Written by Lucy Eland, edited by Nicola Simcock
On the 21st of November SciBar welcomed Ríona McArdle from the Brain and Movement Research group at Newcastle University, who asked us this very question. We have all seen videos of people walking into things while texting, which, in addition to providing comedic relief, shows that walking becomes more difficult when our brain is distracted. This is because walking is a complex task. Although we rarely notice it, walking requires lots of brain power to coordinate movement with visual information about where we are heading. As we get older our brains shrink and so our walking tends to slow down. For patients with dementia, both brain shrinkage and slow walking becomes even more pronounced.
There are two major types of dementia: Alzheimer’s disease and Lewy body disease. While most people have heard of Alzheimer’s, the less recognised Lewy body disease has a slightly different set of symptoms, including hallucinations and movement problems. Ríona, a passionate neuropsychologist, explained how this link ─ between physical movement and dementia ─ has the potential to make dementia diagnosis cheaper, quicker and easier. One goal of her work is to assess whether you can tell the difference between people with and without dementia, by looking at the way they walk. Additionally, as differentiating between these two dementia subtypes can be tricky, Ríona hopes that this method might prove to be a useful addition in the diagnostic toolkit. This second goal is critical, as treating patients who have Lewy body disease with Alzheimer’s medication may actually make them worse.
So how did she test walking in relation to dementia? Ríona’s study recruited patients with both Lewy body disease and Alzheimer’s, along with healthy controls of the same age and then she watched them walk. To help her do this she had a lab full of gadgets and movement sensors, to detect things like speed, symmetry, variability, rhythm and postural control of gait. In fact, the one of the systems used to capture gait metrics in Ríona’s study (the Vicon Motion Capture analysis system) was also used by Benedict Cumberbatch while playing Smaug in The Hobbit film, adding a touch of showbiz to the whole affair!
The outcome of the walking trials offer some good news, with the dementia vs. non-dementia groups appearing to walk differently. Dementia patients demonstrate more variable step lengths, generally shorter strides and less symmetry between the two sides of their body when walking. With Lewy body disease there was also significantly more asymmetry, probably reflecting the way the brain degenerates unevenly during the course of the disease.
One valid flaw that Ríona drew our attention to was how lab walking is a bit different to normal walking, with many patients trying to ‘do their best’ when their walking is measured and they’re conscious of being observed. To solve this problem Ríona told us how she looked for ways to monitor patients in their natural environments. This gives researchers more information on how much people walk on a day to day basis and whether they vary the length, location and time of their walks. This work included strapping a fancy monitor, about the size of a large watch face, to the subjects back to record their movement. Ríona could then assess walking style without influencing the patients and additionally, follow-up about any unusual activity (such as the patient who was clocking up an impressive 300+ minutes of walking a day, who owned 2 large dogs in need of much exercise!)
Ríona explained that while the results look promising, a larger study with more participants is needed before the research can be used to help diagnose patients. The need for a large study number was highlighted when the intrigued audience raised questions about how leg and foot injuries may influence walking results. Riona assured us that with enough participants any influence of ‘unique walking styles’ or unrelated walking-problems, should not significantly affect the study outcome.
Ríona left the SciBar audience feeling pleasantly optimistic as she spoke of her hope of seeing a day when a dementia diagnosis is not so feared, because of the knowledge we’ve gained, improvements in the diagnostic process and effective treatment options. That day may arrive sooner than we think if novel research such as this continues to bring useful new insights to the conditions facing today’s society.
If you are interested in getting involved in Ríona’s labs latest research, please go to https://research.ncl.ac.uk/bam/ to find out more.
We look forward to seeing you at the next SciBar event on Wednesday 12th of December where we will hear Audrey Perry’s talk ‘Cystic fibrosis and lung transplantation: bugs, drugs and new therapies’