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Childhood hearing impairment
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Childhood hearing impairment
globally a better start in life and improve not just their development but their life chances.
How common is hearing impairment in the UK and worldwide?
Tamsin Holland Brown
Two in 1000 children in the UK have a permanent hearing loss. Approximately half (1 in 1000) will be picked up by the newborn hearing screen (mild hearing losses, auditory neuropathy and a narrow frequency loss affecting one or two isolated frequencies can be missed on newborn hearing screens). School hearing screening is currently inconsistently delivered around the UK. Where school entry screening programs exist, a further 1 in 10 children are found to have temporary hearing loss from glue ear, also known as Otitis Media with Effusion (OME), in which fluid builds up behind the ear drum during a cough/cold/ear infection. The World Health Organisation (WHO) reported in 2019 that 5% of the world population has a hearing impairment. This includes the 34 million children with, what WHO describe as, a ‘disabling hearing loss’ which is hearing impairment worse than 30 decibels (dB) in the better hearing ear. These numbers are likely to double by the year 2050. The WHO also report 1.1 billion young people are at risk of hearing loss due to noise exposure. 60% of worldwide hearing impairment is preventable and early identification is important to minimise the developmental, speech, language, social, and economic impact on the child’s life. Globally, fewer than 10% of those that require hearing aids have access to them. Emerging research has identified that a child’s hearing should be stimulated in both ears where possible (not just one ear, as previously thought) in order for the brain to develop functional auditory pathways. See Figure 1.
Abstract Hearing impairment is one of the most common disabilities in the UK and globally. Worldwide, 60% of cases are thought to be preventable and fewer than 10% globally have access to the hearing support they need. Childhood hearing impairment can impact on development, speech, language, auditory processing, listening skills, behaviour, self-esteem, quality of life and learning. Our responsibility as clinicians is to prevent developmental impairment in these areas and ensure children with a hearing impairment have the same life chances as children who hear well. There are 45,000 children in the UK diagnosed with a hearing impairment. Hearing impairment can be isolated or part of a more complex presentation. Visual, neurodevelopmental, balance and communication difficulties as well as safeguarding issues are more common in children with hearing impairment.
Keywords auditory neuropathy; conductive; deafness; hearing aid; hearing impairment; sensorineural; paediatric audiology; aetiology; cytomegalovirus; CMV; otitis media with effusion; OME; children hearing; newborn hearing screen; childhood hearing; mild hearing loss; moderate; severe hearing; balance; vestibular; development
Introduction Simple prevention, treatment and early hearing support is not yet universal in the UK or globally. 91% of the UK population do not know about cytomegalovirus (CMV) and therefore do not know about preventative measures that can be taken in pregnancy; not enough research is dedicated towards hearing loss prevention and early intervention; school hearing screening is patchy; and children with temporary hearing losses often do not have early access to hearing support. Deaf CAMHS (Deaf Child and Adolescent Mental Health Services) are underresourced and often absent from services. Vision services and ophthalmologists are making positive strides in eye health for children. The older population feel more comfortable going for an eye check-up than they do booking a routine hearing test. This is probably due to stigma and perceptions of old age. Hearing aids have considerably less acceptability than glasses. Unless we embrace and normalise routine hearing tests, and stop trying to hide hearing aids, this reluctance trickles down to children. Working together with eye services to offer joint screening could make this easier. If we address eye and hearing health, we can prevent the most common disabilities which would give more than 1 in 10 children
Common paediatric conditions Cleft palate, craniofacial conditions or skeletal dysplasia are associated with a high risk of conductive hearing losses. Syndromes such as Down syndrome have a high lifetime risk (up to 70%) of a hearing impairment (conductive, sensorineural or a mix of the two). For these conditions audiological follow up is life long and rapid access to services (such as speech and language therapists) is essential to maximise development. Hearing impairment can mimic other important developmental conditions. Hearing impairment should be considered before ADHD (Attention Deficit and Hyperactivity Disorder) or Autism diagnosis is made.
Diagnosis Hearing impairment is defined as hearing worse than 20 dB (or 15 dB in parts of America) in at least one ear. The World Health Organisation defines disabling hearing loss as “hearing loss greater than 30 dB in the better hearing ear in children”. The term mild hearing impairment, referring to hearing loss between 20 and 40 dB, is sometimes considered unhelpful as it does not communicate the potential impact on education, learning and quality of life. The National Deaf Children’s Society (www.ndcs. org.uk) have gathered experiences of young people with mild to moderate hearing loss. These indicate that “there is a bigger
Tamsin Holland Brown MBBS MRCPCH PGCME, Community Paediatrician, Department of Community Paediatrics, Brookfields Hospital, Cambridge, UK. Conflict of interest: Tamsin Brown is the author of the East of England guidelines for CMV management and creator of the Hear Glue Ear app.
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impact of mild/moderate hearing loss on family and education than generally recognised.”
Children with auditory processing difficulties can find it difficult to separate and filter the auditory information which their hearing system picks up. They can be easily distracted and uncertain about which noises to focus on. It can be harder to follow instructions and background noise is particularly challenging (one young patient described listening in background noise to be similar to trying to read through a scribble). The British Society of Audiology has valuable guidelines about auditory processing including diagnosis and supportive strategies. This includes ensuring visual support to spoken information or instructions; playing games with the child that focus on listening skills; using audiobooks or reading stories but supporting the child’s listening with repetition and questions to check they can follow the story. Interestingly everyone, with or without a hearing loss, has slightly different degrees of auditory processing especially when there is background noise. Auditory processing is sometimes raised as an educational difficulty or part of a more complex learning difficulty; in these cases it is sometimes described as an ‘auditory dyslexia’.
Types of hearing loss Acknowledging the type and degree of hearing loss can contribute towards an accurate diagnosis, and a more holistic approach to managing a child’s communication, development, quality of life, and access to learning. These are summarized in Table 1.
What’s the difference between auditory neuropathy and auditory processing disorder? Auditory neuropathy (AN) results in abnormal transfer of auditory information across the auditory pathways of the brain. It is often described very simply as being similar to listening to a poorly tuned radio. The nerves themselves are often damaged from neonatal insults e.g. hypoxic ischaemic encephalopathy (HIE) or significant hyperbilirubinaemia although there are also infectious, autoimmune or genetic aetiologies. One of the most common genetic condition is the otoferlin gene mutation. Progressive AN is seen in neurodegenerative diseases such as Freidreich’s Ataxia or Charcot-Marie-Tooth motor and sensory neuropathy. Auditory processing difficulties can be seen even when a child has normal hearing. Paediatric audiologists most often see children with auditory processing difficulties when a child has previously experienced a hearing loss early in life which then resolves. Examples would include glue ear self-resolving, or an operation to repair an ear drum. Children with significant brain injuries can sometimes find processing auditory information is slower than before their injury.
Embryology and pathogenesis The outer ear is derived from ectoderm from first and second pharyngeal (branchial) arches. It is designed to collect the correct frequencies for speech. As the mandible develops, the ears move into position on each side of the head for optimal localisation of sound. If cell migration of the ear or surrpunding structures is disrupted it can contribute to characteristic craniofacial features such as clefting of the lip/palate, micrognathia, atresia of the ear canal. Branchial arch conditions include PierreRobin sequence, hemifacial microsomia, Treacher-Collins and Stickler syndrome.
Figure 1 Prevalence of disabling hearing loss in children aged 0e14 years per world region (2011 estimates; threshold is 31 dB). Source: Duthey, D (2013) Background Paper 6.21 Hearing Loss; Update on 2004 Background Paper. WHO, Geneva.
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Types of hearing loss in children
Table 1 (continued )
Type of Definition hearing loss
Type of Definition hearing loss
How is the Common diagnosis made? examples of management
Sensorineural Damage to the inner ear cochlear and 8th cranial nerve.
