A
common cause of acquired hearing loss in children, is a conductive hearing loss
(CHL) associated with Otitis Media with Effusion (OME) (National Institute of Health, 2000)RM1 .
OME is the development of thick and sticky fluid in the middle ear, in the
absence of infection. (Bluestone, 1999). Understanding the link between OME and CHLs,
diagnosing the condition, and treating OME leads to appropriate management
strategies for OME and  associated hearing
loss (Shott, 2006). Children with DS present with behaviours which often result
in self-injury, damage to their environment and social isolation. (Doss et al
1991). Poor diagnosis and management of OME may contribute in developing these
behaviours. (Bennet, 1999). As well as adversely affecting speech development (Ptok,
2005), and quality of life (Zon, 2012).RM2    RM3 

Children
with Down Syndrome (DS) have an abnormal otological structure which predisposes
them to hearing deficits (Fausch and Roosli, 2015). The middle ear is normally
air filled and ventilated via the wide Eustachian Tube (ET) (Gelfand, 2013).
The ET in DS is narrower (Carrico, 2014), easily becoming blocked due to
mucosal build up (Dahle and McCallister, 1986). Lack of ventilation and
drainage of fluid often leads to infected fluid, resulting in OME and
consequently a CHL (Sacks, 2003). Therefore, appropriate management of OME in
children with DS is imperative to aid speech development and QOL.

Epidemiology
of children with Down Syndrome

The
Down Syndrome Association state that for every 1000 children born, at least one
child will be born with DS. Average life expectancy for babies with DS born in
2011 is 51 years of age (Wu, 2011).This is a noticeable increase of life
expectancy in comparison to data from 1950 where only 47% of live births
survived to 1 year of age. This prolonged life expectancy may mean that symptoms
associated with DS will require longer-term intervention from appropriate
services.

OME
and the DS Population

OME
has a particularly high incidence in children with DS ranging from 38-78%. RM4 (Bess,
1985; Roizen et al., 1993; Shott, 2000). The prevalence of OME in children
without DS is 20% (Paludetti al., 2012) compared to the prevalence of OME in children
with DS at 67%–93% (Barr et al., 2011; Maris et al., 2014). O high prevalence
of OME in individuals with DS compared to a normal-developing population (Cunningham
et al, 1984). In a population of children without DS, a decreasing prevalence
of OME is normally expected around age 6 due to improved tubal function and
immunity (Maw
& Bawden  1994RM5 ).
Children with DS, however, suffer from frequent upper respiratory tract
infections due to an immature immune system and persistent tubal dysfunction (Weichert,
2016). Iino et al. (1999) argued that OME therefore persists for a longer
period in children with DS, signifying the increased need for audiological
management in children with DS and OME over their lifetime.

Otological
Characteristics of Down Syndrome

Children
with DS commonly have mid-face hypoplasia (Weichert, 2016). This is associated
with abnormalities in the area of the nasopharynx, where the ET is located.
External auditory canal stenosis, persistent mesenchymal tissue in the tympanic
cavity, and hypoplasia of the mastoid contribute to the increased incidence of
OME (Hassman, 1998). RM6 Decreased
cartilage cell density within the ET in children with DS contributes to poor ET
function and predisposition to ET collapse, preventing aeration of the middle
ear cavity (Yamaguchi et al, 1990; Strome, 1981; Roy, 2011). Together these
otological characteristics make children with DS prone to OME (Fausch &
Roosli, 2015; Ramia et al.,  2014; Rodman
& Pine, 2012).

RM7 The
majority of hearing impaired children with DS have CHL (Shott, 2006RM8 ):
The reported incidence of CHL was 61-83% in children with DS (Balkany, 1979;
Maroudias, 1994).

Histological
findings reveal ossicular ear abnormalities consisting of fixation and
superstructure deformity of the stapes as well as dehiscence of the fallopian
canal (Balkany, 1979). Histopathological findings have disclosed numerous
abnormalities of the middle ear, for example, 40% of CHLs found were associated
with ossicular abnormalities (Harado, 1981). Ossicular abnormalities may be a primary cause
of CHLs in children with DSRM9 
(REF). However, 10 temporal bones from patients without pathologic ear lesions
but with congenital heart disease served as controls. This choice of control
group may undermine the findings of this study as children with congenital
heart disease experience weakened immune systems and problems with growth and
development (NHS
Choices, 2017RM10 ). Such conditions facilitate
increased risk of ossicular abnormalities, and OME (Fausch, 2015), therefore the
control group may have been affected by ossicular abnormalities. Arguably the
study of histopathology is objective and sensitive. (REF) Consequently, ascertaining
reliable results, aiding better understanding of CHLs found in children with
DS.RM11 

