Brain structure, widespread connectivity changes seen with long COVID

Gray matter atrophy and severe disruption of brain functional connectivity have been observed in long COVID patients with anxiety and depression approximately 3 months after mild acute infection with SARS-CoV-2.

Compared to people who were asymptomatic after SARS-CoV-2 infection, long-time COVID patients with both anxiety and depression showed limbic atrophy and a generalized pattern of hyperconnectivity, Clarissa reported. Yasuda, MD, PhD, of the University of Campinas in São Paulo, Brazil, and colleagues, in an abstract published before the American Academy of Neurology annual meeting.

The magnitude of the changes suggests an association with cognitive dysfunction, they observed.

“Our findings suggest a severe pattern of changes in how the brain communicates as well as in its structure, primarily in people with anxiety and depression with long COVID syndrome, which affects so many people,” Yasuda said in a statement. “Our results are concerning because even people with a mild case of COVID-19 show changes in their brains months later.”

The findings add to the growing body of evidence that shows brain structure and function are affected by SARS-CoV-2, noted Ziyad Al-Aly, MD, director of the Center for Clinical Epidemiology and Chief of Research. and development at the VA St. Louis Health Care System, which did not participate in the study.

“Anxiety and depression are manifestations of neurological damage caused by SARS-CoV-2 and this summary provides additional objective evidence for structural and functional impairment of the brain following SARS-CoV-2 infection” , Al-Aly said. MedPage today. “Our understanding of this is evolving, but it is clear that SARS-CoV-2 infection can affect the brain.”

Many studies have shown brain problems persist long after acute infection, some symptoms persist as long as 2 yearsbut why this happens is unclear.

“Some hypothesize that microglia are activated in some people with SARS-CoV-2 and the ensuing inflammatory response creates an environment that disrupts neuronal health,” Al-Aly said. “Other hypotheses revolve around autoimmunity. At this point, we are still learning more and more every day.”

Yasuda and colleagues evaluated 254 people with mild COVID-19 on average 82 days from the RT-PCR test with the Beck Depression Inventory and Beck Anxiety Inventory tests. The overall sample included 177 women with a median age of 41 years.

Participants were separated into asymptomatic (152 people) and concurrent (102 people with concurrent symptoms of anxiety and depression based on test results).

Gray matter atrophy was assessed with voxel-based morphometry comparing the two groups with 148 healthy controls on MRI. Connectivity data were assessed by resting-state MRI of 12 large-scale brain networks in 84 individuals from the asymptomatic group, 70 individuals from the concurrent group, and 90 controls. Researchers have reported results with P<0.05.

In the concurrent group, gray matter atrophy was observed in the left cingulum (86 voxels) and the lower frontal lobe (91 voxels). The asymptomatic group had no gray atrophy.

The concurrent group exhibited a generalized bilateral pattern of hyperconnectivity involving all 12 networks; the asymptomatic group showed hyperconnectivity involving only five networks.

“This summary, along with all other evidence, is a compelling reason to redouble our efforts to better understand the long COVID and its various sequelae or consequences,” Al-Aly said.

“Understanding the long-term health effects of SARS-CoV-2 infection will help us not only to understand the long COVID, but more broadly to deepen our understanding of the chronic diseases associated with infection – an entity that has been ignored for over 100 years,” he added. “It will also help us better prepare for the next pandemic.”