In January of 2022, researchers asked how the SARS-CoV-2 virus that causes COVID-19 could complicate the nervous system. Since then, new findings have shed light on post-COVID neurological symptoms.*

Current thought on COVID and the brain

One of the researchers, Avindra Nath, M.D. of the National Institute of Neurological Disorders and Stroke, says COVID brain-related complications vary widely and can persist for a long time. They are largely brought on by the immune system, a main target being the brain’s endothelial cells that form the lining of blood and lymphatic vessels.

Since previous studies, including an autopsy study, showed no SARS-CoV-2 virus in the brain, scientists remained baffled by exactly how and why the brain cells were being affected. The  December 2022 report in the journal Nature helped explain this phenomenon.

What the researchers did

The study, led by National Institutes of Health (NIH) investigators, involved autopsies of 44 unvaccinated individuals of varied race and ethnicity who died from COVID-19 during the pandemic ‘s first year.

• 13 individuals (about 30%) were female
• 61.4% had three or more concurrent diseases

The individuals’ ages ranged from mid-40s to early 70s, and average time from death to autopsy was around 22 hours.

What they found

Unlike the previous studies, the authors of this study found SARS-CoV-2 throughout the body and brain, with the virus lingering in tissue for months. Still, they found little inflammation and few cellular changes outside the respiratory system. 

Co-author Daniel Chertow, M.D., MPH, explained that in 11 of the 44 autopsies, “we were able to do a detailed evaluation of the brain. In most of those individuals where we had brain [samples], we did find evidence of viral RNA and protein across multiple regions we sampled.” What’s more, “live” replicable virus—not just viral components—was cultured from the brain in one of the deceased patients.

The authors noted that several factors set this study apart from previous autopsy analyses.

• There was a short interval from death to autopsy.
• Brain tissue was “freshly dissected” during each autopsy.
• Tissue from 10 different brain regions was collected and preserved for analysis.  

What it means

The study shows SARS-CoV-2’s ability to invade the brain along with the rest of the body. Since virtually no inflammation or cell damage was present in brain tissue, however, it doesn’t explain the virus’ lingering neurological effects after recovering from infection. The real question now, says Nath, is whether the virus’ presence in the brain is “driving the pathology” or “just sitting there.” 

Chertow adds that, because the 44 deceased patients were unvaccinated, older, and had multiple underlying illnesses and severe COVID, the findings may not be applicable to healthier, younger, vaccinated people with Long COVID. Ultimately, more research is needed. 

*George, J. (2022, December 27). Autopsies Show COVID-19 in the Brain. MedPage Today. https://www.medpagetoday.com/neurology/longcovid/102384