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21 Osseointegrated Implants for Children
Madell et al., Pediatric Audiology: Diagnosis, Technology, and Management, 3rd Ed. (ISBN 978-1-62623-401-7),
copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.
More specifically, all children showed significant improvements
in HINT scores and CHILD scores. Preimplant mean scores for
the CHILD were 4.49 for the children and 4.60 for the parents.
Postimplant mean scores were 6.90 for the children and 7.10 for
the parents, with higher scores representing improved listening
abilities. These improvements in understanding speech in background noise with the HINT and daily listening abilities make the
osseo implant a viable treatment for children with SSD. However,
it should be noted that use of an osseo implant for SSD does not
provide binaural hearing. It does, however, reduce the head-
shadow eect and improve patient satisfaction. The only way to
gain true binaural hearing benefits for SSD patients is through
cochlear implants.
21.7.1 Unilateral Losses/
SSD and Softbands
Young children with SSD or unilateral conductive or mixed
hearing losses due to atresia or microtia can also be candidates
for osseo systems utilizing a softband. It is important to be able
to verify benefit for these children. Infants with bilateral hearing
loss can be tested for functional gain in the soundfield, but when
a child has a unilateral loss (SSD or atresia), the better-hearing
ear will always respond. In cases with unilateral hearing loss
due to atresia or other issue that causes a CHL or MHL, the better
ear can be masked, and aided thresholds can be obtained in the
soundfield utilizing the osseo system through either softband or
testband. For older children, speech-in-noise testing is recom-
mended to demonstrate even more benefit of binaural hearing.
When there is SSD in a young child, simply masking the
better-hearing ear will not demonstrate good aided benefit. If
only one cochlea is properly functioning, the use of masking and
functional gain to test the child is not appropriate. In these cases,
outcome measures and speech-in-noise testing must be used to
gain information about benefit. Outcome measures should be
ones that determine listening abilities. For infants and toddlers
these outcome measures should be given to parents, guardians, or
other care givers. A detailed list of assessments is found in Table
6.2 in Chapter 6. Osseo implants’ benefit for unilateral losses and
SSD can be shown by performing speech-in-noise testing. See
Chapter 9 for detailed information about speech testing.
In addition, if an infant or toddler with a unilateral hearing loss
or SSD does not have enough head control to keep a processor on a
softband near or on the mastoid, the fitting of the softband should
wait until that head control can be achieved. Placing the processor
on a softband on the forehead for SSD or unilateral conductive/
mixed losses will not yield a binaural eect as well as when the
processor is properly placed on the mastoid. Recommended fitting
times for unilateral losses utilizing softbands is typically 9 months
of age to 1 year of age, when the infant is spending a large amount
of time each day sitting upright.
21.7.2 SSD Preimplant Counseling
When working with children with SSD and their families, it is
important to remember these preimplant counseling topics.
First, an osseo implant is not a cure for SSD; it will not make the
child’s hearing normal or even near normal in the implanted ear.
It is important to explain how bone conduction works and how
the osseo implant transfers the sound from the SSD ear quickly
through bone conduction to the better ear, thus imitating
binaural hearing. As previously noted, binaural hearing for SSD
patients can be achieved only with cochlear implants.
It is beneficial to have demonstration devices for these children
and families to utilize during preimplantation counseling. This is
an excellent opportunity to show the child and the family exactly
what the device looks like and how it works. The child can wear
a testband or a softband with the sound processor attached for
a few minutes in the clinic, while walking around the clinic, or
during an extended trial period set by the audiologist, allowing
the child to listen to an approximation of the implanted device.
During this preimplant counseling appointment, it is important
to document what diculties the child is having due to the hearing
loss. This process not only gives the audiologist documentation on
diculties to use in counseling the family or the child’s school, but
it also gives some tangible information to document for insurance
providers regarding reimbursement. Speech-in-noise testing in
soundfield and outcome measures that specifically look at daily
listening situations should be completed at this time. By utilizing
speech-in-noise noise testing and outcome measures in the pre-
implant condition, the level of diculty experienced by the child
an be demonstrated, and the osseo implant can be recommended
c
if appropriate.
