Structural brain changes detected in novel long COVID imaging study

New research to be presented at the Radiological Society of North America’s annual meeting is the first to reveal microstructural brain changes in long COVID patients compared to fully recovered patients and uninfected subjects. The findings indicate long COVID symptoms can be associated with changes to specific cerebral networks.

“To the best of our knowledge, this is the first study comparing patients with long COVID to both a group without history of COVID-19 and a group that went through a COVID-19 infection but is subjectively unimpaired,” explains Alexander Rau, lead author on the study from University Hospital Freiburg in Germany.

The research utilized a relatively new brain imaging technique called diffusion microstructure imaging (DMI). The technique tracks the movement of water molecules through brain tissue to deliver a high-resolution picture of the microstructures of the brain.

Looking generally for brain lesions or abnormalities, the researchers detected no notable differences between COVID patients and those uninfected. However, zooming in on the microstructural brain differences revealed significant alterations in the COVID cohorts.

“Here, we noted gray matter alterations in both patients with long-COVID and those unimpaired after a COVID-19 infection,” says Rau “Interestingly, we not only noted widespread microstructural alterations in patients with long COVID, but also in those unimpaired after having contracted COVID-19.”

So what separated the long COVID patients from the fully recovered COVID patients?

The researchers discovered three long COVID symptom constellations (fatigue, loss of sense of smell, cognitive impairment) could be correlated with specific patterns of microstructural changes in the brain. So what distinguished long COVID patients from recovered patients seemed to be how the illness particularly reshaped the brain.

“Expression of post-COVID symptoms was associated with specific affected cerebral networks, suggesting a pathophysiological basis of this syndrome” Rau notes.

While the results affirm the real pathological foundations underpinning long COVID they do raise a number of questions the researchers hope to investigate in the future. For example, do these microstructural alterations improve over time as a long COVID patient’s symptoms change? And is there anything that predisposes a COVID patient to develop the brain changes that characterize long COVID?

The new research will be presented at the 2023 Radiological Society of North America Annual Meeting this week.

Source: RSNA