DD SIG Episode 55: Freezing of Gait with Alice Nieuwboer

Summary

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Podcast Summary: 4D Deep Dive into Degenerative Diseases – Episode 55

“Freezing of Gait with Alice Nieuwboer”

Host: Parm Padgett
Guest: Dr. Alice Nieuwboer, Emeritus Professor in Rehabilitation Sciences, Catholic University of Leuven, Belgium
Date: May 1, 2025

Episode Overview

This episode explores the topic of “freezing of gait” (FOG) in Parkinson’s disease—a complex, frustrating symptom for patients and clinicians alike. Dr. Alice Nieuwboer, a leading researcher in Parkinson's rehabilitation, shares her expertise on FOG's pathophysiology, guiding theories, patient subtypes, clinical assessment, and evidence-based therapeutic approaches. The conversation highlights both scientific uncertainty and practical hope for clinicians working to improve mobility and quality of life in people with Parkinson’s.

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Key Discussion Points & Insights

Dr. Nieuwboer’s Background and Interest in FOG

• Dr. Nieuwboer recounts her journey from physical therapy in the UK to her academic and research career in Belgium, focusing on neurorehabilitation, specifically Parkinson’s disease and FOG.
  • “I was forced into that topic by my then supervisor… But once I was forced into it, I never looked back.” (01:42)
• Emphasizes her enduring passion for research and mentorship post-emeritus, balancing involvement and stepping back when needed.

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Pathophysiology of Freezing of Gait

• FOG is episodic and unpredictable; the “bottleneck” model is a leading but incomplete explanation.
  • “First of all, we don’t truly understand why we have this very episodic problem... There is a moment whereby within the basal ganglia there is an overload of neural input, and that overload brings on a breakdown of the gait network.” (05:10)
• Multiple brain networks contribute to FOG:
  • Cognitive (e.g., distraction)
  • Limbic (e.g., anxiety, stress)
  • Motor (e.g., turning, adapting gait to the environment)

Notable Quote

“As a physiotherapist, you want to undo complexity and avoid overload. So that is a helpful thought, I think, for dealing with freezing of gait.”
— Dr. Nieuwboer (08:10)

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Automaticity, Dopamine, and Subtypes

• Decreased dopamine impairs automatic movements, forcing patients to compensate with attention.
  • “Because people have an automaticity problem, it means that they overcompensate by using attention a lot.” (09:35)
• FOG subtypes (emerging model):
  1. Cognitive overload (dual tasking)
  2. Limbic overload (stress/anxiety)
  3. Motor overload (environmental adjustments/turns)
• Early in Parkinson’s, FOG may respond to medication; later, all three subtypes may converge as disease progresses.

Notable Quote

“Some people may have more difficulty with cognitive overload, others may have more difficulty with limbic overload… eventually... they will have freezing in all three circuits.”
— Dr. Nieuwboer (10:48)

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Freezing, Festination, and Variability

• Festination (hastened, shuffling steps) may be a mild or related form of FOG, though definitions and consensus vary.
  • “I think that fascination type, shuffling type movements are part of, say, a more mild form of freezing probably, or is a phenomenon that is related but slightly different.” (14:40)
• FOG varies greatly between patients and within the same individual—making research and clinical management challenging.

Notable Quote

“It is very, very difficult to do this type of research, but very exciting as well at the same time.”
— Dr. Nieuwboer (17:32)

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Deep Dive: Freezing of Gait Subtypes

1. Cognitive (Dual Tasking) [18:11]

• Patients freeze more with cognitive load, especially challenging tasks.
  • “There is a correlation between cognitive load and the duration of freezing and the number of freezing episodes.” (18:26)
• Cognitive decline appears slightly more pronounced in freezers, even when controlling for disease severity.

2. Limbic (Stress/Anxiety) [20:26]

• Stress triggers FOG both in anticipation of known triggers (e.g., elevators) and during risky tasks.
  • “It is people that are very sensitive to worrisome thoughts about freezing....patients started to freeze more.” (22:25)
• Stress and cognitive distraction may synergize but are hard to fully separate.

3. Motor (Environmental Adjustments/Turning) [23:27]

• Rapid, complex turns are the most potent and reliable trigger for FOG—even in patients who don’t self-identify as “freezers”.
  • “Performing a 360 turn fast... brings on freezing quite regularly, even in people that do not say that they are a freezer.” (24:34)

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Clinical Assessment Practices

Key Assessment Tools:

• 360-degree turn test (with/without dual task, both directions; most sensitive trigger)
  • “It becomes even more sensitive when you also have patients doing a dual task as well during the 360.” (25:43)
• Dual-task Timed Up and Go (TUG) (walking + cognitive task; combines cognitive, motor, stress triggers)
  • “It was also high on our list of situations which triggered freezing of gait.” (27:30)
• Mini-BESTest (for balance assessment)
  • “I would also do items from the mini best test to see whether patients are unstable...” (31:37)
• Questionnaires to understand “hot spots” and specific situations at home where FOG occurs

Clinical Emphasis

“What brings on freezing in this particular patient? … The analysis is more important, in my view, than separating them out necessarily in three subtypes.”
— Dr. Nieuwboer (28:36)