21.7.3 SSD Postimplantation
When the processor is fitted, it is important to discuss care and
maintenance of the processor, as in a hearing aid fitting, but the
audiologist must also include osseo implant specifics, such as
care and cleaning of the abutment for percutaneous implants,
use of magnets and comfort pads for transcutaneous implants,
proper placement and removal of the processor, specific processor features, and any accessories needed. The timeframe
for fitting for SSD is identical to the timeframe for basic osseo
implantation. At the processor fitting, speech-in-noise testing
can be completed. However, outcome measures should not be
completed until the child has had an adequate amount of time
to experience listening with the osseo implant on a consistent
basis. As with any typical osseo implantation, the goal is to see
the child often during the first year, because that is when most
complications occur with skin around the abutment (Table 21.2).
21.8 Complications
When using a percutaneous implant, complications can occur.
There are two main categories of postoperative complications:
adverse skin reactions and osseointegration failures (OIF),
which cause the implant to extrude.
complications to be more likely in children. Fifty-seven devices
were implanted in 42 children, and 20 were implanted in 18
adults. All implantations were completed by a single surgeon
using the same technique, yet they yielded vastly dierent rates
of implant extrusions. The adult extrusion rate was 0%, but the
40,41
In 2011, Lee et al42 found
231
III Hearing Access Technologies for Infants and Children
Madell et al., Pediatric Audiology: Diagnosis, Technology, and Management, 3rd Ed. (ISBN 978-1-62623-401-7),
copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.
pediatric implants had an extrusion rate of 21%. Five of the 12
implant failures involved two patients; both were identified as
having specific syndromes, and one had known vestibular issues.
Of the 12 OIFs in the children, four experienced trauma to the
abutment, three had skin infections around the abutment prior
to the extrusion, and the remaining four had no known cause for
the extrusion.
Previous studies of pediatric osseointegration failure rates
ranged from 5 to 29%.
15,40,41,42,43,44,45,46,47
Lee et al42 noted OIFs higher
in syndromic patients and noted that the activity and play levels
of most children place the osseo implant at risk of forceful extru-
sion if not anchored firmly. They concluded that there is a need
for routinely implanting a sleeper fixture for pediatric patients in
the event of OIF. Many times, uncovering of the sleeper implant
can be performed in the clinic under local anesthesia without the
additional operating room visit, which may require the use of a
general anesthetic.
21.9 Conclusion
The eectiveness of osseo implant usage in children has been
demonstrated. Special considerations for working with children,
as with any other amplification device, need to be designed, and
audiologists need to follow protocols, FDA guidelines, national
pediatric guidelines, and state licensure laws. When these guidelines are followed, osseo implant use for children shows great
promise for improvements in auditory access and listening skills.
More research is needed to oer additional evidence to assist
in future reimbursement for softbands, transcutaneous osseo
implant eectiveness, bilateral implants, and unilateral hearing
losses that do not occur only with craniofacial anomalies. For
now, audiologists must be clear in their recommendations and
provide documentation and research evidence to support the
use of osseo implants.
Discussion Questions
1. When tting softbands, what are some potential verication
measures that can be used for infants? Toddlers?
2. When discussing osseo devices, what is the role of the pediatric audiologist? Surgeon? Family?
3. What are some possible advantages to using a transcutaneous
coupling over a percutaneous coupling system?
4. Explain how the osseo device diers from traditional bone
conduction hearing aids.
5. What are the main components of the percutaneous osseo
system? Transcutaneous osseo system? Which of the components are MRI compatible?
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copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.
22 Considerations for Pediatric Cochlear Implantation
Madell et al., Pediatric Audiology: Diagnosis, Technology, and Management, 3rd Ed. (ISBN 978-1-62623-401-7),
copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.
22 Considerations for Pediatric Cochlear Implantation
Jace Wolfe and Erin C. Schafer
Summary
This chapter outlines cochlear implant devices and their
function, candidacy, assessment, programming, and expected
outcomes. Contemporary cochlear implants, consisting of an
external sound processor and an internal implant, are an eective solution for many children with severe to profound hearing
loss. Children who are implanted by the age of 12 months often
develop age-appropriate literacy skills and excel in mainstream
educational settings. However, to achieve these successes,
children must receive ongoing objective and behavioral assessments, careful management, and individualized programming
from audiologists who have advanced training in cochlear
implants.
