COVID-19 linked to sudden permanent hearing loss in some rare cases, say scientists

Although uncommon, infection with the novel Coronavirus may cause sudden permanent hearing loss in some patients, according to a study which is the first case report linking the disabling condition to COVID-19 in the UK. According to the scientists, including those from the University College London in the UK, awareness of this possible side effect is important since a prompt course of steroid treatment can reverse the hearing loss.

They said while the causes are not very clear, the condition sometimes follows a viral infection, such as flu or herpes. The research, published in the journal BMJ Case Reports, describes the case of a 45-year-old man with asthma who was referred to the Royal National Throat Nose and Ear Hospital in the UK after suddenly experiencing hearing loss in one ear while being treated for COVID-19.

According to the scientists, the patient had been admitted to hospital with COVID-19 symptoms which had been going on for 10 days during which he was transferred to intensive care as he was struggling to breathe. He was put on a ventilator for 30 days, and developed other complications as a result, the study noted.

The researchers noted that he was treated with the antiviral drug remdesivir, intravenous steroids, and a blood transfusion after which he started to get better. However, the patient noticed ringing (tinnitus) in his left ear followed by sudden hearing loss in that ear a week after the breathing tube was removed and he left intensive care.

According to the scientists, he had not lost his hearing or had ear problems before, and apart from asthma, he was otherwise fit and well. On examining his ear canals, they found that there were no blockages or inflammation, but a hearing test showed that he had substantially lost his hearing in the left ear. He was treated with steroid tablets and injections after which his hearing partially recovered, the study noted.

The scientists said he tested negative for other potential causes, including rheumatoid arthritis, flu and HIV, prompting his doctors to conclude that his hearing loss was associated with COVID-19 infection.

"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," the researchers wrote in the case report. "Hearing loss and tinnitus are symptoms that have been seen in patients with both COVID-19 and influenza virus, but have not been highlighted," they added.

The scientists assessed similar cases reported since the beginning of the novel coronavirus pandemic, including the the first study of hearing loss mentioning COVID-19 alone in April. They said the SARS-CoV-2 virus binds to a particular type of cell lining the lungs, and could also infect similar cells lining the middle ear.

According to scientists, the virus also generates an inflammatory response and an increase in the chemicals that have been linked to hearing loss. "Given the widespread presence of the virus in the population and the significant morbidity of hearing loss, it is important to investigate this further," the researchers wrote in the study.

"This is especially true given the need to promptly identify and treat the hearing loss and the current difficulty in accessing medical services," they added. The scientists said doctors should ask patients in intensive care about hearing loss and refer them for urgent treatment. 

(Image credits: AP)