COVID-19 can cause worrying neurological symptoms like a loss of smell and taste, but Australian scientists are warning the damage the virus causes to the brain may also lead to more serious conditions such as Parkinson’s disease.
- Researchers are warning some well-known COVID-19 symptoms indicate there may be long-term neurological impacts of the disease
- There is a fear a “silent wave” of Parkinson’s disease will follow the COVID-19 pandemic, as it did after the Spanish flu in the early 20th century
- Medical experts have designed a smell test to improve the early detection of Parkinson’s disease and treatment options
It has happened before.
Five years after the Spanish flu pandemic in the 1910s, there was up to a three-fold increase in the incidence of Parkinson’s disease.
Kevin Barnham from the Florey Institute of Neuroscience and Mental Health said he believed a similar “silent wave” of neurological illness would follow this pandemic.
“Parkinson’s disease is a complex illness, but one of the causes is inflammation, and the virus helps to drive that inflammation,” he said.
“Once the inflammation gets into the brain, it starts a cascade of events which can ultimately lead to Parkinson’s disease.
Researchers outlined their concerns in a study published in the Journal of Parkinson’s Disease.
The process is known as the “two-hit hypothesis”.
The brain gets inflamed from something like a virus, then something else comes along later causing more damage and eventually Parkinson’s disease develops.
“Evidence is already suggesting the triggers for Parkinson’s disease are there with this virus,” Professor Barnham said.
Medical experts said it was too early to know how many people who had COVID-19 would go on to develop the disease.
“I believe the risk is real,” Professor Barnham said.
“We can’t put a number on it, but with 30 million people worldwide affected by this virus, even a small shift in the risk of getting Parkinson’s would lead to many more people being diagnosed.
“We know COVID-19 has short-term effects, but we are realising more about the potential long-term effects.”
Head of the cognition ageing laboratory at the University of Adelaide, Lyndsey Collins-Praino, said it was not a certainty every person who had COVID-19 would develop Parkinson’s disease.
She said researchers needed a better understanding of just how people with COVID-19 were likely to develop the disease in the future.
“We need to know what that may look like and how symptoms may change and evolve over time,” Dr Collins-Praino said.
“We need to understand not just how to treat the virus itself, but to understand what challenges survivors may face, given how many people may find themselves in that camp.”
Smell-test screening to pick up early signs of disease
In people with Parkinson’s disease, problems such as a loss of smell can show up 10 years before they have any physical symptoms.
Researchers from the Florey Institute are working on a smell-test screening tool that could be rolled out to everyone over the age of 50.
It would measure your ability to smell properly and test the function of other parts of the brain, the results of which may signal early indications of Parkinson’s disease.
Dr Collins-Praino said early diagnosis could lead to early intervention and stop brain cells from dying off.
“The earlier we can detect [the damage], the better our chances of really effective and meaningful therapeutics for individuals,” she said.
Six million people worldwide have Parkinson’s disease and the figure is expected to double in the next 20 years.
“Add to that the silent wave from COVID, and those numbers will explode and there will be serious societal and economic consequences from that,” Professor Barnham said.
Florey Institute scientist and co-author of the paper, Leah Beauchamp, said there was an opportunity to get ready.
“We weren’t prepared the last time — more than 100 years ago. We have the tools and we can get ahead of this now,” she said.
Parkinson’s ‘wasn’t anything we had considered’
Getting an earlier diagnosis would have helped Melbourne woman Sheenagh Bottrell.
One of the first signs something was amiss was when her friend noticed she was limping while they were out on their regular walks.
“I had already had problems with my shoulder, but I really didn’t worry about it very much,” Ms Bottrell said.
“But my friend was constantly at me to go and see the doctor.”
After seeing a neurologist, Ms Bottrell, 47, was diagnosed with Parkinson’s disease in 2011.
“It was a shock. It wasn’t anything we had considered,” she said.
Ms Bottrell said if she had been diagnosed earlier, she might have done things differently.
“I am fortunate that I have mild symptoms, but for people who have tremors, earlier detection and getting onto good treatment early would be much better,” she said.
Doctors advised Ms Bottrell not to let the illness take over her life and her thinking.
“I have tried to get on with life and not let it get in the way,” she said.
The Florey Institute has applied to the Federal Government’s Medical Research Future Fund for a grant to move to the next phase of testing the smell screening tool.