Keywords
cochlear implant, deaf, profound, pediatric, sound processor
Key Points
Cochlear implants (CIs) allow children with severe or pro-
•
found hearing loss to develop age-appropriate auditory,
speech, language, and academic abilities.
The FDA has approved indications for CI use in children. These
•
indications for use serve as guidelines for clinicians to determine pediatric CI candidacy. Ultimately, the CI team should
seek to determine whether a CI will improve an individual
child’s quality of life and enable better auditory, speech,
language, and academic progress than may be obtained with
hearing aids.
Management of the pediatric CI recipient is complex and
•
should be achieved by an interdisciplinary team of professionals who seek to optimize the outcome of the child through
the provision of evidence-based subjective and objective
intervention procedures.
hearing health care professionals. The purpose of this chapter is
to acquaint the reader with contemporary CI technology and to
discuss factors that inuence outcomes in children with CIs.
Modern CI systems possess two basic components: an external
sound processor and an internal implant (Fig. 22.1). The external
sound processor can vary considerably in design and appearance,
but all external sound processors contain (1) a microphone (or a
dual-microphone directional system) to capture external sound,
(2) a digital signal processor, (3) a power source (e.g., battery) that
powers the external sound processor and CI, and (4) an external
transmitting/receiving coil (i.e., an external antenna). The internal
implant also varies in design and appearance, but all include (1)
an internal receiving/transmitting coil (i.e., an internal antenna),
(2) a digital signal processor to analyze the incoming signal and
determine the magnitude and pattern of electrical pulses neces
sary to optimally convey the signal to the cochlear nerve, (3) a
s
timulator/current source, and (4) an electrode lead and array to
deliver electrical stimulation to the cochlear nerve.
22.1.1 Basic Operation
The microphone (or microphone array) of the external sound
processor captures external sound inputs and delivers the signal
to a digital signal processor (DSP), which analyzes the signal and
determines the type of input processing necessary to maximize
the recipient’s access to the incoming sound. An audiologist
programs the processor to define the magnitude and pattern
of electrical stimulation necessary for the recipient to perceive
sound optimally across the speech frequency range (e.g., typi-
cally 100 to 8,000 Hz). The incoming sound is digitally filtered
into dierent frequency bands, which are typically referred to
as channels. The DSP, then, determines the optimal stimulation
necessary for the recipient by analyzing both the input signal
-
22.1 Basic Description and
Operation of a CI System
Cochlear implants (CIs) are the most successful sensory prosthetic device developed for clinical use in children with severe
or profound hearing loss. Children who are born deaf and receive
a CI by 12 months of age often develop normal spoken language
abilities by the time they enter kindergarten.
many children with CIs develop age-appropriate literacy skills
and excel in mainstream educational settings.
order for pediatric CI recipients to achieve their optimal outcome,
they must receive satisfactory support from family members and
1,2
Furthermore,
3,4
However, in
a b
Fig. 22.1 An example of a cochlear implant (CI) system. (a)
External sound processor. (b) Internal implant. (Images courtesy of
Cochlear Americas.)
235
III Hearing Access Technologies for Infants and Children
Madell et al., Pediatric Audiology: Diagnosis, Technology, and Management, 3rd Ed. (ISBN 978-1-62623-401-7),
copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.
and the individual needs of the recipient based on the program
created by the audiologist. The majority of signal processing
within a CI system is accomplished within the external sound
processor in order to reduce processing demands of and power
consumption by the internal implant.
Next, this information is delivered to the sound processor’s
external coil to be transmitted to the internal coil of the CI via
digital radiofrequency transmission (e.g., short-range electro-
magnetic induction at a carrier frequency ranging from 2.5 to 50
MHz). This signal determines how the CI should deliver electrical
stimulation to the cochlear nerve and also provides the power
necessary to operate the internal implant. In other words, the
internal implant does not contain its own power source (e.g., battery) and must rely on the electromagnetic link for its operation.
The CI stimulator continuously delivers electrical pulses at
a moderate to fast rate (ranging from 250 to 5,000 pulses per
second). The magnitude of the pulses in each channel is modulated (i.e., varied) based on the amplitude of the input signal in
the corresponding channel. Finally, the electrical pulses of varying amplitude are delivered to intracochlear electrode contacts.
