Transcript Cochlear Implants

COCHLEAR
IMPLANTS
Chapter 18
THE
FACTS
CI Manufacturers
• Medel
• Bionics
• Cochlear
Who Makes the Decision for CI
and
When Should CI for Children with HI?
• Educator of the Deaf? Parents? Physician?
Audiologist? Child? Team? Others?
• Before 1 year, 18 months, 2 years, before 5?
• When person is old enough to make
decisions?
• Never?
CI Factoids
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About 70,000 people worldwide have cochlear implants
About 25,000 people in the United States have cochlear implants
About half of all CI recipients are children
CIs can help an estimated 200,000 children in the United States who do not
benefit from hearing aids.
The demand for CIs is increasing annually by 20%.
About 250 hospitals across the country perform cochlear implant
procedures.
A recent study on cochlear implants demonstrated that special education in
elementary school is less necessary when children have had "greater than
two years of implant experience" before starting school. These children are
mainstreamed at twice the rate or more of age-matched children with
profound hearing loss who do not have implants.
The benefits of a CI to society amount to a lifetime savings of $53,198 per
child.
By the time a child with hearing loss graduates from high school, as much
as $420,000 can be saved in special education costs if the child is identified
and given appropriate early intervention.
CI Study of 181 Children
• Most parents had normal hearing, majority (white) and had more education
and higher incomes than the general population.
• Families tended to be intact with both a mother and a father who involved
their child with CI in family activities on a regular basis.
• Children enrolled in the full range of educational placements available across
the United States and Canada.
• Fairly even distributions of children from public and private schools, special
education and mainstream classes and oral and total communication
methodologies were represented.
• Educational placement changed as children gained increased experience
with a cochlear implant.
• They received an increased emphasis on speech and auditory skills in their
classroom settings and tended to move from private school and special
education settings to public school and mainstream programs.
• Data support the position that early cochlear implantation is a cost
effective procedure that allows deaf children to participate in a normal
school environment with hearing age mates.
Geers A, Brenner C. (2003) Background and educational characteristics of prelingually
deaf children implanted by five years of age. Ear Hear. 24(1 Suppl):2S-14S.
Study of Children in US and CA
• Use of a cochlear implant has had a dramatic impact on the linguistic
competence of profoundly hearing-impaired children.
• More than half of the children in this sample with average learning
ability produced and understood English language at a level
comparable with that of their hearing age mates. Such mature
language outcomes were not typical of children with profound
hearing loss who used hearing aids.
• Use of a visual (i.e., sign) language system did not provide the
linguistic advantage that had been anticipated.
• Children educated without use of sign exhibited a significant
advantage in their use of narratives, the breadth of their vocabulary,
in their use of bound morphemes, in the length of their utterances and
in the complexity of the syntax used in their spontaneous language.
• An oral educational focus provided a significant advantage for both
spoken and total language skills.
Geers AE, Nicholas JG, Sedey AL. (2003). Language skills of children with early
cochlear implantation. Ear Hear. 24(1 Suppl):46S-58S.
Canadian Study
Children with cochlear implants have
increased educational opportunities, with
those children in mainstream and those who
have moved toward mainstream
demonstrating improved progress in speech
perception ability.
Daya H, Ashley A, Gysin C, Papsin BC. (2000). Changes in educational placement and
speech perception ability after cochlear implantation in children. J Otolaryngol.
29(4):224-8.
British Study
• Age at implantation and duration of deafness were found to be
significant predictors of placement two years after
implantation.
• The duration of deafness of children in schools for the deaf or
units was twice that of children in mainstream education.
• Fifty-three per cent of children who were in pre-school at the
time of implantation were in mainstream schools two years
after implantation, whereas only 6% of those who were
already in educational placements at the time of implantation
were in mainstream education.
• The results indicate that children who are given implants early,
before an educational decision has been made, are more likely
to go to mainstream schools than those given implants when
already in an educational setting.
Archbold S, Nikolopoulos TP, O'Donoghue GM, Lutman ME. (1998) Educational
placement of deaf children following cochlear implantation. Br J Audiol. 32(5):295-300.
Cost Effective
• Children with greater than 2 years of implant experience were
mainstreamed at twice the rate or more of age-matched children with
profound hearing loss who did not have implants.
• Also placed less frequently in self-contained classrooms and used fewer
hours of special education support.
• A cost-benefit analysis based on conservative estimates of educational
expenses from kindergarten to 12th grade shows a cost savings of cochlear
implantation and appropriate auditory (re)habilitation that ranges from
$30000 to $200000.
