COVID-19 might shrink parts of the brain, scientists say

SARS-CoV-2, the coronavirus that causes COVID-19, is seen under a microscope.
This transmission electron microscope image shows SARS-CoV-2, also known as 2019-nCoV, the coronavirus that causes COVID-19.
(National Institute of Allergy and Infectious Diseases Rocky Mountain Laboratories)

A new study suggests that COVID-19 might shrink parts of the brain.

The study‘s results were mentioned by former Food and Drug Administration commissioner Dr. Scott Gottlieb on the Sunday news program “Face the Nation” on CBS as another example of why it is so important that unvaccinated people get inoculated. The results also underscore how evidence is mounting that people can still suffer from illness related to COVID-19 many months after infection, a condition known as “long COVID.”

“Certain areas of their brain showed a decline in actual tissue — a shrinkage of parts of their brain,” Gottlieb said on the news program. “It’s very concerning because it does suggest that the virus could be having a direct effect on certain portions of the brain. ... And I think what it suggests is that the balance of the information that we’re accruing does indicate that COVID is a disease that could create persistent symptoms.”

Some of those persistent illnesses long after coronavirus infection include ongoing abnormally fast heart rates, Gottlieb said, which might be explained as a result of COVID-19 damaging the body’s nervous system.


It’s not clear how the virus causes a shrinkage of parts of the brain, Gottlieb said — if the virus itself caused the decline in brain tissue, or if it was symptoms of COVID-19 that caused the troubling reduction.

Dozens of grass-roots organizations have formed to make sure that COVID-19 and its lingering symptoms remain in the public eye.

April 26, 2021

Whatever the mechanism, though, the results underscore just how problematic COVID-19 can be for unvaccinated people.

“This isn’t a benign disease. This is something you want to avoid. And the bottom line is we have the tools to avoid it — through vaccination,” Gottlieb said.

In their report, the authors of the study said they identified “significant effects of COVID-19 in the brain,” finding a loss of brain tissue known as gray matter in some regions of the brain that affect a person’s sense of taste and smell. The authors also identified consistent abnormalities among COVID-19 survivors in a part of the brain that deals with memory.

Losses of smell or taste are symptoms of COVID-19. And in long COVID, symptoms can include difficulty thinking or concentrating, sometimes referred to as “brain fog.”

The authors cautioned that they can’t “make claims of disease causality with absolute certainty.” Still, they wrote, their observations are based on “a consistent pattern of abnormalities caused by the disease process” that they found, which points to “a possible mechanism for the spread of the disease inside the central nervous system.”


The observational study was conducted by scientists at the University of Oxford and Imperial College in the United Kingdom and the National Institutes of Health in Maryland and posted on MedRxiv last week. The authors studied 394 people who happened to have brain scans in medical records before being infected with the coronavirus, and also had their brains scanned after infection.

The records were compared to the brain scans of 388 people who did not contract the coronavirus but had similar age, sex and ethnicity, and who also had a similar time interval between the two brain scans.