Electrical pulses associated with low-frequency channels are
sent to apically located intracochlear electrode contacts, while
pulses associated with high-frequency channels are sent to
basally located intracochlear electrode contacts. Fig. 22.2 shows
a visual representation of the basic operation of a four-channel
CI system.
22.2 CI Hardware
At the time of this writing, three CI manufacturers are approved
by the U.S. Food and Drug Administration (FDA) to develop and
distribute CI systems for commercial use with children and
adults: (1) Advanced Bionics (Santa Clarita, CA), (2) Cochlear, Ltd.
(Sydney, Australia), and (3) MED-EL (Innsbruck, Austria). Oticon
Medical (Gothenburg, Sweden) and Nurotron (Hangzhou, China)
also manufacture CI systems, but these were not currently
approved for commercial use in the United States as of the end
of 2017 (Fig. 22.3).
5
Fig. 22.2 A visual representation of how a CI system captures sound and converts into an electrical code that conveys the meaningful infor-
mation in the original signal via conventional continuous interleaved sampling (CIS) signal coding. (1) The speech token, in this case “ees,”
is captured by the processor microphone and delivered to the digital signal processor (DSP). (2) DSP separates signal into frequency bands/
channels; each channel is subjected to rectication and low-pass ltering to extract the amplitude envelope of the audio signal; the sound
processor, programmed by an audiologist, determines the magnitude of stimulation necessary to elicit a desired auditory response in each
channel. (3) Processed signal delivered across skin from the transmitting coil of the processor to the receiving coil of the implant via digital
near-eld magnetic induction radiofrequency transmission. (4) Signal received by the coil is delivered to the implant processor to determine
the magnitude of electrical current required to elicit the intended auditory response; processed signal is delivered to band-specic current
generators that produce a continuous train of electrical pulses. (5) Electrical pulses are delivered to intracochlear electrode contacts in a
place-specic manner (i.e., low-frequency inputs to apical contacts; high-frequency inputs to basal contacts). (Images courtesy of Cochlear
Americas.)
236
22 Considerations for Pediatric Cochlear Implantation
Madell et al., Pediatric Audiology: Diagnosis, Technology, and Management, 3rd Ed. (ISBN 978-1-62623-401-7),
copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.
a
d
b
c
Fig. 22.3 CI manufacturers typically oer alternative styles
of external sound processors. Common behind-the-ear (BTE)
sound processors include: (a) Advanced Bionics Naida CI Q90.
(b) Cochlear Nucleus 7 CP1000. (c) MED-EL SONNET, whereas
a common body-worn processor is the (d) Advanced Bionics
Neptune, which is a submersible, water-proof sound processor.
Manufacturers also oer options for (e) wearing all or parts of
the BTE processor o the ear or (f) processors that can be worn
entirely on the head (MED-EL RONDO 2). (Images courtesy of
Cochlear Americas.)
f
e
22.2.1 External Sound Processors
a
b c
d
e
f
Fig. 22.4 Examples of: (a) Advanced Bionics HiRes Ultra cochlear
implant. (b) Cochlear Nucleus CI532 cochlear implant. (c) MED-EL
SYNCHRONY cochlear implant. (d) A perimodiolar vs. a lateral
wall electrode array. (e) Electrode lengths of electrode arrays
from MED-EL, Advanced Bionics, and Cochlear, Ltd. (f) The diverse
electrode portfolio of one cochlear implant manufacturer. (Images
courtesy of Cochlear Americas.)
In an eort to meet the wide range of diverse needs of both
pediatric and adult recipients, CI manufacturers have several
dierent types of external sound processors (Fig. 22.3). Every
manufacturer has a behind-the-ear (BTE) processor, although
they vary in appearance and configuration. In most cases, BTE
sound processors include a short cable that is used to transmit
signals from the sound processor to the transmitting coil and
vice versa. The conducting wires within this short cable often
become faulty over time, resulting in an intermittent connection
or loss of signal altogether, making this the first component for
audiologists and parents to check during troubleshooting. When
children have processor retention issues (i.e., small ears or active
children), a portion of the processor may be clipped into the hair
or worn on the body.
