Childhood hearing loss/deafness management

Dr Moirangthem Niteshore Singh *

"A child who struggles to hear may also struggle to learn to speak, underachieve at school and end up socially isolated"

There are 360 million people in the world with disabling hearing loss. This is around 5% of the world's population – 32 million of these people are children. Disabling hearing loss is defined as:

1. Adults (15 years and older): hearing loss greater than 40 decibels (dB) in the better hearing ear

2. Children (0 – 14 years of age): hearing loss greater than 30 dB in the better hearing ear.

Worldwide, over 275 million people are estimated to have moderate to profound hearing loss in both ears. Fewer than one in 40 people who need hearing aids have them. Eighty percent of hearing impaired people live in low- and middle-income countries, and one quarter of hearing impairment begins during childhood. Up to 5 of every 1000 infants are born with or develop disabling hearing loss in early childhood. Age-related hearing loss (presbycusis) affects nearly 1 out of every 3 people over 65 years.

Among children, chronic otitis media is the leading cause of hearing loss. More than 1 billion young people (12-35 years) are at risk of hearing loss due to recreational exposure to loud sounds like using speaker, loud music, extensive use of headphones, bar etc

Functional impact: One of the main impacts of hearing loss is on the individual's ability to communicate with others. Spoken language development is often delayed in children with deafness. Hearing loss and ear diseases such as otitis media can have a significantly adverse effect on the academic performance of children.

However, when opportunities are provided for people with hearing loss to communicate, they can participate on an equal basis with others. The communication may be through spoken/-written language or through sign language.

Social and emotional impact: Limited access to services and exclusion from communication can have a significant impact on everyday life, causing feelings of loneliness, isolation and frustration, particularly among older people with hearing loss. If a person with congenital deafness has not been given the opportunity to learn sign language as a child, he or she may feel excluded from social interaction. Early detection and management are important in providing appropriate support for deaf and hearing-impaired infants and toddlers that will help them enjoy equal opportunities in society.

Economic impact: In developing countries, children with hearing loss and deafness rarely receive any schooling. Adults with hearing loss also have a much higher unemployment rate. Among those who are employed, a higher percentage of people with hearing loss are in the lower grades of employment compared with the general workforce.

Improving access to education and vocational rehabilitation services, and raising awareness especially among employers about the needs of people with hearing loss, would decrease unemployment rates among this group. In addition to the economic impact of hearing loss at an individual level, hearing loss substantially affects social and economic development in communities and countries.

Causes of hearing loss and deafness: There are many causes of childhood hearing loss. It is estimated that 40% is attributable to genetic causes; 31% to infections such as measles, mumps, rubella and meningitis; and 17% to complications at birth, including prematurity, low birth weight and neonatal jaundice. In addition, an estimated 4% results from expectant mothers and new-borns unknowingly using medicines which are harmful to hearing.

The causes of hearing loss and deafness can be divided into congenital causes and acquired causes.

Congenital causes: Congenital causes may lead to hearing loss being present at or acquired soon after birth. Hearing loss can be caused by hereditary and non-hereditary genetic factors or by certain complications during pregnancy and childbirth, including:

1. Maternal rubella, syphilis or certain other infections during pregnancy;
2. Low birth weight;
3. Birth asphyxia (a lack of oxygen at the time of birth);
4. Inappropriate use of particular drugs during pregnancy, such as aminoglycosides, cytotoxic drugs, antimalarial drugs and diuretics;
5. Severe jaundice in the neonatal period, which can damage the hearing nerve in a newborn infant.

Acquired causes: Acquired causes may lead to hearing loss at any age, such as:

1. Infectious diseases such as meningitis, measles and mumps;
2. Chronic ear infections;
3. Collection of fluid in the ear (otitis media);
4. Chronic allergic rhinosinusitis with eustachian tube dysfunction;
5. Chronic and enlarged adenoid;
6. Use of particular drugs, such as some antibiotic and antimalarial medicines;
7. Injury to the head or ear;
8. Excessive noise, including occupational noise such as that from machinery and explosions, and recreational noise such as that from personal audio devices, concerts, nightclubs, bars and sporting events;
9. Ageing, in particular due to degeneration of sensory cells;
10. Wax or foreign bodies blocking the ear canal;
11. Recurrent attacks of common cold; upper respiratory tract infections, and exanthematous fevers like measles, diphtheria, whooping cough.
12. Infections of tonsils and adenoids;
13. Chronic rhinitis and sinusitis;
14. Nasal allergy;
15. Tumours of nasopharynx, packing of nose or nasopharynx for epistaxis and
16. Cleft palate.

Chronic ear infections are a leading cause of hearing loss in children and young adult. WHO outlines ways to prevent and mitigate childhood hearing loss. Nearly 32 million children across the world live with disabling hearing loss out of which 60% can be prevented. It also highlights that if hearing loss is detected early enough, and if children receive the care they need, they can reach their full potential.

The global prevalence of chronic otitis media (COM) or chronic ear infections ranges from 1-46% in developed and developing countries. COM leads to hearing loss and can cause life-threatening complications and mortality. COM is largely preventable. It can be managed effectively through medical and surgical means.

People with hearing loss can benefit from hearing aids, cochlear implants and other assistive devices; captioning and sign language; and other forms of educational and social support. Current production of hearing aids meets less than 10% of global need and less than 3% of developing countries' needs.

Identification and management: Early detection and intervention are crucial to minimizing the impact of hearing loss on a child's development and educational achievements. In infants and young children with hearing loss, early identification and management through infant hearing screening programmes can improve the linguistic and educational outcomes for the child.

Prevention of childhood hearing loss: Half of all cases of hearing loss can be prevented through primary prevention.

Some simple strategies for prevention include:

1. Immunizing children against childhood diseases, including measles, meningitis, rubella and mumps;
2. Immunizing adolescent girls and women of reproductive age against rubella before pregnancy;
3. Screening for and treating syphilis and other infections in pregnant women;
4. Improving antenatal and perinatal care, including promotion of safe childbirth;
5. Following healthy ear care practices;
6. Screening of children for otitis media, followed by appropriate medical or surgical interventions;
7. Early treatment of upper respiratory tract infection
8. Avoiding the use of particular drugs which may be harmful to hearing, unless prescribed and monitored by a qualified physician;
9. Referring infants at high risk, such as those with a family history of deafness or those born with low birth weight, birth asphyxia, jaundice or meningitis, for early assessment of hearing, prompt diagnosis and appropriate managementa and
10. Reducing exposure (both occupational and recreational) to loud sounds by raising awareness about the risks; developing and enforcing relevant legislation; and encouraging individuals to use personal protective devices such as earplugs and noise-cancelling earphones and headphones.

Early diagnosis and treatment:

1. Watchful waiting,
2. Antimicrobial, anti-allergic, decongestants,
3. Hearing aids and
4. Speech & language therapy.

Surgical management:

1. Myringotomy +/- tympanostomy tube insertion,
2. Adenoidectomy +/- tonsillectomy,
3. Tympanoplasty +/- mastoidectomy and
4. Cochlear implant & other audiological implants.