Virtual reality can detect problems early in Alzheimer's disease

The University of Cambridge found that virtual reality can better identify early Alzheimer's disease than the "standard" cognitive tests currently used

The study highlights the potential of new technologies to diagnose and monitor diseases such as Alzheimer's disease, which affects more than 525,000 people in the UK.

In 2014, Professor John O'Keefe of UCL was awarded the Nobel Prize in Physiology or Medicine for his "discoveries of cells that constitute a positioning system in the brain". It basically means that the brain contains a mental 'satnav' of where we are, where we have been and how to find ourselves.

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 affected by Alzheimer's disease, which may explain why "loss" is one of the first symptoms of the disease. However, the paper-pen cognitive tests used in the clinic to diagnose the disease do not make it possible to test the difficulties of navigation.

In collaboration with Professor Neil Burgess of UCL, a team of scientists from the Department of Clinical Neuroscience at the University of Cambridge, led by Dr. Dennis Chan, a former PhD student of Professor O & # 39; Keefe, has developed and tested a virtual reality navigation test for at-risk patients. to develop dementia. The results of their study are published today in the journal Brain.

During the test, a patient dons a virtual reality helmet and performs a navigation test while walking in a simulated environment. Successful completion of the task requires intact functioning of the entorhinal cortex. Dr. Chan's team hypothesized that patients with early Alzheimer's disease would be disproportionately affected by the test.

The team enrolled 45 patients with mild cognitive impairment (MCI) in Cambridge Hospital Hospitals NHS Trust memory and cognitive impairment clinics. Patients with MCI usually have memory problems, but while IBD may indicate early Alzheimer's disease, it can also be caused by other conditions such as anxiety and even normal aging. As such, establishing the cause of MCI is crucial in determining whether those affected are likely to develop dementia in the future.

The researchers took samples of cerebrospinal fluid (CSF) to search for biomarkers of underlying Alzheimer's disease in their patients with MCI, of which 12 were tested positive. The researchers also recruited 41 healthy matched age – matched controls for comparison.

All patients with MCI had worse performance of the navigation task than healthy controls. However, the study provided two other crucial observations. First, MCI patients with positive CSF markers – indicating the presence of Alzheimer's disease, thus exposing them to the risk of developing dementia – performed worse than those with negative CSF markers presenting with low risk of future dementia.

Secondly, the Virtual Reality Navigation task helped to differentiate these patients with low or high risk MCI from a battery of commonly used tests considered to be the gold standard for early diagnosis of Alzheimer's disease.

Dr. Chan said:

"These findings suggest that a navigation VR navigation test might be more effective at identifying early Alzheimer's disease than the tests we currently use in clinical and research studies."

VR could also facilitate clinical trials of future drugs to slow or even stop the progression of Alzheimer's disease. Currently, the first step in drug testing is to test animals, usually murine models of the disease. To determine whether the treatments are effective, scientists study their effects on navigation using tests such as an aquatic maze, where mice must learn the location of hidden platforms beneath the surface of puddles. opaque water.

If new drugs improve memory during this task, they perform tests on human subjects, but using word memory and image tests. This lack of comparability of memory tests between animal models and human participants represents a major problem for ongoing clinical trials.

Dr. Chan commented:

"The brain cells underlying navigation are similar in rodents and humans. As a result, navigation tests could help us overcome this hurdle in Alzheimer drug trials and help translate fundamental scientific discoveries into clinical applications.

"We have wanted to do this for years, but it is only now that virtual reality technology has evolved to the point that we can easily undertake this research on patients."

In fact, Dr. Chan thinks that technology could play a crucial role in the diagnosis and monitoring of Alzheimer's disease. He is working with Professor Cecilia Mascolo of Cambridge's Center for Mobile Systems and Portable Systems and Augmented Intelligence to develop applications to detect and track disease. These applications would run on smartphones and smartwatches. In addition to seeking changes in the way we navigate, applications will track changes in other daily activities such as sleep and communication.

Dr. Chan added:

"We know that Alzheimer's disease affects the brain long before the symptoms become apparent.

"We are reaching the point where everyday technologies can be used to detect the warning signs of the disease long before we become aware of it.

"We live in a world where mobile devices are almost ubiquitous and application-based approaches therefore have the potential to diagnose Alzheimer's disease at a minimal additional cost and on a scale much greater than that of people living with Alzheimer's disease. badysis of the brain and other current diagnostic approaches. "

Virtual reality research was funded by the Medical Research Council and the NIHR Biomedical Research Center (Cambridge). Application-based research is funded by Wellcome, the European Research Council and the Alan Turing Institute.

Reference

Howett, D, Castegnaro, A et al. Differentiation of mild cognitive impairment using a VR navigation test based on the entorhinal cortex. Brain; May 28, 2019