22.2.2 Cochlear Implants
Fig. 22.4 provides examples of the dierent CI system internal
implants approved for commercial use by the FDA. Dierences
exist in the electronic design, capabilities, physical dimensions,
and surgical techniques associated with the dierent CIs. The
design properties of the electrode arrays also dier and are cate-
gorized with two characteristics: the proximity of the electrode
rray to the modiolus and the length of the electrode array.
a
Perimodiolar electrode arrays are curved and inserted in close
proximity to the modiolus, while lateral wall electrode arrays
are inserted next to the lateral wall of the scala tympani. Because
of their close proximity to cochlear nerve fibers, perimodiolar
electrode arrays facilitate lower stimulation levels, lower electrode impedances, less channel interaction, better battery life,
nd better hearing performance.
a
also known as straight arrays, are accid to avoid damage to the
delicate structures within the organ of Corti and to improve the
likelihood of preserving residual hearing.
structures likely results in the loss of retrograde transmission of
maintenance signals between the cochlea and cochlear dendritic
fibers, resulting in degeneration of cochlear nerve fibers.
eort to capitalize on the conicting benefits and limitations of
perimodiolar and lateral wall electrode arrays, Advanced Bionics
has developed a mid-modiolar electrode array, the Mid-Scala,
6, 7,8, 9
Lateral wall electrodes,
10, 11
Damage to cochlear
12,13
In an
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copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.
which is designed to be inserted in the middle of the lumen of
the scala tympani.
Electrode arrays are available in a wide range of lengths.
Perimodiolar electrode arrays are shorter because they course
along the inside wall of the cochlea. For example, as shown in
Fig. 22.4, the perimodiolar electrode array inserted 17 mm into
the cochlea reaches the same insertion depth as the lateral wall
electrode inserted 25 mm into the cochlea. Lateral wall electrodes
are available in a wide variety of lengths including the Nucleus
Hybrid electrode array at 17 mm (avoids apical regions of the
cochlea to preserve low-frequency hearing), Nucleus Slim Straight
array at 25 mm, and the MED-EL Standard electrode array at
31 mm. Although shorter electrode arrays aim to preserve lowfrequency hearing, hearing preservation may also be achieved
with longer, exible electrode arrays, particularly inserted
through the round window with the use of atraumatic surgical
techniques.
14,15,16,17
Pearl
Advances in surgical techniques and electrode array design
have reduced the likelihood that CI electrode array insertion
will damage delicate cochlear structures and have increased the
potential for preservation of a child’s natural acoustic hearing.
22.3 Candidacy for Cochlear
Implantation in Children
22.3.1 Assessment of Candidacy
Ideally, children should be evaluated by a team of people who
each provide valuable insights into the potential advantages and
limitations of a CI. At a minimum, this team should include the
child’s family members/caregivers, an audiologist, a speech-language pathologist (SLP) who is well acquainted with auditory
and spoken language development of both children with normal
hearing and children with hearing loss (e.g., Auditory-Verbal
clinician [AVT/AVEd]/Listening and Spoken Language Specialist
[LSLS]), and a pediatric CI surgeon. Other members of the team
may include a social worker, a pediatric psychologist, an educator for children with hearing loss, the child’s pediatrician, a
neurodevelopmental specialist, and an early interventionist.
A CI candidacy evaluation should include an audiologic
assessment consisting of tympanometry, acoustic reex thresholds, otoacoustic emissions, air and bone conduction pure tone
thresholds, and speech recognition, when possible. Infants and
young children, as well as children for whom auditory neuropathy
spectrum disorder (ANSD) must be ruled out, should also receive
an auditory brainstem response (ABR) assessment. Even if previous testing has been completed, it is still good practice to repeat
comprehensive audiometric testing as part of the CI candidacy
evaluation. See Chapters 6, 7, 8, 9, and 11 for an overview of the
basics underlying behavioral and electrophysiologic testing of
children.
In addition to FDA guidelines, the decision to pursue a CI for a
child is based on several factors. Ultimately, however, the CI team
should determine candidacy on the basis of three basic principles:
1. Are there any medical or psychosocial contraindications that
will compromise the child’s safety, well-being, or quality of life?
