The Irish research group says that the post-corona symptoms can be explained by a disturbance in the functioning of the blood-brain barrier.
One One of the prolonged symptoms reported after corona infection is the so-called brain fog. Brain fog means, for example, a feeling of slowing down of brain functions, unusual fatigue, concentration difficulties and memory problems.
Researchers from the Irish Trinity College write in their recent research report In Nature Neurosciencethat the symptoms can be explained by a disturbance in the functioning of the blood-brain barrier.
The blood-brain barrier is formed by the tight inner surface of the brain’s capillaries, which prevents harmful substances from entering the brain tissue from the blood.
Irish the research team collected blood samples from 76 hospital patients of the first corona wave in the spring of 2020. In addition, there were 25 controls from whom the corresponding samples had been taken before the corona pandemic.
There were 14 patients in the database who later suffered from brain fog. They had a significantly increased amount of a marker in their blood, which the blood-brain barrier would not normally allow to pass from the brain into the blood.
Correspondingly, proteins that did not belong there had reached the brain from the blood.
In addition, subsequent brain scans revealed changes suggestive of blood-brain barrier leakage in patients suffering from brain fog. The same changes were not seen in those without brain fog.
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The group of patients examined was so small that no definite conclusions can be drawn.
Many markers of inflammatory reaction and blood clotting were elevated in brain fog patients.
In a previous study there have been indications that blood clots in cerebral blood vessels are associated with brain fog. That, too, is compatible with blood-brain barrier failure.
Excessive blood clotting is a feature of severe corona infection and the associated inflammatory reaction.
For research attended Trinity College Professor Matthew Campbell says in The Guardian that he finds it very exciting to think that neurological problems linked to the phenomenon could be treated simply by adjusting the functioning of the blood-brain barrier.
He thinks that the blood-brain barrier could be important in other ways than in the brain fog that appears as an after-effect of corona, for example in patients suffering from chronic fatigue syndrome.
However, it is not worth rushing to certain conclusions, even with regard to post-corona symptoms, comments the professor Claire Steves From King’s College in The Guardian. According to him, the studied group of patients was so small that the differences seen between the groups could be a coincidence.
Also Professor of Coagulation Diseases at the University of Helsinki Riitta Lassila says that the number of patients examined was not representative.
“The interesting research result cannot therefore be generalized. And there are currently no ways to repair the blood-brain barrier,” Lassila points out.