• CI accompanied by aural (re)habilitation increases access to acoustic
information of spoken language, leading to higher rates of mainstream
placement in schools and lower dependence on special education support
services.
• The cost savings that results from a decrease in the use of support services
indicates an educational cost benefit of cochlear implant (re)habilitation for
many children.
Francis HW, Koch ME, Wyatt JR, Niparko JK. (1999). Trends in educational placement
and cost-benefit considerations in children with cochlear implants. Arch Otolaryngol
Head Neck Surg. 1999 125(5):499-505.
Profound vs. Severe Loss & CI
• Highly significant difference between the educational
placement of implanted children and hearing-aided profoundly
deaf children (p<0.00001)
• No statistically significant difference between implanted
children and hearing-aided severely deaf children.
• Implanted profoundly deaf children who have received their
implants before beginning school have the same profile of
educational placement as aided severely deaf children rather
than aided profoundly deaf children of the same age in the UK.
• This is likely to have significant implications for the future
management of profoundly deaf children and to influence
future planning of educational support services.
Archbold SM, Nikolopoulos TP, Lutman ME, O'Donoghue GM. (2002). The educational
settings of profoundly deaf children with cochlear implants compared with age-matched
peers with hearing aids: implications for management. Int J Audiol. 41(3):157-61.
CI by 6 Months
• By the age of 2 years the subject implanted in
infancy achieved scores on the GAEL-P which
were nearly equivalent to those achieved at the age
of 5 1/2 years by children implanted at later ages.
• Age-equivalent scores on the Reynell
Developmental Language Scales were achieved by
the subject implanted in infancy and the ability to
discriminate speech patterns was demonstrated
using the Visual Habituation Procedure.
• CONCLUSION: This report demonstrates
enhanced language development in an infant who
received a cochlear implant at the age of 6 months.
Miyamoto RT, Houston DM, Kirk KI, Perdew AE, Svirsky MA. (2003). Language
development in deaf infants following cochlear implantation. Acta Otolaryngol.
123(2):241-4.
Advocating Oral with CI?
• Data from Clarion cochlear implant pediatric clinical trials were examined
retrospectively to uncover trends in candidacy and postimplant benefit
over time.
• In particular, age at implantation, educational setting, and
communication mode were examined with respect to speech
perception performance after implantation.
• The results showed:
1) age at implantation is decreasing,
2) children in oral education programs obtain more benefit from a cochlear
implant than children in total communication programs,
3) children who undergo implantation before 2 years of age show greater
benefit than children who undergo implantation between 2 and 3 years of
age,
4) more younger children are using oral communication than older
children, and
5) more children with good auditory skills before implantation and more
residual hearing are undergoing implantation.
Osberger MJ, Zimmerman-Phillips S, Koch DB. (2002). Cochlear implant candidacy and
performance trends in children. Ann Otol Rhinol Laryngol Suppl. 189:62-5.
TC vs. Oral
• Spoken word recognition improved at a faster rate
in the oral children with early implantation.
• Children who underwent implantation before 3
years of age had significantly faster rates of
language development than did the children with
later implantation.
• The oral children demonstrated more rapid gains
in communication abilities than did the children
who used total communication.
Kirk KI, Miyamoto RT, Lento CL, Ying E, O'Neill T, Fears B. (2002). Effects of age at
implantation in young children. Ann Otol Rhinol Laryngol Suppl. 189:69-73.
Families of Children with CI
• Children with hearing loss and their families who
sought CIs are not significantly different from
children with hearing impairments whose parents
were not seeking a CI.
• Results provided no support for the notion that
children with hearing loss from families seeking a
CIs for their child evidence more behavioral
deviance than children with hearing impairments
whose parents have not sought an implant.
Knutson JF, Boyd RC, Goldman M, Sullivan PM. (1997). Psychological characteristics of
child cochlear implant candidates and children with hearing impairments. Ear Hear.
18(5):355-63.
Sign vs. Oral & CI (Sweden)
• The aim of the study was to explore patterns of communication between 22
children with cochlear implants (CI) and their parents, teachers and peers in
natural interactions over a 2-year period.
• The children, between 2 and 5 years old when implanted, had used the implant
between 1 and 3.5 years at the end of the study.
• Analyses of videorecorded interactions showed that meaningful oral
communication was more easily obtained in the home setting than in the
preschool setting.
• Patterns of communication between parent-child, content and complexity of
dialogues, quality of peer interactions, communicative styles of adults, and the
use of sign language in communication turned out to be important factors
when explaining the result of the CI on the individual child's development.
• The children with the best oral skills were also good signers.
Preisler G, Tvingstedt AL, Ahlstrom M. (2002). A psychosocial follow-up study of
deaf preschool children using cochlear implants. Child Care Health Dev. 2002
Sep;28(5):403-18.
