London, May 24: Virtual reality (VR) can identify early symptoms of Alzheimer's disease more accurately than 'gold standard' cognitive tests currently in use, a study claims.
Researchers at the University of Cambridge in the UK noted that brain contains a mental 'satnav' (satellite navigation) of where we are, where we have been, and how to find our way around.
A key component of this internal satnav is a region of the brain known as the entorhinal cortex.
This is one of the first regions to be damaged in Alzheimer's disease, which may explain why 'getting lost' is one of the first symptoms of the disease.
However, the pen-and-paper cognitive tests used in the clinic to diagnose the condition are unable to test for navigation difficulties.
In collaboration with Professor Neil Burgess at University College London (UCL) in the UK, a team at Cambridge led by Dennis Chan developed and trialed a VR navigation test in patients at risk of developing dementia.
In the test, a patient dons a VR headset and undertakes a test of navigation while walking within a simulated environment.
Successful completion of the task requires intact functioning of the entorhinal cortex, so Chan's team hypothesised that patients with early Alzheimer's disease would be disproportionately affected on the test.
The study, published in the journal Brain, recruited 45 patients with mild cognitive impairment (MCI).
Patients with MCI typically exhibit memory impairment, but while MCI can indicate early Alzheimer's, it can also be caused by other conditions such as anxiety and even normal ageing.
Establishing the cause of MCI is crucial for determining whether affected individuals are at risk of developing dementia in the future.
The researchers took samples of cerebrospinal fluid (CSF) to look for biomarkers of underlying Alzheimer's disease in their MCI patients, with 12 testing positive.
They also recruited 41 age-matched healthy controls for comparison.
All of the patients with MCI performed worse on the navigation task than the healthy controls.
MCI patients with positive CSF markers -- indicating the presence of Alzheimer's disease, thus placing them at risk of developing dementia -- performed worse than those with negative CSF markers at low risk of future dementia.
The VR navigation task was better at differentiating between these low and high-risk MCI patients than a battery of currently-used tests considered to be the gold standard for the diagnosis of early Alzheimer's.
"These results suggest a VR test of navigation may be better at identifying early Alzheimer's disease than tests we use at present in the clinic and in research studies," said Chan.
VR could also help clinical trials of future drugs aimed at slowing down, or even halting, a progression of Alzheimer's disease, researchers said.
Currently, the first stage of drug trials involves testing in animals, typically mouse models of the disease.
"The brain cells underpinning navigation are similar in rodents and humans, so testing navigation may allow us to overcome this roadblock in Alzheimer's drug trials and help translate basic science discoveries into clinical use," said Chan.
"We've wanted to do this for years, but it's only now that VR technology has evolved to the point that we can readily undertake this research in patients," he said.
Chan believes technology could play a crucial role in diagnosing and monitoring Alzheimer's disease.
He is working with Professor Cecilia Mascolo at Cambridge to develop apps for detecting the disease and monitoring its progression.
These apps would run on smartphones and smartwatches, researchers said.
As well as looking for changes in how we navigate, the apps will track changes in other everyday activities such as sleep and communication, they said.
VR can spot early symptoms of Alzheimer's: Study