard about Parkinson disease, or their family has not been made aware that that's the one reason why they're coming to see a movement disorder specialist, then I will start at the beginning After we finish our history, do a very thorough physical exam, I will talk about things that I heard in the history and that I see on the physical exam that make me concerned for a disease like Parkinson disease. I make sure to tell them where I'm getting my criteria from and not just start off, I think you have Parkinson, here's your medication. I think that's very jarring when you're talking with patients and their families, particularly if they had no idea that this could be a potential diagnosis on the table. Like I said, I will start off with recounting, this is what I've heard in your history that makes me concerned. This is what I've seen on your physical exam that makes me concerned. And I think you have Parkinson disease and here is why. And I'll tell them about the tenants like we discussed about Parkinson disease, both the motor and nonmotor symptoms that we see. So that's kind of the first part is, I make sure to lay it out and then open the room up for some questions and clarification. The other portion of this is that, when I'm talking about counseling the patient, I say, we do not expect Parkinson disease to decrease your lifespan. However, over time, our persons, because it is a neurodegenerative illnesses will accumulate deficits over time. So, more stiffness, more slowness, more walking problems. They may, if they have tremor, the tremor may become worse. If they don't have tremor, they might develop tremor in the future. If we're talking about the nonmotor symptoms that we talk about, the main ones are going to be issues with urinary problems, issues with bowels, and then the other thing is going to be neuropsychiatric issues like anxiety and depression. And those things become more prominent, usually, the nonmotor symptoms later on in the disease process, and then also cognitive impairment as well. I really want to make sure that they have the information that I'm seeing, and if there's anything that they want to correct on their end, as in they're saying, oh wait, well, actually I noticed something else, then that's usually when that comes out around kind of the wrapping-up portion of the visit.
So, I think that's really important to, one, be very clear in what I am seeing and if there's red flags, and then tell them, okay this is not going to shorten your lifespan. However, over time, we do have other issues and problems that will arise and we can support you as best as we can through that. The one thing I also been very open with people about is- because our patients will say, is there anything I can do? What can be done? Is there any medication to slow down or stop things? And I let people know that unfortunately, right now there's not an intervention that slows down, stops, or reverses disease progression, with the exception of exercise. Consistent exercise has been found to help to slow down disease progression, okay? And also, it can help to release the dopamine already being made innately in the brain. And also, it can help with our cardiovascular health in the big thing: being balanced. Core strength, quadricep strength. So that's also something that people can work on that they should. And I let people know that exercise is as important as the medications themselves.
Dr Nevel: Absolutely. And it's incredible how much they incorporate exercise into their daily lives and get active, people who weren't active before their diagnosis, and how much that can help. One question that I think patients sometimes ask is, when they understand how carbidopa/levodopa works and what the expectations are for that medication, that it's not a disease-modifying medication, but that it can help with their symptoms. And then they kind of hear, well as time goes on, they need higher doses or, you know, it doesn't control their motor symptoms as well. They'll say, okay well, is it better to wait then? Should I wait to start carbidopa/levodopa? Like in my mind, I'm only maybe going to get X amount of time from carbidopa/levodopa. So, I'd rather wait to start it than start it now. What do you say to them and how do you counsel them through that?
Dr Rawls: So that is a common question that I do get with my patients. So, I tell people, I'm here for you. And it really depends on how you feel at this time. Because you have to weigh the risks and benefits of the medication itself. If someone who's very, very mild decides to take the medication, they feel nauseous, they're just going to say, hey, listen, it's not for me right now. I don't feel like I need it, and then stop, which is with definitely within their right. But what I always counsel patients as well is to say, the dopamine-producing neurons in the substantia nigra are starting to die over time. That is why we are getting the signs and symptoms of Parkinson disease. At some point, your brain is not going to produce enough dopamine that is needed for you to move when you want to move and not move when you don't want to move. Okay? Giving you at least the motor symptoms of Parkinson disease. With this, it's not that the medication stops working, it's just that you need more dopamine to help replace the dopamine that's being lost. However, the dopamine that you are taking or levodopa that you're taking orally is not going to be released as consistently as it is in your brain on demand and shut off when you don't need it. Hence the reason we get more motor fluctuations. Also, potential side effects in the medication like orthostatic hypertension, hallucinations, impulse control disorders. Because you're having to take more escalating doses, those side effects can become more prominent and also lead us to have to balance between the side effects and the medication itself. So, it's not that the medication does not work, your body needs more of it.
Some people will say, oh, well, I want to wait, and I say, that's completely fine. However, my cutoff is basically saying, if you are finding that you, as the person who's afflicted is not able to get up in the morning like you want to, you're avoiding going to walk your dog or working in your garden, you know, because you feel stiff and feel slow; you're avoiding, you know, going out to the community, having lunch with your friends or your family because you're embarrassed by your tremor; this is something that is keeping you from living your life. And that's the time that we need to strongly consider starting the medications.So, a person afflicted will accumulate deficits. However, it's how much the deficits are going to affect you. So, if it's really affecting your life, we have tools and ways to help mitigate that.
Dr Nevel: Yeah, absolutely. Are there any aspects of Parkinson disease management that you feel are maybe underrecognized or perhaps underutilized? In other words, you know, are there things that we the listeners should be maybe more aware of or think about offering or recommending to our patients that you think maybe aren't as much as they could be?
Dr Rawls: I will say the nonmotor symptoms---in particular the neuropsychiatric symptoms with the anxiety and depression, usually later on disease process but also can be earlier as well---I think that is going to be something that is recognized but maybe undertreated in a lot of our patient population. I think part of that is also the fluctuations in dopamine that are occurring naturally in the person, but also, our patients, oftentimes with their medication regimen, really have to be on the ball taking the medication. If they're even 15 minutes late, 10 minutes late, 5 minutes late, we're now off, and now we're waiting for it to kick in. And so that can cause a lot of anxiousness even throughout the day. And then knowing that slowly over time that they're going to accumulate these motor and nonmotor deficits can definitely be problematic as well. There is obvious reason for this underlying potential anxiety and depression. And while we do talk about that and bring that up, sometimes patients will say, oh well, I don't think it's a problem right now. I don't have to mess with this. But usually at some point it does become an issue that usually the family members will bring up and saying, hey, you know, my loved one is very anxious. Or I've noticed that they're just really disengaged from what's going on in their lives and they are not talking as much, they're not going out as much. Again, that could be a combination of depression/anxiety, but it also can be a physical- a combination of, I'm not physically able to do these things, or, they're much more difficult for me to initiate doing these activities. I always want to be mindful. If my patients come in and they already have a diagnosis of depression or anxiety and they're already being treated by a mental health counselor, provider, or a psychiatrist, then I will work with providers so that we can try to optimize their medication regimen. The other thing is, well, if this is the first time that they're really being seen by someone and talking about their anxiety and depression, then oftentimes I will have them go back to their primary care and see if maybe an SSRI or SNRI will be helpful to try to help with the neuropsychiatric symptoms they may be experiencing.
So that's one big one. Another one that I think that might be a little bit underappreciated is going to be drooling. Sometimes I'll come in and see my patients and notice some drooling that's happening with the mouth being open, not being able to initiate the swallowing reflex consistently throughout the day. Or they may be patting their face a lot with a napkin or a towel and then bringing that up and bringing it to light. Oh yeah. I have a lot of drooling while I'm awake. It's on my shirt. It's embarrassing. I feel like it's a little bit too much for me or my family. We have to put a bib on because I'm just drooling all throughout the day. That can really be uncomfortable and cause skin breakdown. It can also be socially embarrassing. So, there are some tools that I talk to people about with drooling. One thing I start with is going to be using sugar-free gum or candy while the person is awake to help initiate the swallow reflex, and sometimes that's all that's needed. There are other agents that can be used---like glycopyrrolate, sublingual atropine drops, and scopolamine patches---that can help with decreasing saliva production. But there can be side effects of making the entire body feel dry, and then also potential cardiac arrhythmias. If those are not helpful or they're contraindicated with the patient, another thing is going to be botulinum toxin injections. So those can be done on the parotid and salivary glands to decrease the amount of saliva that's being produced. So oftentimes people will come to me, because I'm also a botulinum toxin injector. I've been sent by some of my colleagues to inject our persons that have significant sialorrhea.