Conductive
Mixed
Auditory neuropathy
Auditory processing
Poor otoacoustic emissions on neonatal hearing screen. Audiology assessment shows hearing loss during bone conduction testing. Peaked tympanometry traces. Sound waves Audiology impeded from assessment transfering from shows hearing the outer ear or loss when using ear drum or headphones (air across the middle conudction) but ear ossicles not when using bone conduction testing. Flat tympanometry traces. Both both inner and sensorineural middle ear (as and conductive above) loss 8th cranial nerve Abnormal, and linked nerve absent or pathways across distorted the brainstem are auditory unable to brainstem transfer a clear responses with auditory signal. A preserved loss of neural newborn synchrony. Often otoacoustic described as emissions (which trying to tune in can later an old-school disappear) and radio that has a preserved poor signal. cochlear microphonics. The brain has ‘Normal’ hearing cognitive test. Testing a difficulty range of hearing processing the skills such as gap sounds heard. detection tasks, dichotic paired listening and
frequency discrimination.
Hearing aids or cochlear implant
hearing support if needed.
Table 1
Abnormalities of pharyngeal cleft development result in cysts, pits or fistulas from the ear to the neck, along the boarder of the sternocleidomastoid muscle. Fistulae can extend to communicate with the mouth, and therefore can occasionally be seen to express saliva or can become infected.
History The key in taking an efficient history is to screen for risk factors for hearing loss (see Box 1), ask about balance (since this can be affected without being part of the inital presenting complaint) and identify genetic factors in a 3 generation family history. If the hearing loss is not picked up on the newborn hearing screen and the child is older, document the impact of the hearing loss on developmental skills, speech, language and communication. Since 2015 the British Society of Audiology has recommended that a child is asked about tinnitus where they are old enough. This is always an interesting question to ask, since many children who do have tinnitus assume it is part of life and rarely seem to mention it to their parents beforehand.
Grommets, Bone conduction hearing aids, surgical bone anchored hearing aid, middle ear implants
Reactions to a diagnosis of tinnitus Be prepared for parents to run a spectrum of reactions to reports of tinnitus in their child from surprise and dismay, to dismissing it and doubting it’s real. Continue with asking the child what it sounds like (some kids find it difficult to describe if it’s not the usual buzzing or ringing and prefer to draw their tinnitus. This makes for some abstract pictures and a pretty crazy looking pin board in your clinic room). Ask the child whether they hear it in one ear or both ears, whether it’s all the time or some of the time, whether it bothers them at school or at bedtime. Tinnitus can impact on concentration, fatigue and sometimes behaviour at school. Children may try to drown out tinnitus by singing or shouting in class which can lead to misdiagnosis. Alerting the school to a child’s tinnitus, including how exhausting it is for a child, how it can affect their psychological wellbeing and behaviour is helpful.
Hearing aids
Response to hearing aids is variable amongst patients. Cochlear implants can also give variable outcomes.
Commoner risk factors for hearing loss in children.
Strategies as described by the British Asscooaition of Audiologists (BSA). FM system
Exposure to noise Ototoxic medications Radiation or chemotherapy Acquired brain injury from trauma or meningitis Ear disease Incomplete immunisation status Bacterial or viral illnesses
(continued on next page)
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How is the Common diagnosis made? examples of management
Box 1
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Signs
Syndrome or condition
Note
Hearing aids Craniofacial structure
Not worn/working Dysmorphology
See examine hearing aids. Associated with conductive hearing loss
Palate
Cleft palate
Teeth
Conical, small or widely spaced teeth
Ears
Low set, cupped Accessory auricles
Otoscopy
Visual fields Hair
Dull tympanic membrane (TM). Fluid and/or mucus behind TM. Optic atrophy Mypoia Visual field loss White forelock
Consider safeguarding issues Treacher Collins, CHARGE syndrome, Goldenhar syndrome, hemifacial microsomia Pierre Robin sequence, van der Woude, 22q11.2 deletion, CHARGE, Stickler, Goldenhar, TreacherCollins, Kabuki and Down syndromes Ectodermal dysplasia, LAMM (Labyrinthine Aplasia, Microtia, Microdontia) and otodental dysplasia syndromes Brancho-oto-renal, Beckwith-Wiedemann (BWS), Smith-Lemli-Opitz, Rubinstein-Taybi syndromes. Trisomy 13 or 18 Isolated or part of Goldenhar, Treacher Collins syndromes Glue ear (OME) is common in children
Skin
Hyper or hypopigmentation
Nails Neck
Nail hypoplasia Webbing
Surface of Sternocleido-mastoid muscle Thyroid
Pits, sinus tracts, fistulae, remnants thyroglossal duct Signs of goitre
Cardiovascular
Murmurs or arrhythmias
Abdominal examination Neurological examination
Hepatospleno-megaly
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OPA1, Leber’s Optic Neuropathy, Myopia in Sticklers syndrome Ushers syndrome Waardenburg syndrome although rarely presents with ‘text book’ whiteforelock. Heterochromia/v. pale blue eyes often present Ectodermal dysplasia (ED), Waardenburg or Kallman syndromes ED syndromes Turners (TS) and Klippel-Feil syndrome. Chronic ear infections, OME and conductive hearing loss occurs in 80% of children with Turners syndrome. SN loss in older children. Branchial arch syndromes (disruptions of the embryonic development usually of the first 2 brachial arches); Branchio-oto-renal syndrome Pendred syndrome (progressive hearing loss and thyroid conditions) CHARGE associated with deafness and recurrent OME. Some long QT syndromes associated with deafness Mucopolysaccahridoses (MPS)
Children with cleft palate are more likely to have recurring and prolonged episodes of glue ear. Early referral to a paediatric dentist recommended
BWS associated with conductive hearing loss Often confused with skin tags or branchial cysts
Exclude cholesteatoma by careful examination. Often malodourous. Leber’s optic neuropathy is associated with AN.
Look for other changes to pigmentation in the hair, skin or eyes. ED’s affect nails, teeth, hair, skin and hearing Over 100 types of ED. Sensorineural or conductive or mixed deafness is a feature of Klippel-Feil syndrome.
Test hearing in children with preauricular pits. Consider renal tests Goitre likely to form in late childhood or adulthood Long QT syndrome is associated with ventricular tachycardia MPS associated with progressive hearing loss
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Important signs to be looked for on examination of child with hearing impairment
Asking about balance problems The history of balance difficulties are elicited mostly with questions about recreation: Park/playground activities. Does the child avoid the swings or the roundabout (fear of imbalance) or are they overly obsessed with them? Riding a bike: Most children can ride a bike by the age of 5 years and if they are finding it difficult it could be part of a vestibular picture. Frequent falls. Although all children fall over, this improves rapidly after infancy. School or nursery may report concern. Swimming. If vestibular function is affected, the child relies more heavily on vision and proprioception to know which way is up and where they are in space. A child can fear swimming because they often have to close their eyes and the water gives reduced proprioceptive feedback, thus swimming can be disorientating or frightening. Children can fear swimming or putting their head underwater.
Conductive and sensorineural hearing loss
Assessment needed to understand impact of hearing loss Congenital CMV can lead to hearing loss after birth.
See the British Society of Audiology, Tinnitus in Children, Practice guidance 2015 for further reading.
AN in Friedreich’s ataxia and Hereditary Motor Sensory neuropathies (HMSN). HSMN Usher, Pendred, CHARGE, Waardenburg, brachio-otorenal syndromes Developmental delay common particularly if hearing impairment has been undetected and untreated Congenital CMV syndrome. Hydrocephalus and auditory neuropathy Skeletal dysplasia’s
Gene tests available for the > 50 different HMSN types including Charcot Marie Tooth. Difficult to detect balance difficulties clinically.
