Neurological Consequences of COVID-19: The “Silent Wave”

22 September 2020

Mebourne, Australia – Is the world prepared a wave of neurological consequences that may be on its way as a result of COVID-19? This question is at the forefront of research underway at the Florey Institute of Neuroscience and Mental Health. A team of neuroscientists and clinicians are examining the potential link between COVID-19 and increased risk of Parkinson’s disease, and measures to get ahead of the curve.

"Although scientists are still learning how the SARS-CoV-2 virus is able to invade the brain and central nervous system, the fact that it's getting in there is clear. Our best understanding is that the virus can cause insult to brain cells, with potential for neurodegeneration to follow on from there," said Professor Kevin Barnham from the Florey Institute of Neuroscience & Mental Health.

In a review paper published today in the Journal of Parkinson's Disease, researchers put spotlight on the potential long-term neurological consequences of COVID-19, dubbing it the "silent wave". They are calling for urgent action to be taken to have available more accurate diagnostic tools to identify neurodegeneration early on and a long-term monitoring approach for people who have been infected with the SARS-CoV-2 virus.

The researchers report that neurological symptoms in people infected with the virus have ranged from severe, such as brain hypoxia (lack of oxygen), to more common symptoms such as loss of smell.

"We found that loss of smell or reduced smell was on average reported in three out of four people infected with the SARS-CoV-2 virus. While on the surface this symptom can appear as little cause for concern, it actually tells us a lot about what's happening on the inside and that is that there’s acute inflammation in the olfactory system responsible for smell,” explained Florey researcher Leah Beauchamp.

Inflammation is understood to play a major role in the pathogenesis of neurogenerative disease and has been particularly well studied in Parkinson's. Further research into these illnesses may prove critical for future impacts of SARS-CoV-2.

"We believe that loss of smell presents a new way forward in detecting someone's risk of developing Parkinson's disease early. Armed with the knowledge that loss of smell presents in around 90% of people in the early stages of Parkinson's disease and a decade ahead of motor symptoms, we feel we are on the right track," added Ms Beauchamp.

Clinical diagnosis of Parkinson's disease currently relies on presentation of motor dysfunction, but research shows that by this time 50–70% of dopamine cell loss in the brain has already occurred.

"By waiting until this stage of Parkinson's disease to diagnose and treat, you've already missed the window for neuroprotective therapies to have their intended effect. We are talking about an insidious disease affecting 80,000 people in Australia, which is set to double by 2040 before even considering the potential consequences of COVID, and we currently have no available disease-modifying therapies," said Professor Barnham.

The researchers hope to establish a simple, cost-effective screening protocol aiming to identify people in the community at risk of developing Parkinson's, or who are in early stages of the disease, at a time when therapies have the greatest potential to prevent onset of motor dysfunction. They plan to put the proposal forward for funding from the Australian Government's Medical Research Future Funding scheme.

Additionally, the team have developed two neuroprotective therapies currently under investigation and have identified a cohort of subjects who are ideally suited to study the treatments. Through their research they gained new evidence that people with REM sleep behaviour disorder have a higher predisposition to go on to develop Parkinson's disease.

Parkinson's disease is a significant economic burden costing the Australian economy in excess of $10 billion a year.

"We have to shift community thinking that Parkinson's not a disease of old age. As we've been hearing time and time again, the coronavirus does not discriminate – and neither does Parkinson's," said Professor Barnham. "We can take insight from the neurological consequences that followed the Spanish Flu pandemic in 1918 where the risk of developing Parkinson's disease increased two to three-fold. Given that the world's population has been hit again by a viral pandemic, it is very worrying indeed to consider the potential global increase of neurological diseases that could unfold down track."

He added, "The world was caught off guard the first-time, but it doesn't need to be again. We now know what needs to be done. Alongside a strategized public health approach, tools for early diagnosis and better treatments are going to be key.”

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NOTES FOR EDITORS
Full open access study: "Parkinsonism as a Third Wave of the COVID-19 Pandemic?" by Leah C. Beauchamp, David I. Finkelstein, Ashley I. Bush, Andrew H. Evans, and Kevin J. Barnham (doi.org/10.3233/JPD-202211) published online in Journal of Parkinson's Disease in advance of Volume 10, Issue 4 by IOS Press. This article is openly available at: content.iospress.com/articles/journal-of-parkinsons-disease/jpd202211.

Contact
For media and interview enquiries, contact Claire Smoorenburg, Media and Communications Manager, The Florey Institute of Neuroscience & Mental Health (+61 438090208 or claire.smoorenburg@florey.edu.au). Researchers from the Florey Institute of Neuroscience & Mental Health are available for interview to speak about:
• Screening proposal for early diagnosis
• Development of neuroprotective therapies underway
• Proposed link between SARS-CoV-2 virus and Parkinson's disease.

About the Florey
The Florey Institute of Neuroscience and Mental Health is a medical research institute specialising in the brain and mind. We are the largest brain research group in the southern hemisphere and in the top 10 of the world's best brain research centres. Every year, 4.7 million Australians are diagnosed with one of the conditions that we study. florey.edu.au

About the Journal of Parkinson's Disease
Celebrating its 10th anniversary in 2020, the Journal of Parkinson's Disease (JPD) is dedicated to providing an open forum for original research in basic science, translational research and clinical medicine that will expedite our fundamental understanding and improve treatment of Parkinson’s disease. The journal is international and multidisciplinary and aims to promote progress in the epidemiology, etiology, genetics, molecular correlates, pathogenesis, pharmacology, psychology, diagnosis and treatment of Parkinson’s disease. It publishes research reports, reviews, short communications, and letters-to-the-editor and offers very rapid publication and an affordable open access option. JPD has a Journal Impact Factor of 5.178 according to Journal Citation Reports (Clarivate, 2020) and is published by IOS Press. journalofparkinsonsdisease.com

About IOS Press
IOS Press is headquartered in Amsterdam with satellite offices in the USA, Germany, India and China and serves the information needs of scientific and medical communities worldwide. IOS Press now publishes more than 80 international peer-reviewed journals and about 75 book titles each year on subjects ranging from computer science, artificial intelligence, and engineering to medicine, neuroscience, and cancer research. iospress.com