A link between weakened lung function and alterations in cognitive function such as brain fog has been highlighted thanks to a new study on long covid.
- Researchers observed pulmonary gas exchange in people suffering from long covid; that is, how oxygen moves from the lungs into the bloodstream, while carbon dioxide moves from the bloodstream into the lungs.
- They found that reduced gas exchange was linked to brain fog.
- An increase in cerebral blood flow is also associated with a reduction in gas exchange in patients with long covid.
Memory problems, concentration problems, slowed thinking… brain fog – as this cognitive difficulty is nicknamed – is a complaint that often recurs in patients suffering from long-term covid.
Researchers at the University of Iowa in Iowa City have made a major discovery about this symptom. In people with long covid, lower gas exchange between air and blood is associated with impaired cognitive function. The team will present their discovery at the annual conference of Radiological Society of North America which will be held December 1-5, 2024 in Chicago.
Long Covid: reduced lung function linked to cognitive disorders
To better understand the symptoms presented by people with long Covid, researchers brought together 12 people who suffered from shortness of breath and/or persistent fatigue several weeks after recovering from Covid-19.
Participants had lung and brain MRIs. They were also subjected to cognitive tests. Additionally, their respiratory capacity was examined.
“There was a range of cognitive difficulties among the study patients”explains researcher Keegan Staab in a press release. “Some were minimal and indicated mild dysfunction, while others were more serious and showed that some patients had slow thinking and difficulty concentrating several times a day.”
Data reveal that lower pulmonary gas exchange may be associated with these cognitive dysfunctions as well as lower gray matter and white matter volumes in patients with long covid.
Cognitive fog: a compensatory mechanism involved?
Another observation by the team: the increase in cerebral blood flow is associated with a reduction in gas exchange in patients with long covid. “This relationship could be a compensatory mechanism where lower lung function is compensated by higher cardiac output and higher cerebral blood flow, explains Keegan Staab. It is also possible that the disease mechanism that impairs pulmonary gas exchange also results in higher cerebral blood flow through downstream vascular damage in the lungs and brain.”
These different elements lead researchers to suggest that gas exchange abnormalities can help identify long-term Covid patients who require treatment.