1 / 24

Auditory Dys-Synchrony Among Very Low Birth Weight Infants Preliminary Data

Auditory Dys-Synchrony Among Very Low Birth Weight Infants Preliminary Data. Courtney A. O’Neil, MS, CCC-A Winnie Chung, AuD Betty Vohr, MD Supported in part by Natus Medical, Inc. Women & Infant’s Hospital and RIHAP (Rhode Island Hearing Assessment Program).

jhoey
Télécharger la présentation

Auditory Dys-Synchrony Among Very Low Birth Weight Infants Preliminary Data

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Auditory Dys-Synchrony Among Very Low Birth Weight InfantsPreliminary Data Courtney A. O’Neil, MS, CCC-A Winnie Chung, AuD Betty Vohr, MD Supported in part by Natus Medical, Inc

  2. Women & Infant’s Hospital and RIHAP(Rhode Island Hearing Assessment Program) • ~13,000 infants born in RI annually • ~ 9,000 infants born at W&I • ~1,500 admitted to NICU

  3. Literature Review • Absent ABR with present OAEs and/or CM with or without measurable hearing has been reported since 1979 – Davis H, Hirsh S. (1979). Audiology 18: 445-461. • 10% of all hearing loss– Starr et al (1996). Brain 119: 741-53. • 1/433 or 2.3 in 1000 children with risk factors • Rance et al (1999). Ear & Hearing June: 238-251. • At least 10 % of children who fail AABR have normal OAEsNorton et al.(2000). Ear & Hearing 21: 508-528. • Occurs in as many as 40% of NICU infants secondary to hypoxiaRea et al.(2003). Laryngoscope 113: 257-263. • 24% of NICU graduates pass OAE, but fail AABR Berg et al. Pediatrics 116: 933-938

  4. Risk Factors for AN/AD By order of frequency of occurrence in AN/AD: • High levels of bilirubin • Hypoxia • Low birth weight • Hydrocephalus • Syndromic disorder such as Charcot-Marie-Tooth • Cerebral Palsy • Cranio-facial anomaly • Neonatal meningitis Rance G, Beer DE, Cone-Wesson B, Shepherd RK, Dowell RC, King AM, Rickards FW, & Clark GN (1999). Clinical finding for a group of infants and young children with auditory neuropathy. Ear & Hearing June: 238-251. Starr A, Picton TW, Sininger Y, Hood LJ, & Berlin CI (1996). Auditory neuropathy. Brain 119: 741-53.)

  5. Auditory Neuropathy/Dys-synchrony Screening Results • Pass oto-acoustic emissions – normal outer hair cell function • Fail automated ABR (AABR) – poor conduction along auditory (VIII) nerve

  6. Auditory Neuropathy/Dys-synchrony Physiological Definition • Absence of wave V in ABR test • Presence of Cochlear Microphonic with/out wave I • Presence of Oto-acoustic Emissions • Absence of contralateral suppression of OAE emissions • Absent Acoustic Reflexes with Normal Tympanometry

  7. Auditory Neuropathy/Dys-synchrony Behavioral Findings • Behavioral testing in older children often reveals variable thresholds which can range from normal hearing sensitivity to severe/profound hearing loss • Word recognition scores do not correlate well with behavioral thresholds • Speech perception difficulties, especially in noise

  8. ABR Waveforms of an Infant with Normal Auditory Function

  9. ABR Waveforms of an Infant with a Profound Sensorineural Hearing Loss

  10. ABR Waveforms of Infant with Auditory Neuropathy / Dys-synchrony Note “ringing microphonic”

  11. Study Objective • To determine the incidence of auditory neuropathy / dys-synchrony in a cohort of very low birth weight infants (<1500 grams) • ~10-12% of NICU admits have birth weight <1500g

  12. Current Hearing Screen Protocol at W&I Hospital • 2 stages • TEOAE performed first • AABR only if infants fail TEOAE • Are we missing infants with AN?

  13. Study Protocol • Study period: March 1st-Dec. 31st, 2006 • Infants <1500g at birth received OAE & AABR • For OAE : OtoDynamics ILO-V6 TEOAE • For AABR: Natus algo 3i (handheld)

  14. Subjects: 03/01-12/31/06 • 180 eligible: • 149 screened with study protocol • 5 (2.8%) screened without protocol @ W&I • 13 (7.2%) transferred – screened without protocol - results available • 13 (7.2%) transferred – no screen results available

  15. Study Sample 03/01-12/31/06

  16. 149 Infants Completed Protocol 83 56% 34 20 23% 12 13% 8%

  17. 20 Infants Failed Both OAE & AABR • 15 had normal dx ABR • 1 transferred from W& I – no dx avail • 3 suspected HL, awaiting confirmation • 1 diagnosed with Auditory Neuropathy

  18. 12 Infants Passed OAE, but Failed ABR • 10/12 (83%) Normal ABR • 2 Awaiting final ABR results

  19. 18 Infants Screened Without Protocol • 5 @ Women & Infant’s Hospital • 2 pass OAE only - infant transferred before AABR • 3 pass AABR only • 1 O2 too high for OAE to run • 2 transferred before OAE could be administered • 13 Screened @ other hospitals • 3 OAE only: all pass • 10 AABR only: • 9 pass • 1 fail – no diagnostic information available

  20. Incidence of Confirmed AN/AD in infants with BW <1500 grams • Recall: babies with AN/AD will pass OAE, but fail AABR • 149 infants - screened with OAE/AABR protocol • 129 infants - passed AABR • 33 infants – AN/AD ruled-out with diagnostic ABR testing • 1 infant diagnosed with AN/AD Rate: 1 in 163 Incidence: 6.1 in 1000

  21. Conclusions: For infants <1500g • The Pass OAE / Fail AABR rate was (12/149) or 8.05% • AN rate: (1/163) 0.61% or 6.1 per 1000 • Lower than some prior reports, higher than others • Total HL rate: (5/163): 3.07% or 30.7 per 1000 • VLBW infants remain at risk of HL

  22. Strengths of This Study • 83% of all infants in a tertiary care center who weighed under 1500 grams were screened with the study protocol • Follow-up diagnostic testing was completed to confirm or rule-out AN/AD in those who failed the screen

  23. Speculation: • Early screening with both OAE and AABR of unstable VLBW infants may result in high false positive screen rates for Auditory Neuropathy / Dys-Synchrony. This contributes to false conclusions about rates of both AN/AD and SNHL.

More Related