VR can spot early symptoms of Alzheimer's: Study

Agencies
May 24, 2019

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.

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Agencies
June 23,2020

The record levels of new daily COVID-19 cases are due to the fact that the pandemic is peaking in a number of big countries at the same time and reflect a change in the virus' global activity, the World Health Organisation said.

At a media briefing on Monday, WHO's emergencies chief Dr Michael Ryan said that the numbers are increasing because the epidemic is developing in a number of populous countries at the same time.

Some countries have attributed their increased caseload to more testing, including India and the US But Ryan dismissed that explanation.

We do not believe this is a testing phenomenon, he said, noting that numerous countries have also noted marked increases in hospital admissions and deaths neither of which cannot be explained by increased testing.

There definitely is a shift in that the virus is now very well established, Ryan said. The epidemic is now peaking or moving towards a peak in a number of large countries.

He added the situation was definitely accelerating in a number of countries, including the US and others in South Asia, the Middle East and Africa.

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Agencies
July 7,2020

The World Health Organization (WHO) is reviewing a report that suggested its advice on the novel coronavirus needs updating after some scientists told the New York Times there was evidence the virus could be spread by tiny particles in the air.

The WHO says the Covid-19 disease spreads primarily through small droplets, which are expelled from the nose and mouth when an infected person breaths them out in coughs, sneezes, speech or laughter and quickly sink to the ground.

In an open letter to the Geneva-based agency, 239 scientists in 32 countries outlined the evidence they say shows that smaller exhaled particles can infect people who inhale them, the newspaper said on Saturday.

Because those smaller particles can linger in the air longer, the scientists - who plan to publish their findings in a scientific journal this week - are urging WHO to update its guidance, the Times said.

"We are aware of the article and are reviewing its contents with our technical experts," WHO spokesman Tarik Jasarevic said in an email reply on Monday to a Reuters request for comment.

The extent to which the coronavirus can be spread by the so-called airborne or aerosol route - as opposed to by larger droplets in coughs and sneezes - remains disputed.

Any change in the WHO's assessment of the risk of transmission could affect its current advice on keeping one-metre physical distancing. Governments, which also rely on the agency for guidance policy, may also have to adjust public health measures aimed at curbing the spread of the virus.

"Especially in the last couple of months, we have been stating several times that we consider airborne transmission as possible but certainly not supported by solid or even clear evidence," Benedetta Allegranzi, the WHO's technical lead for infection prevention and control, was quoted as saying in the New York Times.

WHO guidance to health workers, dated June 29, says that SARS-CoV-2, the virus that causes Covid-19, is primarily transmitted between people through respiratory droplets and on surfaces.

But airborne transmission via smaller particles is possible in some circumstances, such as when performing intubation and aerosol-generating procedures, it says.

Medical workers performing such procedures should wear heavy-duty N95 respiratory masks and other protective equipment in an adequately ventilated room, the WHO says.

Officials at South Korea's Centers for Disease Control said on Monday they were continuing to discuss various issues about Covid-19, including the possible airborne transmission. They said more investigations and evidence were needed.

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