Transcript Implication of Auditory Neuropathy for EHDI Programs

Implications of Auditory Neuropathy
for EHDI Programs
Vickie Thomson MA
Sandra Gabbard, PhD
Arlene Stredler Brown, MA
Marion Downs Hearing Center
Denver, CO
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Contributing Researchers
Yvonne Sininger, Ph.D.
 Arnold Starr, M.D.
 Linda Hood, Ph.D.
 Charles Berlin, Ph.D.
 Lazlo Stein, Ph.D.
 Jon Shallop, Ph.D.
 Gary Rance, MSc.

Auditory Neuropathy vs Auditory
Dys-synchrony
Berlin, Hood and Rose coined the term
“dys-synchrony” to provide a more
comprehensive view of auditory
neuropathy
 The auditory nerve may not be affected
 AN may lend towards not considering
cochlear implants as an option

What is AN/AD?
Abnormal auditory brainstem responses
 Normal otoacoustic emissions
 Normal outer hair cell function
 Abnormal neural function
 No acoustic reflexes
 Large cochlear microphonic

What is AN/AD?
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Speech perception worse than expected
based on the audiogram
Inconsistent responses to sound
Worse in noise
Fluctuating hearing loss
If a maturational problem recovery may return
by 12-18 months
Perceptual ability may improve although ABR
remains abnormal.
Variability
Progressive loss of peripheral auditory
function (e.g. loss of OAE’s, CM)
 Stable
 Worsen
 Partial recovery

Historical Perspective

1980’s first published accounts of
‘normal’ hearing and absent ABR’s
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•
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Davis and Hirsh, Worthington and Peters
1984 Kraus et.al reported 1.3% of the
children with hearing loss had absent
ABR’s
Addition of OAE increased the diagnostic
capabilities
Incidence?
Davis and Hirsh – .5%
 Berlin – 12%
 Kraus – 1.3%
 Rance - 12-14% of the severe to
profound

NICU vs. Well Baby
Rance reported that 85% were NICU
graduates
 Berg et al reported 24% of a NICU
cohort had AN/AD profiles (23% were
bilateral)

39% > 38 weeks gestation

Colorado study
Colorado Screening Rates
Confirmed
hearing
loss
Year
# of
Births
#
#
Screened Referred
2003
68957
66567
(97%)
2997/4.5%
139
2004
69801
67697
(97%)
2368/3.3%
143
Methods
Data from both the Colorado Department
of Public Health and Environment and
the Colorado Home Intervention
Program was analyzed.
 All hearing losses were identified by
local audiologists and reported to these
agencies

Increasing Identification Rate for
AN/AD
AN/AD Incidence
2003
2004
Combined
(2003&2004)
Cases
Identified
8
9
17
Total
Screened
67,778
66, 567
134,345
Incidence
rate
1.18:10,000
1.35:10,000
1.27:10,000
Hispanic Incidence Rates
2003
2004
Combined
(2003&2004)
Cases
Identified
3
3
6
Total
Screened
21,533
21,582
43,115
Incidence
rate
1.39:10,000
1.39:10,000
1.39:10,000
Age of Identification
Risk Factors
15 of 20 (75%) bilateral AN/AD cases
were admitted to the NICU
 7 of 20 (35%) bilateral AN/AD cases
were premature births

Associated Risk Factors
Anoxia
 Hyperbilirubinemia
 Infectious diseases (e.g. mumps)
 Immune disorders (e.g. Guillain-Barre
syndrome)
 Genetic Syndromes (e.g. Charcot-MarieTooth and Fredreich’s Ataxia)
 Hereditary recessive and dominate

Recommendations for Screening
Use AABR in the NICU
 Recognize that AN/AD is present in ‘well
baby infants’
 Educate medical homes about the
importance for referring whenever there
is a concern regardless of the screening
outcome

