Mild COVID-19 infection affects brain structure, UT research finds

AUSTIN (KXAN) — Scientists are scrambling to understand the long-term effects of COVID-19, including on those who haven’t had serious infections. Research, including at the University of Texas at Austin, is focusing on the effect of the coronavirus on the central nervous system and why some patients have persistent symptoms.

In the UK, researchers are studying the long-term effects of mild to moderate cases of COVID-19. A study conducted by the Wellcome Center for Integrative Neuroimaging at the University of Oxford looked at how infection affects brain structure.

The researchers carried out brain scans and cognitive tests on 785 participants at the UK Biobank, 401 of whom had been infected with COVID-19 between their first and second scans. UK Biobank is a biomedical database that collects information from UK participants. It contains data from half a million participants that can be viewed by researchers or licensed scientists.

“I think one of the really important things about this study is that it was the first longitudinal imaging study of patients who were imaged with brain MRI scans before and after being infected with COVID,” said said Dr. Esther Melamed, director of COVID Post-Clinical Research at Dell Medical School. “It really allowed researchers to be able to compare what happened in different regions of the brain before and after COVID.”

Dr. Anderson Winkler, a senior research associate at the National Institute of Mental Health, was one of the researchers on the study, which was published in “Nature.” By examining brain scans, researchers found that infected participants showed greater loss of gray matter volume in the cerebral cortex of the brain, which is the outermost sheet of neural tissue. Gray matter is important in processing information because it sends signals to the brain.

“We saw cortical thinning in areas associated with smell,” Winkler said. “We noticed a blurring of the contrast between gray and white matter and we also saw changes in the scattering of water molecules.”

The red-yellow coloring in the scan below shows the areas of the brain that have shrunk the most from Covid19 infection. These regions are linked to where the brain processes smell, Winkler said.

Red-yellow regions shrunk the most due to COVID-19 infection. This scan shows the brain in the left hemisphere with inferior, lateral, and medial views. (Courtesy of “SARS-CoV-2 is associated with changes in brain structure in the UK Biobank”)

Winkler said the reduction in gray matter was “more pronounced” in the group that had COVID-19 compared to the group that did not.

“These changes are indicative of tissue damage at the microstructure level and also an overall reduction in brain size,” Winkler said.

Trail making test

Winkler said the researchers also gave the participants another test to measure the long-term effects of mild COVID-19 infections. Participants were given a sheet with numbered dots and asked to connect the dots as quickly as possible.

“In terms of cognition, we also noticed that in one of the tests that they did, the group that had COVID, it took a little longer to do those tests,” Winkler said. mentioned.

Dr. Melamed and his team

Meanwhile, a team of collaborating researchers at UT Austin led by Melamed study the neurological consequences of COVID-19 and why some people have long-term symptoms of COVID-19.

“(The American Medical Association) has estimated that 10-30% of COVID-19 survivors may continue to experience different types of symptoms post-COVID,” Melamed said.

These long-term symptoms are also called post-acute sequelae of COVID-19 infection (PASC).

“There are now several studies that have confirmed that patients, even those who are not hospitalized, who had mild disease, continue to experience different types of symptoms,” Melamed said. She added that the most common tend to be “neurological in nature”, including brain fog, where an individual has difficulty with memory, attention and concentration.

“People also experience headaches, visual changes, problems swallowing, problems with pain in the mouth, changes in taste and smell which may be persistent, changes in hearing or hearing sounds that they weren’t used to being there,” Melamed said. .

There is a wide range of long-term symptoms that individuals have identified after becoming infected with COVID-19. UT Health Austin created a post-COVID-19 program in the summer of 2021 to better understand them, giving patients the opportunity to participate in research studies.

Additionally, the clinic provides training to community physicians through seminars and case presentations.

“There are different aspects of the clinic, including clinical patient care. There are educational programs that are part of the post-COVID agenda, as well as research,” Melamed said.

The Health Transformation Building houses the UT Health Austin Clinic.  (KXAN Photo/Maggy Wolanske)
The Health Transformation Building houses the UT Health Austin Clinic. (KXAN Photo/Maggy Wolanske)

Symptoms of the long form of COVID-19 and impact on the immune system of patients

In the Health Discovery Building, Melamed and his team conduct immunological research that closely examines patient cells and their communication proteins. The group is using patient blood samples to study the consequences of COVID-19 on patients’ immune systems.

First-stage procedures are performed before specific immune research occurs.

One procedure uses blood samples to see if a patient’s immune system may be impaired and cause long-form COVID-19 symptoms to develop.

Another procedure is a cell count of immune cells. In cases where patients are infected with COVID-19, their white blood cell count will be higher. The cell count distinguishes those who have had a COVID-19 infection.

Artistic program

A member of the Melamed research team, Sam Bazzi, enjoys art as a hobby and has participated in chalk festivals before. When the pandemic hit, he used art as a way to pass his free time and as a coping mechanism to deal with pandemic nerves.

Bazzi then presented the idea of ​​an artistic program to Melamed.

“We thought this would be a really wonderful way to help people struggling with long COVID,” Bazzi said.

Bazzi has created an eight-part lesson series on introductory drawing. The program is offered free of charge. Participants bring their own supplies such as pens, pencils, paper and rulers.

Each week, the program introduces a new technique like drawing a subject, setting up shading, or setting up a still life.

“Being able to have some sort of creative control over their art can be a very therapeutic way of coping with this disease,” he said.

He also saw the benefits for participants of adding art into their lives as a way to slow down daily tasks and sharpen their creative skills.

Bazzi said the art program brings together a sense of community and a space for these people to connect with each other over similar symptoms.

“So long-term COVID tends to alienate people, because a lot is not yet known about it. And there’s a lot of information that we don’t have yet. So building a sense of community was really important to them,” Bazzi said.

Several members of the art program agreed to present their art.

To look forward

Melamed and his research team hope to conduct further research into what exactly affects these patients after infection.

“What we are trying to understand is not just how the immune system changes, but how other environmental, genetic and hormonal states may influence patients developing persistent symptoms of brain fog and other neurological complications,” Melamed said.

Ida M. Morgan