Auditory neuropathy spectrum disorder (ANSD) in referrals from neonatal hearing screening at a well-baby clinic.

UNLABELLED: Auditory neuropathy spectrum disorder (ANSD) is a particular kind of hearing disorder characterised by normal outer hair cell function and abnormal or absent auditory brain stem responses. Little data are available regarding the prevalence of this condition in healthy newborns. We performed a retrospective medical records review of 791 referrals from universal neonatal hearing screening (UNHS) at a well-baby clinic to investigate the prevalence of ANSD. Hearing screening was performed by automated auditory brain stem response (ABR) testing. A diagnosis of ANSD was established when ABR tracings were absent in the presence of otoacoustic emissions and/or a cochlear microphonic. Amongst 201 infants with confirmed congenital hearing loss, 13 infants were diagnosed with ANSD. The condition was unilateral in six and bilateral in seven infants. A risk factor for hearing loss could be identified in three infants. Abnormalities on magnetic resonance imaging were found in six infants; five of them had cochlear nerve deficiency. CONCLUSION: The prevalence of ANSD was 6.5 % amongst well babies with confirmed congenital hearing loss identified through UNHS. The estimated incidence of ANSD in our population of newborns at the well-baby clinic was 0.09/1000 live births. Magnetic resonance revealed an underlying anatomical abnormality in about half of the patients. WHAT IS KNOWN: • Auditory neuropathy dyssynchrony spectrum disorder (ANSD) is a particular form of hearing loss, mostly encountered in neonatal intensive care unit (NICU) graduates. • Little data are available on the prevalence and risk factors for ANSD in healthy newborns. What is new: • The estimated prevalence of ANSD in healthy newborns is 0.09/1000 live births. • In about half of the healthy newborns with ANSD, a structural abnormality was detected on magnetic resonance imaging of the posterior fossa/brain.

Otitis media with effusion: an underestimated cause of hearing loss in infants.

OBJECTIVE: Otitis media with effusion (OME) is the major reason for failure of neonatal hearing screening. However, little is known about the impact on hearing status of OME in infants during the first months of life. PATIENTS: Infants who failed universal newborn hearing screening. METHODS: Prospective evaluation for the presence of OME, the degree of hearing loss and the disease evolution. RESULTS: Between 2007 and 2008, approximately 152 infants were referred because of unilateral or bilateral failure on universal newborn hearing screening with an automated auditory brainstem response device. Eighty-four (55.3%) had OME, 20 of them were lost to follow-up. The remainder 64 infants comprised 37 boys and 27 girls, with a median age of 49 days (range, 40-65 d) at admission. Auditory brainstem response thresholds were 50 dB nHL (range, 40-60) in both ears. A spontaneous resolution of OME was documented in 15 infants. In the remaining, hearing normalized after tympanocentesis or placement of ventilation tubes. Normal hearing could be ascertained in all children at a median age of 4.8 months (range, 3.3-7.8 mo). In the group of infants analyzed, no permanent hearing loss could be detected. CONCLUSION: OME is an important cause of transient, moderately severe hearing loss during the first months of life--a critical period for development of the auditory system. Active treatment should be considered if spontaneous resolution does not occur to prevent any delay in language acquisition and to exclude an underlying sensorineural hearing loss.