Dr Nevel: Wonderful. Well, thank you so much for chatting with me today about your article. Again, today I've been interviewing Dr Ashley Rawls about her article on Parkinson disease, which appears in the August 2025 Continuum issue on movement disorders. Be sure to check out Continuum Audio episodes from this and other issues. And thank you to our listeners for joining today. And thank you, Ashley, for sharing all your knowledge with us today.
Dr Rawls: Thank you, Kate, I appreciate your time. And have a great day, everyone.
Dr Monteith: This is Dr Teshmae Monteith, Associate Editor of Continuum Audio. If you've enjoyed this episode, you'll love the journal, which is full of in-depth and clinically relevant information important for neurology practitioners. Use the link in the episode notes to learn more and subscribe. AAN members, you can get CME for listening to this interview by completing the evaluation at continpub.com/audioCME. Thank you for listening to Continuum Audio.
Dr Jones: Our ability to move through the world is one of the essential functions of our nervous system. Gross movements like walking ranging down to fine movements with our eyes and our hands, our ability to create and coordinate movement is something many of us take for granted. So what do we do when those movements stop working as we intend? Today I have the opportunity to speak with one of the world's leading experts on movement disorders, Dr Michael Okun, about the latest issue of Continuum on Movement Disorders.
Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum. Thank you for listening to Continuum Audio. Be sure to visit the links in the episode notes for information about subscribing to the journal, listening to verbatim recordings of the articles, and exclusive access to interviews not featured on the podcast.
Dr Jones: This is Dr Lyle Jones, Editor-in-Chief of Continuum: Lifelong Learning in Neurology. Today, I'm interviewing Dr Michael Okun, who is Continuum's guest editor for our latest issue on movement disorders. Dr Okun is the Adelaide Lackner Distinguished Professor of Neurology at the University of Florida in Gainesville, where he's also the director of the Norman Fixel Institute for Neurological Diseases. Dr Okun, welcome, and thank you for joining us today. Why don't you introduce yourselves to our listeners?
Dr Okun: It's great to be here today. And I'm a neurologist. Everybody who knows me knows I'm pretty simple. I believe the patient's the sun and we should always orbit around the person with disease, and so that's how I look at my practice. And I know we always participate in a lot of research, and I've got a research lab and all those things. But to me, it's always the patients and the families first. So, it'll be great to have that discussion today.
Dr Jones: Yeah, thank you for that, Dr Oaken. Obviously, movement disorders is a huge part of our field of neurology. There are many highly prevalent conditions that fit into this category that most of our listeners will be familiar with: idiopathic Parkinson's disease, essential tremor, tic disorders and so on. And having worked with trainees for a long time, it's one of the areas that I see a lot of trainees gravitate to movement disorders. And I think it's in part because of the prevalence; I think it's in part because of the diversity of the specialty with treatment options and DBS and Botox. But it's also the centrality of the neurologic exam, right? That's- the clinical examination of the patient is so fundamental. And we'll cover a lot of topics today with some questions that I have for you about biomarkers and new developments in the field. But is that your sense too, that people are drawn to just the old-fashioned, essential focus on the neurologic encounter and the neurologic exam?
Dr Okun: I believe that is one of the draws to the field of movement. I think that you have neurologists from all over the world that are really interested and fascinated with what things look like. And when you see something that's a little bit, you know, off the normal road or off the normal beaten path… and we are always curious. And so, I got into movement disorders, I think, accidentally; I think even as a child, I was looking at people who had abnormal movements and tremors and I was very fascinated as to why those things happened and what's going on in the brain. And, you know, what are the symptoms and the signs. And then later on, even as my own career developed, that black bag was so great as a neurologist. I mean, it makes us so much more powerful than any of the other clinicians---at least in my biased opinion---out on the wards and out in the clinic. And, you know, knowing the signs and the symptoms, knowing how to do a neurological examination and really walking through the phenomenology, what people look like, you know, which is different than the geno- you know, the genotypes, what the genes are. What people look like is so much more important as clinicians. And so, I think that movement disorders is just the specialty for that, at least in my opinion.
Dr Jones: And it helps bring it back to the patient. And that's something that I saw coming through the articles in this issue. And let's get right to it. You've had a chance to review all these articles on all these different topics across the entire field of movement disorders. As you look at that survey of the field, Dr Okun, what do you think is the most exciting recent development for patients with movement disorders?
Dr Okun: I think that when you look across all of the different specialties, what you're seeing is a shift. And the shift is that, you know, a lot of people used to talk in our generation about neurology being one of these "diagnose and adios" specialties. You make the diagnosis and there's nothing that you can do, you know, about these diseases. And boy, that has changed. I mean, we have really blown it out of the water. And when you look at the topics and what people are writing about now and the Continuum issue, and we compare that the last several Continuum issues on movement disorders, we just keep accumulating a knowledge base about what these things look like and how we can treat them. And when we start thinking about, you know, all of the emergence of the autoimmune disorders and identifying the right one and getting something that's quite treatable. Back in my day, and in your day, Lyle, we saw these things and we didn't know what they were. And now we have antibodies, now we can identify them, we can pin them down, and we can treat many of them and really change people's lives. And so, I'm really impressed at what I see in changes in identification of autoimmune disorders, of channelopathies and some of the more rare things, but I'm also impressed with just the fundamental principles of how we're teaching people to be better clinicians in diseases like Parkinson's, Huntington's, ataxia, and Tourette. And so, my enthusiasm for this issue of Continuum is both on, you know, the cutting edge of what we're seeing based on the identification on our exams, what we can do for these people, but also the emergence of how we're shifting and providing much better care across a continuum for folks with basal ganglia diseases.
Dr Jones: Yeah, I appreciate that perspective, Dr Okun. One of the common themes that I saw in the issue was with these new developments, right, when you have new tools like new diagnostic biomarker tools, is the question of if and when and how to integrate those into daily clinical practice, right? So, we've had imaging biomarkers for a while, DAT scans, etc. For patients with idiopathic Parkinson disease, one of the things that I hear a lot of discussion and controversy about are the seed amplification assays as diagnostic biomarkers. What can you tell us about those? Are those ready for routine clinical use yet?
