New Delhi: While a majority of people seem to recover completely from COVID 19, there are some who experience lingering symptoms and after-effects long after they have turned negative. From blood clots to strokes to heart attacks, a series of potentially dangerous long-term complications have been associated with COVID 19 in some patients. Hearing loss is one such after-effect experienced by some patients post-COVID recovery. In this article, Dr. Dhirajkumar Nemade (MS ENT), ENT Clinic, Mumbai & Medical Consultant – ENTOD International shares insights on how the novel coronavirus can affect the ears, and even lead to hearing loss in some patients.
One of the first documented cases of hearing loss in a post COVID patient was published in the British Medical Journal last year which reported the experience of a 45-year-old man who noticed sudden left-sided hearing loss and tinnitus after recovering and leaving the intensive care unit at University College London. He had no previous history of hearing loss or ear problems, leading doctors to deduce a COVID connection to the case. Diagnosed with sudden sensorineural hearing loss which involves a rapid loss in inner ear hearing – usually in one ear, the patient received treatment with steroids which partially restored his hearing.
Another study published in the American Journal of Otolaryngology as early as April 2020 cited the case of an elderly female patient in Thailand who reported hearing loss following COVID infection.
While several studies over the past year have confirmed the link between COVID and hearing loss in some patients, the exact cause of co-relation is still being deliberated upon. More research is needed in this area to clearly understand how coronavirus causes hearing loss, balance problems or tinnitus. However, experts have postulated some theories about the possible link. While some studies have linked the COVID virus with effects on the brain stem, others deduced it as a neuro-auditory complication.
Awareness about this side-effect is therefore pertinent for every individual since quick detection and treatment can reduce the effects and reverse hearing disability in patients.
What causes sudden hearing loss due to Covid-19?
Researchers across the world have been able to link two major links behind the sudden hearing loss after the body comes in contact with the Covid 19 virus. ACE2, an enzyme found in different organs of the body, plays the role of a receptor for the SARS-CoV-2 virus enabling it to infect the cells. ACE 2 receptors are also found in the epithelial cells in the middle ear where the SARS COV 2 virus is believed to bind with them. The other reason behind this could be how the immune system responds to the infection. An increase in cytokines (proteins released by cells have a specific effect on the interactions and communications between cells) due to the infection can be responsible for hearing loss if there is a direct entry into the cochlea leading to cell stress and inflammation.
A series of viral infections have been proposed as a cause of SSNHL (Sudden sensorineural hearing loss) earlier through damage of inner ear structures or by precipitating inflammatory responses which then cause this damage.
Whatever the exact cause, there is clear evidence of a neuro-auditory involvement in Covid-19 infections.
Treatment for hearing loss caused by Covid-19
Immediate prescription of steroids is the best way to improve prognosis in such patients. Administration of intra-tympanic injection of corticosteroid in multiple sessions has been found to have a positive impact on patients with post-COVID hearing loss.
In some cases, there may have been virus triggered inflammation of the meninges with subsequent spread to the cochlea, leading to acute hearing loss. Virus-triggered, immune-mediated inflammation seems likely, considering that severe cases of COVID-19 have been associated with a dysregulation of the immune system. In these severe cases, an increased neutrophil-to-lymphocyte ratio and elevated inflammatory cytokines such as interleukin 6 can be given to address the condition.
It is important to underline here that early administration of steroids and anti-virals is critical in reversing the hearing loss of preserving some part of the hearing. The auditory symptoms must therefore be investigated in every COVID patient to ensure timely diagnosis and treatment to prevent permanent hearing loss.
During Covid-19 treatment, patients should be regularly asked about any hearing-related difficulty or signs of tinnitus or loss of balance. And if at all they see any symptoms, they must be referred to otolaryngology on an emergency basis.
Patients recovering from COVID must also consider any hearing-related development as an emergency and immediately seek medical help for the same.
Disclaimer: Tips and suggestions mentioned in the article are for general information purposes only and should not be construed as professional medical advice. Always consult your doctor or a professional healthcare provider if you have any specific questions about any medical matter.