 

Nevertheless, these histopathological
findings were based on the analysis of 7 children.  A small sample size limits the strength of
this evidence, RM12 preventing
results being accurately extrapolated to a wider population. Considering the
large incidence of hearing losses found in a DS population (Shott, 2000;
Marris, 2014 ), the inability to extrapolate findings to such a population,
invalidates the evidence found, as children with DS can vary from one another
in terms of age, gender, type of DS, and developmental ability (JOURNAL REF?). RM13  STATISTIAL ANALYSIS USED?

In
support of Harado (1981) and Balkany (1979), Roizen et al. (1993) also
attributed 64% of CHLs to ossicular abnormalities. In contrast, Roizen et al.
(1993) argued these abnormalities were resultant of untreated and poorly treated
of OME in children with DS, suggesting that OME was the stem cause of ossicular
abnormalities and consequent CHLs in these patients. Roizen et al. (1993) used
telephone interviews to establish links between OME and ossicular
abnormalities. Parents were asked whether their children experienced symptoms
associated with colds and flu such as fever, coughs, and an ear infection. Asking
parents of children with DS retrospectively about symptoms associated with
colds and flu may not be entirely accurate due to other conditions commonly
found in children with DS. For example, children with DS are prone to suffering
from upper respiratory tract infections (JOURNAL REF), causing symptoms similar
to OME. Consequently, parents may have been confused about how to differentiate
between these symptoms and ultimately  lead to ineffective management strategies.

Diagnosis
of OME in children with DS

Children
with DS should be assessed regularly for OME to accurately manage this
population group (NICE Clinical Guidelines, 2008).

Maurizi
(1994) claimed that tympanometry, an effective measure of diagnosing middle ear
pathology (BSA, 2013; Palmu, 2001), provides an accurate diagnosis of OME in
children with DS (Maurizi ,1994). RM14 The use of a 226-Hz probe tone for
tympanometry is recommended in all children above 6 months of age (BSA 2013; RM15 Katz, 2002; Nozza, Bluestone,
Kardatzke & Bachman, 1994). For populations younger than six months of age,
and thus with narrower ear canals, a 1000-Hz probe tone is used as standard
practice and has been shown to produce valid results (Alaerts et al.,  2007; Baldwin, 2006; Meyer et al.,  1997; Paradise et al.,  1976).

A
pilot study (Lewis et al., 2011) consisting of 26 patients with DS investigated
the use of a 1000-Hz probe tone compared to a 226-Hz probe tone in diagnosing
OME within the DS population. The results of this study indicated sensitivity
of both measures as 100%. However, 100 % specificity was found with the 1000-Hz
probe tone compared to 71% specificity with the use of the 226-Hz probe tone. Sensitivity
and specificity can be used to determine good diagnostic tests for diagnosing
OME. This is important as good diagnosis provides the foundation for specific
and accurate individual management plans for each individual child.
Consequently, for best practice, and due to the narrow and stenotic ear canals
that children with DS have, a 1000-Hz probe tip should be used when diagnosing
the DS population for OME (Lewis et al.,  2011). However, this pilot study simply
demonstrated that further research on the most effective probe tip for children
with DS is warranted, as opposed to confirming that a 1000-Hz probe tip is most
effective to use in clinical practice. This questions whether diagnosis of OME is
handled effectively within the DS population.RM16  Therefore, if inaccurate diagnosis
are made, then management of children with OME and DS may be missed and not
dealt with.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

 

 

Treatment
of OME in children with DS

Pressure
Equalisation Tubes (PETs) can treat children with OME (Browning, 2010). PETs
temporarily ventilate the middle ear whilst the ET remains dysfunctional.
Normally the PET remains in the child’s ear for 6-9 months, until it is
naturally expelled out of the ear (Browning, 2010).

NICE
guidelines (2008) for surgical intervention of OME suggest that OME in children
with DS requires critical assessment prior to any surgical intervention (PET
tubes). Such assessments take into account the severity of the child’s hearing
loss and age.

