Rachel Byrne:
Hi, and welcome everybody. My name's Rachel Byrne. I'm the executive director at the Cerebral Palsy Foundation, and I'm so excited to be joined today by Dr. Heather Riordan from Kennedy Krieger Institute in Baltimore. And today we're going to be talking about motor disorders in cerebral palsy, the different types, maybe why that's important to know and different elements of potentially what we can do about it. So Heather, before we get started, could you just give a little bit of the audience of background of what you do and even why you got into this field?
Dr. Heather Riordan:
Oh, that's a great question. So I currently work as the medical director for the Phelps Center for Cerebral Palsy at the Kennedy Krieger Institute. I honestly didn't anticipate that I was going to do cerebral palsy when I first started out my career. I started as a movement disorders specialist, studying movement disorders in general in pediatrics. Of course, cerebral palsy becomes a really important part of that and kind of fell in love with it over time. And now I've chosen to make it the entire center of my career. I also have a brother-in-law who has cerebral palsy, which probably in the background influences me somewhere in there with that.
Rachel Byrne:
And your role as a neurologist when we're thinking about cerebral palsy, both in diagnosis and the treatment, what do neurologists usually do thinking around cerebral palsy?
Dr. Heather Riordan:
The neurologist's role in cerebral palsy will vary significantly from institution to institution in general, neurologists are heavily involved in the initial diagnosis of cerebral palsy, particularly if any imaging or genetic workup is necessary to make that diagnosis. Additionally, they may be involved in epilepsy or treatment of other neurological co-occurring conditions that may occur in cerebral palsy. In some centers, neurologists are primarily involved in the care of tone management and long-term management. In other places you have other people like physical medicine, rehab doctors or developmental pediatricians who are the primary providers for those types of care. And in many centers, like at Kennedy Krieger, there's a mixture of different types of providers who are involved, including neurologists, pm and r doctors and developmental pediatricians.
Rachel Byrne:
Yeah, absolutely. And I think when we're going to get into talking about the motor disorders in cerebral palsy, there are obviously different types. Can we just go over the different types and if everyone who is watching, if you have any questions, but Dr. Riordan as we're going through, please put them in the chat and we'll make sure we try to answer them as we go.
Dr. Heather Riordan:
So when we think about cerebral palsy, you can divide it in different ways, but perhaps the most important way to divide it is by what kind of movements we're seeing, or we'll say phenomenologic or phenotypic categorization. The most common movement we see in cerebral palsy is something called spasticity, and this is defined by when you rapidly move the muscle, it kind of tightens up. It's similar to what we see in reflexes where you suddenly hit a muscle and you see it pop up. The second category of types of movements we see in cerebral palsy is something called dyskinesia, and dyskinesia is kind of a catchall term that includes dystonia as well as something called chorea athetosis. Dystonia is a group of movement disorders where you get the slow postures that are oftentimes stereotypes. So you may see the same posture over and over again.
Dr. Heather Riordan:
That comes out more when the individual's excited in pain under stress or stimulated in some other way. They can have a twisting quality to it, although it does not have to. Some of the things that really tip me off to thinking about dystonia is when somebody is having times where they're nice and loose and other times really tight, although that can be difficult if they also have spasticity. If you see kind of swanning fingers, arms pulling back and twisted, those are some of the more easy things to key on. But sometimes it can be much more subtle and it's important to differentiate from spasticity because while some treatments address both, some treatments may be different between the two.
Rachel Byrne:
Can someone develop dystonia or chorea? Is this something that if they didn't have as a child, they can get in as adult, or is it something that we know, okay, that would be your motor type forever, maybe it just wasn't diagnosed?
Dr. Heather Riordan:
So I think there's a few things that's tricky about these dyskinetic symptoms, and I should mention, we define dystonia. We didn't really define chorea. Chorea is another dyskinetic symptom that's characterized by more fluid or jerky movements that go across. Joints kind of move from one part of the body to another. And with both of them, with people with cerebral palsy for reasons they're not fully understood, sometimes you don't see them very prominently in early childhood, but as a child gets a little older, five, six, or even as they hit puberty, sometimes you see these movements popping up more then we had seen previously. So certainly that's where serial exams and long-term relationships with the physicians can be helpful and being thoughtful from one time or another if you're seeing something change to have the discussion. The other thing that we always want to be mindful of is that we know that at least almost a fourth of people with cerebral palsy have a genetic contributing factor. And for many of these people, there may be a genetic cause that also predisposes them for dystonia. Sometimes that can change over time as well. So sometimes we see somebody who's diagnosed with cerebral palsy and they suddenly develop severe dystonia. We realize that there's an underlying genetic cause that may help explain that, and knowing that can sometimes change what kinds of treatments we think would be most helpful.
