The Many Causes of Hearing Impairment

Flu Can Leave You in Silence

Deafness or hearing impairment is most often associated with old age. While old age is the most common cause of hearing loss, there are many other causes too. Repeated exposure to loud sounds, certain medications, ear infections, etc can lead to deafness. Now and then, we do see patients coming with a hearing loss following a fever or severe cold attack. There are a number of viruses which can cause a hearing loss. Hearing loss caused by viruses may range from mild to profound and can affect one or both the ears. The inflammatory changes following these viral attacks cause changes in the delicate inner ear structures and most often lead to permanent damage. Very young children, elderly and immunocompromised individuals are more prone for this. The onset of hearing loss following a viral infection can be classified into three categories – congenital, acquired and both.

Congenital infections are those viral attacks that involve pregnant women and cause considerable defects in the unborn baby. One such harm is hearing loss. Cytomegalovirus and rubella virus infections are commonly associated with hearing loss in early childhood. Cytomegalovirus infection can cause mild to severe and also progressive hearing loss. It may be unilateral initially and then may involve the other ear too. Rubella (German measles) can present as a fever with mild rash in the antenatal mother but can lead to a significant risk and congenital defects in the baby. There is severe damage to the cochlea; the hearing loss usually is bilateral and may be moderate to severe.

Infections with mumps, measles, varicella zoster and recently COVID-19 viruses are causes of acquired hearing loss. The actual infection may be mild or even asymptomatic. Hearing loss due to these infections usually presents 3-7 days after the onset of primary symptoms. Mumps and varicella usually involve one ear and the hearing loss may be variable. Measles infections leading to hearing loss are most often bilateral and profound.

Certain infections with the herpes virus family and HIV can present as congenital or acquired hearing loss. HIV infection can have direct effects on the inner ear hearing system; it can also cause conductive hearing loss. The patients are prone to opportunistic infections which may affect the ear and brain leading to a hearing loss. Certain medications prescribed can be harmful to the ear, thus leading to a sensorineural hearing loss.

As the saying goes, prevention is better than cure; there are effective vaccines available now to prevent such viral infections. Vaccination programmes all over the world target pregnant women and infants and are thus helpful in decreasing the incidence of deafness induced by viruses. In case of viral cause of hearing loss, early recognition plays a key role. Sometimes this hearing loss can be limited or reversed if appropriate treatment is started early. Antiviral medications, steroids and hyperbaric oxygen therapy can be initiated with a guarded prognosis for hearing recovery. Since most viruses leave a permanent hearing deficit, patients with moderate to severe hearing loss may need to be aided. Hearing aids are a boon to them and considerably improve their personal, professional and social life.