2. Is a CI medically necessary to optimize a child’s listening, spoken
language, academic, or social development?
3. Is the child likely to achieve better hearing performance with a
CI than is possible with use of the best available, optimally fitted
hearing aid technology?
The following section describes the process of pediatric CI
candidacy assessment.
Pearl
The primary determinant underlying pediatric CI candidacy
should be the likelihood of a CI improving the child’s quality of
life and communication abilities.
22.3.2 Guidelines for Implantation in
Children
Implant manufacturers propose indications for use for a specific
CI system, and the FDA ensures that the proposed guidelines are
appropriate given the potential benefits and limitations likely to
be experienced by the recipient. Because each manufacturer has
its own guidelines for use, the indications for CI dier slightly
across manufacturers and are outlined in Table 22 .1.
Guidelines for all three manufactures suggest that it is imperative to ensure that the child has been appropriately fitted with
contemporary hearing aid technology prior to determining CI
candidacy. At a minimum, the CI team should ensure that the
output of the child’s hearing aids closely matches evidence-based
prescriptive targets as measured with real-ear probe microphone measurements (see Chapter 20). The audiologist should
monitor the data log in the hearing aid to ensure that the child
is using the hearing aid during all waking hours because (1) it
optimizes outcomes possible with the child’s residual acoustic
hearing, and (2) it promotes full-time use of hearing technology.
Guidelines for all manufacturers also suggest that the hearing
aid trial period may be waived if the child has hearing loss following bacterial meningitis and imaging suggests the presence
of cochlear ossification. In addition to the speech recognition
testing suggested by the manufacturers, which is often at more
intense levels (e.g., 70 dB SPL), open-set speech recognition performance with recorded test materials should also be assessed
at conversational levels (60 dBA), quiet levels (50 dBA), and in
noise conditions in monaural and binaural conditions, when
applicable. Speech awareness thresholds to the Ling six-sound
test18 should be accomplished when other speech perception
testing is not possible.
The aforementioned guidelines were developed to assist clinicians in identifying appropriate candidates for CIs; however, these
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copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.
Table 22.1 Manufacturer-specic guidelines for cochlear implantation in children
Advanced Bionics Cochlear MED-EL
12 mo of age
•
Bilateral, severe to profound SNHL (> 90 dB
•
HL)
< 2 yrs: HA trial 3 mo
•
2–17 yr s: HA trial 6 mo
•
< 4 yrs: Lack of HA benet on MAIS/IT-MAIS
•
or < 20% word recognition at 70 dB SPL on
simple test (e.g., MLNT)
> 4 yrs: < 12% word recognition (e.g., PBK) or
•
< 30% on sentence recognition at 70 dB SPL
with HA (e.g., HINT-C)
Abbreviations: ESP, Early Speech Perception test; HINT-C, Hearing in Noise Test for Children; HA, hearing aid; LNT, Lexical Neighborhood Test; MAIS/IT-MAIS,
Meaningful Auditory Integration Scale or Infant-Toddler Meaningful Auditory Integration Scale; MLNT, Multisyllabic Lexical Neighborhood Test; PBK, Phonetically
Balanced—Kindergarten test; SNHL, sensorineural hearing loss; SPL, sound pressure level.
12 mo of age
•
Bilateral, profound SNHL for 12–23 mo;
•
severe to profound for 2–17 yrs
3–6 mo HA trial and habilitation
•
Young child: Lack of HA benet on MAIS or
•
ESP
Older child: ≤ 30% word recognition on MLNT
•
or LNT with HA
12 mo of age
•
Bilateral, profound SNHL (≤ 90 dB HL at 1,000
•
Hz)
Young child: Lack of HA benet after 3–6 mo
•
use and habilitation
Older child: < 20% word recognition on MLNT
•
or LNT with HA
guidelines have been in place for over a decade. CI technology and
clinical procedures have improved steadily over that time period,
and it is likely that the existing guidelines are quite conservative.