Rachel Byrne:
Yeah, absolutely. So with the different types of, obviously motor types, one thing we didn't really talk about, is it different areas of the brain that are damaged? Is it different areas that are impacted that are leading to these different motor types and the signals that are going to the muscles?
Dr. Heather Riordan:
So the answer is yes and no. Okay. So historically we know that there are certain parts of the brain that are more involved with dyskinesia, particularly these deep gray centers, very deep in the brain called the basal ganglia and the thalamus. These parts of the brain are also involved in other movement disorders like Tourette syndrome, Huntington's Disease, and Parkinson's. So if we see injury there, certainly I'm going to watch that patient more closely for dystonia. All that said, there's an increasing body of research that shows that people who have no evidence of basal ganglia injury on their MRIs that have injury in other parts of the brain can also have dystonia. And so we need to be very careful about being too confident in looking at that M R I and prediction of what motor phenotypes an individual will or will not have.
Rachel Byrne:
You just brought up a really good point though that some people potentially have both correct. So you said obviously spasticity is the most common type of cerebral palsy, but there are many people with spasticity that actually also have dystonia. And can you just describe how that can be presented and what that can look like? Yes.
Dr. Heather Riordan:
So the truth is that oftentimes it can be different to differentiate how much of somebody's movements are due to spasticity or from dystonia, but it's important to note because it does sometimes change treatment, and especially if the dystonia or the spasticity is causing more difficulty with function than the other. We used to feel like spasticity was just 80%, only 10% of people have both. Now we know that it's closer to 55% of people have a mixed phenotype. So it's kind of challenging this way that we've always thought about cerebral palsy, where we had these nice little categories that maybe we need to think about it in a much more complicated way as thinking about them as groups of movement disorders as opposed to distinct entities. So
Rachel Byrne:
That's a pretty big change, right, thinking that it was potentially only 10% of those with cerebral palsy that had dystonia or dyskinesia type cerebral palsy, and now thinking that it's up to 50%. So some of you watching actually might be go, hang on, I got diagnosed with spasticity. I have the spastic form of cerebral palsy. What should they be thinking about that? Is it something that they would need to potentially have a conversation with their doctor about to say this is important to understand because as you said, interventions might change. I imagine a lot of people listening and going, oh, hang on a second. What does this mean for me?
Dr. Heather Riordan:
Yeah, no, absolutely. So what a recent study has shown is that more people have a mixture of dystonia and spasticity as their cerebral palsy movement disorder than people who have alone. So if you do have some of these other moves where you're like, wow, when we hear about dystonia, this sounds familiar to me.
Absolutely bring it up with your physician because it may change what types of treatment options are available. There's some medications that work for dystonia that don't usually used in spasticity. Similarly, there's some surgical options and things like that that work really well for spasticity but may not help with the dystonia. So it's really important to differentiate those two things. And I think it was also helpful for you to have more understanding of your own body and how it works and interacts with these movements and why your body may be doing things that's different than other people that you see that have pure spasticity.
Rachel Byrne:
So this is sort of like a new thinking that we have as a field that obviously dystonia is more present than we actually originally thought. How do you test for it? How do we know if somebody has dystonia? Is it just from looking at their movement or are there specific tests that can be done?
Dr. Heather Riordan:
Absolutely. So this, I think in the end, dystonia is a clinical diagnosis. We don't have a blood test that shows that there's not some sort of an EEG exam that can say, yes, this is dystonia. There are some other research level tests that you can use, but we don't use those very often in the clinic. There are some scales that can be in addition to knowing what dystonia feels like, what it looks like from reading about it or from looking at the patient or experience, there are some tools that we can use to help differentiate it. Most commonly is the hypertonia assessment tool or the hat scale that can help to differentiate what spasticity and see if somebody may actually have both as opposed to pure spasticity or pure dystonia.
