Mechanisms of hearing loss in prematures and fullterms with perinatal or postnatal hypoxia


Objective:  Preoperative evaluation of the type of deafness before cochlear implant for all deaf children   with severe bilateral sensorineural hearing loss after perinatal and postnatal hypoxia and asphyxia in order to assess the mechanism of deafness among prematures and full term with a history of hypoxia. 

Study Design: A longitudinal study of all pediatric cochlear implant patients between referred to Sydney Cochlear Implant Centre who had history of perinatal or postnatal hypoxia or asphyxia.  Electrophysiological data were collected retrospectively and prospectively and analyzed. Some oto-acoustic emissions (OAE) data was collected during the neonatal period prior to referral for cochlear implant.  

All subjects were tested using round window electrocochleography (RWEcochG), auditory brainstem responses (ABR), and implant-evoked electric auditory brainstem responses (EABR).

The tested group consisted of 57 profoundly deaf child who experienced hypoxia or asphyxia in their perinatal period is further divided into two subgroups, prematures (their gestatic age is below 31w ) and fullterms ( born after 31weeks of gestation).

Institution: Sydney Cochlear Implant Centre, University of Sydney, Sydney, Australia

Keywords: Auditory neuropathy, otoacoustic emissions, round window electrocochleography,  electric auditory brainstem potentials.

Address for correspondence:
Ahmed Mohamed Mehanna,
Otolaryngology Department
Alexandria school of Medicine Egypt,
Faculty of medicine Alexandria Egypt

Posted by: Ahmed Mohamed Mehanna, ENT Lecturer, Alexandria school of medicine, Egypt (06-Nov-2011)
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