Stated dierently, there are many children who may not meet
current indications for use but are likely to receive considerable
benefit from a CI. When a CI team determines that a child who
does not meet current guidelines is likely to obtain better outcomes with a CI than with hearing aids, the team may recommend
o-label usage of a CI. O-label implantation may be pursued
when clinicians recommend a CI based on clinical need, and not
for research purposes, and when it is determined to be medically
necessary to advance the child’s auditory, speech, academic, and
psychosocial outcomes. When a CI team recommends o-label
cochlear use, the CI team must be thoroughly informed about the
device, base its use on solid scientific principle and medical evidence, and maintain records of the device’s use and the recipient’s
progress.
Ultimately, the CI team must evaluate each child individually
and determine what type of hearing technology is necessary to
optimize the potential development of the child. For older children
who are equipped with the best available hearing aid technology,
a CI should be considered when aided word recognition in quiet
is fair or poorer (i.e., less than 70% correct) for a linguistically
appropriate speech recognition test, even though aided word rec-
ognition may exceed the criterion specified in labeled indications
of use. One must remember that a child will likely experience
considerable diculty with speech recognition in real-world
situations if he or she is scoring less than 70% correct on a word
recognition test administered in a quiet audiometric test booth.
To use more ecologically valid test conditions, the clinician may
consider assessing speech recognition at multiple levels to assess
performance at soft and normal conversational volumes as well
as in background noise. Overall, it is the responsibility of the CI
team to consider a child’s aided word recognition score and to
determine whether it is likely that aided speech recognition will
improve with the provision of a CI.
22.3.3 Special Considerations
There are many children for whom it is dicult or impossible
to evaluate aided word recognition, including infants, toddlers,
and children with no spoken language, significant speech
articulation errors, additional disabilities, or late audiologic
intervention. In these cases, it may be necessary to consider
the degree and configuration of hearing loss. Ching and Dillon
reported that children with CIs achieved similar language outcomes as did children who used hearing aids and had a four-fre-
quency pure tone average of 66 dB HL. It is likely that children
who have hearing loss in the upper end of the severe range or
worse (i.e., > 75 dB HL) or those who have severe to profound
high-frequency hearing loss (2,000 Hz or higher) will obtain
better hearing performance with use of a CI(s) than with binaural
hearing aids. CI candidacy should never be based on audiometric
criteria alone. A child’s functional auditory and spoken language
development are the most important determinants on which to
base CI candidacy. As a result, the child’s AVT/AVEd/LSLS/SLP is
very instrumental in the CI candidacy process. At a minimum,
the child’s speech production, expressive and receptive vocabulary, and auditory comprehension should be evaluated via
the use of standardized measures on a regular basis to ensure
satisfactory performance and progress with spoken language
development. With the use of modern hearing technology and
audiologic services, a reasonable objective is for children with
hearing loss to achieve outcomes that are similar to those of
their peers with normal hearing. At the very least, children
with hearing loss should achieve speech and language standard
scores that are equivalent to their nonverbal IQ standard score.
Additionally, children with hearing loss should achieve at least 1
year in speech and language progress for every 1 calendar year.
When children with hearing loss do not meet these benchmarks,
the CI team should explore the potential reasons underlying the
inadequate progress and consider whether implantation is likely
to provide a better outcome.
The child’s audiologist or SLP should administer subjective
questionnaires to evaluate the child’s functional auditory progress, such as the LittlEARS19 and Parents’ Evaluation of Aural/
oral performance of Children (PEACH) questionnaires.20 For each
of these norm-referenced preschool questionnaires, the child’s
caregiver indicates whether the child has mastered a variety of
dierent functional auditory tasks that routinely occur in real-
world listening situations. If a child’s score is outside of the range
expected for an age-matched peer with normal hearing, the CI
team should explore the reasons for the poor functional auditory
1
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Madell et al., Pediatric Audiology: Diagnosis, Technology, and Management, 3rd Ed. (ISBN 978-1-62623-401-7),
copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.
progress and consider whether implantation will promote better
functional auditory development.
An emerging trend in the pediatric CI candidacy process is
the use of aided cortical auditory evoked response assessment
(Chapter 13) to determine whether hearing aid use is supporting
auditory brain development. Researchers have shown that the
presence and latency of the P1 component of the speech-evoked
cortical auditory evoked response is a biomarker of auditory brain
development.
can provide an objective indication of whether hearing aids are
providing adequate stimulation to promote auditory brain development. Although the cortical auditory evoked response measure
cannot be used in isolation to determine CI candidacy, it should
be used as one component in the battery of tests employed to
determine pediatric CI candidacy.