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FOG and Falls

• There is a strong relationship between FOG episodes and fall risk; freezing often involves instability and fear.
  • “It is an enormous fall trigger...A moment of freezing for them is also a moment of instability.” (32:39)

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Evidence-Informed Treatment Strategies

Key Principles

1. Rescue Strategies

   • Teach patients to stop when freezing begins and then “reset.”
   • Emphasis on weight shifting (side-to-side) to unweight the swing leg:

     “The first thing that they have to learn is to stop wanting to move ... and then try and shift your weight, whereby you then release your swing leg.” (34:38)

2. Cueing Techniques

   • Auditory cues (metronomes, rhythmic music), visual cues, and emerging vibration devices
     • Auditory cues are most practical and adjustable in clinic.
     • On-demand cueing devices still have technical challenges but show promise for reducing both duration and frequency of FOG ([44:45], [47:15])
   • Importance of training patients to wean off cues and maintain rhythm without them:

     “What you want patients to take away from training is that they maintain their gait rhythm even through all kinds of clutter and complexities... Now you keep on going.” (42:19)

   • Internal cueing strategies like “mental singing” are effective; patients can use these discreetly.

     “It can be counting, it can be singing ... singing is very effective.” (43:35)

3. Gait Adaptation Training

   • Frequent practice in complex, variable, environment-rich settings (turns, clutter, changes in speed)
   • Promote adjustments to gait in real-life “hot spot” situations to increase patient carryover

4. Strength, Balance, and Cognitive Training

   • Early and ongoing focus on strengthening balance, lower limb strength, cognitive reserve, and adaptability to potentially delay the onset or worsening of FOG.
   • “Can we postpone freezing...Can we make the brain stronger so that it takes a little bit longer before it comes home?” (48:55)

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Notable Quotes & Memorable Moments

• “You cannot undo that part of your brain, you cannot take it out with a neurosurgical technique or so.” – Dr. Nieuwboer on lifelong passion for Parkinson’s research (02:03)
• “There are people that say, no [festination is not FOG], and there are people that say, yes. I belong to the latter group.” (14:34)
• “It is an excellent starting point for therapy...try and almost mimic the situations where they had a freeze.” (29:13)
• On hope and the future:

  “Even the incomplete system was effective...I think there’s hope in that technology will start to become better in detecting freezing episodes.” (47:30)

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Timestamps for Major Segments

| Segment | Start Time | |-------------------------------------------------|------------| | Guest Intro & Background | 01:17 | | Pathophysiology of FOG | 05:03 | | Automaticity, Dopamine, and Subtypes | 09:21 | | Festination vs. Freezing, Definitions | 14:07 | | Subtype Deep Dive: Cognitive, Limbic, Motor | 18:11 | | Assessment Tools & Clinical Pearls | 25:43 | | FOG & Falls | 32:20 | | Treatment: Rescue, Cueing, Gait Training | 34:27 | | Vibratory & On-demand Cueing Devices | 38:47, 44:45| | Internalizing Cues, Mental Singing | 42:47 | | Building Resilience, Early Interventions | 48:55 | | Closing Reflections | 51:44 |

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Tone & Style

The conversation is expert yet relatable, balancing humility about science’s current limits with pragmatic optimism. Dr. Nieuwboer conveys deep respect for patients’ experiences and a collaborative, hopeful spirit toward research and clinical advances in Parkinson’s care.

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Useful For:

• Clinicians seeking fresh strategies for addressing FOG
• Therapists wanting to better predict, provoke, and assess FOG
• Anyone interested in nuanced discussions of Parkinson’s rehab research and its real-world translation

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Transcript

[A]

This is for informational and educational purposes only. It does not constitute and should not be used as a substitute for medical advice, diagnosis, rehabilitation or treatment. Patients and other members of the general public should always seek the advice of a qualified healthcare professional regarding personal health and medical conditions. Welcome to 4D Deep Dive into degenerative Diseases, gaining insights through casual and amusing clinical conversations. Welcome to 4D, a podcast brought to you by the Degenerative Diseases Special Interest Group of the Academy of Neurologic Physical Therapy, a component of the apta. I'm Parm Padgett, a physical therapist in the Outpatient Neuro Clinic at Dartmouth Hitchcock Medical center and I'm on the podcast committee of the DD sig. I'm very excited to be here for this episode with Dr. Alice Neubauer. Alice is Emeritus professor in Rehabilitation Sciences at the Catholic University of Iluvin in Belgium. So Alice, welcome and tell us a little bit about yourself and your day to day work that you're doing as an Emeritus professor.

[B]

Thank you, Pam. And thank you very much for the invitation to be here at the podcast. Yes, so I'm a physical therapist that became interested in research when I was in England for a while and working in England in the National Health Service. And then I undertook a PhD that brought me to Leuven in Belgium. And after finishing that I became a professor in rehabilitation sciences. And I have always been interested in neurorehabilitation. So that was also my area of teaching and doing research. But my research was dedicated to patients with Parkinson's disease. I was forced into that topic by my then supervisor because like all therapists, I was very interested in stroke. But once I was forced into it, I never looked back. And in fact I'm very, very dedicated to research in rehabilitation for Parkinson's disease. Since my emeritus status, gaining debt a little bit more than a year, I'm still of course passionate about the same topic. So you cannot undo that part of your brain, you cannot take it out with a neurosurgical technique or so. So that means that, that I'm still, still doing things for this topic. The things that I still feel very committed to, while at the same time also making sure that I'm not in the way of other people and so that I also let go when I need to. So that is a challenge. But it's also a very nice challenge.

