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Fergal O'Duffy,IJ Keogh
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Ir Med J. 2013 Feb;106(2):38-9
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Children with Down’s syndrome are at risk of a multitude of health related problems such as visual difficulties, congenital heart disease, thyroid disease, obstructive sleep apnoea and immunodeficiency1. Crainofacial features such as cleft or high-arched palate with a hypoplastic maxilla may be observed in Down's syndrome, as well as hypodontia or anodontia2. Here we examine the most common health problem experienced in Down’s syndrome; hearing loss. At least 75% of children are affected along a mild to profound spectrum of hearing loss3. Optimising hearing is essential to minimise speech delay which is also common in this group of children. This patient cohort has an increased incidence of sensorineural hearing loss and the main cause of conductive hearing loss is persistent otitis media with effusion (OME). In the general population up to 80% of children are reported as having at least one episode of OME by age four4. The most effective management of OME is still contentious5, 70-80% will resolve without intervention within 3-4 months6. However because of the anatomically and physiological co morbidities outlined above Down’s syndrome children with almost universally get OME. It occurs at a younger age and persists to an older age than in other children14. These children require special consideration and early intervention to avert the secondary handicap caused by hearing loss.
Impact
Hearing loss in any child can have a detrimental effect on their emotional, educational, linguistic and social development. Identifying a hearing loss is the first step towards helping alleviate the handicap that can result from it. International best practice now aims for early identification of permanent hearing loss through newborn hearing screening programs. It has been shown that children who are identified and managed early have better outcomes7. As recommended by the Irish Audiology review8, the roll out of the newborn hearing screen in Ireland is underway. It is expected that by the end of 2013, all newborns will be offered a hearing screening soon after birth9. Continued vigilance and treatment remains important as the prevalence of permanent hearing loss in children doubles by aged nine10. In adults with Down’s syndrome hearing assessment is essential in the differential diagnosis of depression and dementia11.
Assessment
Children with Down’s syndrome are at a greater risk of developing a hearing impairment and it is recommended that frequent hearing assessments should be undertaken to identify problems early. These children are considered to be at audiological risk. International guidelines recommend testing with oto-acoustic emissions (OAE), followed by automated auditory brainstem response (AABR) within six weeks9. Testing should be carried out by suitably trained audiologist using modern calibrated technology12. The presence of narrow canals also predisposes to wax accumulation which may affect hearing and impedance testing11. The recommended timetable is at birth, between 6 and 10 months, annually up to age 5 and biannually after this for life. More frequent assessments and intervention maybe necessary should a deficit be found13.
Management options
Virtually all children with Down’s syndrome develop OME and with it a reversible conductive hearing loss14. They present with particular problems of assessment and management. This difficulty is multifactorial including; earlier age of onset, prolonged course, greater risk of complications and potential diagnostic difficulties. Where a child with Down’s syndrome has OME, surgical management such as insertion of ventilation tubes is often considered. This is to alleviate otitis media effusion and prevents recurrence, however the benefits may be short lived compared to other children. Insertion of ventilation tubes is made more difficult or occasionally impossible by the narrow external auditory canals. Chronic otorrhoea can occur and may hamper the wearing of hearing aids14.
The use of hearing aids is indicated if there is a patient/parent preference, contraindication to anaesthetic, previous multiple ventilatory tube insertion, chronic otorrhoea or canal stenosis. In these circumstances early consideration of hearing aid provision is required14. Small hearing aids that fit neatly behind the ear are widely available and when fitted appropriately can help mitigate the handicap caused by the hearing loss. There are disadvantages to hearing aids and these can include acceptance by the child and if there is a change in hearing levels, the hearing aids may be rejected as a result of being too loud or being too quiet. However with gradual introduction and persistence most children with accept the hearing aids.
Another tool in our armoury is the use of bone conduction amplification. This is where sound reaches the cochlea through bone vibration on the skull. These hearing aids when appropriate are highly successful. Options include aids that attach onto the leg of glasses, aids that attach onto a head band or cap and aids that are attached to surgically implanted devices known as bone anchored/implanted hearing aids (BAHA). One of the disadvantages include the cost of the devices which are markedly more expensive than standard hearing aids, though this author feels a value cannot be placed on the sense of hearing. A national BAHA program in Ireland is currently at an advanced stage planning and due to commence imminently.