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Other ‘routine’ aspects of the history pertinent to hearing loss Consanguinity and ethnicity Pregnancy: such as maternal alcohol intake, gestational diabetes, ototoxic medications Birth history: such as low birthweight or episodes of hypoxia Postnatal period: did the child go to the NICU, require ventilation, receive ototoxic medication such as gentamicin. Jaundice at the level of requiring a blood transfusion could also be significant.
Examination
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Examination of hearing aids This is really important to include in your examination because if you are trying to work out if a child’s development is that expected of an aided child but the child is not wearing aids or not wearing working aids most of the time then you could be misled about progress. Document whether the child is wearing hearing aids. Ask the family to take out the hearing aid and give it to you. Is the hearing aid on? You can check this by cupping the hearing aid inside both of your hands and see if the aid whistles due to feedback. Open the battery compartment to check the battery. Check the clear plastic tubing that links the aid to the ear mould, is it blocked or dirty? Has the child outgrown the ear mould? The ear’s relationship with the kidney The ear has a special relationship with the kidney. Many syndromes involve both organs; such as branchio-oto-renal syndrome (now better known as brachiootorenal spectrum disorders), CHARGE and diabetic embryopathy. The ear and the kidneys develop in the embryo at a similar time meaning early
Table 2
Microcephaly Macrocephaly Growth concerns Head circumference
Height and weight
Developmental delay Developmental assessment
Ataxia. Loss of ankle reflexes Peripheral neuropathy Balance problems
The important features to look for upon clinical examination are summarized in Table 2. In addition it is important to carefully examine the hearing aids of any child who has them. A structure for this is given below.
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insults can affect both. Additionally early multi-site proteins expressed before birth regulate the activity of genes involved embryonic development of both organs. While ear malformations are associated with an increase in renal anomalies, there is some controversy about whether to screen for renal anomalies when only minor ear anomalies are identified (the most common ear anomaly being a preauricular skin tag). Some papers suggest a renal ultrasound is indicated with any ear anomalies and other papers only recommend renal scans when an ear anomaly is seen in association with at least one other dysmorphic feature or a significant family history of kidney/hearing problems or a maternal history of gestational diabetes.
The multidisciplinary team caring for a child born in the UK with hearing impairment. Hearing screeners first screen a newborn babies hearing with an otoacoustic emission (OAE) and are the first professionals to explain hearing concerns to a parent. In some regions the screeners work closely as part of the multidisciplinary team to help to take early CMV swabs if needed and provide the first parent information verbally and with handouts. Audiologists advise on early aiding with appropriate fitting and appropriately amplified hearing aids, or fast tracking to a cochlear implant service. ENT surgeons and cochlear implant service: The cochlear implant criteria changed in the UK in 2019 allowing more children to qualify for the operation. Previously children had to be deaf with hearing worse than 95 dB at 2 and 4khz, but since 2019 children with hearing worse than 80 dB HL at 2 or more frequencies, can access bilateral cochlear implants. General paediatricians and/or Neonatologists manage early syndromes requiring treatment such as CMV, other congenital infections, jaundice reaching blood transfusion levels, prematurity. Community Paediatricians search for and manage associated syndromes and developmental concerns. The child may need additional educational support with an Educational Health Care Plan. Ophthalmologists report on syndrome-related changes and can contribute towards identifying the aetiology of hearing loss and dual management of any deaf-blind conditions (e.g. Usher syndrome). Geneticists are now crucial since the millennial genomics explosion. Individual gene tests (e.g. connexin 26 for bilateral hearing loss) are now giving way to gene panels with sets of genetic tests. Audiovestibular physicians will not only aid with aetiology but will be skilled at formal balance testing and rehabilitation. Virologists/pathologists are important in the management pathway of early CMV testing and management as well as other congenital infections. Pharmacists: The only childhood pharmaceutical treatment currently for hearing impairment is intravenous gancyclovir or oral valgancyclovir for the treatment of cytomegalovirus (CMV) and further research is being carried out about the most effective management for congenital CMV. Teachers of the deaf, TOD’s (also known as sensory need teachers) are valuable for working with the family on early communication, use of hearing aids, managing school entry and addressing the needs of the school environment. Speech and language therapists (SaLT’s) are essential for advising about whether speech difficulties are related to hearing loss or a more structural concern such as cleft palate. Although the TOD’s are often the first professional working with the family around early communication, the SaLT’s are essential to management of early speech, language, advice and educational placement. Charities are an important source of support, information and advice for families. The National Deaf Children’s Society (NDCS) for example is a trusted source of information and advice. They also offer courses for families and activity days or camps for deaf children and their siblings. CMVaction for example , raises awareness of CMV prevention and management, CLAPA for cleft palate, and LPUK for those with skeletal dysplasias.
Viral infections and hearing loss Measles, Mumps and Rubella may cause acquired hearing loss or congenital hearing loss and all three are preventable by vaccination. Viral infections causing deafness are not always due to an encephalitis but haematogenous spread of the virus in the blood stream seems to be able to affect the cochlear. Cytomegalovirus infection early in pregnancy can affect a fetus in variable ways from asymptomatic to severe multi organ involvement. The asymptomatic newborns are at risk of developing a hearing loss at a later date and the newborns already showing a mild or unilateral hearing loss are at risk of their hearing deteriorating further. Many national and international guidelines recommend that babies born with hearing loss should be investigated early for CMV. A positive saliva or urine sample taken within the first 3 weeks of life more confidently suggests congenital CMV than samples taken later than this. A positive CMV sample can trigger an examination for other CMV related signs (microcephaly, low birth weight, jaundice, rash, splenomegaly) investigations (such as cranial imaging, blood tests and ophthalmology referral) and consideration of treatment which may include antiviral therapy (usually valganciclovir syrup where the baby is otherwise well). Pregnant women can reduce their chances of catching a primary CMV infection by washing their hands regularly and not sharing cutlery, cups, food and direct mouth kisses with toddlers and young children who are at their prime of acquiring and sharing many viruses including CMV.
Investigations Initial investigations are common to most types of sensorineural hearing loss and include family audiograms, an ophthalmology assessment, imaging of internal auditory meati, urinalysis for microscopic haematuria, testing for congenital cytomegalovirus and considering a genetics referral. Audiology: Investigations include early identification of the type of hearing loss for the patient (see the British Society of Audiology, website or NDCS website about types of hearing tests depending on the age of the child). Family audiograms (parents and siblings) are important for all cases of childhood hearing loss and can help to identify a pattern of inheritance. Imaging of the internal auditory meati: MRI is helpful to identify structural anomalies of the cochlear, vestibular system, vestibular aqueduct, audiovestibular nerve and brain.
