Talking: Dementia, cognitive impairment and exercise

 

Currently within Australia, there are approximately 459,000 people living with dementia. Dementia affects the brains ability to perform everyday tasks. Exercise is essential for maintaining good blood flow to the brain, and may encourage new brain cell growth and survival.

In this episode of ‘Talking Physio’, Professor Mark Elkins chats with Professor Marco Pang, about the value of exercise in improving the lives of people with cognitive impairment and dementia. Marco shares important findings from the systematic review published in Journal of Physiotherapy; in particular, that supervised multimodal exercise has beneficial effects on improving physical functioning in people with cognitive impairment and dementia. 

To read the full research study published in the Journal of Physiotherapy click here

Marco Pang is a Professor in the Department of Rehabilitation Sciences and the Associate Director of the University Research Facility in Behavioral and Systems Neuroscience of the Hong Kong Polytechnic University. He is the editor-in-chief of the Hong Kong Physiotherapy Journal and the President of the Hong Kong Physiotherapy Association.

Mark Elkins, APAM, is a Clinical Associate Professor and the scientific editor of Journal of Physiotherapy.

Narrator

Hello and welcome to the Talking Physio podcast. In this episode, clinical associate Professor Mark Elkins, the scientific editor of Journal of Physiotherapy, chats with Professor Marco Pang, from the Department of Rehabilitation Sciences at the Hong Kong Polytechnic University, about the value of exercise in improving the lives of people with cognitive impairment and dementia. Marco shares important findings from the systematic review published in Journal of Physiotherapy; in particular, that supervised multimodal exercise has beneficial effects on improving physical functioning in people with cognitive impairment and dementia. Before we dive in, this episode has been brought to you by the Physiotherapy Research Foundation - supporting the promotion and translation of research - and sponsored by Flexeze, the exclusive partner of the Physiotherapy Research Foundation. Flexeze, Australia's number one heat wrap, has been clinically proven to be effective for back pain relief; lasting up to 15 hours. Let's get started. 

Mark

Marco, your review addressed a topic that's been reviewed many times, I guess, with different slants or different focuses or different criteria to dictate which studies will make it into the review  and which ones won't, and a lot of those were done in recent years. So what was your motivation for revisiting this topic? Was their substantial new evidence, or did you find a new approach to what you'd include in the data? 

Marco

Yes, there was new evidence, em, but it's more than that. We felt a need to do a more updated review because there's a large amount of information out there. But also previous reviews have taken a particular focus, typically. An example would be they just looked at a specific type of exercise or a specific type of patient population such as a mild cognitive impairment. So we tended to use a more inclusive approach to look at the topic of exercise training in general in people with cognitive impairment and dementia. 

Mark

So that made the review much bigger than other recent reviews in this area. It was a really comprehensive look and a mountain of work. Did it also allow you to achieve things that the other reviews didn't? 

Marco

We were able to do a lot more meta-analysis. So whatever conclusions that we draw from that would be more definitive and because of the large amount of data, we were also able to do a lot of the sensitivity analysis, subgroup analysis. So that would tell us something about whether the exercise training effect would differ depending on the patient characteristics or the type of exercise and so on. 

Mark

So I see those meta-analyses as really valuable because they add so much more than what - they provide information that wasn't available in any of the original studies individually and   so I really loved that aspect of your paper. How did you keep the size of the paper manageable when you had so many studies, so much data, and so many sub group analysis? 

Marco

That was a real challenge, I have to say. So in the paper, we tended to put the sub group analysis, sensitivity analysis, under the main analysis, using the same Forest Plot so that makes it more efficient in terms of the use of space. 

Mark

Before we delve into the sub group analyses and the sensitivity analyses, what were some of your main findings? 

Marco

So, based on our review, we have strong evidence that exercise has beneficial effects on improving various aspects of physical functioning, such as sit to stand performance, step length, balance, mobility and walking endurance in people with cognitive impairment and dementia. 

Mark

So they're all really useful functional outcomes. What type of exercise training should this clinical population be doing? Were you able to determine that from your review? 

Marco

In our review we were unable to find that a particular type of exercise is more beneficial than others. Instead, based on what we found, participants who engage in supervised multimodal exercise are more likely to achieve these benefits. 

Mark

Was there a number of times per day, or a number of minutes per day, or a number of times per week that you would be able to recommend from your review? 

Marco

We recommend to 60 minutes a day, or two to three times per week. 

Mark

Okay, so there wasn't clear evidence for resistance exercise being better than aerobic exercise, but this idea of a supervised programme on that sort of regimen 60 minutes a day, two to three times a week, was effective. Okay, so what about the sub group analyses? What did you find there? 

Marco

Well, interestingly, the, those people who have more severe cognitive impairment or more severe physical impairment, actually they tend to improve more after exercise training. So I thought that's quite interesting. 

Mark

Mm. And do you have an idea of why that might be? Have you and your co-authors discussed why someone who is, has more severe impairment would - do you think it's the fact that they're getting supervision, whereas people with mild impairment maybe could do the exercise independently without needing the supervision? 

Marco

We're not certain. But we thought one possibility is that perhaps, you know, their baseline performance is quite poor, and the room for improvement is more with exercise training. Perhaps that's one reason why the degree of improvement is more for people with more severe impairment. 

Mark

And do you think the milder group, would it have been, could it have been a ceiling effect that we get them? Do you think in the trial that people got up to such high levels that they were getting a ceiling effect on the measures that were used in these trials? Because I guess they'd never get to a ceiling effect on their athletic performance if they got sensationally good. But maybe some of tests like. 

Marco

Berg Balance Scale. 