Rovers
et al. (2005) conducted a meta-analysis investigating PETs used for hearing
loss consequent to OME. The meta-analysis found that subgroups of children with
OME could benefit from treatment with PETs (Rovers, 2005). RM17 However stringent inclusion criteria RM18 of the review meant studies that
looked at a DS population to measure PET management on OME were excluded. There
is limited research on the effectiveness of PET insertion within a DS
population. There is a need for future trials studying the effectiveness of PET
insertion in children with DS (Rovers et al, 2005RM19 ).

Shott
(2000) aimed to measure effectiveness of PET tubes in children with DS. In a
study of 48 children with DS, all under the age of 2,  Shott (2001RM20 ) identified that 83% of the children
required PET tubes due to OME. As the OME in the children with DS did not
resolve after the PETs extruded, many of the children required multiple sets of
PETs. . 45% received one set of PET’s, 42.5% 
required two sets of tubes, 7.5% required three sets, and 5% required
four sets of PET’s. Hearing levels were measured before and after the PET
intervention and the best audiogram was found in 40 children after PET re
placement (Shott 2001).

Controversially,
some evidence suggests PETs are not as effective in managing OME in children
with DS as compared with age-matched, typically developing children (Iino,
1999).The low success rate may be attributed to tube blockage which occurs more
frequently in those with DS (NCDS, 2013RM21 ). This is because these children are
more likely to have increased wax in the auditory canal (Dahle and McCollister,
1986). They also produce stickier and thicker mucus due to upper respiratory
infections, causing blockage of PET tubes (NCDS, 2013RM22 ).

ENT
surgeons are less enthusiastic about the use of PETs in children with DS due to
short-term efficacy (Lino, 1999) and the need for continual replacement (Shott,
 XXXXRM23 ) as it can lead to scarring of the
eardrum (Sacks, 2003). In agreement with Shott (XXXX), Davies (1985) also claimed
that DS children require more insertions of PET tubes due to long term failure
of this treatment. On the other hand, Selikowitz retrospectively looked at the
short-term efficacy of PET placement in 24 children with DS aged 6-15. After
PETs were inserted, they found a 40% incidence of hearing loss in the DS group
compared to 9% of hearing loss in age-matched typically developing peers. The
implications of such findings suggest the necessity of raising awareness of the
high failure rate of PET insertion in the DS population, and the need for
alternative treatment strategies. RM24 

One
reason for the difference
in results reported by Selikowitz (XXXX) and Shott (XXXX) RM25 may be that the children in the
Selikowitz (1993) study were aged 6, whereas children who participated in Shott
(XXXX) were aged 2. Therefore the conclusions drawn by Selikowitz (1993) may be
reflective of effects of delayed surgical intervention, as opposed to the effectiveness
of PET tubes. Furthermore, both studies used Pure Tone Audiometry (PTA) to
measure hearing ability. Although PTA is the gold standard for measuring hearing acuityRM26 
(BSA, 2017), PTA is an ineffective measure of hearing ability due to low
intellectual abilities found in children with DS (Hassman, 1985). This
questions the validity of the results found in both studies as the resultant
audiograms may not have been an accurate measure of hearing loss. RM27 

Despite
this, complications due to PET insertion are common in children with DS. Insertion
and retention of PETs are an issue in children with DS, with a repeat insertion
rate of 59% (Tomasevic, 1998), suggesting that PET insertion for OME in
children with DS is ineffective. It still remains unclear how effective PET
insertion is for treating and aiding the management of OME in children with DS.

 

 

Management
of OME in children with DS

The
management of OME in children with DS requires a multidisciplinary approachRM28 . Management of OME involves managing
the consequent hearing loss and effects on the child’s quality of life (Phelan,
2016). The “watchful waiting” procedure is commonly accepted as good practice
for normally developing children (Fortnum et al, 2014). However for children
with DS, this is considered to be a lack of or delayed intervention, causing
detrimental effects on speech and language development (Ptok, 2005). Therefore quick
and effective management is essential in children with DS.

Amplification
devices can also be a method by which consequent hearing losses in children
with OME can be managed (Sacks, 2013).  Behind
the ear (BTEs) hearing aids (HA) are not tolerated by children with DS. (Sense,
2015). This can be due to the abnormal shape of the ear found in the DS
population which makes fitting difficult (REFXXX). Also children with DS are
likely to be fitted with ear moulds which can aggravate ear infections in some
children (REFXXX).  However, there is
limited evidence specifically looking at HA benefit in children with DS and OME
(Fortnum , 2014).

