Implications of Auditory Neuropathy for EHDI Programs

Vickie Thomson MA

Sandra Gabbard, PhD

Arlene Stredler Brown, MA

Marion Downs Hearing Center

Denver, CO

Faculty Disclosure Information

In the past 12 months, I have not had a significant financial interest

or other relationship with the manufacturer(s) of the product(s) orprovider(s) of the service(s) that will be discussed in my

presentation.

This presentation will (not) include discussion of pharmaceuticals or

devices that have not been approved by the FDA or if you will bediscussing unapproved or "off-label" uses of pharmaceuticals or

devices.

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 affectedAN may lend towards not considering

cochlear implants as an option

What is AN/AD?

Abnormal auditory brainstem responsesNormal otoacoustic emissionsNormal outer hair cell functionAbnormal neural functionNo acoustic reflexesLarge cochlear microphonic

What is AN/AD?

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)

StableWorsen Partial recovery

Historical Perspective

1980’s first published accounts of ‘normal’ hearing and absent ABR’s• 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

Year # of Births

# Screened

# Referred

Confirmed hearing loss

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

AnoxiaHyperbilirubinemiaInfectious diseases (e.g. mumps)Immune disorders (e.g. Guillain-Barre

syndrome)Genetic Syndromes (e.g. Charcot-Marie-

Tooth and Fredreich’s Ataxia)Hereditary recessive and dominate

Recommendations for Screening

Use AABR in the NICURecognize 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

ABROtoscopic Acoustic immittance (high

frequency probe)TEOAE &/or DPOAEBOA

ABR Assessment

• 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

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 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

Sound produced by Outer Hair Cell movement in response to a stimulus

Evoked Emissions 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 )

• permits observation of the infant’s auditory development

• demonstrates auditory behaviors to parents and caregivers

Why Behavioral Testing?

• Behavioral tests serve as “cross-checks” of physiologic measures (Jerger & Hayes, 1976)• confirms audiometric configuration

(OAE; ABR)• determines presence of conductive

component (ABR; immittance measures)• confirms threshold predictions (ABR)

Recommendation for Behavioral Assessment

• 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 Developing a Treatment Program for Children with Auditory for Children with Auditory NeuropathyNeuropathy

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 helplessWaiting to reach a definitive diagnosis Variability in skills among childrenIdentifying a communication method Finding comfort in making choices

that may change

Developing an Action Plan.. Helping parents during the diagnostic

process Specific audiologic battery

Helping parents to locate treatment Information, support, navigating the Part C

system, the EHDI system, and other early childhood initiatives

Developing an Action Plan..

Developing a unique intervention program Identify the functional profile of the childAssessment in a variety of developmental

domainsCommunicationLanguageFunctional auditory skillsSpeechCognition

Developing an Action Plan..

Assess at regular intervals to monitor achievementBaserate dataRate of progressMaintain development commensurate with

cognitive age

Trends in Successful Treatment

Visual communicationSpeechreadingEnglish-based signsCued Speech (receptive vs. expressive)

Cochlear Implants

Cautions in Treatment Methods

Amplification (according to some)American Sign Language (ASL)Auditory-Verbal therapy

Creating a Profile of Functional Auditory Skill Development

Expect auditory behaviors that are not hierarchical

Monitor for changes in auditory behavior (may become more systematic)

Document listening in a variety of conditions 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

Monitor with trial amplification Awareness vs. speech discrimination Parents’ desire to be pro-active Caution regarding power of amplification

With a cochlear implant, expect hierarchical auditory skill development 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

The Development of Listening Function - Razack

Creating a Functional Developmental Profile

Assess at regular intervals 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

Types of assessment Parent/caregiver reportdirect observation of the child Observation of child’s interaction with a

parent videotaped interaction Clinician-administered assessments

Multi-disciplinary – all developmental domains

Developmental Domains to Assess

Cognitive skillsFunctional Auditory SkillsCommunication Skills

Gesturecommunication intention facial expression turn-takingVocalizations

Developmental Domains to Assess

Language Skills (receptive & expressive) Language areas

Semantics Syntax Pragmatics

Skill areas: Imitation Initiation of communication Production of sounds, words, sentences

Modalities Visual: Speechreading, sign language Auditory Multiple modes

Developmental Domains to Assess

Speech Development number of utterances quality of utterances

Spontaneous condition Spontaneous imitation Prompted imitation

inventory of specific phonemes Vowels Consonants

Non-true words and true words Speech intelligibility for true words

Subjective Objective (e.g., LIPP)

Considerations When Choosing a Method Options Purpose/goals

Develop languageDevelop language Develop EnglishDevelop English Potential to develop speechPotential to develop speech

Evaluate what is available in the schools Do Do notnot limit choice based on availability limit choice based on availability Prepare local school district to offer Prepare local school district to offer

instruction using the method you have instruction using the method you have chosenchosen

A TEAM EFFORT…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 Audiologist

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

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 Cued SpeechCued Speech Sign language/s: MCE, CASE, PSE, ASLSign language/s: MCE, CASE, PSE, ASL SpeechreadingSpeechreading

Final Note!

Reminder….Do not change method randomly – even

after CI