Implications of Auditory Neuropathy for EHDI Programs

1. Implications of Auditory Neuropathy for EHDI Programs Vickie Thomson MA Sandra Gabbard, PhD Arlene Stredler Brown, MA Marion Downs Hearing Center Denver, CO

2. 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) or provider(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 be discussing unapproved or "off-label" uses of pharmaceuticals or devices.

3. 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.

4. 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

5. 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

6. 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.

7. Variability • Progressive loss of peripheral auditory function (e.g. loss of OAE’s, CM) • Stable • Worsen • Partial recovery

8. 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

9. Incidence? • Davis and Hirsh – .5% • Berlin – 12% • Kraus – 1.3% • Rance - 12-14% of the severe to profound

10. 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

11. Colorado Screening Rates

12. 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

13. Increasing Identification Rate for AN/AD

14. AN/AD Incidence

15. Hispanic Incidence Rates

16. Age of Identification

17. 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

18. Associated Risk Factors • Anoxia • Hyperbilirubinemia • Infectious 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

19. 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

20. RECOMMENDED PROTOCOL FOR INFANT AUDIOLOGIC ASSESSMENTTHE COLORADO INFANT AUDIOLOGIC ASSESSMENT TASK FORCE

21. AUDIOLOGIC DIAGNOSTIC ASSESSMENT • ABR • Otoscopic • Acoustic immittance (high frequency probe) • TEOAE &/or DPOAE • BOA

22. 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

23. 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

24. 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

25. 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.

26. 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

27. 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)

28. 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!!!

29. 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.

30. 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

31. Developing a Treatment Program for Children with Auditory Neuropathy Arlene Stredler Brown, CCC-SLP, CED

32. 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

33. 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

34. 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

35. Developing an Action Plan.. • Developing a unique intervention program • Identify the functional profile of the child • Assessment in a variety of developmental domains • Communication • Language • Functional auditory skills • Speech • Cognition

36. Developing an Action Plan.. • Assess at regular intervals to monitor achievement • Baserate data • Rate of progress • Maintain development commensurate with cognitive age

37. Trends in Successful Treatment • Visual communication • Speechreading • English-based signs • Cued Speech (receptive vs. expressive) • Cochlear Implants

38. Cautions in Treatment Methods • Amplification (according to some) • American Sign Language (ASL) • Auditory-Verbal therapy

39. 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

40. 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

41. 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

42. 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

43. Creating a Functional Developmental Profile • Types of assessment • Parent/caregiver report • direct observation of the child • Observation of child’s interaction with a parent • videotaped interaction • Clinician-administered assessments • Multi-disciplinary – all developmental domains

44. Developmental Domains to Assess • Cognitive skills • Functional Auditory Skills • Communication Skills • Gesture • communication intention • facial expression • turn-taking • Vocalizations

45. 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

46. 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)

47. Considerations When Choosing a Method • 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

48. 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.

49. 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

50. 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 Speech • Sign language/s: MCE, CASE, PSE, ASL • Speechreading