Rachel Byrne:
And as far as thinking about who might be able to implement that tool or look at that from an assessment perspective, is it sort of a neurologist and a movement specialist that will probably have, I suppose, the most understanding around this? Because obviously it is a changing thinking for some who may think, okay, yes, spasticity is the primary type, and that's really all that I see, even though dystonia may actually be there.
Dr. Heather Riordan:
Yeah, absolutely. I mean, there are a group of neurologists that focus on movement disorders, but I don't think it has to be a movement disorder neurologist who uses this tool. There are many PTs that are certified in the use of this tool and have experience with it. And similarly, there are a lot of physiatrists or physical medicine rehab doctors who also have some experience with it. But again, I think every team is so different depending on what part of the country you're located in and how your center is built. So I think that's where going to your providers and saying, Hey, we've heard about this thing called the hat. What do you think about it? Do you think it could be helpful in differentiating things? Do you think it could be helpful in guiding my goals and my treatment?
Rachel Byrne:
I suppose that's why we're talking about this, right, is because as you had mentioned a couple of different times, the different treatments that would happen between something for spasticity compared to say a dyskinesia or dystonia. Can we go through those a little bit? You mentioned surgery and pharmacological treatments, maybe starting in pharmacological treatments. What are the sort of things that can actually help with interventions?
Dr. Heather Riordan:
Yeah, so I think one of the most important things to know about dystonia is it can be triggered by things like pain, anxiety, distress. So sometimes the best way to treat dystonia is actually to be looking at those things, but to understand that those things are triggers, and to pay attention to that if it's really hard, even keeping a diary can be really helpful because those are very low hanging fruits that we can use that help a lot with dystonia. I mentioned that S D R is very helpful for spasticity, but may not be helpful for dystonia. There are other surgeries that we'll used for really severe dystonia devices called a deep brain stimulator, another surgery called pallidotomy that may be helpful for dystonia but wouldn't be used in spasticity. Similarly, while muscle relaxants like baclofen can be helpful for both spasticity and dystonia, there are some medicines specific to dystonia. So medications like trihexyphenidyl, carbidopa levodopa, or medicines like clonidine can be very helpful in dystonia, but may not be thought of in the world of pure spasticity. So again, this can offer us new treatment options that we wouldn't have if we thought about this as a pure spastic syndrome
Rachel Byrne:
For spasticity. I think there's a fair bit of information out there around, say for example, strength training and exercise and the benefits of that on overall muscle and bone health. Is there similar evidence around dystonia as well? Obviously pharmacological treatments, surgical treatments, it's really good to be aware of those, but what are the other types of interventions? Is pt, ot, do we have evidence, or do we need to do more?
Dr. Heather Riordan:
I think the evidence is starting to grow in terms of different things that can be helpful for dystonia. A lot of the literature that we have though on the effectiveness of therapies in dystonia is really coming from the adult literature, from people who have other types of dystonia, from various genetic disorders and things like that. So we really need to bolster what we know about the treatment of dystonia from a therapeutic standpoint in individuals with cerebral palsy. But we are growing more data for this. I think there's a lot of attention right now on the sensory component of dystonia. As I mentioned, dystonia comes out more with stimulation or different emotional triggers, pain triggers, things like that. So thinking about how those things interact and how we can intervene on that level to help with dystonia, which may not be true for spasticity is really important.
Rachel Byrne:
So one of the questions that just came in is what are some symptoms or what do people potentially look for or how do they describe dystonia when they're coming in?
Dr. Heather Riordan:
Absolutely. So one of the important things is that I think sometimes we don't give patients language to talk about this if we're not bringing it up. They may not have heard about it or they may not know how to describe and separate it. So sometimes when people come into me, they do use terms like, oh, it's my muscle spasm or my spasticity that's acting up, but it really may be dystonia. Some of the other things that people will tell me is that they have uncontrolled movements, that they have extra movements or that maybe their arm or their hand just doesn't listen to them, that it does its own thing because it's having an extra movement that they didn't tell it to do, which is different from spasticity, which is more just that tightness when they try and move.
Rachel Byrne:
And obviously cerebral palsy we know is different for everybody, but dystonia particularly, does it really present differently in everyone that comes in?