Dr Okun: I think the main bottom-line point for folks that are out there trying to practice neurology, either in general clinics or even in specialty clinics, is to know that there is this movement toward, can we biologically classify a disease? One of the things that has, you know, really accelerated that effort has been the development of these seed amplification assays, which---in short for people who are listening---are basically, we "shake and bake" these things. You know? We shake them for like 20 hours and we use these prionlike proteins, and we learn from diseases like prion disease how to kind of tag these things and then see, do they have degenerative properties? And in the case of Parkinson's disease, we're able to do this with synuclein. That is the idea of a seed amplification assay. We're able to use this to see, hey, is there synuclein present or not in this sample? And people are looking at things like cerebrospinal fluid, they're looking at things like blood and saliva, and they're finding it. The challenge here is that, remember- and one of the things that's great about this issue of Continuum is, remember, there are a whole bunch of different synucleinopathies. So, Dr Jones, it isn't just Parkinson's disease. So, you've got Parkinson's disease, you've got Lewy body, you know, and dementia with Lewy bodies. You've got, you know, multiple system atrophy is within that synucleinopathy, you know, group primary autonomic failure… so not just Parkinson's disease. And so, I think we have to tap the brakes as clinicians and just say, we are where we are. We are moving in that direction. And remember that a seed amplification assay gives you some information, but it doesn't give you all the information. It doesn't forgive you looking at a person over time, examining them in your clinic, seeing how they progress, seeing their response to dopamine- and by the way, several of these genes that are associated with Parkinson; and there's, you know, less than 20% of Parkinson is genetic, but several of these genes, in a solid third---and in some cases, in some series, even more---miss the synuclein assay, misses, you know, the presence of a disease like Parkinson's disease. And so, we have to be careful in how we interpret it. And I think we're more likely to see over time a gemish: we're going to smush together all this information. We're going to get better with MRIs. And so, we're actually doing much better with MRIs and AI-based intelligence. We've got DAT scans, we've got synuclein assays. But more than anything, everybody listening out there, you can still examine the person and examine them over time and see how they do over time and see how they do with dopamine. And that is still a really, really solid way to do this. The synuclein assays are probably going to be ready for prime time more in choosing and enriching clinical trials populations first. And you know, we're probably 5, 10 years behind where Alzheimer's is right now. So, we'll get there at some point, but it's not going to be a silver bullet. I think we're looking at these are going to be things that are going to be interpreted in the context for a clinician of our examination and in the context of where the field is and what you're trying to use the information for.
Dr Jones: Thank you for that. And I think that's the general gestalt I got from the articles and what I hear from my colleagues. And I think we've seen this in other domains of neurology, right? We have the specificity and sensitivity issues with the biomarkers, but we also have the high prevalence of copathology, right? People can have multiple different neurodegenerative problems, and I think it gets back to that clinical context, like you said, following the patient longitudinally. That was a theme that came out in the idiopathic Parkinson disease article. And while we're on Parkinson disease, you know, the first description of that was what, more than two hundred years ago. And I think we're still thinking about the pathophysiology of that disorder. We understand risk factors, and I think many of our listeners would be familiar with those. But as far as the actual cause, you know, there's been discussion in recent years about, is there a role of the gut microbiome? Is this a prionopathic disorder? What's your take on all of that?
Dr Okun: Yeah, so it's a great question. It's a super-hot area right now of Parkinson. And I kind of take this, you know, apart in a couple of different ways. First of all, when we think about Parkinson disease, we have to think upstream. Like, what are the cause and causes? Okay? So, Parkinson is not one disease, okay? And even within the genes, there's a bunch of different genes that cause it. But then we have to look and say, well, if that's less than 20% depending on who's counting, then 80% don't have a single piece of DNA that's closely associated with this syndrome. And so, what are we missing with environment and other factors? We need to understand not what happens at the end of the process, not necessarily when synuclein is clumping- and by the way, there's a lot of synuclein in the brains normally, and there's a lot of Tau in people's brains who have Parkinson as well. We don't know what we don't know, Dr Jones. And so when we begin to think about this disease, we've got to look upstream. We've got to start to think, where do things really start? Okay? We've got to stop looking at it as probably a single disease or disorder, and it's a circuit disorder. And then as we begin to develop and follow people along that pathway and continuum, we're going to realize that it's not a one-size-fits-all equation when we're trying to look at Parkinson. By the way, for people listening, we only spend two to three cents out of every dollar on prevention. Wouldn't prevention be the best cure, right? Like, if we were thinking about this disease. And so that's something that we should be, you know, thinking about. And then the other is the Global Burden of Disease study. You know, when we wrote about this in a book called Ending Parkinson's Disease, it looked like Parkinson's was going to double by 2035. The new numbers tell us it's almost double to the level that we expected in 2035 in this last series of numbers. So, it's actually growing much faster. We have to ask why? Why is it growing faster? And then we have lots of folks, and even within these issues here within Continuum, people are beginning to talk about maybe these environmental things that might be blind spots. Is it starting in our nose? Is it starting in our gut? And then we get to the gut question. And the gut question is, if we look at the microbiomes of people with Parkinson, there does seem to be, in a group of folks with Parkinson, a Parkinson microbiome. Not in everyone, but if you look at it in composite, there seems to be some clues there. We see changes in Lactobacillus, we see some bacteria going up that are good, some bacteria going down, you know, that are bad. And we see flipping around, and that can change as we put people on probiotics and we try to do fecal microbiota transplantations- which, by the way, the data so far has not been positive in Parkinson's. Doesn't mean we might not get there at some point, but I think the main point here is that as we move into the AI generation, there are just millions and millions and millions of organisms within your gut. And it's going to take more than just our eyes and just our regular arithmetic. You and I probably know how to do arithmetic really well, but this is, like, going to be a much bigger problem for computers that are way smarter than our brains to start to look and say, well, we see the bacteria is up here. That's a good bacteria, that's a good thing or it's down with this bacteria or this phage or there's a relationship or proportion that's changing. And so, we're not quite there. And so, I always tell people---and you know, we talk about the sum in the issue---microbiomes aren't quite ready for prime time yet. And so be careful, because you could tweak the system and you might actually end up worse than before you started. So, we don't know what we don't know on this issue.
Dr Jones: And that's a great point. And one of the themes they're reading between the lines is, we will continue to work on understanding the bio-pathophysiology, but we can't wait until that day to start managing the risk factors and treating patients, which I think is a good point. And if we pivot to treatment here a little bit, you know, one of the exciting areas of movement disorders---and really neurology broadly, I think movement disorders has led the field in many ways---is bioelectronic therapy, or what one of my colleagues taught me is "electroceutical therapy", which I think is a wonderful term. Dr Okun, when our listeners are hearing about the latest in deep brain stimulation in patients who have movement disorders, what should they know? What are the latest developments in that area with devices?
Dr Okun: Yeah. So, they should know that things are moving rapidly in the field of putting electricity into the brain. And we're way past the era where we thought putting a little bit of electricity was snake oil. We know we can actually drive these circuits, and we know that many of these disorders---and actually, probably all of the disorders within this issue of Continuum---are all circuit disorders. And so, you can drive the circuit by modulating the circuit. And it's turned out to be quite robust with therapies like deep brain stimulation. Now, we're seeing uses of deep brain stimulation across multiple of these disorders now. So, for example, you may think of it in Parkinson's disease, but now we're also seeing people use it to help in cases where you need to palliate very severe and bothersome chorea and Huntington's disease, we're seeing it move along in Tourette syndrome. We of course have seen this for various hyperkinetic disorders and dystonias. And so, the main thing for clinicians to realize when dealing with neuromodulation is, take a deep breath because it can be overwhelming. We have a lot of different devices in the marketplace and no matter how many different devices we have in the marketplace, the most important thing is that we get the leads. You know, where we're stimulating into the right location. It's like real estate: location, location, location, whether you've got a lead that can steer left, right, up, down and do all of these things. Second, if you're feeling overwhelmed because there are so many devices and so many settings, especially as we put these leads in and they have all sorts of different, you know, nodes on them and you can steer this way and that way, you are not alone. Everybody is feeling that way now. And we're beginning to see AI solutions to that that are going to merge together with imaging, and then we're moving toward an era of, you know, should I say things like robotic programming, where it's going to be actually so complicated as we move forward that we're going to have to automate these systems. There's no way to get this and scale this for all of the locales within the United States, but within the entire world of people that need these types of devices and these therapies. And so, it's moving rapidly. It's overwhelming. The most important thing is choosing the right person. Okay? For this, with multidisciplinary teams, getting the lead in the right place. And then all these other little bells and whistles, they're like sculpting. So, if you think of a sculpture, you kind of get that sculpture almost there. You know, those little adds are helping to maybe make the eyes come out a little more or the facial expression a little bit better. There's little bits of sculpting. But if you're feeling overwhelmed by it, everybody is. And then also remember that we're starting to move towards some trials here that are in their early stages. And a lot of times when we start, we need more failures to get to our successes. So, we're seeing trials of people looking at, like, oligo therapies and protein therapies. We're seeing CRISPR gene therapies in the laboratory. And we should have a zero tolerance for errors with CRISPR, okay? we still have issues with CRISPR in the laboratory and which ones we apply it to and with animals. But it's still pretty exciting when we're starting to see some of these therapies move forward. We're going to see gene therapies, and then the other thing we're going to see are nano-therapies. And remember, smaller can be better. It can slip across the blood brain barrier, you have very good surface area-to-volume ratios, and we can uncage drugs by shining things like focused ultrasound beams or magnets or heat onto these particles to turn them on or off. And so, we're seeing a great change in the field there. And then also, I should mention: pumps are coming and they're here. We're getting pumps like we have for diabetes and neurology. It's very exciting. It's going to be overwhelming as everybody tries to learn how to do this. So again, if you're feeling overwhelmed, so am I. Okay? But you know, pumps underneath the skin for dopamine, pumps underneath the skin for apomorphine. And that may apply to other disorders and not just Parkinson as we move along, what we put into those therapies. So, we're seeing that age come forward. And then making lesions from outside the brain with focused ultrasound, we're starting to get better at that. Precision is less coming from outside the brain; complications are also less. And as we learn how to do that better, that also can provide more options for folks. So, a lot of things to read about in this issue of Continuum and a lot of really interesting and beyond, I would say, you know, the horizon as to where we're headed.
