Auditory brainstem responses

Question 1

Characterized by 2 things:

Answer 1

• shape (morphology)

- latency (how much time elapses btwn input & response)

Question 2

ABR is _______

Answer 2

• early latency response
• occurs w/in 10-15 ms of stimulus
• happens automatically in healthy system
• as you near threshold, latency increases

Question 3

When do we use this

Answer 3

• threshold estimation for hard-to-test populations
• neonatal screening
• malingering
• site of lesion testing

Question 4

Clear responses should be seen….

Answer 4

• at HIGH intensities, for waves I, III, and V

- then intensity is lowered until V is undetectable

Question 5

ABR threshold

Answer 5

• the point at which wave V is undetectable

Question 6

Conductive hearing loss will ____

Answer 6

• elevate the threshold (air-bone gap!)

- slow all waves down by the same amount

Question 7

Retrocochlear lesions will ______

Answer 7

• prolong interpeak intervals
• abnormal amplitude ratios
• Wave V prolonged or absent

Question 8

ABRs are not ….

Answer 8

• a test of hearing

Question 9

ABRs are….

Answer 9

• reliable & objective

- test of IHC & brainstem function