Continuum Audio Ataxia With Dr. Theresa Zesiewicz
Ataxia is a neurologic symptom that refers to incoordination of voluntary movement, typically causing gait dysfunction and imbalance. Genetic testing and counseling can be used to identify the type of ataxia and to assess the risk for unaffected family members.
In this episode, Katie Grouse, MD, FAAN, speaks with Theresa A. Zesiewicz, MD, FAAN, author of the article “Ataxia” in the Continuum® August 2025 Movement 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. Zesiewicz is a professor of neurology and director at the University of South Florida Ataxia Research Center, and the medical director at the University of South Florida Movement Disorders Neuromodulation Center at the University of South Florida and at the James A. Haley Veteran’s Hospital in Tampa, Florida.
Additional Resources
Read the article: Ataxia
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Full episode transcript available here
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 Theresa Zesiewicz about her article on ataxia, which appears in the August 2025 Continuum issue on movement disorders. Welcome to the podcast, and please introduce yourself to our audience.
Dr Zesiewicz: Well, thank you, Dr Grouse. I'm Dr Theresa Zesiewicz, otherwise known as Dr Z, and I'm happy to be here.
Dr Grouse: I have to say, I really enjoyed reading your article. It was a really great refresher for myself as a general neurologist on the topic of ataxia and a really great reminder on a great framework to approach diagnosis and management. But I wanted to start off by asking what you feel is the key message that you hope our listeners will take away from reading your article.
Dr Zesiewicz: Yes, so, thanks. I think one of the key messages is that there has been an explosion and renaissance of genetic testing in the past 10 years that has really revolutionized the field of ataxia and has made diagnosis easier for us, more manageable, and hopefully will lead to treatments in the future. So, I think that's a major step forward for our field in terms of genetic techniques over the last 10 years, and even over the last 30 years. There's just been so many diseases that have been identified genetically. So, I think that's a really important take-home message. The other take-home message is that the first drug to treat Friedreich's ataxia, called omaveloxolone, came about about two years ago. This was also a really landmark discovery. As you know, a lot of these ataxias are very difficult to treat.
Dr Grouse: Now pivoting back to thinking about the approach to diagnosis of ataxia, how does the timeline of the onset of ataxia symptoms inform your approach?
Dr Zesiewicz: The timeline is important because ataxia can be acute, subacute or chronic in nature. And the timeline is important because, if it's acute, it may mean that the ataxia took place over seconds to hours. This may mean a toxic problem or a hypoxic problem. Whereas a chronic ataxia can occur over many years, and that can inform more of a neurodegenerative or more of a genetic etiology. So, taking a very detailed history on the patient is very important. Sometimes I ask them, what is the last time you remember that you walked normal? And that can be a wedding, that can be a graduation. Just some timeline, some point, that the patient actually walked correctly before they remember having to hold onto a railing or taking extra steps to make sure that they didn't fall down, that they didn't have imbalance. That sometimes that's a good way to ask the patient when is the last time they had a problem. And they can help you to try to figure out how long these symptoms have been going on.
Dr Grouse: I really appreciate that advice. I will say that I agree, it can sometimes be really hard to get patients to really think back to when they really started to notice something was different. So, I like the idea of referencing back to a big event that may be more memorable to them. Now, given that framework of, you know, thinking through the timeline, could you walk us through your approach to the evaluation of a patient who presents to your clinic with that balance difficulties once you've established that?
Dr Zesiewicz: Sure. So, the first thing is to determine whether the patient truly has ataxia. So, do they have imbalance? Do they have a wide base gait? That's very important because patients come in frequently to your clinic and they'll have balance problems, but they can have knee issues or hip issues, neuropathy, something like that. And sometimes what we say to the residents and the students is, usually ataxia or cerebellar symptoms go together with other problems, like ocular problems are really common in cerebellar syndromes. Or dysmetria, pass pointing, speech disorder like dysarthria. So, not only do you need to look at the gait, but you should look at the other symptoms surrounding the gait to see if you think that the patient actually has a cerebellar syndrome. Or do they have something like a vestibular ataxia which would have more vertigo? Or do they have a sensory ataxia, which would occur if a person closes his eyes or has more ataxia when he or she is in the dark?
So, you have to think about what you're looking at is the cerebellar syndrome. And then once we look to see if the patient truly has a cerebellar syndrome, then we look at the age, we look at---as you said before, the timeline. Is this acute, subacute, or chronic? And usually I think of ataxia as falling into three categories. It's either acquired, it's either hereditary, or it's neurodegenerative. It can be hereditary. And if it's not hereditary, is it acquired, or is it something like a multiple system atrophy or a parkinsonism or something like that? So, we try to put that together and start to narrow down on the diagnosis, thinking about those parameters.