Dr Jones: Thank you for that. And it is a lot. It can be overwhelming, which I guess is maybe a good reason to read the issue, right? I think that's a great place to end and encourage our listeners to pick up the issue. And Dr Okun, I want to thank you for joining us today. Thank you for such a great discussion on movement disorders. I learned a lot. I'm sure our listeners will as well, given the importance of the topic, your leadership in the field over many years. I'm grateful that you have put this issue together. So, thank you. And you're a busy person. I don't know how we talked you into doing this, but I'm really glad that we did.
Dr Okun: Well, it's been my honor. And I just want to point out that the whole authorship panel that agreed to write these articles, they did all the work. I'm just a talking head here, you know, telling you what they did, but they're writing, and the people that are in the field are really, you know, leading and helping us to understand, and have really put it together in a way that's kind of helped us to be better clinicians and to impact more lives. So, I want to thank the group of authors, and thank you, Dr Jones.
Dr Jones: Again, we've been speaking with Dr Michael Okun, guest editor of Continuum's most recent issue on movement disorders. 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, you'll love the journal, which is full of in-depth and clinically relevant information important for neurology practitioners. Use the link in the episode notes to learn more and subscribe. Thank you for listening to Continuum Audio.
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Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum. This exclusive Continuum Audio interview is available only to you, our subscribers. We hope you enjoy it. Thank you for listening.
Dr Albin: Hi all, this is Dr Casey Albin. Today I'm interviewing Dr Daniel Correa and Dr Rana Said about their article on bridging the gap between brain health guidelines and real-world implementation, which they wrote with Dr Justin Jordan. This article appears in the June 2025 Continuum issue on disorders of CSF dynamics. Thank you both so much for joining us. I'd love to just start by having you guys introduce yourselves to our listeners. Rana, do you mind going first?
Dr Said: Yeah, sure. Thanks, Casey. So, my name is Rana Said. I'm a professor of pediatrics and neurology at the University of Texas Southwestern Medical Center in Dallas. Most of my practice is pediatric epilepsy. I'm also the associate clinical chief and the director of education for our division. And in my newer role, I am the vice chair of the Brain Health Committee for the American Academy of Neurology.
Dr Albin: Absolutely. So just the right person to talk about this. And Daniel, some of our listeners may know you already from the Brain and Life podcast, but please introduce yourself again.
Dr Correa: Thank you so much, Casey for including us and then highlighting this article. So yes, as you said, I'm the editor and the cohost for the Brain and Life podcast. I do also work with Rana and all the great members of the Brain Health Initiative and committee within the AAN, but in my day-to-day at my institution, I'm an associate professor of neurology at the Albert Einstein College of Medicine in the Montefiore Health System. I do a mix of general neurology and epilepsy and with a portion of my time, I also work as an associate Dean at the Albert Einstein College of Medicine, supporting students and trainees with community engagement and outreach activities.
Dr Albin: Excellent. Thank you guys both so much for taking the time to be here. You know, brain health has really become this core mission of the AAN. Many listeners probably know that it's actually even part of the AAN's mission statement, which is to enhance member career fulfillment and promote brain health for all. And I think a lot of us have this kind of, like, vague idea about what brain health is, but I'd love to just start by having a shared mental model. So, Rana, can you tell us what do you mean when you talk about brain health?
Dr Said: Yeah, thanks for asking that question. And, you know, even as a group, we really took quite a while to solidify, like, what does that even mean? Really, the concept is that we're shifting from a disease-focused model, which we see whatever disorder comes in our doors, to a preventative approach, recognizing that there's a tremendous interconnectedness between our physical health, our mental health, cognitive and social health, you know, maintaining our optimal brain function. And another very important part of this is that it's across the entire lifespan. So hopefully that sort of solidifies how we are thinking about brain health.
Dr Albin: Right. Daniel, anything else to add to that?
Dr Correa: One thing I've really liked about this, you know, the evolution of the 2023 definition from the AAN is its highlight on it being a continuous state. We're not only just talking about prevention of injury and a neurologic condition, but then really optimizing our own health and our ability to engage in our communities afterwards, and that there's always an opportunity for improvement of our brain health.
Dr Albin: I love that. And I really felt like in this article, you walked us through some tangible pillars that support the development and maintenance of this lifelong process of maintaining and developing brain health. And so, Daniel, I was wondering, you know, we could take probably the entire time just to talk about the five pillars that support brain health. But can you give us a pretty brief overview of what those are that you outlined in this article?
Dr Correa: I mean, this was one of the biggest challenges and really bundling all the possibilities and the evidence that's out there and just getting a sense of practical movement forward. So, there are many organizations and groups out there that have formed pillars, whether we're calling them seven or eight, you know, the exact number can vary, but just to have something to stand on and move forward. We've bundled one of them as physical and sleep health. So really encouraging towards levels of activity and not taking it as, oh, that there's a set- you know, there are recommendations out there for amount of activity, but really looking at, can we challenge people to just start growing and moving forward at their current ability? Can we challenge people to look at their sleep health, see if there's an aspect to improve, and then reassess with time? We particularly highlight the importance of mental health, whether it's before a neurologic condition or a brain injury occurs or addressing the mental health comorbidities that may come along with neurologic conditions. Then there's of course the thing that everyone thinks about, I think, with brain health in terms of is cognitive health. And you know, I think that's the first place that really enters either our own minds or as we are observers of our elder individuals in our family. And more and more there has been the highlight on the need for social interconnectedness, community purpose. And this is what we include as a pillar of social health. And then across all types of neurologic potential injuries is really focusing on the area of brain injury. And so, I think the area that we've often been focused as neurologists, but also thinking of both the prevention along with the management of the condition or the injury after it occurs.
Dr Albin: Rana, anything else to add to that? That's a fantastic overview.
Dr Said: Daniel, thank you for- I mean, you just set it up so beautifully. I think the other thing that maybe would be important for people to understand is that as we're talking through a lot of these, these are individual. These sound like very individual-basis factors. But as part of the full conversation, we also have to understand that there are some factors that are not based on the individual, and then that leads to some of the other initiatives that we'll be talking about at the community and policy levels. So, for example, if an individual is living in an area with high air pollution. Yes, we want them to be healthy and exercise and sleep, but how do we modify those factors? What about lead leaching from our aging pipes or even infectious diseases? So, I think that outside of our pillars, this is sort of the next step is to understand what is also at large in our communities.
