Novel MRI Study Detects Brain Changes in Long COVID Patients

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Nov. 27, 2023 -- People who have long COVID exhibit changes in certain sections of their brains not found in people who are fully recovered from COVID, according to a study that used a novel kind of magnetic resonance imaging.

Diffusion microstructure imaging (DMI) looks at the movement of water molecules in tissues and can detect very small changes in brain structure not detectable by traditional MRI, a news release said. 

Researchers looked at brain scans of 89 patients with long COVID, 38 patients who had COVID-19 but did not report any subjective long-term symptoms, and 46 healthy control patients who reported no history of COVID.

The DMI scans showed no loss in brain volume but did show “a specific pattern of microstructural changes in various brain regions, and this pattern differed between those who had long COVID and those who did not,” the release said.

“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,” one of the study’s authors, Alexander Rau, M.D., said in a news release. He is a resident in the Departments of Neuroradiology and Diagnostic and Interventional Radiology at University Hospital Freiburg in Freiburg, Germany.

People who get COVID may experience symptoms for months or years afterwards. Symptoms may include fatigue, joint or muscle pain, brain fog, loss of smell and taste, difficulty concentrating, and shortness of breath. Scientists are still working to determine why some people get long COVID and others don’t. 

The study also found a correlation between microstructural brain changes and brain networks linked with impaired cognition, sense of smell, and fatigue.

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

The study was presented at the annual meeting of the Radiological Society of North America (RSNA).