[A]

Yes, exciting. So you just told us that your area of expertise is Parkinson's and it's a population that is also near and dear to many of us and our listeners as NeuroPT is entrusted in degenerative diseases. The thing I'm most excited about for our discussion today is that your real true expertise lies in freezing of gait. Is that correct? And I'm curious, what brought you toward freezing of gait?

[B]

Yes, that is definitely true. It's been a gait problem that gained my interest when I saw a patient having an episode of freezing of gait. And then many years ago, I went to a conference of the International Society for Posture and Gait Research, and there I listened to a lecture on gait problems in Parkinson's disease and again was confronted with freezing of gait. And then I thought, this is what I want to know, you know, what is bringing on freezing of gait? And how can we do something for people who have this very devastating gait problem? So it's the combination of clinical and research that came together that made me want to really delve into freezing of gait.

[A]

Yes. And I think so important for us, because it's one of the things that really is frustrating as a clinician because it's hard to deal with. And, you know, something where I think we feel like any kind of guidance would be hugely appreciated. So I wanted to start by just having a quick review of the pathophysiology of freezing of gait. So, like, why does it happen, particularly in people with Parkinson's?

[B]

Well, it is a very, very complex problem. So it is not something that you can just summarize in a few sentences and say, well, this is why it is happening. First of all, we don't truly understand why we have this very episodic problem that suddenly brings on this inhibition of the GATE network. To give a very brief definition, I suppose, of what freezing of GATE is. But why that sudden inhibition occurs, we don't truly understand. There are some models that we use, and one of the models that I quite like, but I also think it's still incomplete, is the fact that maybe there is a moment whereby within the basal ganglia there is an overload of neural input. And that overload brings on a breakdown of the GATE network. As I just said, as I say, it is an incomplete model. And it comes mostly from Professor Simon Lewis from Australia, who's actually shown that many different brain networks are involved in freezing. That is something we can see in the clinic as well, because we can see that many different input into the person's daily life can actually bring on a freezing episode. That can be distraction, so that's cognitive. It can be anxiety, stress. So that's the limbic Circuit, the limbic input that has an impact, but also motor challenges that brings on freezing, such as making a turn or adapting gait to circumstances that the patient is in. So all these different triggers of freezing of gait point to different areas in the brain that can lead to this overload, this point at which there is probably something that doesn't go through a bottleneck, a bottleneck of neural activity. And as I say, it's not a good model, in a sense, because it is a very similar model to what's happening in dual tasking as well, whereby you have dual task interference.

[A]

Yeah.

[B]

So it doesn't completely cover everything we know about freezing, but it probably does have an impact on the final common pathway down towards the brainstem and towards the spinal cord that brings on a supple and an adaptive gait pattern. So there is where the bottleneck actually has an impact. So it does help to think about it like that, about freezing when you're thinking about therapy. Yeah, because it means that. Well, it means a lot of things. But one of the implications of the overload model is that as a physiotherapist, you want to undo complexity and avoid overload. So that is a helpful thought, I think, for dealing with freezing of gait.

[A]

Right? Yeah, I think that's a nice way to sort of think about it, because we see that. Right. You see that when you put the patient in a complex situation, you can induce that freezing of gait. And one of the things that I've heard you speak about that I think is another nice thing to sort of separate out and think about is automaticity and how that overload kind of can lead to a decrease in automaticity. And do we have any sense of, like, why that happens? Are things prioritized differently in that overload situation for different people? Is there something about Parkinson's? Is it just that lack of dopamine that kind of leads to that decrease in automaticity?

[B]

Yeah, it is probably the lack of dopamine that leads to that deautomaticity. And that, I think, is always the core problem of motor performance or motor deficits in Parkinson's disease generally, but also is at the core of freezing of gait. And because people have an automaticity problem, it means that they overcompensate by using attention a lot. I think attention is the most important compensatory strategy that patients use, and they often use it without almost consciously thinking about it. They are bringing on their goal, directed attention to achieve a task, despite the fact that the automatic system is having A difficult time because of the low dopamine in the basal ganglia, by the way. The freezing episode could also perhaps be explained by a temporary unavailability of that dopamine, which then brings on again the compensatory system and that brings on a bottleneck or something. But we don't really understand how that works. But I think there is a lot at the moment ongoing about maybe identifying different subtypes in people with freezing. Some people may have more difficulty with cognitive overload, others may have more difficulty with limbic overload or stress or whatever, and others with motor challenges. And so that means that that is quite an attractive idea that we have different freezers that you could separate out into three subtypes. And there has been some evidence produced for that. My own sense is, having seen people with freezing over longer periods of time, that that may be so early on that you can identify certain subtypes in freezers, but eventually, when they have more advanced disease, they will have freezing in all three circuits. And when all three forms of input into the brain starts to clutter.