Dr. Heather Riordan:
Absolutely. I think not only in location of where people have dystonia, but in some patients it's more just very subtle postures and other people, it's much broader, bigger movements where in severe cases that can cause things like dislocations or even fractures if they're severe enough. So it's a very broad spectrum of what dystonia can look like. And I think that's part of what makes it difficult to diagnose because many people are basing it upon one period, one little experience they've had as opposed to this broad spectrum.
Rachel Byrne:
And you brought it up a little bit before that sometimes movement patterns do change over time as we age and as our muscles grow and those different things. And potentially as we do new activities, some things might become more present. But how do you see dystonia impacting people functionally? And then I'll ask you another question is does it always need to be treated? Absolutely. But if we're thinking about functionally dystonia, what do we see? Is it things like, is it everyday activities that it impacts people the most, or what do you see the most?
Dr. Heather Riordan:
So I'm going to answer your first question first because I think it leads into the second, and that is that it doesn't have to be treated unless it's impacting somebody's quality of life and function. So if the dystonia is there, but it's a subtle, it's not bothering somebody as much as the spasticity, it's not causing problems. We don't want to treat something and then potentially give side effects if it's not impacting their quality of life. Ways that it can affect quality of life depend very largely on the severity of the dystonia and where it is and also what the patient's function is outside of just the dystonia by itself. So in more subtle cases, I find that fine motor control is an important thing to pay attention to. So if you have some tightness or posturing of your fingers when you're trying to do things like cooking or writing, that can have very significant impacts on function. In other cases, it can affect gait or walking for more severe cases. It can cause pain or discomfort. It can infect ability to dress, to change diapers, those basic cares that we all need. So it can affect people in a lot of different ways.
Rachel Byrne:
So sort of going on from that, thinking about can it be improved, I suppose, and I know that's a big question, we think about cerebral palsy and what's functional improvement, what does improvement mean? But yeah, the treatments that we currently have, do you see that any improvements can happen?
Dr. Heather Riordan:
Absolutely. So unfortunately we don't have a cure for dystonia at this time. I hope by the time I retire, we'll have a different answer to that question.
Rachel Byrne:
Yeah, we all want to be out of business.
Dr. Heather Riordan:
Yes, please put me out of business, your researchers out there. But in terms of the actual treatments, I think it's very individual. So unfortunately when we don't have a silver bullet for dystonia yet, some patients respond really well to some medicines, others to other medicines. So it can be a frustrating process for families and individuals in terms of going through that trial and error experience. I will be honest that sometimes dystonia can be hard to treat and find the right treatment. I think that's where identifying it and having those really important discussions about what your values are, side effects versus function, what your own personal goals are, and how much of your function is being affected by dystonia versus spasticity is very important. But I definitely have seen some people who have had really good improvement with the right medication or the right surgical or other treatments.
Rachel Byrne:
So we mentioned chorea before and that they are different. So what we would see as a dystonia compared to say a chorea and how they present differently, do they get treated differently as well?
Dr. Heather Riordan:
Sometimes, yes. So there are actually some medicines that can improve dystonia that can potentially worsen chorea. And the alternative is also true that there's some medicines that we think about with chorea that can potentially worsen dystonia. The challenge is when you have both together, you have to really be thoughtful. One of the best pieces of advice I received when I was early in my training is find the movement that's causing the most problems with function and focus on that first. And that can be very helpful.
Rachel Byrne:
And I think that's where dystonia and actually understanding dystonia is really important because it really can impact those functional activities as you've discussed. So it's really important to have those discussions with your physician, with your doctor, with your providers, to really find the best treatment options for you. Because we do know, unfortunately, with cerebral palsy, it's not one size fits all.
Dr. Heather Riordan:
Absolutely.
Rachel Byrne:
But also for any of the, you listening, we've got incredible resources on CP resource.org, which go over different motor types, different opportunities. We also have a series around clinical trials and research that's happening in the us. So if you do want to look up any options and have any opportunities for you or your child, they're all there. But Heather, I just want to say a huge thank you, obviously for joining us here today. And again, any other questions, we'll try to answer them in the chat. Thank you so much.
Dr. Heather Riordan:
Thank you so much for having me. Of course.