How COVID-19 Damages the Brain

Researchers are beginning to pinpoint how COVID-19 damages the brain. New evidence suggests that the virus attacks the brain in multiple ways. It can assault certain brain cells directly, trigger the production of immune molecules that can damage brain cells, and reduce blood flow to brain tissues.

A COVID-19 infection can also cause strokes, memory loss, and other negative effects on the brain. Can early intervention help prevent these effects? Researchers are looking into finding answers. One study showed that 80% of people hospitalized with COVID-19 had neurological symptoms, and doctors hope to find better treatments.

COVID-19 and its effects on the brain

Scientists point to images of people’s brains before and after they had COVID-19, which show a loss of gray matter in several areas of the cerebral cortex. Early in the pandemic, scientists hypothesized that the virus may enter the brain and infect neurons, which are the cells that transmit and process information. However, subsequent studies have shown that the virus has difficulty breaching the blood-brain barrier, making an attack on neurons unlikely.

COVID-19 and the loss of smell and taste

So how does the SARS-CoV-2 virus make it into the brain if it cannot pass the blood-brain barrier? Scientists are looking at the olfactory mucosa as the potential passageway. The olfactory mucosa is the lining of the nasal cavity that borders the brain. The virus is typically found in the nasal cavity, which is why COVID-19 tests are performed with a nasal swab.

Still, there is limited evidence of the virus entering the brain through the olfactory mucosa or even that the virus is infecting brain cells. The most recent studies show that the virus can infect astrocytes, which are cells in the brain with many functions such as providing nutrients to neurons.