Mark

Yeah, for example. 

Marco

Perhaps, you know, there's a ceiling effect there. 

Mark

Yeah. 

Marco

And with these people with mild impairment, the level of performance is quite good already at baseline. So I think it's more challenging to push further for this group, than maybe a ceiling effect. That's possible. 

Mark

Okay, so where to from here? What do you think your group's research priorities will move on to now? 

Marco

One of the knowledge gaps that we identified in our review, is a lack of research related to dual task or cognitive motor exercise training. 

Mark

Can you explain just a little bit, what that is, what that involves? 

Marco

In dual task training you combine basically mobility balance training with cognitive exercise. And when you're engaged in dual task exercise, you do both the motor activity and the cognitive activity simultaneously. 

Mark

Right. So having to read out a list of numbers and walk an obstacle course or walk a particular path, okay. 

Marco

So you engage in various balance and mobility exercises while engaging in a cognitive task currently. 

Mark

So that's often used as an assessment tool, or an assessment method, to try and tease out what's going on in research studies. But you're talking about using it as a clinical training method? 

Marco

Yes, we have done some research on that already in a stroke population, and we found this quite beneficial in terms of reducing the cognitive motor interference, doing walking as well as reducing actual fall rate. And we know in people with cognitive impairment and dementia, fall, it's a major issue and they have both physical impairments and cognitive impairment. So I thought, dual tasks or cognitive motor training might play a role here in this population and we need to do more research on that. 

Mark

That sounds fascinating. So are other groups looking at that as well? Or is this something that's kind of a new - using it in that training way rather than an assessment way is that something? 

Marco

I think some groups have looked at the effect of dual task training on cognitive impairment in people with MCI or dementia. But to use that to reduce fall risk, I think this is something that is quite new, that we need to explore in the near future. 

Marco

So when you're doing that in your research as a training method, so I gave a hypothetical example before, can you tell us more precisely what you are using, how you're combining a physical and cognitive task? 

Marco

I will give you some examples. I would have patients doing an obstacle course while performing series of subtractions, for example. 

Mark

Okay so that from 100 they have to go 93. 

Marco

I'll give him a random number and then they subtract - they do a series of subtractions of threes or sevens, you know, different numbers. Or I could have them tell me a story, you know, with a specific topic and um, so they engage in various cognitive activities while doing different activities that will challenge their balance and mobility. I think that's the main idea. 

Mark

Mm. 

Marco

Yeah. 

Mark

Oh that's great. So for anyone who doesn't know MCI is Minimal Cognitive Impairment. Is dual task training being used clinically? Or is it just in the research domain at the moment? 

Marco

It's not common in our clinical practice. It's something that is relatively new, and we're trying to do a lot of promotion in our local communities in various populations. We're doing it in a stroke population now, and we're trying to, you know, introduce this to the management of people with dementia and mild cognitive impairment. And they do that in Parkinson's disease as well. 
 

Mark

It's interesting what you say about Parkinson's. Are people doing similar research there? 
 

Marco

People with Parkinson's disease they, you know, a lot of them have cognitive impairment. Because we used to think that Parkinson's disease is just a motor disease. But we found a lot of people with Parkinson's disease actually have cognitive impairment, and they, you know, they fall a lot because of a variety of reasons but a lot of the dual task research that they did in Parkinson's disease, they also found that when they engage in a concurrent cognitive task, they're walking really slow down more. And so there's a lot of interference between the two. Yes, so that's why introducing this type of training might be beneficial. 

Mark

What about any other neurological conditions? 
 

Marco

Stroke. I've done research on stroke. The paper has been published, and what is encouraging is that we were able to reduce the amount of interference after eight weeks of training, as well as reducing the fall rate by 25% over a six month period. 
 

Mark

So from a research methods point of view, how do you demonstrate the lack of interference? 

Marco

So we need to measure walking under what we call single task conditions. So just walking. And then we also need to measure cognitive performance under single task conditions. So that means when we assess the cognitive performance, we need to do that in sitting, and then we need to assess the dual task performance. So have them do the cognitive task while engaging in walking task or balance task. And by comparing the dual task performance versus single task performance, then we can use the particular formula to calculate the degree of interference. 

Mark

So you see how well they walk around the course, and then if you retest them doing the cognitive task at the same time and if they don't deteriorate, then we say the interference of the cognitive task. 

Marco

And what is very important to state, when you assess the dual task performance, you need to measure the motor performance, so it's either walking or balance performance as well as cognitive performance, yeah. Because we want to make sure it is a real reduction of interference rather than a cognitive motor trade off. Because the patients might choose to sacrifice performance of the walking task so that they can maintain the cognitive performance or even improve cognitive performance. So we want to make sure we measure both in order to assess whether there's a true reduction of interference. 

Mark

Well, thanks very much for chatting. I think there's some really interesting findings in that review and as we said at the beginning, it really was a mountain of evidence that you managed to summarise really succinctly. So people would get a lot of information just by investing the time in reading one paper, they will learn about a really mammoth amount of evidence. So thanks very much for chatting today. 

Marco

Thanks very much. 

Narrator

That was clinical Associate Professor Mark Elkins, the scientific editor of Journal of Physiotherapy, and Professor Marco Pang, from the Department of Rehabilitation Sciences at the Hong Kong Polytechnic University. And you've been listening to another episode of Talking Physio; brought to you by the Physiotherapy Research Foundation and Flexeze. Thanks for listening and make sure you catch the next episode of the Talking Physio podcast.

This podcast is a Physiotherapy Research Foundation (PRF) initiative supported by FlexEze – the exclusive partner of the PRF.

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