Bera

Bera


BERA

  • Auditory brainstem response (ABR): Also called BAER or BAEP (brainstem auditory evoked response or potential) or BERA (brainstem evoked response audiometry)
  • Elicits brainstem responses to auditory stimulation by clicks or tone bursts.
  • It is a non-invasive technique to find the integrity of central auditory pathways through the VIIIth nerve, pons and midbrain.
  • It measures hearing sensitivity in the range of 1000-4000 Hz.

WAVES OF BERA

  • In auditory brain stem evoked response audiometry, the impulses are generated by the brain stem in the form of waves.

These waves are considered to originate from the following anatomical sites:

  1. Distant Cochlear nerve- Wave I
  2. Proximal Cochlear Nerve-Wave II
  3. Cochlear nucleus – Wave III
  4. Superior olivary complex – Wave IV
  5. Nulclei of lateral lemniscus – Wave V
  6. Inferior colliculus – Wave VI
  7. Medial Geniculate Body-Wave VII
  • These peaks occur in most readable form in response to click stimuli over a period of 1 – 10 milliseconds after the stimulus in normal hearing adults.
  • BERA is resistant to the effects of sleep, sedation, sleep and anesthesia. Its threshold has been found to be within 10dB as elicited by conventional audiometry.

 USES OF BERA 

  • As a screening procedure for infants.
  • Investigation of choice for audiometric evaluation of an infant is BERA
  • Best screening test to evaluate hearing in a neonate is Otoacoustic Emission.
  • Most screening programmes for newborn hearing ability uses otoacoustic emission as the initial test. It this test fails then auditory brainstem response is used for screening.
  • Otoacoustic emissions (OAEs) are objective, noninvasive, and rapid measures (typically less than 2 minutes) used to determine cochlear outer hair cell function.
  • To determine the threshold of hearing in infants; also in children and adults who do not cooperate and in malingerers.
  • It is the most reliable audiological method of differentiating between cochlear and Retrocochlear hearing losses
  • To diagnose retrocochlear pathology particularly acoustic neuroma.
  • To diagnose brainstem pathology, e.g. multiple sclerosis or pontine tumours.
  • To monitor CN VIII intraoperatively in surgery of acoustic neuromas to preserve the function of cochlear nerve.
Exam Question
 
  • Investigation of choice for audiometric evaluation of an infant is BERA.
  • Best screening test to evaluate hearing in a neonate is Otoacoustic Emission.
  • Wave II in BERA originates from Proximal eighth nerve.
Don’t Forget to Solve all the previous Year Question asked on Bera

Leave a Reply

%d bloggers like this:
Malcare WordPress Security