[A]

Right. Okay, I just want to unpack some stuff there. So I think one of the things to kind of point out is this idea that early on we may see freezing in more of the dopamine depleted situation. And so in theory, medication. Right. Should help. So when people are on and on state, at least early in the disease, we'll see less or maybe no freezing of gait. Is that accurate?

[B]

Yes, it is accurate. You see that early on in the disease, actually Levodopa has quite a very good and solid effect on reducing freezing episodes. And with time, of course, that becomes less that dopamine effect. And what I also see a lot is that dopamine has less effect on that freezing. The rhythmic disturbances that are inherent to freezing of gaiter, those typical oscillatory movements that we see accompanying freezing, seem to remain. But having said that, we've just done a study whereby we looked at the impact of Levodopa on different phenomena that can be observed during freezing. And there we saw that Levodopa seems to also have a similar effect on the rhythmic disturbances as it has on the, say, completely akinetic periods of freezing and with a kinetic periods, I mean, really coming to a stop. So we saw, in fact, that both phenomena were affected by Levodopa apart from one group. There was one group that we could identify that showed no effect of Levodopa on the rhythmic disturbances. And also generally, I would say that if Levodopa has an effect, you still see these Little festination or shuffling type movements still continue even if people are on. So I think those elements are less well regulated by Levodopa. But as I said, the jury is still out there.

[A]

Yeah, yeah. So much that we don't know. That was one of the things that I wanted to ask about too, is like festination versus freezing of gate. Are they similar? Is festination like a precursor to freezing of gate? How do you think about that?

[B]

Yeah, that's a very topical question because soon we will have a freezing of gate conference in Atlanta. And one of the sessions in that conference is. Is festination part of freedom of gate at the moment? There are people that say no and there are people that say yes. I belong to the latter group. I think that fascination type, shuffling type movements are part of, say, a more mild form of freezing probably, or is a phenomenon that is related but slightly different than freezing. It can also have maybe a different neurophysiology than freezing has. So I belong to that group. But there are also people that are adamant that it's very different. And it depends a little bit again on the definition because it seems really strange that you have all these experts in freezing. But we're still debating what freezing actually is and what it means. When does it begin? When does it end? Do these oscillatory movements, are they included in freezing? And is freezing only standing still? Or can you also see somebody freezing while still going forward a little bit? So there's lots of debate on that as well. But we are now so far that we will be soon presenting a final definition of this debate. But fascination as it is defined in the literature at the moment, which is like having this hastened, small steps gait, which is progressive in hastening and also often has that leaning forward, if it is defined like that, then there are a number of people that say, no, that's something completely different and freezing. So that is something that we do not have consensus about at this point in time.

[A]

Yeah, yeah, it's interesting. All that stuff is tricky and I think those definitions are going to probably help a lot in defining that. But you know, the disease is a continuum. And I think when you, you know, when you put these problems on that continuum and then you get these individuals that are all a little different for whatever reason, you know, then it's. It's really hard to kind of parse that stuff out. And then like you said, without the science yet on the pathophysiology. And I think that makes it difficult too.

[B]

Yeah, you're pointing to the variability of Breathing within different patients, but also in each episode, things are different again. And so there's a lot of variability and that makes it a very difficult problem to study.

[A]

Yeah. And very frustrating for our patients.

[B]

Very frustrating. And I think a lot of people that have entered into the field, for instance, that they've just got a fantastic gate lab and they have a virtual reality and they say, right, in this gate lab we can find out what freezing is about. And often that is not the case. It is very, very difficult to do this type of research, but very exciting as well at the same time.

[A]

All right, well, I want to get back to the three subtypes of freezing of gait that you talked about and just dive a little bit deeper into each of those. So the one that you mentioned was like cognitive interference. Right. Is interference the right word? I'm not sure.

[B]

Yeah, yeah.

[A]

Okay. So can you just describe that a little bit? Like, what do we see in that subtype of freezing of gait?

[B]

Yeah, those are the patients that typically have more freezing when they are dual tasking. So when there is cognitive load imposed on them, and especially also not any cognitive load, but if the cognitive load is heavy is a real burden, then they start freezing more. So there is a correlation between cognitive load and the duration of freezing and the number of freezing episodes that people experience in that situation. So that is a very clear example of the cognitive type of freezing.

[A]

Okay. And so is there a link between that kind of freezing and cognitive decline?

[B]

That's another interesting question against. A little bit of controversy exists on that. The most recent meta analysis looking at differences between freezers and non freezers, which of course is tricky because freezers usually have worse disease duration than non freezers and therefore also have cognitive differences, et cetera. So it's quite difficult to make that comparison. But in the meta analysis that is most recent and has done that also stringently, they found differences between freezes and non freezes at all components of cognition. But they disappeared when you controlled for disease severity, except for one element, and that was global cognitive decline. And if you look at global cognitive decline and control for disease severity, between the two groups, there's still worse cognitive decline in freezers than in non freezers. So that probably is the most recent findings that we have on that.

[A]

Okay, okay, great. And then what were the other subtypes? One was a motor.

