Infant Hearing Screening and Testing Meredith A. Holcomb, Au.D., CCC-A Coordinator, MUSC Cochlear Implant Program Instructor of Audiology AG Bell / MUSC Pediatric Conference October 18, 2013 \
Hearing Loss Statistics 3-4/1000 live births have HL >30dB 1/1000 profound HL 10% with Auditory Neuropathy In SC 60,000 70,000 live births per year 120-140 children with HL per year 60-70 profound HL per year 12 14 children with AN per year 1-2 unilateral AN 10-12 bilateral AN
Background Infant Hearing Screening 1988: Maternal Child Health Bureau funded newborn screening pilots in 3 states 1993: National Institutes of Health issued consensus statements stating all NICU babies should be screened before hospital discharge and universal screening should occur for all infants within first 3 months of life 1994: Joint Committee on Infant Hearing (JCIH) position statement endorsed goal of universal detection of infants with HL 1999: American Academy of Pediatrics released statement recommending newborn hearing screening and intervention 2000: JCIH position statement 2007: JCIH position statement (changes from 2000) 2013: Supplement to 2007 JCIH position statement
Joint Committee on Infant Hearing Member Organizations American Academy of Audiology American Speech-Language-Hearing Association American Academy of Pediatrics American Academy of Otolaryngology HNS Alexander Graham Bell Association Council on Education of the Deaf Directors of Speech and Hearing Programs in State Agencies Supporting Organizations Centers for Disease Control and Prevention US Maternal and Child Health Bureau Boys Town National Research Hospital
JCIH Principles 1) All infants should have access to hearing screen by 1 mo of age 2) All infants who do not pass the initial screen and subsequent re-screen should have audiological confirmation of hearing loss by 3 mo of age 3) All infants with confirmed hearing loss should receive intervention services by 6 mo of age 4) EHDI system should be family centered
Birth Hospital Other Providers Family Educators Child Pediatrician Speech- Language Pathologist Audiologist ENT Early Interventionist
JCIH Principles 5) Child and family should have immediate access to highquality technology (HA, CI, assistive devices) 6) All infants and children should be monitored for HL in the medical home 7) Interdisciplinary intervention programs should be provided by knowledgeable professionals for HI children and families 8) Information services should be used to measure outcomes and report effectiveness of EHDI services
Communication is Key Birth hospital should convey hearing screen results to parents and medical home Parents should receive appropriate f/u and resource information Information should be communicated in culturally sensitive and understandable format Results of hearing screens and evals should be promptly sent to medical home and state Families should be made aware of ALL communication options and available hearing technologies
Early Intervention Any degree of bilateral or unilateral permanent HL, including ANSD Central referral points of entry for specialty services for infants with HL Services provided by knowledgeable professionals with expertise in HL Families should be offered home-based and centerbased intervention options Connect with other families with children with hearing loss **EI services should begin no later than 6 mo of age!
JCIH 2007: What changes were needed?
Definition of Targeted Hearing Loss Expanded from congenital bilateral and unilateral sensory or permanent conductive hearing loss to include neural hearing loss Auditory Neuropathy Spectum Disorder Normal Cochlear Function (OAE testing) Abnormal ABR with Cochlear Microphonic Hearing loss Speech/language delays Poorer than expected benefit with hearing aids
Initial Hearing Screen/Rescreen Protocol Changes Recommends separate protocols for NICU and wellbaby nurseries: NICU 10-15% of newborns spend time in NICU at birth This population is at risk for neural hearing loss ABR is the only appropriate screening technique for NICU If do not pass ABR initial screen, referral should be made directly to audiologist for rescreen via ABR Well-Baby Nursery OAE or ABR screen can be used, but only ABR will detect neural HL If do not pass initial ABR, should not be rescreened using OAE
Outpatient Rescreening Should occur within 1 month of hospital discharge Both ears should be rescreened always! If infant is readmitted to hospital within first month of life when there are conditions associated with potential hearing loss, repeat hearing screen is necessary JCIH states okay to rescreen with OAE as long as one ear passed ABR at birth
MUSC Infant Screening Recommendations All babies should receive ABR initial screen All babies should be rescreened with ABR OAE should NOT be used alone as hearing screen will likely miss ANSD diagnosis High frequency tympanogams (1000 Hz probe tone) Both ears should be retested
Diagnostic Audiology Evaluation Otoscopy High-frequency (1000 Hz) probe tone tympanogram OAE if middle ear status is clear ABR testing ASSR testing??
Diagnostic Audiology Evaluation For children younger than age 3 years, one ABR test is recommended as part of the completed audiology diagnostic evaluation for confirmation of permanent hearing loss Re-evaluations for infants with risk factors for late onset HL should be customized and individualized Infants who pass initial screen but have risk factors should have at least one diagnostic audiology evaluation by 24-30 mo of age For families who elect hearing aids, fitting should occur within one month of diagnosis of HL
Otoacoustic Emission (OAE) Testing Measurements obtained from ear canal with probe Records cochlear responses to acoustic stimuli Reflects status of peripheral auditory system extending to the cochlear outer hair cells Will NOT identify Auditory Neuropathy
OAEs Pros & Cons Pros of OAEs Frequency specific Present at birth Infant can be awake for testing Cons of OAEs Only provides info about OHC status Requires normal middle ear function Response altered by ambient noise Does not indicate degree of hearing loss
Auditory Brainstem Response (ABR) Testing Measurements obtained from surface electrodes Records neural activity in cochlea, auditory nerve, and brainstem in response to auditory stimuli Reflects status of peripheral auditory system, 8 th nerve, and brainstem auditory pathway Will identify Auditory Neuropathy
Pros of ABR ABR Pros & Cons Indicates degree of hearing loss Assesses greater area of the auditory pathway Cons of ABR Restrictive frequency specificity due to abrupt stimulus Assesses only synchronous neural function Infant must be asleep for testing
ASSR (Auditory Steady State Response) Pros of ASSR Pros & Cons Uses amplitude modulated tone more frequency specific Can stimulate at higher levels than ABR Cons of ASSR Inaccurate estimates of threshold in cases of normal hearing to mild hearing loss
Diagnostic ABR Testing Insert Earphones Natural Sleep or Sedation Two Runs Per Test Scenario Waves Must Be Repeatable
Diagnostic ABR Testing ToneBurst Stimuli 4000 Hz, 1000 Hz, 500 Hz, 2000 Hz Single Polarity Click Stimulus (high intensity) If no response on 4000 Hz toneburst Looking for Cochlear Microphonic (CM) to diagnose Auditory Neuropathy Must reverse polarity when stimulus phase is inverted No sound run to differentiate between stimulus artifact and CM Bone conduction testing
Medical Evaluation Otolaryngologist evaluation With knowledge of pediatric hearing loss Genetics consultation Ophthalmologist evaluation Speech evaluation
Current Challenges Lost to follow-up Shortage of qualified professionals Lack of timely referrals Lack of timely intervention Lack of funding Reimbursement issues
Interesting Case
Full-term infant Case Study ABR newborn screen at birth Pass R, refer L OAE rescreen (child would not sleep for ABR screen) Pass R, some OAE responses L Normal tympanograms Scheduled for diagnostic ABR
Case Study- ToneBurst Testing
Case Study ABR (clicks)
Case Study Sent to ENT for medical work-up MRI ordered to evaluate cochlear nerves Child found to have cochlear nerve deficiency
Key Points To Remember 1 month hearing screen 3 months diagnose hearing loss 6 months early intervention services Child/family is the focus ABR screening is optimal WHEN IN DOUBT, REFER!!!
Thank you!