• Posted November 26, 2024

Long COVID Brain Fog: Could the Lungs Hold Clues?

The “brain fog” of long COVID might be due to impaired lung function following a person’s infection, a new small-scale study says.

Reduced gas exchange in the lungs – oxygen coming in, carbon dioxide going out -- appears to be associated with brain fog in long COVID, researchers will report in Chicago at next week’s annual meeting of the Radiological Society of North America.

“If these findings can be generalized to the long COVID population, the study suggests that there may be a causative relationship between cognitive dysfunction and lung dysfunction, suggesting a potential treatment strategy using methods that target improved gas exchange,” senior researcher Sean Fain, vice chair for research at the University of Iowa’s Department of Radiology, said in a news release.

For the study, researchers performed magnetic resonance imaging (MRI) scans on 10 women and 2 men with long COVID.

“There was a range of cognitive difficulties among the patients in the study,” lead researcher Keegan Staab, a graduate research assistant with the University of Iowa, said in a news release. “Some were mild and indicated slight dysfunction, while others were more serious and indicated that some patients have slow thinking and trouble concentrating several times per day.”

When people breathe, oxygen moves from the lungs into the bloodstream. At the same time, carbon dioxide is removed from the bloodstream and exhaled.

MRI scans revealed that poor lung function was associated not only with brain fog, but also with changes in patients’ brain structure, researchers said.

The scans also found that blood flow to the brain increased in long COVID patients as gas exchange in the lungs decreased, researchers said.

This could mean that the heart must pump more blood into the brain to compensate for carrying less oxygen captured and transferred by the lungs, Staab said.

Based on these findings, researchers said MRI breathing tests might be used to identify people with lung damage that could lead to long COVID.

Findings presented at medical meetings should be considered preliminary until published in a peer-reviewed journal.

More information

The U.S. Centers for Disease Control and Prevention has more on long COVID.

SOURCE: Radiological Society of North America, news release, Nov. 26, 2024