CAMBRIDGE, Massachusetts – COVID-19 safety measures typically focus on particles coming from a person’s mouth or nose. Now, a new study warns that the virus can also infect the inner ear. Researchers at the Massachusetts Institute of Technology (MIT) say it can trigger hearing problems and even balance issues for COVID patients.
Scientists say the results explain why some patients with the virus have also reported hearing loss, ringing in the ears (tinnitus) and dizziness during their illness. The authors of the study found that the SARS-CoV-2 virus is capable of infecting certain cells in the ear.
They also found that the type of infection seen in people’s inner ear tissue matches symptoms in a study of 10 patients infected with the virus who reported ear problems, including tinnitus and heart failure. hearing loss. It is not yet clear how the insect enters the inner ear, but it can enter through a tube connecting the nose to the middle ear or through particles escaping from the nose and spreading throughout the body.
The research team used new cell models of human inner ear cells and hard-to-obtain human inner ear tissue in their work. Other studies have been hampered by a lack of inner ear tissue, the team says. Doctors Konstantina Stanovic and Lee Gherke had sought to find out why mumps and hepatitis affect hearing before the pandemic struck.
They changed their plans in March 2020 as they began to see coronavirus patients experience sudden hearing loss, dizziness or tinnitus. Initially, they couldn’t determine whether or not this was just a coincidence.
2 ear cells are vulnerable to COVID
They took human stem cells and turned them into “pluripotent” stem cells, which can play many different roles in the body. The team then transformed them into different types of inner ear cells, including hair cells, support cells, nerve fibers, and Schwann cells, which can develop into a 2D layer or into 3D organoids.
The study authors then took cells from patients with a disease causing vertigo attacks or a tumor causing severe hearing loss and dizziness. They found that hair cells and Schwann cells had proteins that the virus needs to bind to cells. Hair cells help people maintain balance and understand the movement of their heads. Meanwhile, Schwann cells are part of the peripheral nervous system. They produce the protective coating around neural axons in the body.
The virus was unable to enter the other cell types examined by the researchers. It is still unclear what percentage of patients infected with the virus will experience hearing difficulties, a problem made worse by the lack of testing for these side effects early in the pandemic.
“We still don’t know what the impact is, but our results really call for increased attention to audiovestibular symptoms in people exposed to COVID,” says Dr. Stankovic in a university outing.
The results were published in the journal Communications medicine.
South West News Service writer Gwyn Wright contributed to this report.