CI and Auditory Nerve
Three pictures of auditory nerve
tissue (from top to bottom),
showing normal synapses in a
hearing cat, long and flat synapses
in a deaf cat, and like-normal
synapses -- short and curved -- in a
deaf cat treated with a cochlear
implant. (Image courtesy of Johns
Hopkins Medical Institutions)
Research has clearly demonstrated
the ability of cochlear implants in
very young animals to forge normal
nerve fibers that transmit sound and
to restore hearing by reversing or
preventing damage to the brain’s
auditory system.
Teacher Role
• The study examined factors associated with teachers' ratings of functional
communication skills of students with cochlear implants.
• Deaf students living in and around a metropolitan area were surveyed to locate
51 with cochlear implants.
• Teachers rated each student's functional use of the implant, given three
defined ratings.
• Additional information regarding sex, communication option, placement,
home language, rural or nonrural address, etiology, and presence or absence of
an additional disability was gathered.
• The data indicated that students with a known etiology and a rural address,
and who used sign language at home or school, were less likely than others to
use the implant as a primary channel for receptive communication.
• The authors suggest that the teacher's role in implant use warrants more
attention.
Easterbrooks SR, Mordica JA. (2000) Teachers' ratings of functional communication in
students with cochlear implants. Am Ann Deaf. 145(1):54-9.
Show Video(s)
• 60 Minutes
• Oral Deaf
• Celia’s Story
• Sound & Fury
NAD CI Statement
• The NAD recognizes the rights of parents to
make informed choices for their deaf and
hard of hearing children, respects their choice
to use cochlear implants and all other
assistive devices, and strongly supports the
development of the whole child and of
language and literacy. Parents have the right
to know about and understand the various
options available, including all factors that
might impact development.
NAD CI Statement
• The NAD has always and continues to
support and endorse innovative
educational programming for deaf
children, implanted or not. Such
programming should actively support
the auditory and speech skills of
children in a dynamic and interactive
visual environment that utilizes sign
language and English.
Seven Steps to CI
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Initial contact
Pre-CI counseling
Formal evaluation
Surgery
Fitting/mapping
Follow-up
AR
Roles
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Audiologist
SLP
Educator of the Deaf
ENT
Child CI Candidate Criteria
Pediatric
• Profound bilateral SNHL
• Limited benefit from
appropriate binaural Has
• Lack of progress in auditory
skill development
• High motivation and
appropriate expectations from
family
12 – 24 months
• Severe to profound bilateral
SNHL
• MLNT – 30% or less in best
aided condition (25 mo to 4 yrs
11 mo)
• LNT – 30% or less in best aided
condition (5 yrs to 17 yrs 11 mo)
• Lack of progress in auditory skill
development
• No medical contraindications
• High motivation and appropriate
expectations (including children
when appropriate age
Adult CI Candidate Criteria
Pediatric
• Moderate to profound SNHL
• 50% or less – sentence recognition – in ear to be implanted
• 60% or less – sentence recognition – in opposite ear or
binaurally
• Pre-linguistic or post-linguistic onset of moderate to profound
SNHL
• No medical contraindications
• A desire to be a part of the hearing world
A cochlear implant is an
assistive technology:
• That bypasses the damaged part of the cochlea
and sends electrical signals to the auditory nerve
which relays these signals to the brain
• Designed to provide sound detection to a full
range of sounds to children with severe to
profound hearing loss who obtain minimal benefit
from hearing aids.
• With unknown outcomes related to providing a
child full access to spoken language for education
and life success
Increasing numbers
• Clerc Center- 1999-2000- no students with implants
– Kendall,2002- 10 students (8 in candidacy process)
– MSSD, 2002- 5 students (varying degrees of usage)
• Nucleus Implants- worldwide
– 1994-10,000
– 1999-26,000
– 2002-36,450
(Do not have statistics for Advanced Bionics and Med-El)
Why Are the Numbers Increasing
• Early Identification
• Improved technology
• Changing candidacy requirements
• Lower surgical risk
• Changing attitudes
Implant Components
• Three manufacturers of implants commonly used in the
United States:
– Cochlear Corporation (Nucleus)
– Advanced Bionics- (Clarion)
– Med-El
• Surgically implanted components
– Receiver coil
– Electrode array
• External components
– Microphone
– Speech Processor
– Transmitter with a magnet
How does an implant work?
