CH. 9 - Electrophysio Flashcards
waveform that reflects electrophysiologic function of CNS in response to sound
Auditory Evoked Potential (AEP)
what does AEP stand for?
Auditory Evoked Potential
placing electrodes on scalp and measuring changes in electric potential throughout brain is a process called ___
Electroencephalography (EEG)
extracts a signal for background of noise
signal averaging
four main applications for AEPs
- infant hearing screening
- prediction of hearing sensitivity for anybody
- diagnostics for CANS function
- monitoring auditory nervous system during surgery
the biggest advantage of using an AEP is
patient doesn’t need to have a behavioral response
This type of test is an objective way of measuring PANS and CANS
AEP
In an AEP, the equipment obtains a ___ that is measuring ___ activity in response to ___
waveform; activity; sound
two things that attach to patient in AEP
electrodes and insert headphones
Three types of electrodes in AEP
1) active noninverting (Cz) +
2) Reference inverting earlobe (A1/A2) -
3) Ground electrode on forehead (Fz) ⊥
process in AEP that extracts signal from background of noise
signal averaging
what are the five AEP tests?
Electrocochleography (ECoG)
Auditory Brainstem Response (ABR)
Middle Latency Response (MLR)
Late Latency Response (LLR)
Auditory Steady State Response (ASSR)
what does ECoG stand for?
Electrocochleography
what does ABR stand for?
Auditory Brainstem Response
what does MLR stand for?
Middle Latency Response
what does LLR stand for?
Late Latency Response
what does ASSR stand for?
Auditory Steady State Response
what does ECoG measure?
electric activity of cochlea and VIIIth nerve
which AEP has five peaks?
ABR
the ABR detects electrical activity from the ___ __ to the __ __
8th nerve; lateral lemniscus
ABRs for newborns, or ____, are usually run by ___ and are __
AABR; technicians; automated
this AEP is difficult to record but useful in diagnosing APD
MLR
this AEP is useful for patients who can’t participate in behavioral testing, separating auditory disorders and predicting hearing thresholds
ABR
this AEP is useful for differentiating endolymphatic hydrops from other HL and identifying auditory neuropathy
ECoG
these two AEPs are useful for intraoperative monitoring of the VIIIth nerve
ECoG; ABR
these two AEPs are useful in detecting APD
MLR, LLR
another name for LLR
P300
in these two AEP tests, the patient must be awake
MLR, LLR
in this AEP, best results happen when the patient is asleep
ASSR
The disadvantage of an ASSR is that __
most of time patient has to be under sedation - risk and cost
This AEP is excellent for predicting a pure-tone audiogram
ASSR
This AEP is great for predicting thresholds for patients with high levels of HL
ASSR
If a patient is an unreliable narrator, this test is great for measuring HL
ASSR
T or F - newborn hearing screening will accurately identify all newborns who need an auditory eval or follow-up
F - some missed, some false positives
what are two cases where a newborn would fail a hearing screening but actually be fine long-term?
-Middle ear disorder
-Neuromaturational delay - brainstem hasn’t fully matured for some babies yet
what test is prescribed for a newborn hearing screening?
ABR (AABR for newborns)
what three AEPs are most useful for predicting hearing sensitivity?
ABR, ASSR, LLR (rare)
what AEP is most useful for diagnostic applications?
ABR
what AEP is most useful for surgical monitoring
ECoG
in order to get best results, it’s best to perform ___
multiple tests
AEPs are colloquially known as
electrophys measures
what does OAE stand for?
otoacoustic emissions
when ___ hair cells are healthy, OAEs will be present. when they are damaged, it will not be present
outer
what are otoacoustic emissions?
Low-intensity sounds generated by cochlea
two types of OAEs
evoked and spontaneous
two subtypes of evoked OAEs
-Transient - TEOAE
-Distortion product - DPOAE
TEOAEs are evoked using a ___, whereas DPOAEs are evoked using ___
click; two frequencies
DPOAEs use ___ frequencies, called:
2; f1 and f2
big thing that OAEs can miss
mild sensorineural
OAEs can not catch these four
-mild sensorineural hearing loss
-Auditory neuropathy
-Low-freq hearing loss
-Central auditory processing
OAEs are screening tools, which means they CAN’T predict these three things
-Degree of HL
-Type of HL
-If there is hearing loss definitively
if an OAE is present, middle ear is functioning ___
normally
If OAE is present but there is HL, you can assume problem is ___
retrocochlear disorder
