Post COVID-19 effects: Sudden onset sensorineural irreversible hearing loss
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If COVID symptoms were bad, the post-COVID conditions are much more. From fatigue, brain fogging, body ache to anxiety, the disease has long lasting consequences. What many might not be aware is that the impact of COVID on hearing, with few reported cases of hearing loss following COVID-19. In fact, hearing loss can be a significant cause of morbidity and can easily be missed in the intensive care setting. Being aware and screening for hearing loss following COVID-19 enables an early course of steroids, which offers the best chance of recovering hearing1.
Sudden onset sensorineural hearing loss (SSNHL) is defined as a hearing loss of at least 30 dB in at least three consecutive frequencies that has developed within 3 days2. It is a relatively common pathology seen in otolaryngology, with a worldwide incidence of 5–160 cases per 100 000 people annually3. In most cases, the causal factor is uncertain, and can result from several different pathologies. These include body’s response to cellular stress, viral infection or immune mediated response. People affected with the disorder usually experience hearing loss upon waking up in the morning. Accompanying symptoms include the feeling of ear fullness, tinnitus or ringing in the ear, and dizziness.
Recent studies have shown that COVID-19 can cause sudden and irreversible hearing loss in patients. A team of researchers at the University College London report a few cases of hearing loss, diagnosed as sudden-onset sensorineural hearing loss (SSNHL) after being infected with COVID-194. In a study presented by BMJ Case Reports, a 45-year-old patient with asthma was presented following a week of hearing loss while in hospital for the treatment of COVID-19. Beyond the COVID-19 symptoms and a series of complications, including pneumonia, anemia, and pulmonary hypertension, patient’s hearing was also impacted. The patient developed hearing loss and tinnitus a week after being put off from ventilator support and was required to seek medical care from the otolaryngology department.
It is interesting to note that the patient had not lost his hearing or had ear problems before. Examination of patient’s ear canals revealed that there were no blockages or inflammation. However, a hearing test indicated substantial loss of hearing in the left ear. The patient tested negative for other potential causes, including rheumatoid arthritis, flu and HIV, prompting the physicians to conclude that the hearing loss was associated with COVID-19 infection. Subsequently, the patient was treated with steroid tablets and injections after which the hearing partially recovered5.
Despite the considerable literature on COVID-19 and the various symptoms associated with the virus, there is a lack of discussion on the relationship between COVID-19 and hearing. Hearing loss and tinnitus are symptoms that have been seen in patients with both COVID-19 and influenza virus but have not been highlighted. Despite the low numbers of studies, it is significant to consider the possibility of a relationship between COVID-19 and SSNHL. In this case, SARS-CoV-2, the virus responsible for COVID-19, is thought to lock on to a particular type of cell lining in the middle ear, similar to its mechanism of binding to cell lining in lungs. It then generates an inflammatory response and an increase in the chemicals that have been linked to hearing loss.
Although there is limited data, the sudden SSNHL appears to follow the COVID-19 infection. It would be beneficial if Doctors ask patients in intensive care about hearing loss and refer them for urgent treatment. Further research is also needed to consider the benefit of steroid treatment.
References
- Koumpa FS, Forde CT, Manjaly JG. Sudden irreversible hearing loss post COVID-19. BMJ Case Reports CP 2020;13:e238419.
- Kuhn M, Heman-Ackah SE, Shaikh JA, Roehm PC. Sudden sensorineural hearing loss: a review of diagnosis, treatment, and prognosis. Trends Amplif. 2011;15(3):91-105. doi:10.1177/1084713811408349.
- Chen X , Fu Y-Y , Zhang T-Y . Role of viral infection in sudden hearing loss. J Int Med Res 2019;47:2865–72.doi:10.1177/0300060519847860 .
- Languipo ABB. COVID-19 can cause sudden permanent hearing loss in rare cases. News Medical Life Sciences 2020.
- First reported UK case of sudden permanent hearing loss linked to COVID-19, Science Daily 2020.
