Virtual reality can spot navigation problems in early Alzheimer’s disease


06-06-2019
  Example environment from the virtual reality display  Credit: University of Cambridge

Virtual reality (VR) can identify early Alzheimer’s disease more accurately than ‘gold standard’ cognitive tests currently in use, suggests new research.

We’ve wanted to do this for years, but it’s only now that virtual reality technology has evolved to the point that we can readily undertake this research in patients - Dennis Chan

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

In 2014, Professor John O’Keefe of UCL was jointly awarded the Nobel Prize in Physiology or Medicine for ‘discoveries of cells that constitute a positioning system in the brain’. Essentially, this means that the brain contains a mental ‘satnav’ 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 clinic to diagnose the condition are unable to test for navigation difficulties.

In collaboration with Professor Neil Burgess at UCL, a team of scientists at the Department of Clinical Neurosciences at the University of Cambridge led by Dr Dennis Chan, previously Professor O’Keefe’s PhD student, developed and trialled a VR navigation test in patients at risk of developing dementia. The results of their study are published in the journal Brain.

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 Dr Chan’s team hypothesised that patients with early Alzheimer’s disease would be disproportionately affected on the test.

The team recruited 45 patients with mild cognitive impairment (MCI) from the Cambridge University Hospitals NHS Trust Mild Cognitive Impairment and Memory Clinics, supported by the Windsor Research Unit at Cambridgeshire and Peterborough NHS Foundation Trust. 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 aging. As such, 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. The researchers 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. However, the study yielded two crucial additional observations. First, 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.

Secondly, 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 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 clinic and in research studies,” says Dr Chan.

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Image:  Example environment from the virtual reality display

Credit: University of Cambridge

Reproduced courtesy of the University of Cambridge

 

The University of Cambridge is acknowledged as one of the world's leading higher education and research institutions. The University was instrumental in the formation of the Cambridge Network and its Vice- Chancellor, Professor Stephen Toope, is also the President of the Cambridge Network.

University of Cambridge (cam.ac.uk)