Dr Albin: That's a really awesome point. I love that the article really does shine through and that there are these individual factors, and then there there's social factors, there's policy factors. I want to start just with that individual because I think so many of our patients probably know, like, stress management, exercise, sleep, all of that stuff is really important. But when I was reading your article, what was not so obvious to me was, what's the role that we as neurologists should play in advocating? And really more importantly, like, how should we do that? And again, it struck me that there are these kind of two issues at play. And one is that what Daniel was saying that, you know, a lot of our patients are coming because they have a problem, right? We are used to operating in this disease-based care, and there's just limited time, competing clinical demands. If they're not coming to talk about prevention, how do we bring that in? And so Rana, maybe I'll start with you just for that question, you know, for the patients who are seeing us with a disease complaint or they're coming for the management of a problem, how are you organizing this at the bedside to kind of factor in a little bit about that preventative brain health?
Dr Said: You know, I think the most important thing at the bedside is, one, really identifying the modifiable risk factors. These have been well studied, we understand them. Hypertension, diabetes, smoking, weight management. And we know that these definitely are correlative. So is it our role just to talk about stroke, or should we talk about, how are you managing your blood pressure? Health education, if there was one major cornerstone, is elevating health literacy for everyone and understanding that patients value clear and concise information about brain health, about modifiable risk factors. And the corollary to that, of course, are what are the resources and services? I completely understand---I'm a practicing clinician---the constraints that we have at the bedside, be it in the hospital or in our clinics. And so being the source of information, how are we referring our families and individuals to social workers, community health worker support, and really partnering with them, food banks, injury prevention programs, patient advocacy organizations? I think those are really ways that we can meet the impacts that we're looking at the bedside that can feel very tangible and practical.
Dr Albin: That's really excellent advice. And so, I'd like to ask a follow-up question. With your knowledge of this, trying to get more multidisciplinary buy-in from your clinic so that you really have the support to get these services that are so critically important. And how do you do that?
Dr Said: Yeah, I think it's, one, being a champion. So, what does a champion mean? It means that somebody has to decide this is really important. And I think we all realize that we're not the only ones in the room who care about this. We're all in this, and we all care about it. But how do we champion it and carry it through? And so that's the first. Second you find your partnerships: your social workers, your case managers, your other colleagues. And then what is the first-level entry thing that you can do? So for example, I'm a pediatric epileptologist. One of the things we know is that in pediatric epilepsy, depression and anxiety are very strong comorbidities. So, before we get to the point where a child is in distress, every single one of our epilepsy patients who walks in the door over the age of twelve has an age-appropriate screener that is given to them in both English and Spanish. And we assess it and we determine stratifying risk. And then we have our social workers on the back end and we decide, is this a child who needs resources? Is this a child who needs to be walked to the emergency room, escorted? And anything in between. And I think that that was a just a very tangible example of, every single person can do this and ask about it. And through the development of dot phrases and clear protocols, it works really well.
Dr Albin: I love that, the way that you're just being mindful. At every step of the way, we can help people towards this lifelong brain health. And Daniel, you work with an adult population. So I wonder, what are your tips for bringing this to a different patient population?
Dr Correa: Well, I think---adult or child---one thing that we often are aware of with so many of the other things that we're doing in bedside or clinic room counseling, but we don't necessarily think of in this context of brain health, is, remember all the people in the room. So, at the bedside, whether it's in the ICU, discharge counseling, the initial admission, the whole family is often involved and really concerned about the active issue. But you can look for opportunities- we often try to counsel and support families about the importance of their own sleep and rest and highlighting it not just as being there for their family member, but highlighting it to them as a measure of their own improvement of their brain health. So, looking at ways where, one, I try to find, is there something I can do to support and educate the whole family about their brain health? And then- and with an epilepsy, or in many other situations, I try to look for one comorbidity that might be a pillar of brain health to address that maybe I wasn't already thinking. And then I consider, is there an additional thing that they wouldn't naturally connect to their epilepsy or their headaches that I can bring in for them to work on? You know, we can't often give people twelve different things to work on, and they'd just feel like, okay like, you have no realistic understanding of my life. But if we can just highlight on one, and remind them that there can be many more ways to improve their health and to follow up either with us as their neurologist or their future primary care doctors to address those additional needs. Again, I would really highlight the importance of a multidisciplinary approach and looking for opportunities. We've too often, I feel, relied on primary care as being the first line for addressing unmet social health needs. We know that so many people, once they have a neurologic condition or the potential, even, of a neurologic condition, they're concerned about dementia or something, they may view us, as their neurologist, as their most important provider. And if they don't have the resource of time and money to show up at other doctors, we may be the first one they're coming to. And so, tapping into your institution's resources and finding out, are there things that are available to the primary care services that for some reason we're not able to get on the inpatient side or the outpatient side? Referring to social workers and care workers and showing that our patients have an independent need, that they're not somehow getting captured by the primary care doctors.
Dr Albin: I really love that. I think that we- just being more invested and just being ready to step into that role is really important. I was noticing in this article, you really call that being a brain health ambassador, being really mindful, and I will direct all of our listeners to Figure 3, which really captures what practitioners can do both at the bedside, within their local community, and even at the professional society level, to really advocate for policies that promote brain wellness. Rana, at the very beginning of this conversation, you noted, you know, this is not just an individual problem. This really is something that is a component of our policy and the structure of our local communities. I really loved in the article, there's a humility that this cannot be just a person-by-person bedside approach, that this is a little bit determined by the social determinants of health. And so, Rana, can you walk us through a little bit of what are the social determinants of health, and why are these so crucially important when we think about brain health for all?
Dr Said: Yeah, social determinants of health are a really key factor that it looks at, what are the health factors that are environmental; for example, that are not directly like what your blood pressure is, what, you know, what your BMI is, that definitely impact our health outcomes. So, these include environmental things like where people are born, where they live, where they learn, work, play, worship, and age. It encompasses factors like your socioeconomic status, your education, the neighborhoods where you are living, definitely healthcare access. And then all of this is in a social and community context. We know that the impact of social determinants of health on brain health are profound for the entire lifespan and that- so, for example, if someone is from a disadvantaged background or that leads to chronic stress, they can have limited access to healthcare. They can have greater risk of exposure to, let's say, environmental toxins, and all of that will shape how their brain health is. Violence, for example. And so, as we think about how we're going to target and enhance brain health, we really have to understand that these are vulnerable populations, special high-risk populations, that often have a disproportionate burden of neurologic disorders. And by identifying them and then developing targeted interventions, it promotes health equity. And it really has to be done in looking at culturally- ethnocultural-sensitive healthcare education resources, thinking about culturally sensitive or adaptive assessment tools that work for different populations so that these guidelines that we have, that we've already identified as being so valuable, can be equitably applied, which is one crucial component of reducing brain health risk factors. And lastly, at the neighborhood level, this is where we really rely on our partnerships with community partners who really understand their constituents and they understand how to have the special conversations, how to enhance brain health through resource utilization. And so, this is another plug for policy and resources.
Dr Albin: I love that. And thinking about the neighborhood and the policy levels and all the things that we have to do. Daniel, I'd like to ask you, is there anything else you would add?