1. Sound picked up by microphone
2. Electrical pulses of sound signals
sent to speech processor
3. Speech processor codes sound
signals
4. Code is sent to transmitter
5. Transmitter sends coded sound
across skin to internal receiver
(via FM transmission)
6. Receiver converts code to
electrical signals
7. Electrical signals sent to
electrode array
8. Signals recognized as sound by
the brain
LEVELS OF
PERFORMANCE
• Sound Awareness
• Basic discrimination of sounds
• Voice monitoring
• Understanding environmental sounds
• Understanding single words and/or phrases
• Understands details in sentences
• Understanding connected speech
Why are the outcomes different for
each child?
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Age at time of implant
Pre-implant duration of deafness
Etiology of hearing loss
Residual hearing prior to implant
Family support
Implant technology/channels
Consistency of usage
Appropriate programming of device
Additional special needs
Quality of educational and habilitative
environment
Candidacy Requirements
Who is a candidate:
• Age- FDA says 18months, but doing as young as one year
(some earlier)
• Intact auditory nerve
• Degree of loss- was profound, now increasingly more in
severe range
• Hearing aid trial was 3 months in many places, now not as
strict in many Centers
Issue of who "is not" a candidate
Centers do not seem to be denying children access to this
surgery, however many centers strongly suggest
participation in a full mainstream environment in
coordination with the surgery. Some implant centers may
not consider "signing" students and families as candidates.
Process John's Hopkins Hospital- The
Listening Center
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Initial consult
ABR
Audiology evaluation (with and without hearing aids, may
take many visits
CT scan- looks at anatomy of cochlea
Promontory test- looks at which ear stimulates best to an
electrical signal
ENT consult
Rehab consult
Outreach with educational programs
Surgery
Mapping
Habilitation/Rehabilitation
Deciding which ear to implant-some issues
to consider
• Anatomy (lack of calcification, is there an auditory nerve,
malformed/no cochlea)
• Perhaps one ear accepts electrical stimulation better than
other
• Leave ear with better hearing, implant worse ear, then if not
successful can revert back to aiding that ear
• Implant better ear (opposite argument)- It has already
benefited from hearing aid, will more readily acclimate to
implant
• Facial nerve too close to cochlea-may pick other ear
• If no difference may want it on right- as speech and hearing
centers of brain on left
• Want on right- later for later when driving. Can hear people
in the car
Surgical Considerations
General
· Usually outpatient, 1-2 hours
· Two parts of implant are inserted during
surgery- electrode array in cochlea and
the implant body placed in mastoid bone.
Body holds a magnet that attaches to
external components of the implant.
During
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Shave area
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Mastoid bone uncovered (skin flap)
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Carve space for body of implant
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Drill hole to cochlea
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Small opening in cochlea to insert
electrode array
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Incision closed
After
· Usually up and
around in 1-2 days
·May be some
swelling externally
· Warned of some
possible nausea
from anesthesia
· Wait 4-5 weeks
for all
swelling/healing to
take place before
activation
What about insurance
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Cost of cochlear implant is $40,000-50,000
Most private insurance companies are paying for surgery
Most of the time Medicaid pays 90-100%
May be problems with insurance related to child being too
young based on FDA guidelines
• Implant manufacturers have special departments to handle
insurance related problems and secure payment.
• Some insurance companies pay for post implant
training/mapping
• Only a few insurance companies pay for upgrades (ear
level) ( may get coupon for upgrade from the manufacturer)
Mapping/Programming Issues
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Each person has an individual program called a
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Map based on determining threshold levels, and
maximum comfort levels for each electrode.
Determine how many electrodes can be stimulated
comfortably
Various strategies- one not best for all (SPEAK, CIS,
ACE). Not one program suited for all people.
Takes multiple sessions to program
May initially be uncomfortable
Neural response telemetry-Objective measure of
response to electrode stimulation
Speech perception errors may be used to monitor the
mapping (may be difficult due to impact of articulation
errors, not good for young children)
Research issues
• Change of research playing field now that
candidacy requirements have changed
• Much of the research focuses on speech
perception and speech production
• Age of implantation under 5 indicates advantage
and ease in spoken language learning, yet still
variability
• There does not appear to be an age cut off when
an implant does not appear useful in some way
Research issues
• Oral children may have faster gains than TC kids,
but what about ultimate outcomes?
• CI increases speech and language regardless of
the modality of language programming provided.
