Alzheimer's disease: Why walking difficulties could be an early sign
- Researchers report that people with early Alzheimer’s disease may have difficulty turning when walking.
- The difficulties didn’t occur with healthy older study participants with mild cognitive impairment, convincing researchers the issue was specific to Alzheimer’s.
- The findings could lead to an easier method for diagnosing early Alzheimer’s that doesn’t rely on blood, spinal fluid, or speech tests.
People who have difficulty walking may be showing an early indicator of Alzheimer’s disease.
That’s according to a new study published in the journal Current Biology.
In their findings, researchers reported that people with early Alzheimer’s have difficulty turning when walking, according to the study using virtual reality led by researchers from University College London.
The scientists from University College London used a virtual reality process and a computational model to explore the intricacies of navigational errors previously observed in people with Alzheimer’s.
How the Alzheimer’s walking study was conducted
Professor Neil Burgess and colleagues in the Space and Memory group at the UCL Institute of Cognitive Neuroscience grouped participants into three categories: 31 healthy younger participants, 36 healthy older participants, and 43 subjects with mild cognitive impairment.
The group with mild cognitive impairment was divided into three subgroups based on their cerebrospinal fluid (CSF) biomarker status. Of those, 11 participants tested positive for biomarker evidence of underlying Alzheimer’s disease.
Researchers then asked subjects to complete a task while wearing virtual reality goggles.
Participants walked an outbound route guided by numbered cones, consisting of two straight legs connected by a turn. They then had to return to their starting position unguided.
Subjects did the test under three different environmental conditions meant to stress their navigational skills: an unchanged virtual environment, the ground details being replaced by a plain texture, and the temporary removal of all landmarks from the virtual reality world.
What researchers observed about walking and early Alzheimer’s
The UCL team reported that participants with mild cognitive impairment that showed biomarkers of underlying Alzheimer’s consistently overestimated the turns on the route and showed increased variability in their sense of direction.
However, the same impairments weren’t observed in the healthy older participants or people with mild cognitive impairment who did not have positive CSF biomarkers for Alzheimer’s.
Researchers concluded the navigational errors are specific to those with Alzheimer’s disease, not an extension of healthy aging or general cognitive decline.
They said the findings could help doctors diagnose Alzheimer’s earlier.
“Our findings offer a new avenue for the early diagnosis of Alzheimer’s disease by focusing on specific navigational errors. However, we know that more work is needed to confirm these early findings,” said Andrea Castegnaro, PhD, the study’s joint first author and a research fellow at the UCL Institute of Cognitive Neuroscience.
How the research may help with Alzheimer’s diagnosis
Castegnaro said the team’s goal is to develop practical tests that can be easily integrated into clinical settings while considering common constraints such as limited space and time.
“Traditional navigation tests often have requirements that are challenging to meet in a clinical environment,” he told Medical News Today. “Our research focuses on specific aspects of navigation that are more adaptable to these constraints.”
Quick and comprehensive tests resulting in a reliable diagnosis increase the likelihood of their widespread adoption, Castegnaro said.
The authors noted there are 944,000 people living with dementia in the United Kingdom and more than 60% of those diagnosed are thought to have Alzheimer’s disease.
The study authors said similar projections in the United States estimate the number of people aged 65 and older living with Alzheimer’s dementia could double, growing to nearly 14 million in the U.S. by 2060 if there are no medical breakthroughs.
The researchers said these trends indicate the increasing burden of Alzheimer’s on healthcare systems and society at large.
Why walking may be difficult for people with Alzheimer’s
Ryan Glatt, a certified personal trainer, senior brain health coach, and director of the FitBrain Program at Pacific Neuroscience Institute in California, told Medical News Today the study builds on previous research looking at someone’s gait as an Alzheimer’s indicator.
“In clinical settings, gait-based tests can be helpful for determining fall risk, especially with distractions, and perhaps can be part of a more comprehensive cognitive evaluation in the near future,” he said.
Glatt added that there are various potential reasons why individuals with cognitive impairment demonstrate challenges with certain aspects of walking.
“One reason individuals with Alzheimer’s might struggle with visuospatial navigation is due to the changes that occur to the hippocampus, a region of the brain partially responsible for spatial memory,” Glatt said.
Diagnosing Alzheimer’s disease early
Dr. Jonathan Fellows, who leads the Michigan Institute for Neurological Disorders Alzheimer’s Disease and Memory Disorder Center, told Medical News Today the data collected in the study could be quite helpful.
“Observation of gait is an important assessment in the diagnosis of various dementias, including Alzheimer disease,” Fellows said. “Patients with this disorder can have what is called dyspraxia, or difficulty doing a previously learned task – in this case walking or turning.”
“Identifying any form of dyspraxia is crucial in the early diagnosis of Alzheimer’s disease because we now have effective infusion-based treatments to rid the brain of the abnormal protein, amyloid, which renders brain cells (neurons) less effective or ineffective,” he added. “This study is a great reminder that degenerative brain conditions including Alzheimer disease affect not just cognition but virtually all functions of daily living.”
Heather Sandison is a naturopathic doctor and the operator of Solcere, a clinic specializing in Alzheimer’s and related dementia treatment.
She told Medical News Today the study needs to be done with more subjects before it is adopted for clinical purposes.
“Having a low cost, easily administered clinical tool without the need for labs either from blood or cerebrospinal fluid that does not rely on language could allow for early detection of Alzheimer’s in a broad population and be helpful for identifying patients who would best respond to treatment targeting Alzheimer’s specific markers,” Sandison said.
Dr. Howard Pratt, D.O., a psychiatrist and medical director at Community Health of South Florida, told Medical News Today the idea of walking issues indicating Alzheimer’s “is and isn’t a new idea.”
“What I mean by that is that whenever I see a patient, I assess them even while in the waiting room,” he said. “I watch them get out of their chair, for example, and I watch to see how well they walk and to see how well they balance when they move. I also look to see if they are having any trouble standing.”
“So, it’s not a new idea that having trouble walking can be a sign of a problem with a person’s overall health, but it is a new idea when it comes to being a specific indicator of Alzheimer’s disease,” Pratt said. “And when we consider falls while walking, most healthy adults, if they don’t have an impairment, typically have not fallen in years.”
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