We all know the main symptoms of COVID-19: fever, cough, shortness of breath, loss of taste/smell, etc. But did you know that the coronavirus can also cause ear-related symptoms? One review published in the International Journal of Audiology indicates COVID-19 can lead to hearing loss, tinnitus and vertigo.
About the Research
In June of 2020, researchers at the Manchester Centre for Audiology and Deafness reviewed seven studies that indicated there is a link between audiovestibular (hearing and balance related) problems and COVID-19. The researchers later updated their review to include information from 56 studies that were published in 2020.
According to their analysis, 14.8% of COVID patients experience tinnitus (ringing in the ears), 7.6% experience hearing loss and 7.2% experience vertigo (spinning sensation).
This is consistent with other types of viral infections, such as rubella, measles and cytomegalovirus; these illnesses are known to cause hearing problems.
Why the Link Between COVID-19 & Ear Problems?
In order to understand how COVID-19 can affect the ears, it’s important to know how we hear and balance.
Within the inner ears are tiny hair cells called stereocilia, which convert soundwaves into electrical energy that the brain interprets as sound. The inner ears also contain the semicircular canals, which contain fluid that moves in response to head and body movements, helping orient you in space.
The researchers propose three possible explanations for how COVID can cause audiovestibular symptoms:
- The viral infection directly affects the inner ear or the auditory nerve, which carries signals to the brain.
- Antibodies, immune cells or cytokines (immune-signaling molecules that cause inflammation) create an autoimmune attack.
- Blood clots block the blood supply to the inner ears, depriving them of oxygen.
Limitations of the Study
The authors admit that the review may overestimate the number of cases. There are a few reasons for this.
One reason is that the studies they reviewed did not always express whether the symptoms were new after getting COVID-19 or whether they were preexisting symptoms that were made worse by COVID.
Another reason is that most of the studies were based on medical records or questionnaires in which patients self-reported their symptoms rather than getting a full audiological evaluation.
The authors emphasize that further research is needed to uncover the potential effects of COVID-19 on the auditory system.
If you’ve had COVID-19 and are now experiencing audiovestibular symptoms that affect your ability to work out at GreatLIFE or participate in other activities, call Topeka ENT today.