The novel coronavirus uses the nose as a gateway into the brain, autopsy findings suggest.
The presence of the virus in the brain and cerebrospinal fluid has been linked with neurological symptoms, but exactly how the virus enters the central nervous system has not been clear.
During autopsies of 33 patients who died of COVID-19, researchers examined the nasopharynx — the region where the nasal cavity connects with the back of the throat — which happens to be in close proximity to the brain. By dissecting cells and following the path of infection, they saw that the virus invades the brain by crossing through the mucous membranes that separate it from the nasopharynx.
From there, according to a report published on Monday in Nature Neuroscience, it may travel along the nerve fibers that connect the nasal cavity to the part of the brain involved in the sense of smell, which would explain “some of the well-documented neurological symptoms in COVID-19, including alterations of smell and taste perception.”
The researchers also found virus particles in brain regions with no direct connection to the nose, which suggests there may be additional routes of viral entry into the brain.