RECOMMENDED PROTOCOL
FOR INFANT AUDIOLOGIC
ASSESSMENT
THE COLORADO INFANT AUDIOLOGIC
ASSESSMENT TASK FORCE
AUDIOLOGIC DIAGNOSTIC
ASSESSMENT
ABR
 Otoscopic
 Acoustic immittance (high
frequency probe)
 TEOAE &/or DPOAE
 BOA

ABR
Assessment
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Threshold search to clicks in 10 dB
steps
If NR, compare rarefaction &
condensation click response (auditory
neuropathy)
Threshold search to 500 & 3000 Hz
tone pip (or ASSR)
Threshold search to clicks by bone
conduction
Issues in Infant
ABR Assessment
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Always look for cochlear microphonic
when neural response is abnormal or
absent (Auditory Neuropathy)
 Must have frequency specific thresholds
(tones or ASSR)
 Bone Conduction may be useful
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Placement of oscillator
Calibration
Head band versus hand held position
ASSR and Behavioral Thresholds

In general, ASSR thresholds are within 20
dB of behavioral thresholds
 Largest discrepancies when hearing is
normal
 Best correlated for severe to profound
hearing losses
 Differences greatest in the low
frequencies
Aoyagi et al, 1994, Levi et al, 1995, Rance et al, 1995, Lins et al, 1996, Picton et al, 1998
Otoacoustic Emissions
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Sound produced by Outer Hair
Cell movement in response to a
stimulus
Evoked Emissions
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Distortion Product (DPOAE)
Transient Evoked (TEOAE)
Spontaneous (SOAE)
Present for hearing better than
approximately 35 dB with
normal middle ear function.
Why Behavioral Testing?
•
Behavioral tests are the only “true”
tests of hearing (Sininger, 1993 cited in
Hicks,Tharpe & Ashmead, 2000 )
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permits observation of the infant’s
auditory development
demonstrates auditory behaviors to
parents and caregivers
Why Behavioral Testing?
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Behavioral tests serve as “crosschecks” of physiologic measures
(Jerger & Hayes, 1976)
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confirms audiometric configuration
(OAE; ABR)
determines presence of conductive
component (ABR; immittance measures)
confirms threshold predictions (ABR)
Recommendation for Behavioral Assessment
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Use age appropriate techniques and
use child's developmental level.
Use insert phones when possible.
Use audiologist in room with child.
Use quiet distracting toys.
Use multiple reinforces to keep
attention.
Use a variety of interesting stimuli.
Always include as part of test
battery!!!
Recommendations for
Middle Ear Assessment
•
Do not rely of 226-Hz tympanometry in
infant under 6 months of age.
• Between 4-6 months, it appears that
226-Hz tympanograms begin to be
effective for detection of MEE.
• For ages birth to 6 months, use a
higher probe frequency (800-1000 Hz),
with criteria of any discernable peak
within normal range.
• Correlate results with other diagnostic
measures.
Medical testing

Genetic testing
 Ophthalmologic evaluation by 12 months of
age
 CMV titers- test ASAP after birth
 FTA-ABS
 EKG (Jervell and Lange-Neilson Syndrome)
 CT/MRI
 Cochlear dysplasia/large vestibular
aqueduct syndrome
 Cochlear ossification following
meningitis
Developing a Treatment Program
for Children with Auditory
Neuropathy
Arlene Stredler Brown, CCC-SLP, CED
What do we know?
Diagnosis is difficult for parents to
understand
 Course of the condition is
unpredictable
 The greatest need is to monitor
language development and auditory
development in order to develop an
appropriate treatment plan

