A new study conducted by researchers from Thomas Jefferson University explored how COVID-19 may affect brain health long-term. According to the findings, the virus may increase the risk of developing Parkinson's disease.
“Parkinson’s is a rare disease that affects 2% of the population above 55 years, so the increase in risk is not necessarily a cause in panic,” said researcher Richard Smeyne, Ph.D. “But understanding how coronavirus impacts the brain can help us prepare for the long-term consequences of the pandemic.”
COVID-19 and brain health
The researchers conducted their study on mice that were injected with mild variants of COVID-19. About a month and a half after infection, a group of the mice was injected with a low dose of MPTP, a toxin that is closely associated with Parkinson’s. Two weeks later, the researchers analyzed the subjects' brains to understand how the virus and the MPTP affected their brain health.
The study showed that the combination of the COVID-19 infection and the MPTP led to the loss of neurons, which is typically seen in patients who have Parkinson’s disease. While the virus alone wasn’t responsible for the loss of neurons, the combination of the two led the researchers to believe it could contribute to a higher risk of Parkinson’s.
“We think about a ‘multi-hit’ hypothesis for Parkinson’s – the virus itself does not kill the neurons, but it does make them more susceptible to a ‘second hit,’ such as a toxin or bacteria or even an underlying genetic mutation,” said Dr. Smeyne.
While the findings highlight connections between COVID-19 and Parkinson’s, the team believes that more work will be needed down the line to better understand this link.
“First of all, this is preclinical work,” Dr. Smeyene said. “It is too soon to say whether we would see the same thing in humans, given that there seems to be a 5-10 year lag between any changes in clinical manifestation of Parkinson’s in humans. If it does turn out that COVID-19 increases the risk of Parkinson’s, it will be a major burden on our society and health care system. But we can anticipate that challenge by advancing our knowledge of potential ‘second hits’ and mitigating strategies.”