Box 2
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ENT referral: ENT surgeons are often involved in the imaging decisions, discussions around cochlear implantation, examination of the ear and neck and discussions about further investigations. Eyesight: All children with a permanent hearing impairment should have their vision checked, as just under half of children with deafness have an eyesight diagnosis too. Not only is it important to optimise all the senses for development, but ophthalmologists contribute to diagnoses such as Sticklers syndrome, CMV and Ushers syndrome. CMV status: Many hospitals are performing targeted investigations as early as they can for congenital CMV since the diagnosis is much more certain if a sample (saliva or urine) is positive within the first 3 weeks of life, allowing treatment to be started promptly. A CMV pathway enables a paediatrician to work closely with their virology colleagues which only improves life. Balance: Bedside tests are based on removing visual and proprioceptive input (that the child may be relying on) to get a feel of underlying vestibular function. An audiovestibular clinican or vestibular assessment within an audiology service can investigate balance further for example with rotational chair testing, VEMP’s amd bithermal calorics depending on the age of the child. Urinalysis: Microscopic haematuria is seen in patients with Alport’s syndrome. Proteinuria can identify renal disease and is useful to check where there is an identified family history of renal disease. A renal ultrasound scan can be requested if there is an indication or suspicion of a wider condition such as Branchio-Oto-Renal (BOR) syndrome. ECG: is recommended in cases of severe or profound hearing loss to exclude long QT syndrome. Further investigations depend on clinical findings and include thyroid function tests, renal ultrasound scan, autoimmume disease screen, serology for congenital infection, metabolic screens.
technology improves year on year. Since many hearing losses are associated with some vestibular involvement (such as widened vestibular aqueduct or congenital CMV) a discussion about balance being affected (which is turn can affect motor milestones) can be one of the most important discussions with the family. Children compensate quickly for balance difficulties, they learn to use their eyesight and proprioception so well that balance difficulties can be almost impossible to elicit clinically on ‘bedside testing’ by the age of 10 years. Note that conditions such as CMV can cause progressive vestibular deterioration, often within the first 4 years of life, which is unrelated to the severity of the hearing loss. Vestibular involvement can lead to difficulties with dynamic visual function. This is important functionally for a child. The child may have normal visual function when both the child and the image is still, but due to the vestibulo-ocular reflex being affected, the child can struggle with visual stabilization and will not be able to see properly if the child or the image is moving. This can affect a child’s reading ability and confidence with motor skills. Children will need to sit at a table with good lighting to read, and school will need to be aware of these difficulties. What is poor dynamic visual function like? Try reading a message on your mobile phone when you are gently nodding your head up and down. Although not ideal, you will still be able to read the message. Now try reading the message on your mobile phone keeping your head still but this time move the mobile phone up and down in front of you. That is what it is like for children who have poor dynamic visual function. See Box 3.
Prevention of disease and disabilities Prevention of hearing impairment The WHO identified that public health measures such as vaccination, improved maternity care, improved hearing screening, improved medicines, improved education of safe listening, could prevent at least half of all cases of worldwide hearing impairment. CMV Action are a charity raising awareness in the UK about CMV related hearing loss and neurodisability. The research around CMV is exciting at the moment and is guiding clinicians about better prevention, identification and treatment of CMV.
Management In addition to the parents, a great multidisciplinary team is essential for good management. Some of the professionals involved in the delivery of care in the UK are summarized in Box 2.
Reduction in disability Early identification of hearing loss is crucial and has led to digital innovation to solve this problem. The WHO and other non-governmental organisations have funded smart phone/tablet applications to aid hearing screening at home or in rural settings. The free WHO hearing screening app is called HearWHO. The Cambridge Hearing Trust created the free Hear Glue Ear app for children (targeting the 10% of school aged children who have glue ear). Others include Shoebox audiometry and HearX in the UK. The aim is for hearing screening to be easily available. The developmental problems resulting from hearing loss include speech and language delay; auditory processing difficulties; social communication difficulties; listening and attentional difficulties; poorer quality of life; behaviour problems. Prevention of developmental difficulties is best addressed with
Prognosis and explanation to patient The aim of professionals is to provide a deaf child with the same life chances as a child with ‘normal’ hearing. Hearing aids
Problems arising from impaired vestibular function. Children can be later to learn to ride a bike. Children can be delayed developing gross motor skills such as walking. Children might be more afraid of swimming and playground activities and importantly will need more supervision. A swimming buddy is always recommended even if the child compensates well. If the child is underwater with their eyes shut, then proprioceptive and visual cues have been removed and the child may struggle to identify which way is up. Box 3
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hearing support while awaiting definitive operations or resolution. With so few of the world’s population receiving affordable hearing aids, digital innovation is trying to solve these problems. The telecommunications industry is adapting to provide solutions. Some mobile phone solutions can offer customers a hearing test over the phone, followed by amplification of the frequencies needed for that individual to access good communication by telephone.
clinical guideline commissioned by the. London, England: National Institute for Health and Clinical Excellence, 2008. National Institute for Health and Clinical Excellence. Cochlear implants for children and adults with severe to profound deafness’ Technology appraisal guidance [TA566], 2019. Published date: 07 March 2019. Olusanya B, Neumann K, Saunders J. The Global burden of disabling hearing impairment : a call to action. Policy & Practoce. Bull World Health Organ May 2014; 92. https://doi.org/10.2471/BLT.13. 128728. Pagarkar W, Shetye A, British Association of Audiovestibular Physicians. Guidelines for aetiological investigation into mild to moderate bilateral permanent hearing impairment. April 2015. 2015, www. baap.org.uk. Pagarkar W, Shetye A, British Association of Audiovestibular Physicians. Guidelines for aetiological investigation into severe to profound bilateral permanent hearing impairment. April 2015. 2015, www.baap.org.uk. Pagarkar W, British Association of Audiovestibular Physicians. Guidelines for aetiological investigation into progressive permanent hearing impairment. Jan 2018. 2018, www.baap.org.uk. Shetye A, Pagarkar W, British Association of Audiovestibular Physicians. Guidleines for aetiological investigation into unilateral permanent childhood hearing impairment April 2015. 2015, www. baap.org.uk. Walston F, McDevitt K, Walter S, Luck S, Holland Brown T. East of England clinical guideline: diagnosis and management of congenital cytomegalovirus, March 2018.
Conclusions Hearing loss is one of the most common disabilities worldwide that contributes to poor education, poor employment and poverty, but the solutions available are not affordable for lower income countries. In the developed world, newborn screening programmes will only identify half of children with permanent hearing impairment and many more children will experience temporary hearing losses as a result of conditions such as OME (glue ear). By being aware of hearing impairment and alert to its aetiologies, clinicians can make a difference to the education, communication and life time trajectories of millions of children. Patients need cost effective accessible hearing tests. We need to support hearing loss early with affordable solutions. A FURTHER READING Austen’s ME, Akre H, Overland B, Abdelnoor M, Falkenberg ES, Kvaerner KJ. Otitis media with effusion in children with Down syndrome. Int J Pediatr Otorhinolaryngol 2013; 77: 1329e32. https://doi.org/10.1016/j.ijporl.2013.05.027. Chadha S, Cieza A, Kring E. Global hearing health: future directions. Bull World Health Organ 2018; 96: 146. https://doi.org/10.2471/ BLT.18.209767. Harrop-Griffiths K, Pagarkar W, Mac Ardle B, British Association of Audiovestibular Physicians. Guidelines for aetiological investigation into auditory neuropathy spectrum disorder in children and young adults. July 2018, www.baap.org.uk. Kentish R, Benton C, Kennedy V, et al. Paediatric Audiology Interest Group. Paediatric tinnitus working group of the British society of audiology. ‘Tinnitus in children’ Practice guidance. 2015, www. thebsa.org.uk. Alles R, Bambiou D, Batchelor L, et al. The British society of audiology (BSA) position statement and Practice guidance ‘auditory processing disorder’ (APD). April 2017, www.thebsa.org. National Collaborating Centre for Women’s and Children’s Health. Surgical management of otitis media with effusion in children:
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Practice points C
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Permanent hearing impairment is relatively common, affecting about 1 in 1000 children born in the UK. Only half of these will be detected by the newborn screening programme. Temporary hearing loss from otitis media with effusion is common, affecting about 10% of younger children in their first year at school. Tinnitus is only rarely reported unless children are specifically asked about this symptom. Children with permanent hearing impairment often have vestibular dysfunction which is difficult to detect clinically and if left untreated can hamper a child’s developmental progress.
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Childhood hearing impairment
globally a better start in life and improve not just their development but their life chances.
How common is hearing impairment in the UK and worldwide?