It is important to be cognisant of hearing loss in any child and more so in Down’s syndrome patients. Optimising hearing is essential to achieve best possible speech and language development. Down’s syndrome patients require specialist multidisciplinary assessment. An appreciation of the importance of life long surveillance for Down’s syndrome patients, with a need to coordinate assessment between tertiary centres and community audiological services is vital. Parents should be clearly informed of the increased risk of hearing loss as well as being prepared for ongoing assessment/treatment. In order to achieve best care for Down’s syndrome patients the medical profession must firstly ensure adequate knowledge of the specific patient needs as outlined above. Secondly it is implicit that adequate infrastructure and personal are available to implement the recommended frequency of audiological assessment.
F O’Duffy1, D McAskill², IJ Keogh1
1Department of Otolaryngology, Head & Neck Surgery, Galway University Hospitals, Galway
²Audiological scientist, Community Audiology, Sea Road, Galway
Email: [email protected]
References
1. Venail F, Gardiner Q, Mondain M, ENT and speech disorders in children with Down's syndrome: an overview of pathophysiology, clinical features, treatments, and current management. Clin Pediatr (Phila). 2004 Nov-Dec;43:783-91.
2. Cummings: Otolaryngology: Head & Neck Surgery, 4th ed: Inherited and congenital disorders
3. Medical Research Council Multicentre Otitis Media Study Group. Surgery for persistent otitis media with effusion: generalizability of results from the UK trial (TARGET). Trial of Alternative Regimens in Glue Ear Treatment. [Internet]. Clinical Otolaryngology and Allied Sciences. 2001: 417–24.
4. Zielhuis GA, Rach GH, Van Den Broek P. The occurrence of otitis media with effusion in Dutch pre-school children. Clinical Otolaryngology and Allied Sciences [Internet]. 1990;15:147–53.
5. Browning GG, Rovers MM, Williamson I, Lous J, Burton MJ. Grommets (ventilation tubes) for hearing loss associated with otitis media with effusion in children. Cochrane database of systematic reviews. 2010, issue 10. Art No.: CD001801. DOI: 10.1002/14651858.CD001801.pub3.
6. Bull MJ. Health supervision for children with Down syndrome. Pediatrics. 2011 Aug;128:393–406.
7. Yoshinaga-Itano C. Levels of evidence: universal newborn hearing screening (UNHS) and early hearing detection and intervention systems (EHDI). Journal of Communication Disorders [Internet]. 2004;37:451–65
8. Health Services Executive. National Audiology Review. April 2011
9. OA Adelola, V Papanikolaou, P Gormley, J Lang, IJ Keogh, Newborn Hearing Screening: A Regional Example for National Care; IMJ, May 2010, vol 103, 5
10. Fortnum HM, Summerfield a Q, Marshall DH, Davis a C, Bamford JM. Prevalence of permanent childhood hearing impairment in the United Kingdom and implications for universal neonatal hearing screening: questionnaire based; BMJ. 2001 Sep 8;323:536-40
11. Evenhuis HM,van Zanten GA, Brocnar MP, Roerdinkholder WHM.(1992) Hearing loss in middleage persons with Down syndrome. Am.J.on Mental Retardation.97.47-56
12. Evenhuis HM. (1996) Dutch consensus on diagnosis and treatment of hearing impairment in children and adults with intellectual disability. J.Intel. Disabil. Res. 40: 451-456
13. Down’s Syndrome Medical Interest Group Guidelines. Basic Medical Surveillance Essentials for People with Down’s Syndrome, Hearing Impairment:2007;9–11
14. National Collaborating Centre for Women’s and Children’s Health (UK). Surgical Management of Otitis Media with Effusion in Children. London: RCOG Press; 2008 Feb. (NICE Clinical Guidelines, No. 60.) 3
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Author's Correspondence
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No Author Comments
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Acknowledgement
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No Acknowledgement
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Other References
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No Other References
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