Even mild COVID is hard on the brain

Editor’s note: find the latest news and long advice on COVID in Medscape’s Long COVID Resource Center.

Even mild cases of COVID-19 can affect brain function and structure, early research shows.

Dr. Clarisse Yasuda

“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,” the researcher studied. Clarissa Yasuda, MD, PhD, of the University of Campinas, São Paulo, Brazil, said in a press release.

“The magnitude of these changes suggests they could lead to problems with memory and thinking skills, so we need to explore holistic treatments even for those mildly affected by COVID-19,” Yasuda added.

The study was published early, ahead of its presentation at the upcoming 2023 Annual Meeting of the American Academy of Neurology (AAN) in April.

Brain shrinkage

Some studies have shown a high prevalence of symptoms of anxiety and depression in COVID-19 survivors, but few have investigated associated brain changes, Yasuda said. Medscape Medical News.

The study included 254 adults (177 female, 77 male, median age 41) who had mild COVID-19 a median of 82 days earlier. A total of 102 people had symptoms of both anxiety and depression and 152 had none of these symptoms.

On brain imaging, people with COVID-19 and anxiety and depression showed atrophy in the limbic region of the brain, which plays a role in memory and emotional processing.

No narrowing in this area was evident in people with COVID-19 without anxiety or depression or in a healthy control group of individuals without COVID-19.

The researchers also observed a “severe” pattern of abnormal brain functional connectivity in people with COVID-19 and anxiety and depression.

In this functional connectivity analysis, people with COVID-19 and anxiety and depression showed generalized functional changes in each of the 12 networks assessed, while those with COVID-19 but without symptoms of anxiety and depression depression showed changes in only 5 networks.

Unclear mechanisms

“Unfortunately, the underlying mechanisms associated with brain changes and neuropsychiatric dysfunction after COVID-19 infection are unclear,” Yasuda said. Medscape Medical News.

“Some studies have demonstrated an association between symptoms of anxiety and depression with inflammation. However, we hypothesize that these brain alterations may result from a more complex interplay of social, psychological and systemic stressors, including inflammation. It is indeed intriguing that such alterations are present in people who have presented with mild acute infection,” added Yasuda.

“Symptoms of anxiety and depression are commonly seen after COVID-19 and are part of the long COVID syndrome for some people. These symptoms require adequate treatment to improve quality of life, cognition, and work capacity” , she said.

Treating these symptoms can induce “brain plasticity, which can lead to some increase in gray matter and possibly prevent further structural and functional damage,” Yasuda said.

A limitation of the study was that symptoms of anxiety and depression were self-reported, meaning people may have symptoms misreported or misreported.

Commenting on the findings of Medscape Medical News , Cyrus Raji, MD, PhD, of the Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri, said the idea that COVID-19 is bad for the brain is not new.

As previously stated by Medscape Medical Newsat the start of the pandemic, Raji and his colleagues published an article detailing the effects of COVID-19 on the brain and Raji followed it up with a TED talk on the subject. (Raji was not involved with the Yasuda team for this ongoing study.)

“As part of growing what we already know about COVID-19 infection and its adverse effects on the brain, this work incrementally adds to that knowledge by identifying functional and structural neuroimaging abnormalities related to anxiety and depression in people with COVID-19 infection,” Raji said.

The study was supported by the São Paulo Research Foundation. The authors have no relevant disclosures. Raji is a consultant for Brainreader, Apollo Health, Pacific Neuroscience Foundation and Neurevolution LLC.

American Academy of Neurology (AAN) Annual Meeting 2023: Abstract 1998. Due April 24, 2023.

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