BERA
Brainstem Evoked Response Audiometry (BERA)
It is an objective hearing test most popular due to its non invasiveness and standardized parameters.
In this test, brain stem potentials are elicited in response to click or tone burst stimuli & the waveform is recorded by placing electrodes over the scalp.
>>BERA is useful in following conditions -
>It is an effective tool in screening new borns for Hearing impairment.
Detection, quantification & identification of nature of deafness in infants, mentally retarded and malingering subjects.
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Identification of site of lesion in retrocochlear pathologies.
Study of central auditory disorders, Brainstem disorders & certain suspected demyelinated disorders.
Study of maturity of central nervous system in newborn.
PRINCIPLE OF BERA :-
When the sound reaches cochlea, it is converted into an electrical impulse which passes from the cochlea to auditory cortex, where it undergoes some degree of processing at each stations and generates an electrical activity which can be monitored by placing electrode on vertex of scalp. This test evaluates structural integrity of the pathway.
CLINICAL USES OF BERA :-
ABR is thus used mainly for newborn hearing screening, auditory threshold estimation, intraoperative monitoring, determining the type & degree of hearing loss,& auditory nerve & brainstem lesion detection.
