Leakiness in brain may be causing ‘brain fog’ experienced during long Covid: Study

Scientists have claimed that leakiness in the brain could be blamed for memory and concentration problems people generally experience during long Covid. These symptoms occur when the blood-brain barrier gets damaged and becomes ‘leaky.’ The blood-brain barrier controls what enters and exits the brain.

“It’s all about regulating a balance of material in blood compared to brain,” said Prof Matthew Campbell, co-author of the research at Trinity College Dublin.

“If that is off balance then it can drive changes in neural function and if this happens in brain regions that allow for memory consolidation/storage then it can wreak havoc,” he adds.

Campbell and his colleagues published the findings in the journal Nature Neuroscience after analysing serum and plasma samples from 76 patients who were hospitalised with Covid in March or April 2020 as well as 25 people before the pandemic.

Protein S100β

The team made several discoveries, notably finding increased levels of the protein S100β in samples from 14 Covid patients who reported brain fog compared to those without this symptom.

S100β, typically confined to brain cells, appeared in the blood of these patients, indicating a problem with the blood-brain barrier.

Subsequently, the researchers enlisted 10 Covid-recovered individuals and 22 long Covid patients, including 11 with brain fog, none of whom had received a Covid vaccine or been hospitalised.

Following MRI scans with intravenous dye, it was confirmed that long Covid patients experiencing brain fog had their blood-brain barrier leaky, unlike those without this symptom.

Campbell speculated that individuals with a more intact blood-brain barrier might be less susceptible to brain fog during long Covid.

Results not surprising

Campbell said the results were not surprising as disruptions to proteins involved in clotting could go hand in hand with disruption to cells that lined blood vessels. “The whole concept that a lot of these neurological conditions, including brain fog, could be treated by simply regulating the integrity of the blood-brain barrier is really exciting,” he said.

In an earlier study, scientists had speculated that blood clots in the brain may be causing brain fog in people with long Covid. Prof Paul Harrison from the University of Oxford, an author of earlier work, acknowledged that the new study was important.

“It shows that abnormalities in the lining of blood vessels in the brain occur in people with post-Covid brain fog, and adds to the evidence that abnormal blood clotting also contributes,” he was quoted as saying by the Guardian.

(With inputs from agencies)