Bone
anchored hearing aid (BAHAs) are beneficial in the management of hearing loss
caused by OME in children with DS, when BTEs or PETs have been considered or
failed (McDermott, 2008). BAHAs can be used whilst a child has OME and are often more
tolerated RM29 (Ramakrishan 2010). Ramakrishnan
(2010) carried out a retrospective cross-sectional survey using outcome
measures including the Glasgow Benefit Inventory RM30 and Listening Situation Questionnaire RM31 . BAHAs lead to significant social
and educational benefit for the children with DS and OME. McDermott (2008)
similarly evaluated whether BAHAs are a successful form of managing OME in
children with DS. The study acknowledged that this patient group is especially
prone to OME. They concluded that BAHAs have an important role in the overall
management of children with DS, after HAs/PETs have been considered or failed.

McDermott
(2008) and Ramakrishnan (2010) used credible outcome measures (Gatehouse, 2000)
that have good reproducibility and test-retest validity to develop their conclusions
(Hendry, 2015). Using subjective questionnaires as comparators to measure the
benefit of BAHAs strengthened the conclusions made by both researchers. A clear
distinction between overall benefit before BAHA intervention and after BAHA
intervention was demonstrated. Whereas the PET studies, were unable to clearly
establish whether PETs were an effective intervention for the management of
OME, in children with DS.RM32 

However
the study design used by both researchers used a retrospective basis causing
recall bias. Due
to the many conditions that affect children with DS (DSA, 2017) it may have
been difficult for parents to accurately monitor the benefits of BAHAs, and
separate this from other overall improvements in healthRM33  that the child may be experiencing
at the same time. Also from an evidence base perspective, retrospective designs
are considered to be a low quality research (BMJ, 2012). RM34 Although the research may benefit clinical
practice for audiology servicesRM35 , it is difficult to affirm thorough
conclusions due to flaws within the methodology and design chosen for these
studies. This
reaffirms the limited evidence base showing whether BAHAs are the most
effective in the management of children with DS and OME. RM36 

Guidelines
of Surgical Intervention for OME published in 2008 found little studies of
managing OME in children with DS. Concluding that existing studies evaluating
effectiveness of management strategies are limited. RM37 

Limits
of Current Research

Through the critique of current
research of OME in children with DS, it is evident that research into the
effectiveness of management strategies are limited. RM38 

 RM1Why
are all references in italics? I have fixed them throughout…

 RM2Good
motivation for studying this topic.

 RM3″behaviour”
is vague. Can you be more specific?

 RM4I
don’t understand how the incidence can be 38-78% and also 2.5%?

 RM5Is
this meant to be (Maw & Baden, 1994)?

 RM6This
seems a separate issue from the decreased cartilage (?) and needs its own
citation (if it is relevant)

 RM7This
entire document is a review of the literature

 RM8Can
you find more than this one reference?

 RM9Is
there evidence to support this statement?

 RM10A
better reference than NHS choices?

 RM11You
have already said something along these lines at the start of this paragraph

 RM12It
depends on the statistical analyses used. A small sample size is not
necessarily problematic

 RM13I
suggest that you delete this paragraph

 RM14Evidence?

 RM15Do
you follow ASHA guidelines in the NHS?

 RM16Not
sure what this means. Are you saying that the best way to diagnose middle ear
dysfunction remains an open question?

 RM17Why
have you referenced Shott for this meta analysis?

 RM18What
criteria? These will be important to note so that you make sure these are
covered in your research protocol.

 RM19Rovers
et al. (2005)?

 RM20Is
it 2000 or 2001?

 RM21An
online reference?

 RM22Online
reference?

 RM23Add
publication year

 RM24Has
anyone published this suggestion?

 RM25What
about Davies (1985)? How does the age of patients compare?

 RM26Add
reference e.g. BSA

 RM27Good
critical evaluation

 RM28Evidence?

 RM29By
children in general or children with DS?

 RM30Cite
the people who published this

 RM31 RM31Cite
the people who published this

 

 RM32This
sentence does not belong here but will be useful in the summary section

 RM33Expand
on this

 RM34Not
a reference? A paper that someone published in the BMJ?

 RM35Why
would it if the evidence is unreliable?

 RM36Again
a good idea to say this in the summary section

 RM37
You need a clear end to this section that sums up what we know about OME
management in DS children.

Especially as your lit review title is about
management, this section needs to be thorough.

 RM38Needs
some work