Advertisement

COVID-19 brain damage caused by immune response, study says

By HealthDay News
COVID-19 brain damage caused by immune response, study says
Researchers report that the effects of COVID-19 on the brain appear to be caused by the immune system's response to the coronavirus, not the virus itself. File Photo by Riff/Shutterstock

Blood vessel damage and inflammation in the brains of deceased COVID-19 patients suggest the damage is not caused by the virus, but the body's immune response to it.

Researchers from the U.S. National Institutes of Health consistently found signs of damage caused by thinning and leaky brain blood vessels in tissue samples from patients who died shortly after getting COVID-19.

Advertisement

The researchers saw no signs of the virus in the tissue samples, which they said may mean that the damage was not caused by the virus itself.

"We found that the brains of patients who contract [COVID-19] may be susceptible to microvascular blood vessel damage. Our results suggest that this may be caused by the body's inflammatory response to the virus," said Dr. Avindra Nath, clinical director at the NIH's National Institute of Neurological Disorders and Stroke.

RELATED Physical, mental ills of COVID-19 can linger months after recovery

"We hope these results will help doctors understand the full spectrum of problems patients may suffer so that we can come up with better treatments," he explained in an NIH news release.

For the study, Nath and his team examined brain tissue from 19 patients who died after having COVID-19.

In 16 patients, the investigators found bright spots, which contained blood vessels that were thinner than normal and sometimes leaking blood proteins into the brain. The spots were surrounded by T cells -- signs of an immune response.

Advertisement

In contrast, dark spots contained clotted and leaky blood vessels but no immune response.

"We were completely surprised," Nath said. "Originally, we expected to see damage that is caused by a lack of oxygen. Instead, we saw multifocal areas of damage that is usually associated with strokes and neuroinflammatory diseases."

The researchers, however, saw no signs of infection in the brain samples.

RELATED Diabetes, high blood pressure raise odds of COVID-19 harming brain

"So far, our results suggest that the damage we saw may not have been caused by the [coronavirus] directly infecting the brain," Nath said. "In the future, we plan to study how COVID-19 harms the brain's blood vessels and whether that produces some of the short- and long-term symptoms we see in patients."

The findings were published this week in the New England Journal of Medicine.

More information

For more on COVID-19, visit the U.S. Centers for Disease Control and Prevention.

Copyright 2020 HealthDay. All rights reserved.

Latest Headlines

Advertisement
Advertisement

Follow Us

Advertisement