Even in People That Did Not Experience Serious Respiratory Symptoms
By TULANE UNIVERSITY
CT brain scan.
COVID-19 patients commonly report having headaches, confusion, and other neurological symptoms, but doctors don’t fully understand how the disease targets the brain during infection.
Now, researchers at Tulane University have shown in detail how
COVID-19 affects the central nervous system, according to a new study published
in Nature Communications.
The findings are the first comprehensive assessment of
neuropathology associated with SARS-CoV-2 infection
in a nonhuman primate model.
The team of researchers found severe brain inflammation and injury
consistent with reduced blood flow or oxygen to the brain, including neuron
damage and death. They also found small bleeds in the brain.
Surprisingly, these findings were present in subjects that did not
experience severe respiratory disease from the virus.
Tracy Fischer, PhD, lead investigator and associate professor of microbiology and immunology at the Tulane National Primate Research Center, has been studying brains for decades. Soon after the primate center launched its COVID-19 pilot program in the spring of 2020, she began studying the brain tissue of several subjects that had been infected.
Fischer’s initial findings documenting the extent of damage seen
in the brain due to SARS-CoV-2 infection were so striking that she spent the
next year further refining the study controls to ensure that the results were
clearly attributable to the infection.
“Because the subjects didn’t experience significant respiratory
symptoms, no one expected them to have the severity of disease that we found in
the brain,” Fischer said. “But the findings were distinct and profound, and
undeniably a result of the infection.”
The findings are also consistent with autopsy studies of people
who have died of COVID-19, suggesting that nonhuman primates may serve as an
appropriate model, or proxy, for how humans experience the disease.
Neurological complications are often among the first symptoms of
SARS-CoV-2 infection and can be the most severe and persistent. They also
affect people indiscriminately —all ages, with and without comorbidities, and
with varying degrees of disease severity.
Fischer hopes that this and future studies that investigate how
SARS-CoV-2 affects the brain will contribute to the understanding and treatment
of patients suffering from the neurological consequences of COVID-19 and long
COVID.
Reference: “Neuropathology and virus in brain of SARS-CoV-2
infected non-human primate” 1 April 2022, Nature Communications.
DOI: 10.1038/s41467-022-29440-z
The COVID-19 pilot research program at the Tulane National Primate
Research Center was supported by funds made possible by the National Institutes
of Health Office of Research Infrastructure Program, Tulane University and Fast
Grants.