Universal newborn hearing screening

Question 1

What is the incidence of permanent hearing loss?

Answer 1

1-3 per 1000 live births

Question 2

What is normal hearing?

Answer 2

0-20dB

Question 3

What is mild hearing loss?

Answer 3

20-40dB

Question 4

What is moderated hearing loss?

Answer 4

40-60dB

Question 5

What is severe hearing loss?

Answer 5

60-80dB

Question 6

What is profound hearing loss?

Answer 6

> 80dB

Question 7

What is the most common type of congenital hearing loss?

Answer 7

Sensorineural

Question 8

What are the causes of neonatal sensorineural hearing loss?

Answer 8

1. Genetic 50%
   a) Syndromic
   b) Non-syndromic (70%) - cochlear hair dysfunction because of errors in gap junction protein connexin 26 production
2. Congenital infections
3. Hyperbilirubinemia
4. Ototoxic medications

Question 9

What are risk factors for neonatal sensorineural hearing loss?

Answer 9

1. Family history of permanent hearing loss
2. Craniofacial abnormalities including those involving the external ear
3. Congenital infections including bacterial meningitis, cytomegalovirus, toxoplasmosis, rubella, herpes and syphilis
4. Physical findings consistent with an underlying syndrome associated with hearing loss
5. Neonatal intensive care unit stay >2 days OR with any of the following regardless of the duration of stay:
   • Extracorporeal membrane oxygenation
   • Assisted ventilation
   • Ototoxic drug use
   • Hyperbilirubinemia requiring exchange transfusion

Question 10

What is the average age of diagnosis of hearing loss in unscreened children?

Answer 10

~24mo

Question 11

What are the functional outcomes of delayed diagnosis and intervention?

Answer 11

Irreversible deficits in communication, psychosocial skills, cognition, and literacy

Question 12

What tests are used to screen newborns for hearing loss?

Answer 12

1. Otoacoustic emission (OAE)

2. Automated auditory brainstem response (AABR)

Question 13

What are the characteristics of the OAE?

Answer 13

1. Performed by a trained technician; 10–15 min; portable equipment brought to the bedside
2. Screening best performed in infants older than 24 h, with a minimum 34 weeks’ corrected gestational age
3. Results may be affected by the infant’s movements, environmental noise or dysfunction in the middle or external ear (eg, debris in the external ear canal)
4. Noninvasive; ear probe placed in outer ear canal
5. Ear-specific testing; both ears can be tested simultaneously
6. Identifies conductive and cochlear hearing loss from the level of the external ear to the level of the outer hair cells in the cochlea
7. Screening thresholds set to detect at least moderate hearing loss (30–40 dB)

Question 14

What are the characteristics of the AABR?

Answer 14

1. Performed by a trained technician; 15-20 min; portable equipment brought to the bedside
2. Screening best performed in infants older than 24 h, with a minimum 34 weeks’ corrected gestational age
3. Results may be affected by the infant’s movements, environmental noise or dysfunction in the middle or external ear (eg, debris in the external ear canal)
4. Noninvasive; three electrodes taped to the head, earphones or ear probes placed on or in the infant’s ears
5. Ear-specific testing; both ears can be tested simultaneously
6. Identifies conductive, cochlear, and neural hearing loss from the level of the external ear to the level of the brainstem, including assessment of vestibular (8th) nerve function
7. Screening thresholds set to detect at least moderate hearing loss (30–40 dB)

Question 15

What form of hearing loss can only be detected by AABR?

Answer 15

auditory neuropathy

Question 16

What is the recommended screening test?

Answer 16

1. Two step screening:
   OAE 1st in newborns with no risk factors, then AABR if fail OAE
2. AABR in infants with any risk factors or NICU

Question 17

What is the effectiveness of earlier intervention?

Answer 17

Infants who are diagnosed and receive intervention<6mo score 20-40 percentile points higher on school related measures then those diagnosed later

Question 18

Who should be involved in the management of children with hearing loss?

Answer 18

1. Family MD
2. Pediatricians
3. Audiologists
4. ENT
5. SLP
6. Educational specialists

Question 19

What are the intervention strategies for hearing loss?

Answer 19

1. Medical/surgical: hearing aids, cochlear implants, bone-anchored hearing aids, brainstem-implanted auditory devices, surgical options for ear malformations, ossicular chain abnormalities, tumors, cholesteatomas
2. Educational/habilitation strategies: oral and gestural communication

Question 20

What is a cochlear implant?

Answer 20

An electronic device surgically placed in the cochlea to provide stimulation to the auditory nerve

Question 21

What are the recommendations for cochlear implant in eligible children?

Answer 21

Bilateral implantation between 8-12mo coupled with auditory oral therapy

Question 22

What is the false positive rates for universal newborn hearing screening programs?

Answer 22

2-4% usually

0.5-1% in well-established programs

Question 23

Which populations with hearing loss will not be detected by universal newborn hearing screening?

Answer 23

1. Less severe congenital hearing loss <30-40dB
2. Progressive or late-onset hearing impairment e.g. CMV
3. Auditory neuropathy if using OAE

Question 24

Is UNHS considered cost-effective?

Answer 24

Yes

Question 25

What should be assessed in children with confirmed hearing loss?

Answer 25

1. Detailed family history
2. Detailed history and physical examination for comorbidities and/or syndromic
3. Consult peds ENT, ophtho, and genetics
4. Vision screening (r/o Usher syndrome)
5. Neuroimaging, genetic, renal and cardiac evaluation as indicated

Question 26

What does the CPS recommend regarding newborn hearing?

Answer 26

Hearing screening should be provided universally to all Canadian newborns via a comprehensive and linked system of screening, diagnosis and intervention.