21,22,23
Use of the cortical auditory evoked response
22.3.4 Documenting Candidacy
To formally organize and quantify the unique characteristics
inuencing candidacy of each child being considered for a CI,
some centers complete a standard candidacy and expectations
form, such as the Children’s Implant Profile (ChIP), which
addresses several characteristics across a variety of domains
(e.g., audiologic, medical, cognitive, psychosocial-emotional,
economic) known to inuence CI outcomes.24 There is no uni-
versal agreement on a form that should be used routinely to
guide CI teams in weighing the advantages and limitations of
implantation and to predict an individual’s likelihood of success.
However, the ChIP may be a helpful tool to facilitate the CI candidacy discussion for each individual.
outcome when the family ensures that the child’s audiologic
needs are meet and when the family ensures the provision of
a language-rich listening environment for the child. Third, the
family and child’s psychological function should be considered
or evaluated by a psychologist, who may be able to provide
valuable support. Psychologists may provide support to parents
who are dealing with depression or who are struggling to cope
with the stress associated with raising a child with hearing loss.
They may also support the needs of children with personality or
emotional issues. Finally, 30 to 40% of children with hearing loss
have additional disabilities such as motor disorders, cognitive/
neurological delays, and/or other health concerns. A neurodevelopmental specialist may be very helpful in holistically evaluating
the abilities and needs of the child and in coordinating the
services the child needs to optimize development. A geneticist
may also provide valuable insight into the underlying cause of
the hearing loss and additional disabilities; however, the best
time to refer families to a geneticist is at the initial diagnosis.
The CI team is faced with the ethical responsibility of weighing
potential advantages, risks, and limitations of implantation for
children with severe disabilities. In many cases, if no medical
contraindications exist, the provision of a CI is beneficial, even
for children with severe disabilities, because it provides another
channel through which the child may interact with and navigate
his or her environment.
Pearl
The family must be fully committed to the decision to pursue a CI
and the habilitative eorts necessary to support the child’s development in order for the child to reach his or her full potential.
Additional Considerations for Assessment of CI
Candidacy
Several demographic, psychosocial, and medical factors (see
following section) should be considered prior to implantation.
First, psychosocial factors should be thoroughly evaluated to
examine family support, plan to attend therapy and audiology
appointments after implantation, commitment to promoting
CI use during all waking hours, and assurance that the family
will provide a robust model of intelligible speech to optimize
auditory and spoken language development. Second, the child’s
socioeconomic status (SES) should be considered, given that low
levels of parental educational achievement and impoverished
socioeconomic backgrounds place children at risk for poorer
CI outcomes.
greater diculty in providing the satisfactory support the child
needs to optimize CI outcomes. In these cases, a social worker
may be invaluable in assisting the family in overcoming some
socioeconomic challenges and in identifying resources necessary to provide the family with the support needed to care for
the newly implanted child. It is important to note that children
from low-SES families are not guaranteed to have poorer CI
outcomes, and with that same mindset, children from high-SES
families are not always going to have superior CI outcomes.
Also, regardless of a family’s SES, the child will obtain a better
1,3, 25
The poorer outcomes may be attributed to a
22.4 Medical Considerations
Associated with Pediatric
Cochlear Implantation
22.4.1 Basic Medical Assessment
The CI surgeon oversees the medical care of children who
are candidates for CIs and those who receive CIs. The medical
portion of the candidacy process involves a thorough otologic
assessment, general medical evaluation of the child’s overall
health, and consideration of serious contraindications to surgery
(e.g., cardiac, respiratory, neurologic), which are rare in children.
Specialists are consulted, when necessary. Because of concerns
over bacterial infection spreading from the middle ear to the
meninges, CI surgery is typically not conducted in the presence
of active middle ear infection. Many CI surgeons will place pressure equalization (PE) tubes for children who have chronic otitis
media and are being considered for implantation.
After candidacy has been confirmed, patients will receive the
pneumococcal bacterial meningitis vaccine as recommended by
the U.S. Centers for Disease Control and Prevention (CDC).
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