A new study has shown that COVID-19 can infect cells in the inner ear and potentially lead to hearing loss and tinnitus (ringing or tinnitus without external acoustic stimulus). Researchers create models of various types of inner ear cells, including hair cells, supporting cells, nerve fibers, and Schwann cells. These models were then compared with 10 COVID patients who reported a range of hearing-related symptoms. The researchers found that hair cells and Schwann cells contain proteins that the coronavirus needs to enter and infect cells. This explains why some COVID-19 patients complain of hearing loss, tinnitus, dizziness, and balance problems.
New research suggests COVID-19 can infect the inner ear and potentially cause a host of hearing problems. As writes
https://www.dailymail.co.uk/health/article-10145347/COVID-19-infect-cells-inner-ear-potentially-lead-hearing-loss-tinnitu.html
The Daily Mail, researchers from the Massachusetts Institute of Technology (MIT) and Massachusetts Eye and Ear Specialty Hospital studied 10 COVID patients who reported a range of ear-related symptoms. They found that the virus can infect cells in the inner ear, particularly hair cells, which can lead to impaired hearing and balance.
The team says the findings explain why some COVID-19 patients report hearing loss, tinnitus, dizziness, and balance problems.
Study co-authors Dr. Konstantin Stantovich and Dr. Lee Gerke studied why viruses such as mumps and hepatitis affect hearing before the pandemic broke out. In March 2020, when they began to see coronavirus patients reporting deafness, dizziness, or tinnitus, they decided to focus on COVID.
“At the time, it was very unclear if this was causal or accidental because hearing loss and tinnitus are so common,” says Dr. Konstantin Stantovich, former head of Otology and Neurotology at the Massachusetts Ophthalmic Department and current Chairman of the Department of Otolaryngology – Head and Head of the Department of Otolaryngology. at Stanford University School of Medicine.
For the study, published in the journal Communications Medicine, the team used new cell models of human inner ear cells. Other studies are hampered by the lack of inner ear tissue, they said.
“Getting the models is the first step, and this work now paves the way for working not only with SARS-CoV-2, but also with other viruses that affect hearing,” says Dr. Lee Gerke, professor at the Institute of Medical Engineering and Science at Massachusetts Institute of Technology. institute.
The participants in the study took human stem cells and turned them into “pluripotent” stem cells that can take many different forms in the body.
The researchers turned stem cells into various types of inner ear cells, including hair cells, supporting cells, nerve fibers, and Schwann cells, which could be grown in a 2D layer or 3D organelles.
The cells were then taken from 10 COVID patients undergoing surgery for a condition that causes bouts of dizziness or swelling causing severe hearing loss and dizziness.
In both models and human ear samples, the team found that hair cells and Schwann cells contain proteins that the coronavirus needs to invade and infect cells.
This is especially important because hair cells help people maintain balance and understand head movements. The virus could not penetrate other types of cells they studied. It is not known how the virus gets into the inner ear, but it can enter through the tube that connects the nose to the middle ear or out of the nose.
Another theory is that the virus enters from the nose through small openings surrounding the olfactory nerves and affects the cranial nerves, including the one that connects to the inner ear.
Researchers don’t know what percentage of patients with the virus report hearing problems, a problem exacerbated by a lack of testing early in the pandemic. This was originally due to the fact that routine testing was not available for patients diagnosed with COVID, and when patients had more life-threatening complications, they did not pay much attention to whether their hearing was impaired or they had tinnitus. , – says Dr. Stankovic: “We still do not know what the incidence is, but our results do require increased attention to audiovestibular symptoms in people with exposure to COVID.”
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