What is difficult for parents?
Feeling helpless
 Waiting to reach a definitive diagnosis
 Variability in skills among children
 Identifying a communication method
 Finding comfort in making choices
that may change
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Developing an Action Plan..
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Helping parents during the diagnostic
process
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Specific audiologic battery
Helping parents to locate treatment
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Information, support, navigating the Part C
system, the EHDI system, and other early
childhood initiatives
Developing an Action Plan..
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Developing a unique intervention
program
Identify the functional profile of the child
 Assessment in a variety of developmental
domains
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Communication
 Language
 Functional auditory skills
 Speech
 Cognition
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Developing an Action Plan..
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Assess at regular intervals to monitor
achievement
Baserate data
 Rate of progress
 Maintain development commensurate with
cognitive age
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Trends in Successful Treatment
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Visual communication
Speechreading
 English-based signs
 Cued Speech (receptive vs. expressive)
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Cochlear Implants
Cautions in Treatment Methods
Amplification (according to some)
 American Sign Language (ASL)
 Auditory-Verbal therapy
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Creating a Profile of Functional
Auditory Skill Development
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Expect auditory behaviors that are not
hierarchical
 Monitor for changes in auditory behavior
(may become more systematic)
 Document listening in a variety of conditions
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Quality of responses to auditory stimuli
Identify conditions when the child responds
Identify consistency of responses
Look for variability
Aided vs. unaided
Auditory Skill Development
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Monitor with trial amplification
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Awareness vs. speech discrimination
Parents’ desire to be pro-active
Caution regarding power of amplification
With a cochlear implant, expect hierarchical
auditory skill development
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Allow time for spontaneous recovery
Monitor development of speech & language
Identify auditory discrimination skills vs. pure tone
hearing levels
Determine site of lesion
Tools to Measure Functional
Auditory Skill Development
Functional Auditory Performance
Indicators (FAPI) – Stredler-Brown & Johnson
 Auditory-Verbal Ages & Stages of
Development - Estabrooks
 The Developmental Approach to
Successful Listening II (DASL) – Stout &

Windle
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The Development of Listening Function Razack
Creating a Functional
Developmental Profile
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Assess at regular intervals
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IFSP recommends every six months
Expect developmental gains at a rate that is
commensurate with that child’s cognitive
skills
Creating a Functional
Developmental Profile
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Types of assessment
Parent/caregiver report
 direct observation of the child
 Observation of child’s interaction with a
parent
 videotaped interaction
 Clinician-administered assessments
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Multi-disciplinary – all developmental
domains
Developmental Domains to
Assess
Cognitive skills
 Functional Auditory Skills
 Communication Skills
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Gesture
 communication intention
 facial expression
 turn-taking
 Vocalizations
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Developmental Domains to Assess
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Language Skills (receptive & expressive)
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Language areas
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Skill areas:
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Semantics
Syntax
Pragmatics
Imitation
Initiation of communication
Production of sounds, words, sentences
Modalities
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Visual: Speechreading, sign language
Auditory
Multiple modes
Developmental Domains to Assess
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Speech Development
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number of utterances
quality of utterances
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inventory of specific phonemes
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Spontaneous condition
Spontaneous imitation
Prompted imitation
Vowels
Consonants
Non-true words and true words
Speech intelligibility for true words
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Subjective
Objective (e.g., LIPP)
Considerations When Choosing a
Method
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Options
 Purpose/goals
 Develop language
 Develop English
 Potential to develop speech
 Evaluate what is available in the schools
 Do not limit choice based on availability
 Prepare local school district to offer
instruction using the method you have
chosen
A TEAM EFFORT…
It is to be hoped that, in the future, intervention
and education for children with auditory
neuropathy will be more prescriptive.
At this time, however, professionals have the
responsibility to work as a team, to identify the
developmental profile of each child in an effort
to identify appropriate intervention strategies.
And, as professionals, we have a responsibility
to remain committed to the method or
methodology that works for each child.
Identifying the Team
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Audiologist
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diagnosing the condition
monitoring the course of the condition
monitoring the use of amplification
recommending candidacy for a cochlear implant
ENT/Otologist
 Early Interventionist: Educator of the D/HH,
SLP, Educational Audiologist
 Experienced parents
 Other physicians
Qualities to look for in an
Interventionist/Therapist
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Skilled in a variety of modes/communication
methods
supports options
knows parent-centered intervention paradigm
knowledgeable about auditory training
techniques
knows specific visual communication
techniques; advantages & challenges
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Cued Speech
Sign language/s: MCE, CASE, PSE, ASL
Speechreading
Final Note!
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Reminder….
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Do not change method randomly – even
after CI