Dr Grouse: That's really a helpful way to think through it. And it is true, it can get very complex when patients come in with balance difficulties. There's so many things you need to think about, but that is a great way to think about it. Of course, we know that most people who come in to the Movements Disorders clinic are getting MRI scans of their brains. But I'm curious, in which cases of patients with cerebellar ataxia do you find the MRI to be particularly helpful in the diagnosis?
Dr Zesiewicz: So, an MRI can be very important. Not always, but- so, something like multiple system atrophy type C where you may see a hot cross bun sign or a pontine hyperintensity on the T2-weighted image, that would be helpful. But of course, that doesn't make the diagnosis. It's something that may help you with the diagnosis. In FXTAS, which is fragile X tremor/ataxia syndrome, the patient may have the middle cerebellar peduncle sign or the symmetric hyperintensity in the middle cerebellar peduncles, which is often visible but not always. Something like Wernicke’s, where you see an abnormality of the mammillary bodies. Wilson's disease, which is quite rare, T2-weighted image may show hyperintensities in the putamen in something like Wilson's disease. Those are the main MRI abnormalities, I think, with ataxia. And then we look at the cerebellum itself. I mean, that seems self-evident, but if you look at a sagittal section of the MRI and you see just a really significant atrophy of the cerebellum, that's going to help you determine whether you really have a cerebellar syndrome.
Dr Grouse: That's really encouraging to hear a good message for all of us who sometimes feel like maybe we're missing something. It's good to know that information can always come up down the line to make things more clear. Your article does a great review of spinal cerebellar ataxia, but I found it interesting learning about the more recently described syndrome of SCA 27B. Would you mind telling us more about that and other really common forms of SCA that's good to keep in mind?
Dr Zesiewicz: Sure. So, there are now 49 types of spinal cerebellar ataxia that have been identified. The most common are the polyglutamine repeat diseases: so, spinocerebellar ataxia type 3 or type 2, type 6, are probably the most common. One of the most recent spinocerebellar ataxias to be genetically identified and clinically identified is spinocerebellar ataxia 27B. This is caused by a GAA expansion repeat in the first intron of the fibroblast growth factor on chromosome 13. And the symptoms do include ataxia, eye problems, downbeat nystagmus, other nystagmus, vertical, and diplopia. It appears to be a more common form of adult-onset ataxia, and probably more common than was originally thought. It may account for a substantial number of ataxias, like, a substantial percentage of ataxias that we didn't know about. So, this was really a amazing discovery on SCA 27B.
Dr Grouse: Now a lot of us I think feel a little anxious when we think about genetic testing for ataxia simply because there's so many forms, things are changing quickly. Do you have a rule of thumb or a kind of a framework that we can think of as we approach how we should be thinking about getting genetic testing for the subset of patients?
Dr Zesiewicz: Sure. And I think that this is where age comes into play a lot. So, if you have a child who's 10, 11, or 12 who's having balance problems in the schoolyard, does not have a history of ataxia in the family, the teachers are telling you that the child is not running correctly, they're having problems with physical education, that is someone who you would think about testing for Friedreich’s ataxia. A preteen or a child, that would be one thing that would be important to test. When you talk to your patient, it's important to really take a detailed family history. Not just mom or dad, but ethnicity, grandparents, etc. And sometimes, once in a while, you come up with a known spinal cerebellar ataxia. Then you can just test for that. So, if a person is from Portugal or has Portugal background and they have ataxia and the parents had ataxia, you would think of spinal cerebellar ataxia type 3. Or if they're Brazilian, or if the person is from a certain area of Cuba and mom and dad had ataxia and that person has ataxia, you would think of spinal cerebellar ataxia type 2. Or if a person has ataxia and their parent had blindness or visual problems, you may be more likely to think of spinal cerebellar ataxia type 7, for example.
If they have that---either they have a known genetic cause in in the family, first degree family, or they come from an area of the world in which we can pinpoint what type we think it is---you can go ahead and get those tests. If not, you can take an ataxia comprehensive panel. Many times now, if you take the panel and the panel is negative, it will reflex to the whole exome gene sequencing, where we're finding really unusual and more rare types of ataxia, which are very interesting. Spinal cerebellar ataxia type 32, spinal cerebellar ataxia type 36, I had a spinal cerebellar ataxia type 15. So, I think you should start with the age, then the family history, then where the person is from. And then, if none of those work out, you can get a comprehensive panel, and then go on to whole exome gene sequencing.
Dr Grouse: That's really, really useful. Thank you so much for breaking that down in a really simple way that a lot of us can take with us. Pivoting a little bit now back towards different types of acquired ataxias, what are some typical lab tests that you recommend for that type of workup?