Tamsin Holland Brown
Two in 1000 children in the UK have a permanent hearing loss. Approximately half (1 in 1000) will be picked up by the newborn hearing screen (mild hearing losses, auditory neuropathy and a narrow frequency loss affecting one or two isolated frequencies can be missed on newborn hearing screens). School hearing screening is currently inconsistently delivered around the UK. Where school entry screening programs exist, a further 1 in 10 children are found to have temporary hearing loss from glue ear, also known as Otitis Media with Effusion (OME), in which fluid builds up behind the ear drum during a cough/cold/ear infection. The World Health Organisation (WHO) reported in 2019 that 5% of the world population has a hearing impairment. This includes the 34 million children with, what WHO describe as, a ‘disabling hearing loss’ which is hearing impairment worse than 30 decibels (dB) in the better hearing ear. These numbers are likely to double by the year 2050. The WHO also report 1.1 billion young people are at risk of hearing loss due to noise exposure. 60% of worldwide hearing impairment is preventable and early identification is important to minimise the developmental, speech, language, social, and economic impact on the child’s life. Globally, fewer than 10% of those that require hearing aids have access to them. Emerging research has identified that a child’s hearing should be stimulated in both ears where possible (not just one ear, as previously thought) in order for the brain to develop functional auditory pathways. See Figure 1.
Abstract Hearing impairment is one of the most common disabilities in the UK and globally. Worldwide, 60% of cases are thought to be preventable and fewer than 10% globally have access to the hearing support they need. Childhood hearing impairment can impact on development, speech, language, auditory processing, listening skills, behaviour, self-esteem, quality of life and learning. Our responsibility as clinicians is to prevent developmental impairment in these areas and ensure children with a hearing impairment have the same life chances as children who hear well. There are 45,000 children in the UK diagnosed with a hearing impairment. Hearing impairment can be isolated or part of a more complex presentation. Visual, neurodevelopmental, balance and communication difficulties as well as safeguarding issues are more common in children with hearing impairment.
Keywords auditory neuropathy; conductive; deafness; hearing aid; hearing impairment; sensorineural; paediatric audiology; aetiology; cytomegalovirus; CMV; otitis media with effusion; OME; children hearing; newborn hearing screen; childhood hearing; mild hearing loss; moderate; severe hearing; balance; vestibular; development
Introduction Simple prevention, treatment and early hearing support is not yet universal in the UK or globally. 91% of the UK population do not know about cytomegalovirus (CMV) and therefore do not know about preventative measures that can be taken in pregnancy; not enough research is dedicated towards hearing loss prevention and early intervention; school hearing screening is patchy; and children with temporary hearing losses often do not have early access to hearing support. Deaf CAMHS (Deaf Child and Adolescent Mental Health Services) are underresourced and often absent from services. Vision services and ophthalmologists are making positive strides in eye health for children. The older population feel more comfortable going for an eye check-up than they do booking a routine hearing test. This is probably due to stigma and perceptions of old age. Hearing aids have considerably less acceptability than glasses. Unless we embrace and normalise routine hearing tests, and stop trying to hide hearing aids, this reluctance trickles down to children. Working together with eye services to offer joint screening could make this easier. If we address eye and hearing health, we can prevent the most common disabilities which would give more than 1 in 10 children
Common paediatric conditions Cleft palate, craniofacial conditions or skeletal dysplasia are associated with a high risk of conductive hearing losses. Syndromes such as Down syndrome have a high lifetime risk (up to 70%) of a hearing impairment (conductive, sensorineural or a mix of the two). For these conditions audiological follow up is life long and rapid access to services (such as speech and language therapists) is essential to maximise development. Hearing impairment can mimic other important developmental conditions. Hearing impairment should be considered before ADHD (Attention Deficit and Hyperactivity Disorder) or Autism diagnosis is made.
Diagnosis Hearing impairment is defined as hearing worse than 20 dB (or 15 dB in parts of America) in at least one ear. The World Health Organisation defines disabling hearing loss as “hearing loss greater than 30 dB in the better hearing ear in children”. The term mild hearing impairment, referring to hearing loss between 20 and 40 dB, is sometimes considered unhelpful as it does not communicate the potential impact on education, learning and quality of life. The National Deaf Children’s Society (www.ndcs. org.uk) have gathered experiences of young people with mild to moderate hearing loss. These indicate that “there is a bigger
Tamsin Holland Brown MBBS MRCPCH PGCME, Community Paediatrician, Department of Community Paediatrics, Brookfields Hospital, Cambridge, UK. Conflict of interest: Tamsin Brown is the author of the East of England guidelines for CMV management and creator of the Hear Glue Ear app.
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SYMPOSIUM: EYES AND ENT
impact of mild/moderate hearing loss on family and education than generally recognised.”
Children with auditory processing difficulties can find it difficult to separate and filter the auditory information which their hearing system picks up. They can be easily distracted and uncertain about which noises to focus on. It can be harder to follow instructions and background noise is particularly challenging (one young patient described listening in background noise to be similar to trying to read through a scribble). The British Society of Audiology has valuable guidelines about auditory processing including diagnosis and supportive strategies. This includes ensuring visual support to spoken information or instructions; playing games with the child that focus on listening skills; using audiobooks or reading stories but supporting the child’s listening with repetition and questions to check they can follow the story. Interestingly everyone, with or without a hearing loss, has slightly different degrees of auditory processing especially when there is background noise. Auditory processing is sometimes raised as an educational difficulty or part of a more complex learning difficulty; in these cases it is sometimes described as an ‘auditory dyslexia’.
Types of hearing loss Acknowledging the type and degree of hearing loss can contribute towards an accurate diagnosis, and a more holistic approach to managing a child’s communication, development, quality of life, and access to learning. These are summarized in Table 1.
What’s the difference between auditory neuropathy and auditory processing disorder? Auditory neuropathy (AN) results in abnormal transfer of auditory information across the auditory pathways of the brain. It is often described very simply as being similar to listening to a poorly tuned radio. The nerves themselves are often damaged from neonatal insults e.g. hypoxic ischaemic encephalopathy (HIE) or significant hyperbilirubinaemia although there are also infectious, autoimmune or genetic aetiologies. One of the most common genetic condition is the otoferlin gene mutation. Progressive AN is seen in neurodegenerative diseases such as Freidreich’s Ataxia or Charcot-Marie-Tooth motor and sensory neuropathy. Auditory processing difficulties can be seen even when a child has normal hearing. Paediatric audiologists most often see children with auditory processing difficulties when a child has previously experienced a hearing loss early in life which then resolves. Examples would include glue ear self-resolving, or an operation to repair an ear drum. Children with significant brain injuries can sometimes find processing auditory information is slower than before their injury.
Embryology and pathogenesis The outer ear is derived from ectoderm from first and second pharyngeal (branchial) arches. It is designed to collect the correct frequencies for speech. As the mandible develops, the ears move into position on each side of the head for optimal localisation of sound. If cell migration of the ear or surrpunding structures is disrupted it can contribute to characteristic craniofacial features such as clefting of the lip/palate, micrognathia, atresia of the ear canal. Branchial arch conditions include PierreRobin sequence, hemifacial microsomia, Treacher-Collins and Stickler syndrome.
Figure 1 Prevalence of disabling hearing loss in children aged 0e14 years per world region (2011 estimates; threshold is 31 dB). Source: Duthey, D (2013) Background Paper 6.21 Hearing Loss; Update on 2004 Background Paper. WHO, Geneva.
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SYMPOSIUM: EYES AND ENT
Types of hearing loss in children
Table 1 (continued )
Type of Definition hearing loss
Type of Definition hearing loss
How is the Common diagnosis made? examples of management
Sensorineural Damage to the inner ear cochlear and 8th cranial nerve.