Dr Correa: Yeah, you know, so I really wanted to come back to this thing is that often and unfortunately, in the beginning understanding of social determinants of health, they're thought of as a positive or a negative factor, and often really negative. These are just facts. They're aspects about our community, our society, and some of them may be at the individual level. They're not at fault of any individual or community, or even our society. They're just the realities. And when someone has a factor that may predict a health disparity or an unmet social need---I wanted to come back to that concept and that term---one or two positive factors that are social determinants of health for that individual are unmet social needs. It's a point of promise. It's a potential to be addressed. And seeking ways to connect them with community services, social work, caregivers, these are ways where- that we can remove a barrier to, so that the possibility of the recommendations that we're used to doing, giving recommendations about medications and management, can be fully appreciated for that person. And the other aspect is, like brain health, this is a continuous state. The social determinants of health may be different for the child, the parent, and the elderly family member in the household, and there might be some that are shared across them. And when one of those individuals has a new medical illness or a new condition, a stroke, and now has a mobility limitation, that may change a social determinant of health for that person or for anyone else in the family, the other people now becoming caregivers. We're used to this. And for someone after a stroke or traumatic brain injury, now they have mobility changes. And so, we work on addressing those. But thinking on how those things now become a barrier for engaging with community and accessing things, something as simple as their pharmacy.
Dr Albin: I hear a lot of "this is a fluid situation," but there's hope here because these are places that we can intervene and that we can really champion brain health throughout this fluid situation. Which kind of brings me to what we're going to close out with, which is, I'm going to have you do a little thought exercise, which is that you find a magic lamp and a genie comes out. And we'll call this the brain health genie. The genie says that they are going to grant you one wish for the betterment of brain health. Daniel, I'll start with you. What is the one thing that you think could really move the needle on promoting and maintaining brain health?
Dr Correa: I will jump on nutrition and food access. If we could somehow get rid of food insecurity and have access to whole and fresh foods for everyone, and people could go back to looking at opportunities from their ancestral and cultural experiences to cook and make whole-food recipes from their own cultures. Using something like the Mediterranean diet and the mind diet as a framework, but not looking at those as cultural barriers that we somehow all have to eat a certain way. So, I think that would really be the place I would go to first that would improve all of our brain health.
Dr Albin: I love that. So, wholesome eating. Rana, how about you? One magic wish.
Dr Said: I think traumatic brain injury prevention. I think it's so- it feels so within our reach, and it just always is so heart-hurting when you think that wearing helmets, using seatbelts, practicing safety in sports, gun safety---because we know unfortunately that in pediatric patients, firearm injury is the leading cause of traumatic brain injury. In our older patients, fall reduction. If we could figure out how to really disseminate the need for preventative measures, get everyone really on board, I think this is- the genie wouldn't have to work too hard to make that one come true.
Dr Albin: I love that. As a neurointensivist, I definitely feel that TBI prevention. We could talk about this all day long. I really wish we had a longer bit of time, but I really would direct all of our listeners to this fantastic article where you give really practical advice. And so again, today I've been interviewing Drs Daniel Correa and Rana Said about their article on bridging the gap between brain health guidelines and real-world implementation, written with Dr Justin Jordan. This article appears in the most recent issue of Continuum on the disorders of CSF dynamics. Be sure to check out Continuum Audio episodes from this and other issues. And thank you so much for our listeners for joining us today.
Dr Monteith: This is Dr Teshamae Monteith, Associate Editor of Continuum Audio. We hope you've enjoyed this subscriber-exclusive interview. Thank you for listening.
Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum. Thank you for listening to Continuum Audio. Be sure to visit the links in the episode notes for information about earning CME, subscribing to the journal, and exclusive access to interviews not featured on the podcast.
Dr Albin: Hi, this is Dr Casey Albin. Today I'm interviewing Dr Shenandoah Robinson about her article on childhood onset hydrocephalus, which appears in the June 2025 Continuum issue on disorders of CSF dynamics. Dr Robinson, thank you so much for being here. Welcome to the podcast. I'd love to start by just having you briefly introduce yourself to our audience.
Dr Robinson: I'm a pediatric neurosurgeon at Johns Hopkins, and I'm very fortunate to care for kids and children from the neonatal intensive care unit all the way up through young adulthood. And I have a strong interest in developing better treatments for hydrocephalus.
Dr Albin: Absolutely. And this was a great article because I really do think that understanding how children with hydrocephalus are treated really does inform how we can care for them throughout the continuum of their lifespan. You know, I was shocked in reading your article about the scope of the problem for childhood onset hydrocephalus. Can you walk our listeners through what are the most common reasons why CSF diversion is needed in the pediatric population?
Dr Robinson: For the United States, and Canada too, the most common reasons are spina bifida---so, a baby that's born with a myelomeningocele and then develops associated hydrocephalus---and then about equally as common is posthemorrhagic hydrocephalus of prematurity, congenital causes such as from aquaductal stenosis, and other genetic causes are less common. And then we also have kids that develop hydrocephalus after trauma or meningitis or tumors or other sort of acquired problems during childhood.
Dr Albin: So, it's a really diverse and sort of heterogeneous causes that across sort of the, you know, the neonatal period all the way to, you know, young adulthood. And I'm sure that those etiologies really shift based on sort of the subgroup population that you're talking about.
Dr Robinson: Yes, they definitely shift over time. Fortunately for our kids that are born with problems that raise concerns, such as myelomeningocele or if they're born preterm, they sort of declare themselves by the time they're a year old. So, if you're an adult provider, they should have defined themselves and it's unlikely that they will suddenly develop hydrocephalus as a teenager or older adult.
Dr Albin: Totally makes sense. I think many of the listeners to this podcast are adult neurologists who are probably very familiar with external ventriculostomies for temporary CSF diversion, and with the more permanent ventricular peritoneal shines or ventricular atrial or plural shines that are needed when there's the need for permanent diversion. But you described in your article two procedures that provide temporary CSF diversion that I think many of our listeners are probably not as familiar with, which is the ventricular access devices and ventriculosubgaleal shunts. Can you briefly describe what those procedures provide? Who are the candidates for them? And then what complications neurologists may need to think about if they're consulted for comanagement in one of these complex patients?
Dr Robinson: Well, the good thing is that if as an adult neurologist you encounter someone with, you know, residual tubing from one of these procedures, you are unlikely to need to do anything about it. So, we put in ventricular access device or ventriculosubgaleal shunts, usually in newborns or infants. And sometimes when they no longer need the device, we just leave it in because that saves them an extra surgery. So, if you encounter one later on, it's most likely you won't need to do anything. Often if the baby goes on to show that they need a permanent shunt, we go ahead and put in that permanent shunt. We may or may not go back and take out the reservoir or the subgaleal shunt. The reservoir and subgaleal shunts are often put in the frontal location. Sometimes we'll put the permanent shunt in the occipital location and just leave the residual tubing there. So, you're very unlikely to need to intervene with a reservoir or subgaleal shunt if you encounter an older child or adult with that left in. We use these in the small babies because the external ventricular drains that we're very familiar with have a very high complication rate in this population. In the adult ICU, you often see these, and maybe there's, you know, a few percent risk of infection. It actually heads into 20 to 25% in our preterm infants and other newborns that require one of these devices for drainage. So, we try not to use external ventricular drains like we use in older patients. We use the internalized device: either the ventricular reservoir with a little area for us to tap every day, every other day; or the ventriculosubgaleal shunt, which diverts the spinal fluid to a pocket in the scalp. So, we use these in preterm infants that are too tiny for a permanent shunt. And for some of our babies that are born, for example, with an omphalocele, that we can't use their peritoneal cavity and so we need some temporizing device to manage their CSF.
Dr Albin: Totally makes sense. And so just to clarify, I mean, this is a tube that's placed into the ventricles of the brain and then it's tunneled into the subgaleal space and the collection, the CSF, just builds up there, like?
Dr Robinson: Yeah.
Dr Albin: And over time either, you know, the baby will learn how to account for that extra CSF, and then I guess it's just reabsorbed?