[B]

Well, the other one is the stress related subtype. So those are people. And when you talk to patients, you probably will recognize that as well, is that patients describe a sense of stress, a Sense of anxiety when they know that freezing is coming up or they see it coming, for instance, they know that they're going to freeze when they're going out of a lift or elevator and they think, oh, and they get nervous and start to freeze. Even quite apart from the doors opening or not. Or it is stress related to timing. It's stress related. And also some interesting experiments have been done as well whereby patients had to walk over a normal gait trajectory and a beam, whereby they had a risk of falling. And when there was a risk of falling, they froze more. So it is people that are very sensitive to worrisome thoughts about freezing. And the work from Will Young is very important in this area as well as from Kyleena eggoods martens that have done a lot of work on this area as well. So, yes, there seems to be a relationship. Now, having said that, you also see that patients with tremor are worse when they are stressed or when they are exposed to social stress or whatever. So Parkinsonian symptoms are generally sensitive to stress and limbic input. Another thing that is possible as well, and that is something that we also try to figure out in a recent experiment that we're about to publish, is when we actually looked at the impact of dual tasking and the impact of stress as well. And having the two together. So having stress and dual tasking. And we didn't see that when you brought the two together, you also had more freezing. So that was interesting. And it was almost as if sometimes I feel that stress and worrisome thought thoughts are also a kind of a cognitive distractor as well. So how truly separate it is from overload in general, or overload as from attention or, you know, I think probably it's quite difficult to really tease them apart.

[A]

Yes.

[B]

But, yeah, so that was an interesting finding as far as we were concerned. But certainly when we induced stress in that experiment, yeah, patients started to freeze more.

[A]

Okay. And then the third subtype.

[B]

The third subtype is the motor subtype. And that is when patients are adjusting their gait pattern, have to adjust their gait pattern to environmental situations. And I think the most important issue is turning. I think turning is the trigger of freezing. We also have now established that in our latest articles. We just published an article just comparing which situation brings on most freezing most consistently. And there's no doubt about that. And that is performing a 360 turn fast. So asking from patients to quickly adjust their gait and then turn one way and then the other way for a minute or so, and asking that particular Task brings on freezing quite regularly, even in people that do not say that they are a freezer. That was our most interesting recent finding, is that there are a lot of people that say, oh, no, I'm not a freezer. I don't have that problem. And then once you get them to do that very, very severe and very important trigger or freezing task, 360 degree turning, then they do freeze, or they did freeze, quite surprisingly.

[A]

Yeah. I find sometimes in the clinic when somebody reports that they're freezing at home, or occasionally freezing, and it's really very upsetting to them. And, you know, we don't see it in the clinic. And I think that's for a variety of reasons. I mean, people are just different when they're in the clinic anyway. Right. Because they're focused on their, you know, they're not in their natural environment. They're focused on movement. They just tend to, I think, do better. So I will sometimes utilize that 360 degree turn in both directions, and that often does elicit. So I think it's something that as clinicians, we've sort of come to or figured out. And so it's exciting that there's this body of work now that demonstrates that now.

[B]

Yeah, it becomes even more sensitive when you also have patients doing a dual task as well during the 360. And then, yeah, it's a real, real, very potent trigger of freezing of gait. Yeah. And it's good that you can see it. It's good that you can see it as a clinician, although it is not a task that you do a lot at home.

[A]

Right, right. Which is why people think they're not freezers. And then when you. When they do that. Right, yeah. So actually this, all of these three subtypes makes me think of our cognitive tug, you know, the timed up and go test that we do often in testing with patients. So I'm wondering about that. And like, it kind of combines all of these subtypes. Right. Because you're giving them a cognitive task. You're having them, you know, stand, walk, turn. Only 180 degrees, not the 360, but they're still turning. And then I find often when asking people to do the math task, that induces stress in people because, you know, the number of times that people will say, well, I have never been good at math. They just get stressed about the idea of having to do math. And so, you know, I'm just thinking, like, okay, like that I might see freezing of gait then. But then I feel like maybe we I would need to step back and try to figure out, like, if I wanted to classify into one of these subtypes which, you know, which one is it, and just kind of separate out exactly that task with walking. I don't know. I'm just curious what you think about the dual task, tug, and its value to us as clinicians.

[B]

I think it's a very valuable task, and it was also high on our list of situations which triggered freezing of gait. So it's less potent than the 360, but still a very, very good trigger. So we ended up with a few situations that we would recommend for assessing freezing, and the TUG plus a dual task was one of them. So I think it's a good clinical task to use. I think it's good to think about the possible three types of freezing and to think well. But the real question is, what brings on freezing in this particular patient? And the real question is, when does it happen when patients are at home and when they are in their own environment and at which hot spot at home occurs it more than others, and why? So it is that analysis that is more important, in my view, than separating them out necessarily in three subtypes, if you like, because, as I say, the subtypes have some evidence behind them, but we still have to see whether that theory holds. Right. So I think you probably will learn a lot about asking patients about their most frequent situations where they experience freezing at home or when they are doing things in daily life that I think will be the most informative. And in my view, it is an excellent starting point for therapy for physiotherapy.

[A]

Yeah.