Conductive
Mixed
Auditory neuropathy
Auditory processing
Poor otoacoustic emissions on neonatal hearing screen. Audiology assessment shows hearing loss during bone conduction testing. Peaked tympanometry traces. Sound waves Audiology impeded from assessment transfering from shows hearing the outer ear or loss when using ear drum or headphones (air across the middle conudction) but ear ossicles not when using bone conduction testing. Flat tympanometry traces. Both both inner and sensorineural middle ear (as and conductive above) loss 8th cranial nerve Abnormal, and linked nerve absent or pathways across distorted the brainstem are auditory unable to brainstem transfer a clear responses with auditory signal. A preserved loss of neural newborn synchrony. Often otoacoustic described as emissions (which trying to tune in can later an old-school disappear) and radio that has a preserved poor signal. cochlear microphonics. The brain has ‘Normal’ hearing cognitive test. Testing a difficulty range of hearing processing the skills such as gap sounds heard. detection tasks, dichotic paired listening and
frequency discrimination.
Hearing aids or cochlear implant
hearing support if needed.
Table 1
Abnormalities of pharyngeal cleft development result in cysts, pits or fistulas from the ear to the neck, along the boarder of the sternocleidomastoid muscle. Fistulae can extend to communicate with the mouth, and therefore can occasionally be seen to express saliva or can become infected.
History The key in taking an efficient history is to screen for risk factors for hearing loss (see Box 1), ask about balance (since this can be affected without being part of the inital presenting complaint) and identify genetic factors in a 3 generation family history. If the hearing loss is not picked up on the newborn hearing screen and the child is older, document the impact of the hearing loss on developmental skills, speech, language and communication. Since 2015 the British Society of Audiology has recommended that a child is asked about tinnitus where they are old enough. This is always an interesting question to ask, since many children who do have tinnitus assume it is part of life and rarely seem to mention it to their parents beforehand.
Grommets, Bone conduction hearing aids, surgical bone anchored hearing aid, middle ear implants
Reactions to a diagnosis of tinnitus Be prepared for parents to run a spectrum of reactions to reports of tinnitus in their child from surprise and dismay, to dismissing it and doubting it’s real. Continue with asking the child what it sounds like (some kids find it difficult to describe if it’s not the usual buzzing or ringing and prefer to draw their tinnitus. This makes for some abstract pictures and a pretty crazy looking pin board in your clinic room). Ask the child whether they hear it in one ear or both ears, whether it’s all the time or some of the time, whether it bothers them at school or at bedtime. Tinnitus can impact on concentration, fatigue and sometimes behaviour at school. Children may try to drown out tinnitus by singing or shouting in class which can lead to misdiagnosis. Alerting the school to a child’s tinnitus, including how exhausting it is for a child, how it can affect their psychological wellbeing and behaviour is helpful.
Hearing aids
Response to hearing aids is variable amongst patients. Cochlear implants can also give variable outcomes.
Commoner risk factors for hearing loss in children.
Strategies as described by the British Asscooaition of Audiologists (BSA). FM system
Exposure to noise Ototoxic medications Radiation or chemotherapy Acquired brain injury from trauma or meningitis Ear disease Incomplete immunisation status Bacterial or viral illnesses
(continued on next page)
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How is the Common diagnosis made? examples of management
Box 1
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Signs
Syndrome or condition
Note
Hearing aids Craniofacial structure
Not worn/working Dysmorphology
See examine hearing aids. Associated with conductive hearing loss
Palate
Cleft palate
Teeth
Conical, small or widely spaced teeth
Ears
Low set, cupped Accessory auricles
Otoscopy
Visual fields Hair
Dull tympanic membrane (TM). Fluid and/or mucus behind TM. Optic atrophy Mypoia Visual field loss White forelock
Consider safeguarding issues Treacher Collins, CHARGE syndrome, Goldenhar syndrome, hemifacial microsomia Pierre Robin sequence, van der Woude, 22q11.2 deletion, CHARGE, Stickler, Goldenhar, TreacherCollins, Kabuki and Down syndromes Ectodermal dysplasia, LAMM (Labyrinthine Aplasia, Microtia, Microdontia) and otodental dysplasia syndromes Brancho-oto-renal, Beckwith-Wiedemann (BWS), Smith-Lemli-Opitz, Rubinstein-Taybi syndromes. Trisomy 13 or 18 Isolated or part of Goldenhar, Treacher Collins syndromes Glue ear (OME) is common in children
Skin
Hyper or hypopigmentation
Nails Neck
Nail hypoplasia Webbing
Surface of Sternocleido-mastoid muscle Thyroid
Pits, sinus tracts, fistulae, remnants thyroglossal duct Signs of goitre
Cardiovascular
Murmurs or arrhythmias
Abdominal examination Neurological examination
Hepatospleno-megaly
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OPA1, Leber’s Optic Neuropathy, Myopia in Sticklers syndrome Ushers syndrome Waardenburg syndrome although rarely presents with ‘text book’ whiteforelock. Heterochromia/v. pale blue eyes often present Ectodermal dysplasia (ED), Waardenburg or Kallman syndromes ED syndromes Turners (TS) and Klippel-Feil syndrome. Chronic ear infections, OME and conductive hearing loss occurs in 80% of children with Turners syndrome. SN loss in older children. Branchial arch syndromes (disruptions of the embryonic development usually of the first 2 brachial arches); Branchio-oto-renal syndrome Pendred syndrome (progressive hearing loss and thyroid conditions) CHARGE associated with deafness and recurrent OME. Some long QT syndromes associated with deafness Mucopolysaccahridoses (MPS)
Children with cleft palate are more likely to have recurring and prolonged episodes of glue ear. Early referral to a paediatric dentist recommended
BWS associated with conductive hearing loss Often confused with skin tags or branchial cysts
Exclude cholesteatoma by careful examination. Often malodourous. Leber’s optic neuropathy is associated with AN.
Look for other changes to pigmentation in the hair, skin or eyes. ED’s affect nails, teeth, hair, skin and hearing Over 100 types of ED. Sensorineural or conductive or mixed deafness is a feature of Klippel-Feil syndrome.
Test hearing in children with preauricular pits. Consider renal tests Goitre likely to form in late childhood or adulthood Long QT syndrome is associated with ventricular tachycardia MPS associated with progressive hearing loss
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Important signs to be looked for on examination of child with hearing impairment
Asking about balance problems The history of balance difficulties are elicited mostly with questions about recreation: Park/playground activities. Does the child avoid the swings or the roundabout (fear of imbalance) or are they overly obsessed with them? Riding a bike: Most children can ride a bike by the age of 5 years and if they are finding it difficult it could be part of a vestibular picture. Frequent falls. Although all children fall over, this improves rapidly after infancy. School or nursery may report concern. Swimming. If vestibular function is affected, the child relies more heavily on vision and proprioception to know which way is up and where they are in space. A child can fear swimming because they often have to close their eyes and the water gives reduced proprioceptive feedback, thus swimming can be disorientating or frightening. Children can fear swimming or putting their head underwater.
Conductive and sensorineural hearing loss
Assessment needed to understand impact of hearing loss Congenital CMV can lead to hearing loss after birth.
See the British Society of Audiology, Tinnitus in Children, Practice guidance 2015 for further reading.
AN in Friedreich’s ataxia and Hereditary Motor Sensory neuropathies (HMSN). HSMN Usher, Pendred, CHARGE, Waardenburg, brachio-otorenal syndromes Developmental delay common particularly if hearing impairment has been undetected and untreated Congenital CMV syndrome. Hydrocephalus and auditory neuropathy Skeletal dysplasia’s
Gene tests available for the > 50 different HMSN types including Charcot Marie Tooth. Difficult to detect balance difficulties clinically.