Dr Robinson: Yeah. When it's present, though, it looks like maybe, I don't know if you're familiar with like a tissue expander. There is this bubble of fluid under the scalp, but it's prominent, it can be several centimeters in diameter.
Dr Albin: Wow, that's just absolutely fascinating. And I don't think I've ever had the opportunity to see this in clinical practice. I've really learned quite a bit about this. I assume that these children are going to go on to get some sort of permanent diversion. And then, you know, over time, those permanent shunts do create a lot of problems. And so, I was hoping you could kind of walk us through, you know, what are some of the things that you're seeing that you're concerned about? And then if you've just inherited a patient who had a shunt placed at, say, a different institution, how do you go about figuring out what kind of shunt it is and if they're still dependent on it?
Dr Robinson: There's a few things that, fortunately, technology is helping with. So, it is much easier now for patients to get their images uploaded to image-sharing software, and then we can download their images into our institutional software, which is very helpful. Another option is that we are strongly encouraging our families to use a app such as HydroAssist that's available from the Hydrocephalus Association. So that's an app that goes on your phone, and you can upload the images from an MRI or a CT scan or x-rays from a shunt series. And then that you can take if you're traveling and you have to go to emergency department or you're establishing care with a new provider, you can have your information right there and not be under stress to remember it. It also has areas so you can record the type of valve. And all of our valves have pluses and minuses, they all tend to malfunction a little bit. And they can be particularly helpful with different types of hydrocephalus. I really doubt that we're going to narrow down from the fifteen or so valves we have access to now. And so, recording your valve type, the manufacturer as well as the setting, is very helpful when you're transferring care or if you're traveling and then have to, unfortunately, stop in the emergency department.
Dr Albin: Yeah, I thought that was a really great pearl that, like, families now are empowered to sort of take control of understanding sort of the devices that they have, the settings that they're using. And what an incredible thing for providers who are going to care for these patients who, you know, unfortunately do end up in centers that are not their primary center. The other challenge that I find… I practice as a neurointensivist, and sometimes patients come in and they have a history of being shunt dependent and they present with a neurologic change. And I think that we as neurologists can be a little quick to blame the shunt and want the shunt to be tapped. And I was really struck in reading this article about the complexity of shunt taps. And I was hoping, you know, can you kind of walk us through what's involved and maybe why we should have a little bit of a higher threshold before just saying, ah, just have the neurosurgeons tap the shunt. Like, it's not that straightforward.
Dr Robinson: And it may depend on the population you're caring for. So, when I was at a different institution, we actually published that there's about a 5% complication rate from shunt taps. And that may be- that was in pediatric patients. And again, that may be population dependent, but you can introduce infection to a perfectly clean shunt by doing a shunt tap. You can also cause an acute shunt malfunction. So that's why we tend to prefer that only neurosurgeons are doing shunt taps for evaluation of a shunt malfunction. There are times that, for example, our patients who are getting intrathecal chemotherapy or something have a CSF access device like an Ommaya reservoir, and other providers may tap that reservoir to instill medicine. But that's different than an evaluation, like, you're talking about somebody with a neurological change. And so, it is possible that if somebody has small ventricles or something, if you tap that shunt, you can take a marginally functioning shunt and turn it into an acute proximal malfunction, which is an emergency.
Dr Albin: Absolutely. I think that's a fantastic pearl for us to take away from this. It's just that heightened level. And kind of on the flip side of that, you know, and I really- I do feel for us when we're trying to kind of, you know, make a case that it's, it's not the shunt. Many of our shunted patients also have a lot of neurologic complexity, which I think you really talked upon in this article. I mean, these are patients who have developmental cognitive delays and that they have epilepsy and that they're at risk for, you know, complications from prematurity, since that's a very common reason that patients are getting shunts. But from your experience as a neurosurgeon, what are some of the features that make you particularly concerned about shnut malfunction? And how do you sort of evaluate these patients when they come in with that altered mental status?
Dr Robinson: It is challenging, especially for our patients that have, you know, some intellectual delay or other difficulties that make it hard for them to give an accurate history. Problem is, if they're sick and lethargic, they may not remember the symptoms that they had when they were sick. But sometimes there's hopefully there's a family member present that does remember and can say, oh, no, this is what they look like when they have a viral illness. And this is different from when they have the shot malfunction, which was projectile emesis, not associated with a fever. It's rare to have a fever with a shunt malfunction, although shunt infection often presents with malfunction. So, it's not completely exclusionary. We often look at the imaging, but it's taking the whole picture together. Some of the common other diagnoses we see are severe constipation that can decrease the drainage from the shunt and even cause papilledema in some people. So, we look at that as well on the shunt series. It's very important to have the shunt series if you're concerned about shunt malfunction or- the shunt tubing is good. It tends to last maybe 20to 25 years before it starts to degrade. And so, you may have had a functioning shunt for decades and it worked well and you're very dependent on it, and then it breaks and you become ill. But on the flip side, we have patients that have had a broken shunt for years, they just didn't know about it. And we don't want to jump in and operate on them and then cause complexities. And so, it is a challenge to sort out. The simplest thing is obviously if they come in and their ventricles are significantly larger, and that goes along with a several-hour or a couple-day deterioration, that's a little more clear-cut.
Dr Albin: Absolutely. And you talked about this shunt series. What other imaging- and, sort of maybe walk us through, what's involved in a shunt series, what are you looking at? And then what other imaging is sort of your preferred method for evaluating these patients?
Dr Robinson: In adult patients, the shunt series is the x-ray from the entire shunt. And so, if they have an atrial shunt, that would be skull x-ray plus a chest x-ray; or the shunt ends in the perineal cavity, it goes to the perineum. And we're looking for continuity. We're looking for the- sometimes as people grow and age, the ventricular catheter can pull out of the ventricle. So, we're looking to make sure that the ventricular catheter is in an optimal position relative to the skull. We can also look at the valve setting to see the type of valve. So, that can also be helpful as well. And then in terms of additional imaging, a CT scan or an MRI is helpful. If you don't know what type of valve they have, they should not, ideally, go in the MRI scanner. We like to know what their setting is before they go in the MRI because we're going to have to reset the valve after they come out of the MRI if it's a programmable valve.
Dr Albin: This is fantastic. I've heard several pearls. So, one is that with the shunt series, which, am I correct in understanding those are just plain X-rays?
Dr Robinson: Yes.
Dr Albin: Right. Then we can look for constipation, and that might be actually something really serious in a pediatric patient that could clue us in that they could actually be developing hydrocephalus or increased ICP just because of the abdominal pressure. And then that we need to be mindful of what are the stunt settings before we expose anyone to the MRI machine. Is that two good takeaways from all of this?
Dr Robinson: Yes. And it's very rare that there'll be an MRI tech that will allow a patient with a valve in the MRI without knowing what it is. So, they have their job security that way. But yeah, if you're not sure, just go ahead and get the CT. Obviously, in our younger kids, we're trying to avoid CT scans. But if you're weighing off trying to decide if somebody has a shunt malfunction versus, you know, waiting 12 or 24 hours for an MRI, go ahead and get the CT.
Dr Albin: Absolutely. I love it. Those are things I'm going to take with me for this. I have one more question about these shunts. So, every now and then, and I think you started to touch on this, we will get a shunt series and we'll see that the catheter is fractured. Do the patients develop little- like, a tract that continues to allow diversion even though the catheter is fractured?