[B]

Because what then, what I would do if I was treating somebody with freezing, I would try and almost sometimes mimic the situations where they had a freeze for where you were working. Sometimes I would go home with them to also see where they had the freezes. And. And then that would really help them and help you as a therapist to try and find out, you know, how can they prevent this freezing in this particular situation? And the advantage of mimicking or being as close as possible to the actual freezing triggers is that they will also remember better to do a strategy or to suppress worrisome thoughts or to make sure that they focus on this or that, which will then help them to undo the freeze or prevent the freeze. So that, to me, is more important than identifying the subtype as such or doing a very clinical test, such as doing the time get up and go first without a dual task and then with a dual task. That, to me, isn't where it is at. I think it is really at where they have the freezing in daily life. Yeah.

[A]

Yes. Yeah, yeah, yeah. I. I agree. And I think that for a lot of us, it's in our current healthcare situation is we can try to do that. We don't have the kind of freedom as much as you guys do, I think, to, like, get into the home, at least when we're in an outpatient setting. I mean, maybe, but it's a little bit trickier. But, yeah, I think you're right. I think it is where it's at. But also I think we as clinicians feel the need to do some kind of assessment and try to sort of objectively change some measures. And so, you know, the questionnaire, I think can be helpful because it gets at what the patient is experiencing a little bit. And we've talked about the dual task tug. Are there any other assessments that you recommend for freezing of gait?

[B]

No, I think that is probably plus the 360 turn as well with. Without a dual task. Left, right, fast. That is one. I would do the dual task tugs, for sure. I would also want to know about patient's balance. So I would also do items from the mini best test to see whether patients are unstable or which areas they are unstable. That is something that I would do in addition to their freezing of gait. But other than that. No, I think that would capture it for me. That's what I would recommend therapists to do.

[A]

Yeah. And I think sometimes we don't always, like, understand how much overlap there is between freezing of gait and falling. I mean, it kind of makes sense, but the literature really supports that. Oh, a lot of falls are related to freezing of gait.

[B]

Very much so. Yeah. There's no doubt anymore. It is an enormous fall trigger. And also when you talk to patients about their freezing experience, they also talk about fear of falling. And a moment of freezing for them is also a moment of instability. It feels feeble. They feel less strong on their feet when they are freezing. So, yeah, it is definitely related. We have never been able to identify which components of balance are most related to freezing. We looked at reactive balance, for instance, that seemed the least related to freezing. And anticipatory postural responses seem stronger related. But it's never been very, very clear that pattern. Which components of balance are most related to freezing. But I certainly would want to have a sense of the balance functions of my freezer if I was a physiotherapist.

[A]

Yes, I totally agree. And I think a lot of us do that, which it is helpful to put those two things together. So let's jump back towards treatment, because I think that's. That's where the rubber hits the road, and that's why we're all here today, is to try to figure out what can we do for our patients with freezing of gait. So, you know, you have your patient, they have told you where they freeze, you are able to set up a similar situation when you're working with them. And then what strategies do you recommend? Where might you start with a patient who's experiencing freezing of gait?

[B]

Well, where I would start is by teaching patients rescue from a freeze. So what do you do when you have a freezing episode and you want to get out of it? Right? So that's a rescue strategy. And the first thing that they have to learn is to stop wanting to move or to stop wanting to walk during a freezing episode. So they have to reset their brain, as it were, and say, okay, I'm stopping now because I can't go on, right? So I'm stopping. Back on the feet, back on the feet and stop. And then there is, I think, a very effective strategy that I teach everyone and that is also centered to the work of William Young, who is a researcher in the UK that I already mentioned. He is very, very active in this field of rescue strategies. And he has a strategy that I also have used for many years, which is weight shifting, weight shifting from right to left. It doesn't matter where you start. You don't have to have any cognitive strategy other than try and shift your weight, whereby you then release your swing leg that you can then bring forward once you have sufficiently shifted your weight to one side. That's a very useful strategy for almost anyone. They can use that as a rescue. You can also use it as a prevention strategy at moments. For instance, during a turn, you can also exaggerate the weight shift during turning with the trunk so as to prevent a freezing from happening. Or when you are walking in a very, very narrow space, you can again exaggerate that weight shift. So weight shifting, in my view, is very crucial to freezing. And then, of course, we also see immediately the link with balance, right? So bringing the center of mass to one leg and initiating gaiting, doing stepping movements just to practice balance on one leg or the other. That is also a layer underneath that strategy and prevention strategy. So that is, for me, core to the training of freezing. Of course, there are other ways as well, which I really like, and you probably know that I also done a Lot of work on cueing.

[A]

Yes.

[B]

So that can be auditory cueing, that can be visual cueing, but I'm more in favor of auditory cueing. And these days there's also very nice mechanisms or devices now that can also bring on vibratory cues. So cueing vibration, you can actually use to make sure that the gait is continued once they have the rhythm, and they can reproduce the rhythm of gait through cues. You also prevent freezing with that in freezing provoking circumstances. Once you give them a rhythm, then they usually do have less freezing, for instance. So that is something that I think is often seen as a user tool. And the problem is with queuing. People don't use it at home. All these cueing devices, I mean, maybe they will once the queuing devices become more handy to use or small or easy to use, then maybe people start using these tools. But often they don't use these aids. But you can still use it as a therapy, as a training tool, but only if you also wean patients off cueing.

