People with early Alzheimer’s disease have difficulty turning when walking, a study suggests.
Experts from University College London (UCL) used virtual reality to help examine navigational errors among people with the first signs of the disease, with the hope of developing simple tests for the condition.
The small study, published in Current Biology, compared 31 healthy younger people with 36 healthy elderly people and 43 patients with mild cognitive impairment.
All three groups were asked to complete a task while wearing virtual reality goggles, which allowed them to make real movements.
People walked along a route guided by numbered cones, consisting of two straight walks connected by a turn.
They then had to return to their starting position guided by their memory alone.
The task was performed repeatedly under three different conditions.
The study found that people with early Alzheimer’s consistently overestimated the turns on the route and had a greater variability in their sense of direction.
Author, Dr Andrea Castegnaro, from the UCL Institute of Cognitive Neuroscience, told the PA news agency there is already evidence that problems with navigation is an important early sign of Alzheimer’s disease.
“What we added here is that there are specific aspects in the navigation in Alzheimer’s that are particular disrupted,” he said.
“In particular, we found out that individuals with early Alzheimer’s consistently overestimated the turns on the given route and showed increased variability in their sense of direction.
“In other words, it seems that when you ask (people with mild cognitive impairment) with Alzheimer’s to turn a certain amount, they think they have turned much more than they actually did.
“More importantly, by including healthy elderly in the study, we also found that these specific aspects are not an extension of healthy ageing (for which we also know navigation ability declines), and they seem rather specific to Alzheimer’s disease.
“It is important to say however that these are early findings and we are working to confirm these.”
In the research, the group with mild cognitive impairment had been further broken down into people with underlying Alzheimer’s (14) and those with no underlying Alzheimer’s (11 people).
An invasive lumbar puncture was needed to confirm early Alzheimer’s and so 18 of the mild cognitive impairment group had declined the procedure.
It is not known if they had Alzheimer’s.
Dr Castegnaro said: “Our findings offer a new avenue for the early diagnosis of Alzheimer’s disease by focusing on specific navigational errors.
“We aim to develop practical tests that can be easily integrated into clinical settings, considering common constraints such as limited space and time.”
Dr Leah Mursaleen, head of research at Alzheimer’s Research UK, said: “There are nearly one million people living with Alzheimer’s in the UK, but thanks to limitations in current methods of detection, only around 60% of them will ever receive a diagnosis.
“So, it’s vital that we develop new, more precise early detection techniques that can be easily used in healthcare systems like the NHS.
It may offer a way to detect disease-specific brain changes in the early stages of dementia, potentially benefiting hundreds of thousands living with the condition in the future— Sian Gregory, Alzheimer’s Society
“This will be particularly important as we enter an era where dementia becomes a treatable condition.
“Thanks to advances in technology, a wide range of devices and platforms are being explored to see if they have the potential to detect early signs of neurological diseases like Alzheimer’s.
“This small, early-stage study looks at using a virtual reality environment to analyse the way people turn while walking.
“The results suggest this can detect differences in participants with early Alzheimer’s disease.
“However, as the group included fewer than 50 people, a larger study is needed to understand the future potential of this promising discovery.
“It will also be important to understand how digital technologies like this can be used in combination with other emerging techniques like blood tests, which are also showing huge promise for detecting Alzheimer’s disease.”
Sian Gregory, Alzheimer’s Society research communications manager, said: “Getting a diagnosis for dementia can be difficult for a multitude of reasons, and we know that very early symptoms can be subtle and hard to detect.
“However, problems with navigation are thought to be some of the earliest noticeable changes in Alzheimer’s disease, so this is valuable insight.
“Though this technology is in its infancy and work is needed to improve its accuracy, it may offer a way to detect disease-specific brain changes in the early stages of dementia, potentially benefiting hundreds of thousands living with the condition in the future.”