SYMPOSIUM: EYES AND ENT
Other ‘routine’ aspects of the history pertinent to hearing loss Consanguinity and ethnicity Pregnancy: such as maternal alcohol intake, gestational diabetes, ototoxic medications Birth history: such as low birthweight or episodes of hypoxia Postnatal period: did the child go to the NICU, require ventilation, receive ototoxic medication such as gentamicin. Jaundice at the level of requiring a blood transfusion could also be significant.
Examination
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Examination of hearing aids This is really important to include in your examination because if you are trying to work out if a child’s development is that expected of an aided child but the child is not wearing aids or not wearing working aids most of the time then you could be misled about progress. Document whether the child is wearing hearing aids. Ask the family to take out the hearing aid and give it to you. Is the hearing aid on? You can check this by cupping the hearing aid inside both of your hands and see if the aid whistles due to feedback. Open the battery compartment to check the battery. Check the clear plastic tubing that links the aid to the ear mould, is it blocked or dirty? Has the child outgrown the ear mould? The ear’s relationship with the kidney The ear has a special relationship with the kidney. Many syndromes involve both organs; such as branchio-oto-renal syndrome (now better known as brachiootorenal spectrum disorders), CHARGE and diabetic embryopathy. The ear and the kidneys develop in the embryo at a similar time meaning early
Table 2
Microcephaly Macrocephaly Growth concerns Head circumference
Height and weight
Developmental delay Developmental assessment
Ataxia. Loss of ankle reflexes Peripheral neuropathy Balance problems
The important features to look for upon clinical examination are summarized in Table 2. In addition it is important to carefully examine the hearing aids of any child who has them. A structure for this is given below.
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SYMPOSIUM: EYES AND ENT
insults can affect both. Additionally early multi-site proteins expressed before birth regulate the activity of genes involved embryonic development of both organs. While ear malformations are associated with an increase in renal anomalies, there is some controversy about whether to screen for renal anomalies when only minor ear anomalies are identified (the most common ear anomaly being a preauricular skin tag). Some papers suggest a renal ultrasound is indicated with any ear anomalies and other papers only recommend renal scans when an ear anomaly is seen in association with at least one other dysmorphic feature or a significant family history of kidney/hearing problems or a maternal history of gestational diabetes.
The multidisciplinary team caring for a child born in the UK with hearing impairment. Hearing screeners first screen a newborn babies hearing with an otoacoustic emission (OAE) and are the first professionals to explain hearing concerns to a parent. In some regions the screeners work closely as part of the multidisciplinary team to help to take early CMV swabs if needed and provide the first parent information verbally and with handouts. Audiologists advise on early aiding with appropriate fitting and appropriately amplified hearing aids, or fast tracking to a cochlear implant service. ENT surgeons and cochlear implant service: The cochlear implant criteria changed in the UK in 2019 allowing more children to qualify for the operation. Previously children had to be deaf with hearing worse than 95 dB at 2 and 4khz, but since 2019 children with hearing worse than 80 dB HL at 2 or more frequencies, can access bilateral cochlear implants. General paediatricians and/or Neonatologists manage early syndromes requiring treatment such as CMV, other congenital infections, jaundice reaching blood transfusion levels, prematurity. Community Paediatricians search for and manage associated syndromes and developmental concerns. The child may need additional educational support with an Educational Health Care Plan. Ophthalmologists report on syndrome-related changes and can contribute towards identifying the aetiology of hearing loss and dual management of any deaf-blind conditions (e.g. Usher syndrome). Geneticists are now crucial since the millennial genomics explosion. Individual gene tests (e.g. connexin 26 for bilateral hearing loss) are now giving way to gene panels with sets of genetic tests. Audiovestibular physicians will not only aid with aetiology but will be skilled at formal balance testing and rehabilitation. Virologists/pathologists are important in the management pathway of early CMV testing and management as well as other congenital infections. Pharmacists: The only childhood pharmaceutical treatment currently for hearing impairment is intravenous gancyclovir or oral valgancyclovir for the treatment of cytomegalovirus (CMV) and further research is being carried out about the most effective management for congenital CMV. Teachers of the deaf, TOD’s (also known as sensory need teachers) are valuable for working with the family on early communication, use of hearing aids, managing school entry and addressing the needs of the school environment. Speech and language therapists (SaLT’s) are essential for advising about whether speech difficulties are related to hearing loss or a more structural concern such as cleft palate. Although the TOD’s are often the first professional working with the family around early communication, the SaLT’s are essential to management of early speech, language, advice and educational placement. Charities are an important source of support, information and advice for families. The National Deaf Children’s Society (NDCS) for example is a trusted source of information and advice. They also offer courses for families and activity days or camps for deaf children and their siblings. CMVaction for example , raises awareness of CMV prevention and management, CLAPA for cleft palate, and LPUK for those with skeletal dysplasias.
Viral infections and hearing loss Measles, Mumps and Rubella may cause acquired hearing loss or congenital hearing loss and all three are preventable by vaccination. Viral infections causing deafness are not always due to an encephalitis but haematogenous spread of the virus in the blood stream seems to be able to affect the cochlear. Cytomegalovirus infection early in pregnancy can affect a fetus in variable ways from asymptomatic to severe multi organ involvement. The asymptomatic newborns are at risk of developing a hearing loss at a later date and the newborns already showing a mild or unilateral hearing loss are at risk of their hearing deteriorating further. Many national and international guidelines recommend that babies born with hearing loss should be investigated early for CMV. A positive saliva or urine sample taken within the first 3 weeks of life more confidently suggests congenital CMV than samples taken later than this. A positive CMV sample can trigger an examination for other CMV related signs (microcephaly, low birth weight, jaundice, rash, splenomegaly) investigations (such as cranial imaging, blood tests and ophthalmology referral) and consideration of treatment which may include antiviral therapy (usually valganciclovir syrup where the baby is otherwise well). Pregnant women can reduce their chances of catching a primary CMV infection by washing their hands regularly and not sharing cutlery, cups, food and direct mouth kisses with toddlers and young children who are at their prime of acquiring and sharing many viruses including CMV.
Investigations Initial investigations are common to most types of sensorineural hearing loss and include family audiograms, an ophthalmology assessment, imaging of internal auditory meati, urinalysis for microscopic haematuria, testing for congenital cytomegalovirus and considering a genetics referral. Audiology: Investigations include early identification of the type of hearing loss for the patient (see the British Society of Audiology, website or NDCS website about types of hearing tests depending on the age of the child). Family audiograms (parents and siblings) are important for all cases of childhood hearing loss and can help to identify a pattern of inheritance. Imaging of the internal auditory meati: MRI is helpful to identify structural anomalies of the cochlear, vestibular system, vestibular aqueduct, audiovestibular nerve and brain.
Box 2
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ENT referral: ENT surgeons are often involved in the imaging decisions, discussions around cochlear implantation, examination of the ear and neck and discussions about further investigations. Eyesight: All children with a permanent hearing impairment should have their vision checked, as just under half of children with deafness have an eyesight diagnosis too. Not only is it important to optimise all the senses for development, but ophthalmologists contribute to diagnoses such as Sticklers syndrome, CMV and Ushers syndrome. CMV status: Many hospitals are performing targeted investigations as early as they can for congenital CMV since the diagnosis is much more certain if a sample (saliva or urine) is positive within the first 3 weeks of life, allowing treatment to be started promptly. A CMV pathway enables a paediatrician to work closely with their virology colleagues which only improves life. Balance: Bedside tests are based on removing visual and proprioceptive input (that the child may be relying on) to get a feel of underlying vestibular function. An audiovestibular clinican or vestibular assessment within an audiology service can investigate balance further for example with rotational chair testing, VEMP’s amd bithermal calorics depending on the age of the child. Urinalysis: Microscopic haematuria is seen in patients with Alport’s syndrome. Proteinuria can identify renal disease and is useful to check where there is an identified family history of renal disease. A renal ultrasound scan can be requested if there is an indication or suspicion of a wider condition such as Branchio-Oto-Renal (BOR) syndrome. ECG: is recommended in cases of severe or profound hearing loss to exclude long QT syndrome. Further investigations depend on clinical findings and include thyroid function tests, renal ultrasound scan, autoimmume disease screen, serology for congenital infection, metabolic screens.