[A]

Okay, so I just want to step back for a second. So can you describe. So let's talk about the vibration cueing devices. So what is the device like? It's typically like something that the patient has to wear. Yes, Right.

[B]

For instance, at the wrist or at the sternum. And then it provides a rhythmic vibration that people then can use as guidance for the rhythm of their stepping. Okay. But I find it easiest in a clinical situation to work with auditory cues. There you can hear the cue yourself, the patient can hear the cue, and you can then first of all make sure that you have the right rhythm, that the rhythm is the correct one, that it also caters for, for instance, turning or slaloming or complex gait. So that I think is really nice. And then you can tweak the rhythm so that it's helpful for patients to prevent freezing. And then you can use it and stop the cues and bring in them on again and stop them and bring them on. So that patients also learn how to walk without the cues and still maintain their gait rhythm. So I think that is a very nice walk of training with patients. And then what I would do, and I think that's really, really important, is do a lot of gait training in situations where they have to constantly adapt their gait pattern. So make it faster, make it slower, and you can use cues for that as well, faster cues, slower cues and things like that. But you can also just do that by bringing on lots of turns and chairs and clutter in an environment. That patients have to negotiate. So adapting gait patterns is crucial to training people with freezing of gait.

[A]

Yeah. So just a question about the cueing and weaning people from the queuing. So is there any research that sort of demonstrates that? I didn't even finish my question.

[B]

Love it.

[A]

You knew exactly where I was going. Because I feel like in my patients in the clinic, and I hear from other people, like, they do fine when it's there, but once it's gone, you know, it doesn't really change or we're not really able to kind of get that automaticity back.

[B]

Can I comment on that? Sorry, that was.

[A]

Please, please.

[B]

And you're right, that is also. There is research that says that, and I totally believe that research as well, that when you take the cues away again, there they lose the impact of a cue. Right. So that is certainly true. But this is about training patients to maintain their own gait rhythm. So that is different. That's a different use. It's not like you give the cue, you look what's happening, and then you take the cue away, and then you look what's happening, and you see that gate returns to the. The automatic state. Right. And so to a worse state. But what I'm saying is what you want patients to take away from training is that they maintain their gait rhythm even through all kinds of clutter and complexities. And to help them, you give them a cue first, and then you say, now I'm taking it away, and now you keep on going. So probably something in their brain has to take it over from the cue. Right. So I'm not saying that you go back to deautomaticity. I'm saying that you're trying to take on board what the cues have taught you and make that explicit to a patient. That's what I'm saying.

[A]

So they're kind of internalizing the cue, and it's. This is making me think of, like, Gammon Earhart did some work. Mental singing.

[B]

Very nice work. Yeah, yeah.

[A]

And we. We've talked to her about that. So little plug if people haven't listened to. To that podcast to go back and check that one out. But that's what this is kind of making me think of, that mental singing. And I use it a lot with people because they will say, like, we'll sing, you know, row, row, row your boat, which is what they did in that study, and it works for people. But then they. They think, like, I don't want to be out in public singing row, row, row your boat. And I was like, no, you don't have to. You can just sing it to yourself in your head. So that's. That is really helpful.

[B]

Yeah, yeah. So it's. It's anything that brings on for them the same rhythm that can be counting, it can be singing, as you say. And singing is very effective. I thought that work from Gamin is very, very nice and interesting. So. Yeah, I certainly also recommend it. Yeah, yeah.

[A]

And I also think there's something about singing, like, especially, you know, a kid song or whatever that makes you think, like, it's simple, but it's also fun. Right. And so it can be de Stressing, I think, in the moment, or. Yeah, I certainly. I feel like we end up having a lot of laughs about it in the clinic, which I think is a positive thing with patients. All right, so cueing is huge, right, for freezing of gait. And I think probably the biggest hope for patients in terms of, like, giving them a strategy that they can use in those times when they know it's going to come on or it might be stressful. Is there anything that has been done or that we know might impact, like, the number of episodes of freezing that somebody might experience?

[B]

So one of the hopeful developments of queuing and the impact on the number of freezing episodes and the duration of freezing episodes is indeed something that we have published last year, which is an on demand queuing apparatus. So it means that people have earphones, they have a smartphone and sensors, two sensors at the feet. And the sensors at the feet pick up when a patient is starting to freeze and at that moment, the cues come on. Now, the system that we have developed is at the moment incomplete again, because the detection of freezing is very, very difficult. So the technical detection of when an episode starts to occur is really not up to the accuracy level that we wanted. Right. So of course, the system is dependent on that. Patients must trust it. They must trust that indeed they are about to have a freezing episode. So that is still lacking, but it is in development. And even the incomplete system was effective in reducing percentage time frozen, but also reducing the number of freezing episodes. If we brought patients in a freezing provoking protocol. So we made them do the 360, we made them do the dual task, tug, et cetera, et cetera. We brought them to the hotspots at home. So we did all that. And so, yes, it was definitely effective, as effective almost as medication and medication. And cueing also had a little bit of an additive effect, so they were even more effective. So I think there's hope in that that technology will start to become better in detecting freezing episodes. And then I also think that that kind of on demand cueing system could help patients to learn about their own freezing. We haven't done that at the moment so far. We've only given the device to the home situation and said get on with it, use it as much as possible. But I think we can use it as therapists as well because then we could say okay, will have the queuing and so what are you learning? So what are you feeling? Oh, you're going to freeze. Oh, now the cues come on. So to learn more explicitly, a bit like the weaning of the cues that I was just talking about learning about their own freezing patterns and hopefully also thereby preventing freezing. So yeah, I see definitely hope there in that technology being more and more developed.