Dr Robinson: Yes. So, they can develop scar tissue around, and some people have more scar tissue than others. You'll even see that sometimes, say, the catheter has fractured and we'll take out that old fractured tubing and put in new tubing on the other side. But if you go and palpate their neck or chest, you'll still feel that tract is there because it calcifies along the tract. Some patients drain through that calcified tract for weeks or months without symptoms, and then it can occlude off. So, we don't consider it a reliable pathway. It's also not a reliable pathway if you're positioned prone in the OR. So some of our orthopedic colleagues, for example, if they go to do a spine fusion, we like to confirm that the shunt is working before you undergo that long anesthesia, but also that you're going to be positioned prone and you could potentially- you know, the pressure could occlude that track that normally is open.
Dr Albin: This is fantastic. I feel like I've gotten everything I've ever wanted to know about shunts and all of their complications in this, which is, you know, this is really difficult. And I think that because we are not trained to put these in, sometimes we see them and we just say, oh, it's fractured that must be a malfunction. But it's good to know that sometimes those patients can drain through, you know, a sort of scarred-down tract, but that it may not be nearly as reliable as when they have the tubing in place. Another really good thing that I'm going to put in my back pocket for the next time I see a patient with a potential shunt malfunction.
Dr Robinson: And we do have some patients that the tubing is fractured years ago and they don't need it repaired, and that totally can be challenging when they then transfer to your practice for follow-up care. We tend to follow those patients very closely, both our clinic visits as well as having them seen by ophthalmology. So, there are teenagers and young adults out there that have… their own system has recovered and they are no longer shunt-dependent; and they may have a broken shunt and not actually be using that track, but they usually have had fairly intensive follow up to prove that they're not shunt-dependent. And we still have a healthy respect there that, you know, if they start to get a headache, we're going to take that quite seriously as opposed to, you know, some of our shunt patients, about 10 to 20%, have chronic headaches that are not shunt-related. So, not everybody who has a headache and has a shunt has a shunt malfunction. It's tough.
Dr Albin: This is really tough. That actually brings me to sort of the last clinical scenario that I was hoping we could get your perspective on. And I think this would be of great interest to neurologists, especially in the context that these children may develop headaches that have nothing to do with the shunt. I'd like to sort of give you this hypothetical case that I'm a neurologist seeing a patient in clinic and it's a teenager, maybe a young adult, and they had a shunt placed early in childhood. They've done really well. And they've come to me for management of a new headache. And, you know, as part of this workup, their primary care provider had ordered an MRI. And, you know, I look at the MRI, and I don't think that the ventricles look really enlarged. They don't look overdrained. Is having an MRI that looks pretty okay, is that enough to exonerate the shunt in this situation?
Dr Robinson: In most cases it is. The one time that we don't see a substantial change in the ventricles is if we have a pseudocyst in the abdomen. The ventricles cannot enlarge initially, and then later on they might enlarge. So, we see that sometimes that somebody will come in and their ventricles will be stable in size, but we're still a little bit suspicious. They've got this persistent headache. They may have, you know, some emesis or loss of appetite, loss of activity, and a slower presentation than you would get with an acute proximal malfunction. We can check an abdominal ultrasound for them. And sometimes, even though the ventricles haven't changed in size, they still have a malfunction because they have that distal pseudocyst.
One of the questions that we ask our patients when we're establishing care, in addition to what valve type they have and what sort of their shunt history or other interventions such as endoscopic third ventriculostomy, is to ask if their ventricles enlarge when they have a shunt malfunction. There is a small fraction where they do not. They kind of have a stiff brain, if you will. And so, it's good to know that. That's one of the key factors is asking somebody, do the ventricles enlarge when they have a malfunction? If they have enlarged in the past, they're likely to enlarge again if they have a malfunction. But again, it's not 100%. So, in peds, 20% of the time the ventricles don't enlarge. So, in adults, I'm not that- you know, I don't know what percentage it is, but it's something to consider that you can have a stable ventricular size and still have a shunt malfunction. So, if your clinical judgment, you're just kind of, like, still uneasy, you know, respect that and maybe do a little more workup. That's why we so much want patients to establish care with somebody, whether it's a neurologist or a neurosurgeon or other provider in some areas that have fewer neurospecialists, but to establish care so that you all know what a change is for that patient. That's really important.
Dr Albin: That's fantastic. So, to summarize that, it's really important to understand the patient's baseline and how they presented with prior shunt complications, if they've had some. That if they're coming in with a new headache that we don't have a baseline, so, we should just have a heightened level of awareness that, like, the shunt has a start and it has an end. And even if the start of the shunt in the brain looks okay, there still could be the potential for complications in the abdomen. And maybe the third thing I heard from that is that we should look for GI symptoms and sort of be aware of when there could be a complication in the abdomen as well. Does that all sound about right?
Dr Robinson: And especially for our kids with spina bifida and for posthemorrhagic hydrocephalus are now adults, because the preterm infants are prone to necrotizing enterocolitis. And they may not have had surgery for it, but they still may have adhesions and other things that predispose them to develop pseudocysts over time. And then our individuals with spina bifida often have various abdominal surgeries and other procedures to help them manage their bowel and bladder function. And so that can also create adhesions that then predisposes to pseudocysts. So, we do have a healthy respect for that. In addition, it used to be---because we have gotten a little better with shunts over time---it used to be, like, when I was in training that you heard, you know, if you haven't had a shunt malfunction for 10 or 15 years, you must- you may no longer be dependent. And that's not really true. There are some people who outgrow their need for shunt dependence, but not everyone does outgrow it. And so, you can be 15, 20 years without a shunt revision and still be shunt-dependent.
Dr Albin: Those are fantastic pearls. I think most of them, walking away with this, like, a very healthy respect for the fact that these are complex patients, which the shunt is one component of sort of the things that can go wrong and that we have to have a really healthy respect and really detailed investigation and sort of take the big picture. I really like that.
Dr Robinson: Yeah, I know. I think it's- there's a very strong push amongst pediatric neurosurgery and a lot of the related, our colleagues in other areas, to develop multidisciplinary transition clinics and lifespan programs for these patients to help keep everything else optimized so that they're not coming in, for example, with seizures. But then you have to figure out if this is a seizure or a shunt; you know, if we can keep them on track, if we can keep them healthy in all their other dimensions, it makes it safer for them in terms of their shunt malfunction.
Dr Albin: Absolutely. I love that, and just the multidisciplinary preventative aspect of trying to keep these patients well. So important. Dr Robinson, I really would like to thank you for your time. We're getting towards the end of our time together. Are there any other points about the article that you just are anxious that leave the readers with, or should I just direct them back to the fantastic review that you've put together on this topic?
Dr Robinson: No, I think that we covered a lot of the high points. I think one of the really exciting things for hydrocephalus is that there's a lot of investigations into other options besides shunts for certain populations. We are seeing less hydrocephalus now with the fetal repair of the myelomeningocele, which is great. And we're trying to make inroads into posthemorrhagic hydrocephalus as well. So, there are a lot of great things on the horizon and, you know, hopefully someday we won't have the need to have these discussions so much for shunts.
Dr Albin: I love it. I think that's really important. And all of those points were touched on the article. And so, I really invite our listeners to go and check out the article, where you can see sort of, like, how this is evolving in real time. Thank you, Dr Robinson. Please go and check out the childhood-onset hydrocephalus article, which appears in the most recent issue of Continuum on the disorders of CSF dynamics. And be sure to check out Continuum Audio episodes from this and other issues. Thank you again to our listeners for joining us today. And thank you, Dr Robinson.
Dr Robinson: Thanks for having me.
Dr Monteith: This is Dr Teshamae Monteith, Associate Editor of Continuum Audio. If you've enjoyed this episode, you'll love the journal, which is full of in-depth and clinically relevant information important for neurology practitioners. Use the link in the episode notes to learn more and subscribe. AAN members, you can get CME for listening to this interview by completing the evaluation at continpub.com/audioCME. Thank you for listening to Continuum Audio.
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