‘Leaky’ blood vessels behind Long Covid brain fog

Brain fog symptoms, including difficulties concentrating and forgetfulness, in Long Covid sufferers are caused by “leakiness” in blood vessels in the brain, research shows.

Patients with Long Covid experienced a host of lingering symptoms after suffering from the initial infection, with most reporting fatigue, shortness of breath, problems with memory and concentration, as well as joint or muscle pain.

Brain fog, the feeling some describe as their brain being lost in a maze, is a common complaint.

The cause had mystified doctors, but a team of scientists from Trinity College Dublin and FutureNeuro found there was a disruption to the integrity of the blood vessels in the brain of patients who suffered from Long Covid and brain fog.

The researchers were able to use the blood vessel “leakiness” to objectively distinguish between patients with brain fog and cognitive decline and those who have Long Covid but no brain fog. “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,” said Prof Matthew Campbell, head of genetics at Trinity and principal investigator at FutureNeuro.

He said the concept that many other viral infections that lead to post-viral syndromes might drive blood vessel leakage in the brain was potentially game-changing.

The research has been published in the Nature Neuroscience journal.

Trinity’s School of Genetics and Microbiology and neurologists in the School of Medicine also uncovered a novel form of MRI scan that can be used to show how Long Covid can affect the human brain’s blood vessels.

“The findings will now likely change the landscape of how we understand and treat post-viral neurological conditions,” said Prof Colin Doherty, head of the School of Medicine at Trinity and principal investigator at FutureNeuro.