Freezing in Parkinson’s, and how to thaw
We look at a symptom of Parkinson’s that can be stressful, frustrating and lead to falls. How are researchers working to develop coping strategies for freezing of gait?
Some people with Parkinson’s find that they suddenly can’t move, as if their feet are glued to the ground. This can happen at any time and is known as freezing of gait, and affects about a third of people with Parkinson’s.
Although freezing is a motor symptom, someone’s mental state can have a big impact. Feeling depressed, anxious or stressed are all likely to make freezing worse. Freezing is also more likely when navigating around objects in a room, passing through doorways, changing direction or multitasking.
Freezing is a major contributor to falls in Parkinson’s. To take the first step out of a freeze, balance need to be adjusted in a specific way, which can make people unsteady and increase the likelihood of them having a fall. We know that falls can have a big impact on people with Parkinson’s, leading to hospital admissions, loss of mobility and social isolation. Falls were identified by people affected by Parkinson’s as a priority area of research to improve life.
We don’t fully understand what causes people with Parkinson’s to freeze. However, problems with the way the brain processes visual information from the environment and how it uses that information to plan movements both seem to be involved in freezing.
What can people with Parkinson’s do if they find themselves stuck like this? And how are researchers helping?
What can you do about freezing?
Many people have established their own ways of managing this symptom, as highlighted by one Parkinson’s UK forum user:
My hubby walks backwards whilst holding my hands, I walk forwards and…. now this is the best bit…. I call one leg ‘Tina’ and the other leg ‘Turner’. Off we go saying, ‘Tina’, ‘Turner’ and repeat this until we reach our destination! We are usually in hysterics by the time we get to what ever room we are going to. But it does work!
Counting, chanting or singing in this way can help people to take that first step — these are known as temporal cues as they tell people when to move. Imagining something to step over, or placing tape on the ground where freezing usually happens, can also help people to get moving again. These are spatial cues that inform people where to step.
How is research helping?
Researchers are interested in optimising these cueing tactics to help people start moving again after freezing.
Cathy Craig is a researcher at Queen’s University Belfast whose work focuses on how the brain controls movement. Cathy’s research at the movement innovation lab makes use of a range of technologies, such as sensors and virtual reality, to study movement.
Previous research at the lab found audio cues useful for people with Parkinson’s who freeze. The sound of footsteps in gravel worked particularly well. As footsteps are relevant to the action of walking and provide a continuous audio cue (as opposed to a transient cue — such as footsteps walking down a corridor) participants were able to keep their attention focused on the task at (ahem) foot.
Freezing is difficult to provoke in a clinical setting — which can make it hard for researchers to study. Cathy was interested in testing if virtual reality could be used to induce freezing.
Using virtual reality, you can create very realistic environments. We used virtual doorways to induce freezing in people with Parkinson’s. Being able to induce freezing allows us to study it in a more systematic way.
Cathy was also interested in testing if visual cues in a virtual reality environment could be used to overcome freezing.
We tested a visual cue in a virtual reality environment — a series of black footprints on the floor that light up at different times to give the impression of following someone— similar to walking in someones footprints in snow.
Cathy found that following the footsteps helped people to overcome their freezing. But how would this work outside of the lab?
I think augmented reality is way to implement this in real world. In augmented reality you still see and interact with the real world as normal, but you see digital information as well — through augmented reality glasses or through a smartphone camera.
Will Young and his team at Brunel University are investigating if analogies can be used to help people overcome freezing. Analogy learning involves turning a sequence of movements into one simple analogy or metaphor. This technique was originally developed to learn skills for sports, as analogies may be easier to remember and follow when under the pressure of a game. Will explains:
Analogy learning relates to imagining a metaphor for a given movement. For example, if I move my balance from side to side, I might think about the analogy of a tree swaying in the wind. This type of metaphoric imagery is thought to create activity in areas of the brain affected by Parkinson’s, which consequently improves movement control — in theory!
One of Will’s collaborators, Mark Wilson from Exeter University, has previously shown that analogies can improve walking. Mark found that the analogy ‘following footsteps in the sand’ could increase stride length in people with Parkinson’s. Will now wants to explore if analogy learning could also be used to promote movement when someone freezes.
What the project will do
Will and his team will train 20 people with Parkinson’s to use movement analogies. These will help the participants to picture the movement and — hopefully — to move.
In this project, Will and his team will put people with Parkinson’s in situations where they are likely to freeze and see if using analogies can help them to start walking again.
In our sessions we describe to participants the specific movements we would like them to make when attempting to make a step during a freeze. We then show them various pictures of analogies and help them imagine a relevant movement. These pictures include: standing on a set of scales, a corkscrew turning, a slalom skier. Participants are also encouraged to suggest their own analogies that they might find easier to imagine. We then ask participants to practice using their chosen analogy, at first when seated, then stood up, and finally during a freeze.
Whilst the team hope the participants will find the analogies helpful in initiating a step out of a freeze, Will does not expect this technique to work for everyone.
We are running several additional tests (mostly short questionnaires) that may help us to find out why some people find analogies more useful than others. Our hope is that, in the future, we will be able to use these simple tests to help people find specific strategies that they will find useful.
If the team find that analogies are useful for people with Parkinson’s, Will is hopeful that the technique could be widely adopted in the ‘real world’ and not just in the laboratory:
People generally need very little training to use analogies for movement. Our current participants seem to find it useful to discuss ideas for their own analogies with researchers. However, it is plausible that this could be achieved over the phone, Skype, or even email. From what we have observed so far, people do need to practice using analogies for at least 20–30 minutes before they really ‘get the hang of it’. People would probably need to practice for much longer than this if they are to feel comfortable using analogies when freezing (and potentially feeling anxious) in daily life.
Special thanks to Cathy Craig and Will Young for their help with this blog.