Hearing Loss in Children
Posted by The Little Pages - Jun 29, 2016
IT DOESN'T HAVE TO BE A DISABILITY
What is Brain Plasticity?
This is the critical period between ages 0 to 5 years of age. This is the period during which a child learns to see and hear, as well as eating and breathing control. It is a critical period during which they learn language and communication skills Plasticity can be likened to a plasticine mould, the brain is pliable and well suited to development and learning new information. It is a vital period for learning. If a child does not develop vision and hearing during this time, that child will remain permanently blind or deaf.
Can my child hear?
This is the vital question. Deafness (sensori-neural hearing loss) is rare, about 1:1000, but it is important to find these children as soon as possible. The earlier a diagnosis is made, the earlier effective intervention can be implemented so that child can learn to hear (the brain can learn what sounds are). The earlier the intervention, the more normal the life of that child will be.
Unfortunately, in a newborn child there are no signs to alert you.
Testing my child:
The current drive in ENT is to test every new-born infant. OAEs (oto-acoustic emissions) is easy and is the first-line test performed.
What if the test is deferred?
This does not mean the child cannot hear. It just means that further tests are required. This is why we talk about the test being “deferred” rather than “failed”.
What if test show my child is deaf?
Early diagnosis is vital. The sooner the diagnosis is made, the sooner a plan can be implemented. The earlier hearing can be restored, the sooner the child’s brain gets stimulated during the plasticity period.
It is vital to know the exact degree of hearing loss. There are a wide variety of hearing aids available. Most hearing aids consist of a receiver and amplifier worn behind the ear, with a delivery mechanism to the ear canal. For more severe hearing loss, the level of amplification required increase, increasing the size of the device. For complete deafness, cochlear implants are an option. These require surgery and work from a dedicated team of audiologists and therapists. (currently done by Dr Retief at St Georges Hospital)
Do I need to repeat the tests?
If the initial test is a “pass” then your child can hear. There is no need to repeat the OAE again. However, many children can develop ear infections and fluid in the middle ear.
If deafness is treated early, the child can enter a mainstream school and lead a near-normal life.
FLUID IN THE MIDDLE EAR AND GROMMETS
This is the reason why repeat ear tests are recommended. These tests are tympanometry. These do not test hearing (like OAEs do) but rather for ear drum function. Tympanometry will detect fluid in the middle. Many schools run a yearly ear testing program.
What is Otitis Media?
Fluid to accumulation in the middle ear. This fluid can be sterile or infected. Children are more prone to this condition than adults due to the anatomy of their Eustachian tubes. Their tubes are shorter and more horizontal than an adult’s, allowing easier transit of bacteria. This is important in that most affected children will outgrow their condition.
What causes this fluid to accumulate?
Upper Respiratory Tract infections (URTIs), commonly known as colds or flue are the most common cause. Infection in the nose causes mucosal swelling and blockage of the Eustachian tubes. This condition is usually temporary and managed medically. Oral steroids are useful for speeding up resolution by reducing swelling. In severe cases, infection can enter the middle ear. For this reason, antibiotics are usually also given.
The Link between Adenoids and middle ear fluid.
This link has been shown by numerous studies. The adenoids can become colonised with bacteria which repeatedly cause middle ear infection. For this reason, adenoids are often also removed. Children with enlarged adenoids will often have a blocked nose, breath through their mouths, snore excessively or have a very runny nose.
What does fluid do?
Fluid is not compressible so it impedes the ear drum’s ability to vibrate. This blocks transmission of sound and equates to about 20decibels of hearing loss (often spoken of as 20% percent hearing loss, although this term isn’t strictly accurate). This degree of hearing loss is enough to cause trouble: speech delay, difficulty hearing the teacher and inattention in class. This is a significant handicap.
When must something be done?
The general consensus is 3 months. Fluid due to an URTI usually resolves spontaneously. If the duration exceeds 3 months, then the resulting hearing loss is going to start affecting the child’s education. It is also less likely that the condition will resolve. Intervention is also recommended if repeated attacks occur (3 or more per year).
What are ventilation tubes (commonly known as grommets)?
These are tubes inserted into the ear drum. They allow the fluid to drain and restore normal hearing. They are very easy to insert and the improvement is usually very quick. Grommet insertion and adenoid removal both cause very little discomfort to a child. Most children are back to normal by the next day. 90% of children only require 1 set of grommets.