Deaf children and balance
It can be difficult to detect balance disorders in children as they might struggle to describe their symptoms or understand concepts like vertigo and imbalance.
Not all balance disorders are associated with deafness, but balance disorders can be caused by things like glue ear, sensorineural deafness, viral infections, meningitis , cytomegalovirus (CMV) and enlarged vestibular aqueducts (EVA).
Balance problems can occur when the organ of balance doesn’t work properly. This is known as vestibular hypofunction.
Children can be born with this or acquire it with illness or trauma.
Vestibular hypofunction can delay the development of balance function. This might mean that babies and young children take longer to reach developmental milestones such as sitting unsupported and walking. Older children may have difficulties with certain activities such as learning to ride a bike. This is called imbalance.
Other types of balance problem can cause dizziness or vertigo or episodes of unsteadiness. These can occur at any time in childhood. Young children may not understand or be able to describe the concepts of vertigo or feeling unsteady on their feet, so balance problems can be more difficult to detect than with adults and older children.
If you have any questions or concerns about your child’s balance discuss them with your child’s doctor.
Diagram of the ear
The inner ear consists of the cochlea, the vestibule and the semicircular canals. The cochlea is the organ of hearing and looks like a snail’s shell.
The organ of balance includes the vestibule and the semicircular canals. These structures are filled with fluid and have sense organs made up of small hair cells which detect movement and gravity. As we move in space these sense organs send information about our balance to the brain.
As well as the vestibular system in the inner ear, the brain also uses information from two other systems to maintain balance:
- visual information from the eyes tells the brain where we are in relation to the environment around us
- special pressure receptors in the legs and body, known as proprioceptors, send signals to the brain that tell it about posture and movement and also about the surrounding physical environment such as uneven or sloping ground.
Information from these three systems is received and interpreted by the brain, which then sends instructions to the muscles controlling our movement so that we can keep our balance.
A temporary change or problem with one part of the system, such as an inner ear infection or glue ear, can result in temporary dizziness or unsteadiness.
Sometimes the vestibular system is affected by injury, illness or a long-term condition, for example migraine.
Sometimes the vestibular system and the cochlea have been affected by the same problem and so deafness and balance problems can occur together, for example meningitis, enlarged vestibular aqueducts (EVA), CHARGE and other syndromic causes of deafness. For more information on these conditions see Causes of deafness.
However, this is not always the case and many deaf children have excellent balance while dizzy children can have normal hearing.
Tests of the balance system can be done when:
- there is a history of dizziness
- there is some difficulty with balance.
A deaf child may also have balance tests when:
- there has been delay in learning to sit or walk
- the deafness is one-sided (unilateral) or a different level in each ear (asymmetrical)
- the level of deafness is changing
- a cochlear implant is being considered
- the cause of the deafness is being examined in detail.
The tests can:
- help to find out the cause of balance problems and/or dizziness
- give more information about the function of the inner ear
- help find the cause of the child’s deafness.
Even if a deaf child appears to have good balance it can still be useful to look more closely at their balance system. Children are clever at compensating for weaknesses in the balance system and it may not be obvious until full testing is done.
Identification of balance problems can help your doctor understand more about your child and can sometimes help to understand the cause of their deafness.
Your child’s doctor will carry out a clinical examination to assess your child’s balance. These will include observation of some simple activities such as walking, marching on the spot and hopping on one foot, often with the eyes open and then closed.
In very young babies an assessment of head control and muscle tone will give the doctor information about the child’s balance system.
Your child’s doctor may recommend that a more detailed assessment of the balance is done. Some of the tests used in this assessment are described below. Your child’s doctor will discuss which tests are planned and why they are recommended. A full balance assessment may last between one and a half to three hours.
Preparation for the tests
Balance tests are painless, but some of them may make your child feel unsteady, dizzy, or occasionally, sick. Most children don’t have any trouble with testing and many even enjoy them. If your child does experience problems during testing, the tester will stop so they can recover.
Some tests are carried out in the dark. If your child lip-reads or uses sign language it’s important that they understand what will happen before the lights are turned off.
One test may involve putting water into the ear canal and therefore the removal of any hearing aids.
Some medication can affect balance tests and you may be advised to stop using them before coming to the clinic.
Alcohol can also affect results and young adults should not drink for 48 hours before testing.
Balance tests rely on looking for and recording eye movements. Eye movements are recorded because there is an interaction between the eyes, eye muscles, and the vestibular system in the inner ear.
VNG measures movement of the eyes using special goggles. Your child will wear these goggles in a darkened room while their eye movements are recorded.
ENG records eye movements using small stickers called electrodes, which are placed on the skin around the eyes. These electrodes pick up changes in the electricity within the eye as it moves.
With both VNG and ENG your child will have eye movements recorded while they watch a bright light or a striped curtain.
In addition your child may be tested when sitting in a computer-controlled chair that rotates gently back and forth or round and round. Very young children may be tested sitting on their parent’s lap. Most of these tests are performed in a very dark room.
Caloric testing is performed using either VNG or ENG recordings. A small earpiece is placed at the entrance of the ear canal and through this warm and/or cool water is washed into the outer ear for about 30 seconds.
The water is a few degrees above or below body temperature. The temperature change caused by the water stimulates a response from the balance system. Eye movements are measured to record this response. Caloric testing is not painful, but may make your child feel lightheaded or dizzy for a short time.
Your child will stand barefoot on a platform that measures how much they sway. The platform moves back and forth during the test and records how well they keep their balance. Your child will be wearing a safety harness so that they can’t fall.
Vestibular evoked myogenic potentials (VEMP)
VEMP are used to measure the function of the sense organs of the vestibule. Small sticky electrodes are placed on the muscles of the neck and a sound is played into the ear. The sound waves stimulate the balance sense organ and the resultant change in tension of the muscle in the neck is measured. VEMP tests are painless and aren’t carried out very often.
Dizziness or vertigo
Some causes of dizziness will clear up without the need for any intervention.
However, children who develop recurrent or persistent dizziness often need specialist help. Depending on the cause this may involve medication, physiotherapy exercises, occupational therapy or psychology. Your child’s doctor will advise if these are necessary.
If a child is born with or acquires a balance problem early in life it’s likely that they will develop ways of compensating naturally without the need for any special help or therapy.
However it’s helpful to know that there are weaknesses in their system so that simple steps can be taken to help if needed.
For example, a child may manage extremely well during the day but have difficulty walking in a straight line in the dark. It might be helpful for this child to have a night light in hallways in case they need to get up at night to prevent them bumping into doorways etc.
It is unlikely that a balance problem will prevent a child from doing normal childhood activities but it’s also important to know if there are any safety precautions to be aware of.
For example, making sure that children are closely supervised when swimming in case they become disorientated underwater, and giving children extra time and support when learning to ride a bike.