technology improves year on year. Since many hearing losses are associated with some vestibular involvement (such as widened vestibular aqueduct or congenital CMV) a discussion about balance being affected (which is turn can affect motor milestones) can be one of the most important discussions with the family. Children compensate quickly for balance difficulties, they learn to use their eyesight and proprioception so well that balance difficulties can be almost impossible to elicit clinically on ‘bedside testing’ by the age of 10 years. Note that conditions such as CMV can cause progressive vestibular deterioration, often within the first 4 years of life, which is unrelated to the severity of the hearing loss. Vestibular involvement can lead to difficulties with dynamic visual function. This is important functionally for a child. The child may have normal visual function when both the child and the image is still, but due to the vestibulo-ocular reflex being affected, the child can struggle with visual stabilization and will not be able to see properly if the child or the image is moving. This can affect a child’s reading ability and confidence with motor skills. Children will need to sit at a table with good lighting to read, and school will need to be aware of these difficulties. What is poor dynamic visual function like? Try reading a message on your mobile phone when you are gently nodding your head up and down. Although not ideal, you will still be able to read the message. Now try reading the message on your mobile phone keeping your head still but this time move the mobile phone up and down in front of you. That is what it is like for children who have poor dynamic visual function. See Box 3.
Prevention of disease and disabilities Prevention of hearing impairment The WHO identified that public health measures such as vaccination, improved maternity care, improved hearing screening, improved medicines, improved education of safe listening, could prevent at least half of all cases of worldwide hearing impairment. CMV Action are a charity raising awareness in the UK about CMV related hearing loss and neurodisability. The research around CMV is exciting at the moment and is guiding clinicians about better prevention, identification and treatment of CMV.
Management In addition to the parents, a great multidisciplinary team is essential for good management. Some of the professionals involved in the delivery of care in the UK are summarized in Box 2.
Reduction in disability Early identification of hearing loss is crucial and has led to digital innovation to solve this problem. The WHO and other non-governmental organisations have funded smart phone/tablet applications to aid hearing screening at home or in rural settings. The free WHO hearing screening app is called HearWHO. The Cambridge Hearing Trust created the free Hear Glue Ear app for children (targeting the 10% of school aged children who have glue ear). Others include Shoebox audiometry and HearX in the UK. The aim is for hearing screening to be easily available. The developmental problems resulting from hearing loss include speech and language delay; auditory processing difficulties; social communication difficulties; listening and attentional difficulties; poorer quality of life; behaviour problems. Prevention of developmental difficulties is best addressed with
Prognosis and explanation to patient The aim of professionals is to provide a deaf child with the same life chances as a child with ‘normal’ hearing. Hearing aids
Problems arising from impaired vestibular function. Children can be later to learn to ride a bike. Children can be delayed developing gross motor skills such as walking. Children might be more afraid of swimming and playground activities and importantly will need more supervision. A swimming buddy is always recommended even if the child compensates well. If the child is underwater with their eyes shut, then proprioceptive and visual cues have been removed and the child may struggle to identify which way is up. Box 3
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Please cite this article as: Brown TH, Childhood hearing impairment, Paediatrics and Child Health, https://doi.org/10.1016/j.paed.2019.10.002
SYMPOSIUM: EYES AND ENT
hearing support while awaiting definitive operations or resolution. With so few of the world’s population receiving affordable hearing aids, digital innovation is trying to solve these problems. The telecommunications industry is adapting to provide solutions. Some mobile phone solutions can offer customers a hearing test over the phone, followed by amplification of the frequencies needed for that individual to access good communication by telephone.
clinical guideline commissioned by the. London, England: National Institute for Health and Clinical Excellence, 2008. National Institute for Health and Clinical Excellence. Cochlear implants for children and adults with severe to profound deafness’ Technology appraisal guidance [TA566], 2019. Published date: 07 March 2019. Olusanya B, Neumann K, Saunders J. The Global burden of disabling hearing impairment : a call to action. Policy & Practoce. Bull World Health Organ May 2014; 92. https://doi.org/10.2471/BLT.13. 128728. Pagarkar W, Shetye A, British Association of Audiovestibular Physicians. Guidelines for aetiological investigation into mild to moderate bilateral permanent hearing impairment. April 2015. 2015, www. baap.org.uk. Pagarkar W, Shetye A, British Association of Audiovestibular Physicians. Guidelines for aetiological investigation into severe to profound bilateral permanent hearing impairment. April 2015. 2015, www.baap.org.uk. Pagarkar W, British Association of Audiovestibular Physicians. Guidelines for aetiological investigation into progressive permanent hearing impairment. Jan 2018. 2018, www.baap.org.uk. Shetye A, Pagarkar W, British Association of Audiovestibular Physicians. Guidleines for aetiological investigation into unilateral permanent childhood hearing impairment April 2015. 2015, www. baap.org.uk. Walston F, McDevitt K, Walter S, Luck S, Holland Brown T. East of England clinical guideline: diagnosis and management of congenital cytomegalovirus, March 2018.
Conclusions Hearing loss is one of the most common disabilities worldwide that contributes to poor education, poor employment and poverty, but the solutions available are not affordable for lower income countries. In the developed world, newborn screening programmes will only identify half of children with permanent hearing impairment and many more children will experience temporary hearing losses as a result of conditions such as OME (glue ear). By being aware of hearing impairment and alert to its aetiologies, clinicians can make a difference to the education, communication and life time trajectories of millions of children. Patients need cost effective accessible hearing tests. We need to support hearing loss early with affordable solutions. A FURTHER READING Austen’s ME, Akre H, Overland B, Abdelnoor M, Falkenberg ES, Kvaerner KJ. Otitis media with effusion in children with Down syndrome. Int J Pediatr Otorhinolaryngol 2013; 77: 1329e32. https://doi.org/10.1016/j.ijporl.2013.05.027. Chadha S, Cieza A, Kring E. Global hearing health: future directions. Bull World Health Organ 2018; 96: 146. https://doi.org/10.2471/ BLT.18.209767. Harrop-Griffiths K, Pagarkar W, Mac Ardle B, British Association of Audiovestibular Physicians. Guidelines for aetiological investigation into auditory neuropathy spectrum disorder in children and young adults. July 2018, www.baap.org.uk. Kentish R, Benton C, Kennedy V, et al. Paediatric Audiology Interest Group. Paediatric tinnitus working group of the British society of audiology. ‘Tinnitus in children’ Practice guidance. 2015, www. thebsa.org.uk. Alles R, Bambiou D, Batchelor L, et al. The British society of audiology (BSA) position statement and Practice guidance ‘auditory processing disorder’ (APD). April 2017, www.thebsa.org. National Collaborating Centre for Women’s and Children’s Health. Surgical management of otitis media with effusion in children:
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Permanent hearing impairment is relatively common, affecting about 1 in 1000 children born in the UK. Only half of these will be detected by the newborn screening programme. Temporary hearing loss from otitis media with effusion is common, affecting about 10% of younger children in their first year at school. Tinnitus is only rarely reported unless children are specifically asked about this symptom. Children with permanent hearing impairment often have vestibular dysfunction which is difficult to detect clinically and if left untreated can hamper a child’s developmental progress.
Crown Copyright Ó 2019 Published by Elsevier Ltd. All rights reserved.
Please cite this article as: Brown TH, Childhood hearing impairment, Paediatrics and Child Health, https://doi.org/10.1016/j.paed.2019.10.002