Dr Zesiewicz: Again, if there's no genetic history and the person does not appear to have a neurodegenerative disease, we do test for acquired ataxias. Acquired ataxias can be complex. Many times, they are in the autoimmune family. So, what we start with are just basic labs like a CBC or a CMP, but then we tried to look at some of the other abnormalities that could cause ataxia. So, celiac disease, stiff person syndrome. So, you would look at anti-glutamic acid decarboxylase antibodies, Hashimoto's---so, antithyroglobulin antibodies or antithyroperoxidase antibodies would be helpful. You know, in a case of where the patients may have an underlying neoplasm, maybe even a paraneoplastic workup, such as an anti-Hu, anti-Yo, anti-Ri. A person has breast cancer, for example, you may want to take a paraneoplastic panel. I've been getting more of the anti-autoimmune encephalitis panels in some cases, that were- that are very interesting. And then, you know, things that sometimes we forget now like the syphilis test, thyroid-stimulating test, take a B12 and folate, for example. That would be important. Those are some of the labs. We just have on our electronic chart a group of acquired labs for ataxia. If we can't find any other reason, we just go ahead and try to get those.
Dr Grouse: Now, I'm curious what you think is the most challenging aspect of diagnosing a patient with cerebellar ataxia?
Dr Zesiewicz: So, for those of us who see many of these patients a day, some of the hardest patients are the ones that---regardless of the workup that we do, we've narrowed it down, it's not hereditary. You know, they've been through the whole exome gene sequencing and we've done the acquired ataxia workup. It doesn't appear to be that. And then we've looked for parkinsonism and neurodegenerative diseases, and it doesn't appear to be that either; like, the alpha-synuclein will be negative. Those are the toughest patients, where we think we've done everything and we still don't have the answer. So, I've had patients in whom I've taken care of family members years and years ago, they had a presumed diagnosis, and later on I've seen their children or other family members. And with the advent of the genetic tests that we have, like whole exome gene sequencing, we have now been able to give the patient and the family a definitive diagnosis that they didn't have 25 years ago. So, I would say don't give up hope. Retesting is important, and as science continues and we get more information and we make more landmark discoveries in genetics, you may be better able to diagnose the patient.
Dr Grouse: I was wondering if you had any recommendations regarding either some tips and tricks, some pearls of wisdom you can impart to us regarding the work of ataxia, or conversely, any big pitfalls that you can help us avoid? I would love to hear about it.
Dr Zesiewicz: Yeah, there's no easy way to treat or diagnose ataxia patients. I've always felt that the more patients you see- and sounds easy, but the more patients you see, the better you're going to become at it, and eventually things are going to fall into place. You'll begin to see similarities in patients, etc. I think it's important not only to make sure that a person has ataxia, but again, look at the other signs and symptoms that may point to ataxia that you'll see in a cerebellar syndrome. I think it's important to do a full neuroexam. If a person has spasticity, that may point you more towards a certain type of ataxia than if a person has no reflexes, for example, that we see in Friedreich's ataxia. Some of the ocular findings are very interesting as well. It's important to know if a person has a tremor. I've seen several Wilson's disease cases in my life with ataxia. They're very important. I think a full neuroexam and also a very detailed history would be very helpful.
Dr Grouse: Tell us about some promising developments in the diagnosis and management of ataxia that we should be on the lookout for.
Dr Zesiewicz: The first drug for Friedreich's ataxia was FDA-approved two years ago, which was an NRF2 activator, which was extremely exciting and promising. There are also several medications that are now in front of the FDA that may also be very promising and have gone through long clinical trials. There's a medication that's related to riluzole, which is a medication used for amyotrophic lateral sclerosis, that has been through about seven years of testing. That is before the FDA as well for spinal cerebellar ataxia. Friedreich's ataxia has now completed the first cardiac gene therapy program with AAV vectors, which- we're waiting for full results, but that's a cardiac test. But I would assume that in the future, neurological gene therapy is not far behind if we've already done cardiac gene therapy and Friedreich's ataxia. So, you know, some of these AAV vector-based genetic therapies may be very helpful, as well as ASO, antisense oligonucleotides, for example. And I think in the future, other things to think about are the CRISPR/Cas9 technology for potential treatment of ataxia. It is a very exciting time, and some major promising therapies have been realized in the past 2 to 3 years.
Dr Grouse: Well, that's really exciting, and we'll all look forward to seeing these becoming more clinically applicable in the future. So, thank you so much for coming to talk with us today.
Dr Zesiewicz: Thank you.
Dr Grouse: Again, today I've been interviewing Dr Theresa Zesiewicz about her article on ataxia, 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.