Researchers from Charité – Universatätsmedizin Berlin have figured out the mechanisms through which SARS-CoV2 can reach the brains of patients who have Covid-19 after testing and analysing tissue samples from diseased patients.
According to their findings, the virus enters the brain via nerve cells which are located in the upper region of the nasal cavity and contain receptors for our sense of smell.
Covid-19 was mainly thought to be a respiratory disease. But scientists uncovered its neurological effects along with its impact on the cardiovascular system as well as on the gastrointestinal tract.
The author of the case study states that one in three people infected with Covid-19 experiences neurological symptoms which include loss of smell or taste, headaches, fatigue, dizziness and nausea. Stroke has also been reported in some patients.
The multidisciplinary team of researchers found that the olfactory mucosa contained the highest viral load. Special tissue stains also allowed the team to produce the first ever electron microscopy images of intact SARS-CoV-2 particles within the olfactory mucosa.
“These data support the notion that SARS-CoV-2 is able to use the olfactory mucosa as a port of entry into the brain” said study co-author, Professor Frank Heppner.
“Once inside the olfactory mucosa, the virus appears to use neuro-anatomical connections, such as the olfactory never, in order to reach the brain” he explained.
“Our data suggest that the virus moves from nerve cell to nerve cell in order to reach the brain” said Dr. Helena Radbruch
“We also found SARS-CoV-2 in areas of the brain which control vital functions, such as breathing. It cannot be ruled out that, in patients with severe Covid-19 presence of the virus in these areas of the brain will have an exacerbating impact on respiratory function, adding to breathing problems due to SARS-CoV-2 infection of the lungs. Similar problems might arise in relation to cardiovascular function” he said.