A recent study from MIT and Massachusetts Eye and Ear explored patients with Covid-19 who reported initial symptoms of hearing loss, tinnitus, dizziness and balance problems after infection.
The study provided evidence that the virus can infect inner ear cells, particularly hair cells.
The researchers conducted the study on 10 patients with Covid-19 who reported various hearing-related symptoms, with the most important symptom being hearing loss.
Each individual’s hearing loss varied from mild to profound; nine of the patients experienced tinnitus and six patients experienced vertigo.
Using adult human inner ear tissue from donor patients who had surgery to treat severe vertigo and had not had Covid-19, as well as new cell models of the inner ear developed by themselves, they were able to lead to complete the study and share your findings. .
They found a pattern of infection observed in human inner ear tissue that is consistent with the patient’s symptoms.
Because it is very difficult to collect tissue from the human inner ear, the team developed models to use for further research. They were able to create the inner ear tissue models by taking human skin cells, reprogramming the cells to become stem cells, and then directing the stem cells to become precursors of hair cells or Schwann cells.
Anatomy of the ear.
Co-director of the study Dr. Lee Gehrke and Dr. Konstantina Stankovic. Gehrke is the Hermann LF von Helmholtz Professor at MIT’s Institute of Medical Science and Engineering. Stankovic is a former associate professor at Harvard Medical School and former chief of Otology and Neurotology at Massachusetts Eye and Ear, who is now a Bertarelli Foundation Professor and chairman of the Department of Otolaryngology-Head and Neck Surgery at Stanford University School of Medicine.
Minjin Jeong, lead author of the paper that appeared in Communications Medicine on October 29, 2021, is a former postdoctoral fellow in Stankovic’s lab at Harvard Medical School and is now a postdoctoral fellow at Stanford Medical School.
Healthy and damaged hair cells inside the cochlea.
discoveries
For an individual to be infected by SARS-CoV-2, they must have specific proteins on their cell surface.
The researchers found the proteins in both types of human inner ear cell samples: hair cells and Schwann cells. Hair cells function to detect sound waves for the ear and movement to maintain balance, while Schwann cells provide electrical insulation for nerve cells in the inner ear.
Similar to inner ear samples collected from donors, the same precursor cells produced by the researchers had the proteins required for SARS-CoV-2 infection. The virus primarily infected hair cell precursors. Schwann cells were less affected.
The results of the experiments strongly suggest that SARS-CoV-2 can infect the inner ear and cause hearing and balance problems associated with Covid-19, although the overall percentage of patients with Covid-19 who experienced it is unknown hearing related problems.
Health and wellness