[A]

Yeah, I think that one of the things from when I saw you talk at CSM I just remember feeling like, oh, I have some hope. So I want to talk to Alice and get this information out there. And I do think that the potential for that in the future is exciting. And I think I'm now like, I love this idea of that teaching people about freezing and when it's going to happen so that they might learn even before the device picks it up and they can start using strategies and then they get that reinforcement from the device and then maybe they won't need the device. Right. That at least for short periods of time, you know, because the other thing that's is always complicating in this disease is that it is progressive. And so, you know, like we started saying over time it's this problem is going to get worse. But I think the longer we can push it out before it's really impacting people's day to day life is huge for folks.

[B]

Exactly. Yeah. And we could also think, of course, and that's one of the thoughts about therapy as well is this, can we postpone freezing that it starts to occur? Can we make the brain stronger so that it takes a little bit longer before it comes home? And that is something that we have recently published as well in a paper that will come out not only about rehabilitation but also about medical treatment of freezing. It's a paper that has been written by Anouk Tosserams and Jorek Nonikos and I'm a co author, just as many people are co authors on it. And it gives a sort of decision tree on how you can deal with this freezing of gait. And part of that is now rehabilitation as well, which is nice that rehabilitation has its own decision tree within that paper. And one of the thoughts that we project there as well is that maybe before freezing comes on or when it's very, very mild, maybe we should also think about training the systems that probably will help people to be more resilient against the development of freezing, such as the cognitive system, of course, but also balance, the balance system that we make sure that people are really trained very well for their balance, that they have good muscle strength in their lower limbs, to feel strong, to have gait capacity, and make sure that that is optimized with treadmill training and with adaptive gait training, so that the systems are strong to deal with freezing before it starts to occur. And I think that's a very important thought as well that we can use as therapists for patients, with or without freezing.

[A]

Yeah. Yeah. I mean, I think for a lot of things, filling those buckets is helpful, and freezing is one of those things. The more that we can get people doing all of the things early. Right. The better. So, Alice, I feel like this has been a lot of really great information on freezing of gait. So I think I'm gonna have to go back and listen a couple times to really get the most out of all of this great information that. And we certainly appreciate your expertise and, you know, just being able to learn from you about one of really the most. The most difficult and most frustrating areas to treat has been super helpful. So thank you so much for sort of sharing that expertise.

[B]

Well, thank you for inviting me, and it was a pleasure to do this podcast and feel the passion of freezing.

[A]

Yes, yes, it's out there. All right. So one more thing, though, before we let you go is what do you like to do when you're not working?

[B]

Yeah, I probably. You would want me to say things like all kinds of physical activity and all this. Actually, I do a very mild physical activity. I walk and I cycle, and I do that with pleasure. So it has to be outside. Yeah. But other than that, I'm not a great sports woman. And the other thing that I do really like is reading, and I'm a. Reading. A reader of English literature, and so I'm. Yeah, I'm a keen reader of. Of novels, and so that is something I truly enjoy.

[A]

Yeah, that's great. Yeah. Well, Alice, again, thank you so much for being here. It's been such a pleasure and an honor to have you on our podcast.

[B]

Okay, well, great. Very nice that you asked me to do this, and good luck with your.

[A]

Endeavor, the Academy of Neurologic Physical Therapy and its collaborators disclaim any liability to any party for any loss or damage by errors or omissions in this publication. The views or opinions expressed are those of the individual creators and do not necessarily represent the position of the Academy of Neurologic Physical Therapy. Thank you for joining us today and a Special thanks to Dr. Alice Neubauer. This podcast was produced and edited by the AMPT Degenerative Diseases Special Interest Group Podcast Team. For more information on the SIG and AMPT, visit www.neuropt.org. our podcast team includes Sarah Zoller, Christina Burke, Ken Bonacco, Jeff Schmidt, Shannon Brown, Skylar Ross, and I'm Karn Padgett. And a special thanks to our reviewers for this episode, Aisha Sanani, Olivia Visagio and Song Bo. Please share this podcast with a colleague today and we do bloopers. I need to record all the podcasts at 8am so much better than 8pm Your picture is so crisp. You look so good. So good.

[B]

Thank you. At my age, I can. I'm glad to get in the and compliment.

[A]

So, Sarah, is this the first time that we've talked to anybody in Europe?

[B]

I think so.

[A]

I think we consider ourselves international because we talked to somebody in Canada. Right. We're not twirling around. Maybe we should be.

[B]

But. And I'm working, of course, a lot.

[A]

Yeah, that's what. Yeah.

[B]

Probably once we've stopped this conversation, I probably think, oh, I should have said that.