Study Confirms “Brain Fog” in COVID-19 Patients Is Not a Direct Result of the Virus

Coronavirus infection or COVID-19 is still considered a respiratory infectious disease, but it can also cause serious problems in the central nervous system of the brain, with clinical manifestations of loss of smell and taste;
Some patients experience headaches, weakness and fatigue, and difficulty thinking normally, or “brain fog,” as if their head is broken.
No one knows yet, but it doesn’t seem to be directly related to the virus. Scientists are hoping to figure out soon whether the symptoms of the patient’s central nervous system are caused by SARS-COV-2 or something else, and how it affects brain function.
Are there any long-term “sequelae”?
Researchers at the National Institutes of Health’s (NIH) Institute of Neurology and Stroke have conducted the first in-depth exploration and study of brain tissue samples from patients infected with novel coronavirus.
The results of the study, published in the latest issue of the New England Journal of Medicine, suggest that the central nervous system symptoms of patients infected with novel coronavirus are most likely caused by the body’s widespread inflammatory response to viral infection and vascular damage, rather than by the brain tissue infected with novel coronavirus.
The researchers used a specially designed high-sensitivity MRI scanner to examine brain tissue samples from 19 dead patients.
The victims ranged in age from 5 to 73, and some had underlying medical conditions such as diabetes, obesity and cardiovascular disease.
The researchers focused on examining the olfactory bulb, which controls smell, and the brain stem, which regulates breathing and heart rate.
According to earlier reports, these two brain regions are thought to be most susceptible to novel coronavirus infection.
On the MRI images, these two areas do show unusual bright spots, but appear to be signs of inflammation, along with dark spots, indicating bleeding leakage (shown below) : closer inspection of these areas reveals that the tiny blood vessels are thinner than those in normal brain tissue.
This suggests that plasma proteins may leak into the space between brain cells under pathological conditions.
Intriguingly, the researchers did not detect evidence of novel coronavirus invading brain cells in these brain tissue samples, which may have triggered an autoimmune response, including T cells and brain microglia.
In fact, several viral tests (viral DNA or protein methods) showed no evidence of the presence of novel coronavirus.
The researchers cautioned that the findings were not final and needed further study.
But the results seen so far in human tissue are not consistent with those found in a mouse infection model.
NIH experts continue to explore how novel coronavirus affects brain tissue and triggers clinical neurological symptoms in patients.
With the more in-depth study of the way that novel coronavirus causes damage to the human body and the long-term consequences, people will gradually understand how this terrible and strange novel coronavirus causes disease, and finally find an effective treatment, perhaps it will be a few years.