Why Scientists Believe COVID-19 Causes Long-Term Brain Tissue Loss

A new study by British researchers has found that Coronavirus can cause long-term brain loss Yes could be the reason some COVID-19 patients lose their sense of smell and taste.

“In summary, the study suggests that there could be long-term loss of brain tissue from COVID-19, and that this would have long-term consequences ”, explained the former commissioner of the Food and Drug Administration (FDA) of the United States. Scott Gottlieb.

“You can compensate for that over time, so the symptoms can go away, but these patients will never recover tissue if, in fact, it is destroyed because of the virus, ”Gottlieb added.

To go to discovery, British researchers have had access to brain imaging tests on some 40,000 people that were performed before the start of the coronavirus pandemic.

In 2021, they asked hundreds of these people to return to medical centers for more. brain scanners. Nearly 800 responsesnm Among these patients, 404 had tested positive for COVID-19 and 394 had usable brain scans that were taken before and after the pandemic.

Comparison of brain scans before and after the discovery “significant effects of COVID-19 on the brain with loss of gray matter“In the parts of the brain related to smell and taste.

“All significant results were found in primary or secondary cortical olfactory and taste areas, in the left hemisphere, using gray matter information. (volume, thickness) ”, found the study, published on the scientific publications website without a review committee MedRxiv.

Loss of smell and taste is one of the hallmarks of COVID-19 infection. Research shows that it can continue for up to 5 months after the virus first appears.

“The decrease in the amount of cortical tissue has occurred in areas of the brain that are close to the places responsible for smellGottlieb warned. “What this suggests is that the smell, the loss of smell, is just an effect of a more primary process going on, and this process actually shrinks the cortical tissue“He added.

Catalog of over 50 long-term effects

Eight out of 10 COVID-19 patients had at least one persistent symptom from 14 days to 16 weeks after acute infection, although some effects may last longer. This is the main conclusion who extracted a fair meta-analysis pre-publish in specialized media medRxiv.

In this work almost 19,000 studies that detected 55 effects persistent after acute infection. The data was extracted from the files of 47,910 people among 17 and 87 years old who participated in 15 studies that evaluated symptoms or long-term laboratory parameters. Each study had a minimum of 100 patients. Nine studies were from Great Britain or Europe, three from the United States and the rest from Asia and Australia. Six studies focused only on people hospitalized with coronavirus; the rest included mild, moderate and severe cases.

A previous study in Wuhan (China) and published in The Lancet, have shown that 76% of patients who required hospitalization reported at least one symptom 6 months later, and the proportion was higher in women. The most common symptoms were fatigue or muscle weakness and difficulty sleeping. In addition, 23% reported anxiety or depression during follow-up.

What do we know about previous coronaviruses, SARS and MERS is that the two share clinical characteristics with COVID-19, including persistent symptoms. The people who survived the SARS showed lung abnormalities months after infection and 28% of those with pulmonary dysfunction up to two years later.

Regarding the psychological symptoms, high levels of depression, anxiety and post-traumatic stress long term in patients previously infected with other coronaviruses. In the case of survivors of SEAS, 33% of people with pulmonary fibrosis were also treated, as well as with long-term post-traumatic stress and anxiety disorders.

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