Even two years after recovery, damage to multiple regions of the brain persists in COVID patients
Although the acute urgency of the COVID-19 pandemic has been in the world’s rearview mirror for some time, the virus continues to affect a portion people who contracted it, even two years after their initial recovery.
A new paper published in The Lancet Regional Health Western Pacific details a handful of brain abnormalities identified on the MRI scans of people who had moderate to severe cases of COVID. The imaging findings align with the patients’ lingering cognitive complaints and fatigue issues, indicating that, for some, the virus’ impact could persist for years.
“A variety of symptoms, particularly cognitive, psychiatric and neurological symptoms, may persist for a long time among individuals recovering from COVID-19,” corresponding author of the paper Yumei Wang, with the Shandong Institute of Brain Science and Brain-inspired Research in China, and colleagues wrote. “However, the underlying mechanism of these brain abnormalities remains unclear.”
For the study, experts had 57 COVID survivors undergo a myriad of cognitive, psychiatric, physical and imaging evaluations, including a resting state functional MRI scan of the brain. For comparison, a group of 35 healthy controls completed the same assessments. Researchers used imaging to calculate measures like the amplitude of low frequency fluctuation (ALFF), fractional amplitude of low frequency fluctuations (fALFF) and regional homogeneity (ReHo).
The COVID and control groups differed significantly in their complaints regarding cognitive function and mental fatigue, though the complaints of both COVID groups—those with moderate versus severe infections—were similar. However, although the COVID groups reported impaired cognitive function, their performances on cognitive assessments were not significantly inferior to that of the control group.
On imaging of the COVID group, researchers observed several alterations in parts of the brain related to emotional regulation, including substantially higher ALFF values in the left putamen, right inferior temporal gyrus and right pallidum, and decreased ALFF values in the right superior parietal gyrus and left superior temporal gyrus. Further, that same group showed decreased ReHo values in the right precentral gyrus, left postcentral gyrus, left calcarine fissure and surrounding cortex and left superior temporal gyrus. There was a significant correlation between these findings and patients’ reported mental fatigue.
Although complaints of cognitive function and mental fatigue can be subjective, imaging offers an objective means of corroborating patients’ concerns. And in this case, the imaging does provide added insight into exactly what might be driving such issues, the authors suggested.
Although more than two years had passed since the patients recovered from their initial infections, the authors indicated that further longitudinal studies are still needed to continue to analyze the trajectory of cognitive and psychiatric symptoms post-COVID.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.