Auditory Neuropathy Spectrum Disorder among DPOAEs Screened Infants

Abstract

Objective : Auditory neuropathy spectrum disorder (ANSD) characterized by absent or severely abnormal auditory brainstem response (ABR) with intact outer hair cells functions, as evidenced by the presence of evoked otoacoustic emissions (OAEs) and/or cochlear microphonics. In Universal Newborn Hearing Screening (UNHS), all infants screened for hearing loss either by OAEs or ABR or both of them. The purpose of this work was to study ANSD among infants passed OAEs based UNHS program. Design : UNHS distortion product OAEs (DPOAEs) based program were done for 10281 infants within six years duration. Click evoked ABR were performed to high risk for hearing loss infants and on parents concern about hearing loss for their passed UNHS program children among attendee of audiology and ORL clinics. Tympanograms and behavioral thresholds were performed for the study group. Results : Thirteen infants met the inclusion criteria of ANSD were discovered among passed UNHS program infants (0.12%). Unilateral ANSD were diagnosed in 2 infants (the other ears were normal in one infant and ABR was preserved down to mild hearing loss in the other infant). All ANSD infants had absent click evoked ABR at the maximum presentation level of 100 dBnHL, the acoustic reflexes were absent while DPOAEs were presented in all affected ears. Discussion and Conclusion : In spite of passing UNHS OAEs based program still some infants are missed for the early diagnosis of ANSD which mandate special concern in the screening procedures to be more inclusive for the diagnosis of those infants.