To learn how COVID affects the ear, scientists turn to cadavers

[marmar]

n a narrow medical school hallway, Matt Stewart opened a large cabinet to reveal dozens of shelves stacked with wooden boxes and trays, some at least 100 years old.

Stewart, tall and silver-haired, pulled out one of the trays and showed off its contents: Thin slices of human skull bones and the organs of hearing and balance they contain, stained shades of pink. Affixed to microscope slides, the anatomical bits resembled abstract rubber stamp art, no bigger than thumbprints. "Our Johns Hopkins history," he said, referring to the university's collection of specimens from more than 5,000 patients.

Stewart's research team at Johns Hopkins University in Baltimore had a long, complicated journey to make slides like these in 2021. The researchers need these specimens, sliced from the portion of skull that houses the inner ear, to ask a fundamental question about the novel coronavirus, SARS-CoV-2: Does it directly invade the cells of tissues that enable hearing and balance?

Data on ear problems as they relate to Covid-19, the disease caused by SARS-CoV-2, is spotty. To date, case reports and small studies have found that some Covid-19 patients experience significant and rapid hearing loss, ringing in the ears called tinnitus, or balance issues. Estimates vary on the prevalence of these symptoms, but because the coronavirus has infected hundreds of millions of people, even a few percent of Covid patients experiencing hearing loss would add up to a large increase globally. Yet no causal link has been drawn between the novel coronavirus and auditory symptoms. Hearing problems aren't even on lists of Covid-19 symptoms, short or long-term, published by the Centers for Disease Control and Prevention.

There are several possible explanations for why the disease might be associated with severe hearing problems, and scientists may never pinpoint all of the underlying mechanisms. But researchers like Stewart are pursuing the theory that the virus could be directly damaging inner ear cells. The coronavirus is already known to infect the cells of the upper nasal cavity, leading to loss of smell. A similar process might occur in the ear, explained Stewart, an associate chief medical officer who specializes in inner ear surgery at the Johns Hopkins Hospital. .............(more)

https://www.salon.com/2022/01/17/to-learn-how-affects-the-ear-scientists-turn-to-cadavers_partner/