A study of deafness in term infants with birth asphyxia by otoacoustic emissions and brain stem evoked response audiometry tests.

Maheswaran, C (2007) A study of deafness in term infants with birth asphyxia by otoacoustic emissions and brain stem evoked response audiometry tests. Masters thesis, Madurai Medical College, Madurai.


Download (10MB) | Preview


INTRODUCTION: There are many causes for hearing impairment in infants. Birth Asphyxia is one among them. The agony and handicap caused by hearing impairment to a child is far beyond hearing alone, as we all know that a good hearing is essential for normal development of speech, language and cognitive functions of the child. So, early diagnosis of hearing impairment is essential for early initiation of rehabilitative measures in a child which is important for future speech, language and cognitive development. Most of the tests used for assessing the hearing status in an individual requires the cooperation of the subjects which is obviously not possible in an infant. In this study, we have used Oto acoustic emissions (OAE) test as a screening test, and Brain Stem evoked response audiometry test (BERA) as a definite test for hearing assessment. These tests are objective tests and does not require the patient’s cooperation for testing, thus can be used effectively in infants. AIM OF THE STUDY: 1. To evaluate for hearing impairment in term birth asphyxiated hypoxic ischemic encephalopathy stage 2 infants using Oto acoustic emissions and Brainstem evoked response Audiometry (BERA) tests. 2. Hearing impairment if present – Assessing its severity, and to look for possible site of pathology : conductive, sensory (cochlear) or Neural (Retro-cochlear). 3. Early referral of hearing impaired children for rehabilitative measures. LIMITATIONS: 1. Oto acoustic emission test and BERA test was not done for all cases. 2. The testing was done only once and was not repeated. 3. The BERA test was done only in those cases who failed in OAE test. 4. All infants in Sick neonatal ward have got aminoglycosides the effect of which could not be ruled out. 5. The presence of BERA waves merely tells us that the auditory pathways are normal from the cochlea to the mid brain only. It does not tell us whether the child is actually hearing the sound in the truest sense of the word. Luckily for us the defects in central auditory processing are rather rare as compared to defect in the peripheral auditory pathways. CONCLUSION: 1. Birth Asphyxia can cause hearing impairment in infants. 2. The incidence of hearing impairment is directly proportional to the severity of asphyxia. 3. The incidence of hearing impairment is more in those who required longer duration of inpatient care at sick neonatal ward for control of seizures. 4. The incidence of hearing impairment is higher in those who required assistance during delivery than those who were delivered by labour natural. 5. Screening for hearing impairment is essential in all high risk infants. 6. Hearing impairment is Bilaterally severe in majority of cases (75%). 7. In almost all cases possible site of pathology could be cochlea.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Deafness; term infants; birth asphyxia; otoacoustic emissions; brain stem evoked response audiometry tests; hearing impairment
Subjects: MEDICAL > Otolaryngology
Depositing User: Devi S
Date Deposited: 06 Jul 2017 09:11
Last Modified: 31 Mar 2018 07:55
URI: http://repository-tnmgrmu.ac.in/id/eprint/1169

Actions (login required)

View Item View Item