(U. of Michigan, 2000)
• Children with better communicative interaction
skills at preverbal level were also most likely to
have good speech perception and production
skills three years after implantation. (Tait and
Lutman, Robinson, 2000)
Parents’ Perceptions and Experiences:
Gallaudet Research Institute findings
(439 families)
• 52% of families chose an implant to
increase ease in development of spoken
language
• 43% of families perceived a significant
increase in their child’s ability to
understand words
• 62% of families continued to use sign
language support in the home although use
of speech increased
The bottom line
• Outcomes related to development of
spoken language will be unique for
each child
• Educational programming must be
designed to address the individual
needs of students with implants
CI Guidelines
In 2002, the FDA lowered the recommended age
requirement to 12 months of age. While this is the
FDA-recommended age, this age is not legally
binding and some hospital centers in clinical trials
are completing the procedure earlier based on
expectations of improved outcomes for early
implantation. In addition, specific circumstances
may allow for earlier implantation. For example, if
meningitis is the cause of hearing loss, it may be
important for the child to be implanted as early as
possible as this condition causes ossification (bone
build up) in the cochlea, making it increasingly
difficult to surgically insert the electrode array as
time passes. Note: There may be questions related
to insurance payment for the procedure if it is
completed prior to 12 months of age.
CI Guidelines
• The FDA states that a child should have
a bilateral (both ears) profound
sensorineural hearing loss; however,
increasing numbers of children with
hearing loss in the severe range are
being considered for cochlear implants.
CI Guidelines
• Negligible functional benefit (limited open-set speech
recognition) from appropriate amplification is often
mentioned as a criterion.
• When such measures cannot be obtained on young
children, hospital centers make individual decisions
regarding whether or not a child would be able to do
well on such tests given documented hearing levels
and traditional hearing aids.
• There are varied implant center requirements
regarding the use of traditional hearing aids prior to
implantation.
• Some centers waive an extended hearing aid trial
requirement in the interest of time when it is clear that
the child would perform better with a cochlear
implant.
CI Guidelines
• A child who is failing to progress in speech, language,
and listening development with traditional hearing aids
based on parent report and educational information may
be considered as a candidate.
• Family willingness to follow recommendations; enroll in
speech, language, and listening therapy; and return for
follow-up appointments is a factor in candidacy.
• Having no medical contraindications to electrode
insertion or receiver placement is a factor in candidacy.
• Educational and home environments that are supportive
of cochlear implants are factors in candidacy.
Not CI Candidates
• a child that does not have the eighth nerve
(auditory nerve) which carries sound from the
cochlea to the brain as determined by a CAT
scan (x-ray) and/or Magnetic Resonance
Imaging (MRI) during the candidacy process.
• a child who has significant residual hearing
levels and receives good benefit from
traditional hearing aid devices.
Other Factors – Non-candidacy
• Some centers may not implant children with
severe emotional, behavioral, or cognitive delays
when it is perceived that these characteristics
may prevent participation in the
educational/training programs necessary to
actualize benefit from the cochlear implant.
• Some children obtain substantial access to
sound from the technology of state-of-the-art
digital hearing aids or other hearing devices.
Without surgical intervention, these devices may
be an equally effective choice for some children.
CI Student Placement Options
• a neighborhood or private school with no additional
supports
• inclusion in a neighborhood or private school with supports
integrated within the school (itinerant teachers, resource
teachers, speech and language specialists, etc.)
• a self-contained classroom for children with hearing loss
using:
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an oral approach,
cued speech,
total communication, or
American Sign Language,
• a day school for deaf children that uses:
– an oral only approach,
– total communication, or
– a bilingual approach (American Sign Language and English).
Communication Mode
• Manual
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ASL
Bilingual/Bicultural
Manually Coded English
Simultaneous Communication
• Total
– Multisensory
• Aural/Oral
– Multisensory
– Unisensory
• Acoupedic
• Auditory/verbal
Sign Language & CI
• "Continued use of a total communication approach might be
the most effective means for facilitating language growth in
a child with a cochlear implant.
• Nonetheless, it is essential that the child be exposed to an
enriched auditory environment for as many hours a day as
possible.
• There is a great need for a strong commitment to maximize
the auditory component with a TC approach.
• In addition, it might be necessary for the school staff to
adjust their expectations and teaching priorities, especially
if manual communication is the focus of the child's
educational placement."
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McKinley, A., & Warren, S. (2000). The effectiveness of cochlear implants for
children with prelingual deafness. Journal of Early Intervention, 23.
Spoken Language
• For educational environments that use either
American Sign Language or other sign
language systems to be appropriate
environments to facilitate development of
spoken language for students with cochlear
implants, there must be an ongoing
commitment of the program to value these
skills and ensure ongoing opportunities for
implanted students to develop and use
spoken language.
CI & Spoken Language
• While development of spoken language
skills should be central to whichever
communication approach is utilized, use
of an approach that provides a student
with support through visual modalities in
addition to spoken language should also
be considered…
Communication Options
• Handout on communication options