Leaky blood vessels behind Long Covid-linked brain fog, says study

Dublin, Feb 22: In a major discovery, a team of scientists discovered disruption to the blood vessels in the brains of patients suffering from Long Covid and 'brain fog'.

The team from Trinity College Dublin showed that this blood vessel "leakiness" was able to objectively distinguish those patients with brain fog and cognitive decline compared to patients suffering from Long Covid but not with brain fog.

They also uncovered a novel form of MRI scan that shows how Long Covid can affect the human brain’s delicate network of blood vessels.

The findings were reported in the journal Nature Neuroscience.

"For the first time, we have been able to show that leaky blood vessels in the human brain, in tandem with a hyperactive immune system may be the key drivers of brain fog associated with Long Covid This is critically important, as understanding the underlying cause of these conditions will allow us to develop targeted therapies for patients in the future," said Prof. Matthew Campbell, Professor in Genetics and Head of Genetics at Trinity.

"The findings will now likely change the landscape of how we understand and treat post-viral neurological conditions. It also confirms that the neurological symptoms of Long Covid are measurable with real and demonstrable metabolic and vascular changes in the brain," added Prof. Colin Doherty, Professor of Neurology and Head of the School of Medicine at Trinity.

In recent years, it has become apparent that many neurological conditions such as multiple sclerosis (MS) likely have a viral infection as the initiating event that triggers the pathology.

However, proving that direct link has always been challenging.

"The concept that many other viral infections that lead to post-viral syndromes might drive blood vessel leakage in the brain is potentially game changing and is under active investigation by the team," Prof. Campbell said.

Long Covid has now become a major public health issue since the outbreak of the pandemic in 2020. While international incidence rates vary, it is estimated to affect up to 10 per cent of patients infected with the SARS-CoV2 virus.

Of these patients suffering from Long Covid, just under 50 per cent of them report some form of lingering neurological effect such as cognitive decline, fatigue, and brain fog. Long Covid has up to 200 reported symptoms to date, but in general, patients report lingering symptoms such as fatigue, shortness of breath, problems with memory and thinking, and joint/muscle pain.