Enlarged vestibular aqueducts (EVA)

Doctors do not know exactly what causes EVA. It can happen on its own or as one part of a syndrome (a collection of symptoms which happen together). Around one-third of people with EVA and deafness have Pendred syndrome.

Children with EVA often also have an underdeveloped or differently shaped cochlea.

Children with sensorineural deafness may be offered a CT or MRI scan. These scans help doctors see if the vestibular aqueduct is enlarged or if there are any other differences inside the ear.

Order or download our free guide 'Understanding your child’s hearing tests' (Shopify) to learn more about CT scans, MRI scans and other medical tests used to help identify the cause of deafness.

Children with EVA have sensorineural deafness (hearing loss in the inner ear). Their deafness may:

• happen at birth or in the first few months or years of life
• be progressive (increases over time)
• fluctuate (goes up and down over time)
• change suddenly
• change after relatively minor head trauma (small hits to the head)

Children with EVA may also have conductive deafness (hearing loss in the middle ear).

EVA can also cause balance problems (known as vestibular dysfunction). Some children will feel dizzy, especially after bumping their head. Other children might find it harder to learn to balance, sit up and walk.

Find out more about balance.

Most children with EVA benefit from hearing aids. Your child should have regular hearing tests. Their hearing aids can be reprogrammed if there are any changes to the child’s hearing. If you notice a change in your child’s hearing levels in between appointments, ask your audiology service if your child can have a hearing test sooner than scheduled.

Glue ear is a very common childhood condition that can cause temporary conductive deafness. Children with EVA may also get glue ear which may make their level of deafness increase temporarily. It’s important that the audiologist takes this into account when programming your child’s hearing aids to make sure they’re not disadvantaged while they have glue ear.

Some children with severe or profound deafness who do not benefit from conventional hearing aids may benefit from cochlear implants.

Find out about hearing aids and implants.

Some children with EVA have sudden changes in their hearing levels. Their deafness may increase or decrease. This could happen on its own, or it could be caused by changes in intra-cranial pressure (pressure inside the head) which damage parts of the inner ear.

Intra-cranial pressure could be caused by:

• a knock to the head
• playing wind or brass instruments
• intense exercise
• changes in atmospheric pressure (such as flying in unpressurised aircraft)

All deaf children should be offered regular hearing tests. If you notice any changes in your child’s hearing levels in between appointments, ask your audiologist if you can get an earlier appointment.

Not all children with EVA have fluctuating or sudden changes in their hearing levels. Some children with EVA are not affected by bumps to the head. Others may have dizziness, tinnitus, or fluctuations in their hearing.

If your child has not had any problems caused by head injury, it's still a good idea to be cautious. Ultimately, you’ll only know if an accident will affect your child’s ears after it’s happened.

As a parent of a child with EVA, it can be difficult to make choices on behalf of your child. You may feel torn between wanting to protect them from knocks to the head or changes in pressure while also letting them take part in normal childhood activities.

We recommend avoiding activities where there is a high chance of being hit on the head or increased intra-cranial pressure. These activities include:

• contact sports such as kickboxing, boxing, ice hockey and rugby
• scuba diving
• go-karting and quad biking
• snowboarding
• rollercoasters and bumper cars
• weightlifting
• bungee jumping

It’s a good idea to wear the right protection in activities with a medium risk of being hit on the head, such as:

• football, netball, hockey and squash
• cycling
• horse-riding
• sailing
• gymnastics

Activities that are generally considered low-risk include:

• swimming
• snorkeling
• trampolining

If your child has problems with their balance, keep a close eye on them when they’re in or near to water.

As your child gets older and starts making decisions for themselves, it can be hard to find the balance between wanting to protect your child and encouraging their independence.

Telling a child or young person that they’re ‘not allowed’ to take part in an activity might keep them safe in the short term, but it does not encourage them to become responsible for their own safety.

• Encourage your child to take responsibility for their choices.
• Talk to your child about why they need to be careful, what might happen if they’re hit on the head, and how their life might change as a result.
• Make sure they understand the dangers of activities like riding a motorbike or taking part in contact sports.
• Help them weigh up risks and benefits.
• Help them plan how they can stay safe in different situations, for example by wearing head protection or avoiding crowded spaces.

Children and young people are more likely to be careful because they’ve made a conscious decision to keep themselves safe, rather than because they’re following their parents’ rules.

All deaf children are entitled to additional support at school. You may be referred to a Teacher of the Deaf (ToD) who can help you with lots of issues related to childhood deafness, such as communication, use of hearing aids and other technology, and choosing a school. They’re also responsible for making sure your child has the right support in place at school.

You may also be offered speech and language therapy.

Children with EVA might need extra support, such as:

• additional classroom support, such as a classroom assistant, to help them access the curriculum and avoid tumbles and knocks
• playground or lunchtime assistants to make sure they do not get hurt at break and lunchtimes
• an education, health and care plan (EHCP), individual education plan (IEP) or coordinated support plan (CSP)
• permission to leave lessons early to avoid getting knocked in crowded corridors

A personal passport or profile can be a useful way to explain your child's needs to teachers and activity leaders.