Term
-Auditory evoked response (AER): activity in the ___ system (ear, auditory nerve, or auditory regions of the brain) produced by ___ stimuli
-Sound presented to the ears elicits ___ activity from the auditory pathway (e.g. the brain) & is recorded by ___ taped to the head |
|
Definition
| auditory; acoustic; electrical; wires |
|
|
Term
| method of recording transient AERs from the cochlea & CN VIII with an ear canal electrode (or promontory electrode) |
|
Definition
| Electrocochleography (ECochG) |
|
|
Term
Electrocochleography (ECochG):
-includes cochlear ___, summating ___, & compound ___ ___
-action potential: ___ change in electrical potential of nerve or muscle tissue; 2. In AERs, ___-___ or ___ action potential of CN VIII, the main component of ECochG and Wave __ of the ABR |
|
Definition
| microphonic; potential; action potential; synchronous; whole-nerve; compound; I |
|
|
Term
| originates from the region of the auditory radiations & cortex |
|
Definition
| Auditory Middle Latency Response (AMLR) |
|
|
Term
Auditory Middle Latency Response (AMLR):
-the primary response component is a vertex positive peak (Pa) at __ to __ ms following signal presentation |
|
Definition
|
|
Term
| Auditory evoked potential, originating from the cortex |
|
Definition
| Auditory Late Response (ALR) |
|
|
Term
| Auditory Late Response (ALR): -Response has 2 main waveform peaks: a vertex negative peak (N1) at about ___ ms & a vertex positive peak (P2) at about ___ ms following signal presentation |
|
Definition
|
|
Term
| major peak of the endogenous event-related potential |
|
Definition
|
|
Term
P300:
-response occurs around ___ ms following acoustic stimulus onset |
|
Definition
|
|
Term
| AER that originates in VIII nerve & auditory brainstem structures |
|
Definition
|
|
Term
ABR:
-Consists of __ to __ peaks that represent neural function of auditory pathways & nuclei |
|
Definition
|
|
Term
| portion of the brain between spinal cord & cerebrum, including the diencephalon, midbrain, pons, and medulla oblongata |
|
Definition
|
|
Term
| structural or functional pathologic change involving the brainstem |
|
Definition
|
|
Term
| hearing mechanism of the peripheral nervous system, including the cochlea & CN VIII |
|
Definition
| Peripheral auditory nervous system |
|
|
Term
| What are AERs also known as? |
|
Definition
| Auditory evoked potentials (AEPs) |
|
|
Term
AERs:
-___: consequence of a temporary change in membrane potential of nerve or muscle tissue upon excitation |
|
Definition
|
|
Term
| What are the wave generators? |
|
Definition
1. distal 8th nerve
2. Proximal 8th nerve
3. CN and/or SOC
4. Multiple brainstem origins
5. LL |
|
|
Term
AEP Measures-The Challenge:
-Neural generators are ___ in the head
-Must be “___ conducted” from neural generator to electrodes taped to head
-Requires compound ___ firing of multiple neurons to generate responses that can be detected by surface electrodes
-Competing ___ noise is greater than response |
|
Definition
| deep; volume; synchronous; electrical |
|
|
Term
-_______: the recording of electrical potentials of the brain from scalp electrodes
-______: electrophysiologic recording of nerve & muscle activity, including the facial nerve
-_____: recording of electrical activity generated by muscles |
|
Definition
| Electroencephalography (EEG); Electroneuronography (EnoG); Electromyography (EMG) |
|
|
Term
During AEP Measurement Try to Minimize Artifact:
-____: unwanted signal that can interfere with the measurement of desired signals
-___ artifact: the unwanted myogenic electrical activity generated from neck or other muscles
-___ ___: in AEP measures, the process of eliminating recording samples that exceed a criterion amplitude level |
|
Definition
| Artifact; Muscle; Artifact rejection |
|
|
Term
| Describe two primary purposes of ABR evaluation |
|
Definition
| Obtain neuro-diagnostic information and to estimate auditory thresholds |
|
|
Term
| time between the stimulus presentation & the presence of a response or peak within a response. Measured in ms |
|
Definition
|
|
Term
| Describe the expected relationship between stimulus intensity & ABR response latency |
|
Definition
| As intensity decreases, latency increases |
|
|
Term
| What are the normal ABR absolute latencies for adults? |
|
Definition
| 1.5 msec for wave 1, 2.5 msec for wave 2, 3.5 msec for wave 3, and 5.5 ms for wave 5 |
|
|
Term
Neuro-diagnostic ABR:
-High-level stimuli (e.g. ___ dB nHL)
-Often recorded in ___ channels as in ___ and ___
-What wave forms are identified?
-Compare absolute latencies to ___ values; compare responses between ___
-Compare ___ latencies |
|
Definition
| 80; 2; (ipsilateral & contralateral); 1, 3, and 5; normative; ears; inter-peak |
|
|
Term
| magnitude of a sound wave, acoustic reflex, evoked potential; (height) of a peak within the response |
|
Definition
| amplitude measured in microvolts |
|
|
Term
| What is the relationship between intensity and amplitude? |
|
Definition
| As stimulus intensity decreases, amplitudes decreases |
|
|
Term
Possible Results of Neuro-Diagnostic Click-Evoked ABR:
-normal absolute & interpeak-latencies=___
-normal inter-peak latencies; prolonged absolute latencies of all waves=___
-normal inter-peak latencies; poorer overall waveform morphology=___
-prolonged latencies of later waves and prolonged inter-peak latencies; ABR may be absent=____
-bnormal ABR=____ |
|
Definition
| normal; CHL; sensory; neural; auditory neuropathy |
|
|
Term
| auditory disorder that appears to disrupt synchronous activity of the auditory nervous system |
|
Definition
|
|
Term
| Auditory Neuropathy is characterized by ___ cochlear OHC function, ___ ABR, ___ reflexes, and threshold and supra-threshold hearing ___ of varying degrees |
|
Definition
| normal; abnormal; absent; disorders |
|
|
Term
What are the electrode placement zones represented in this picture?
[image] |
|
Definition
| left ear lobe (blue) is A1, right earlobe (red) is A2, green is Fz, and purple is Fpz |
|
|
Term
| electrode attached to the positive-voltage, noninverting side of a differential amplifier; vertex electrode in conventional ABR recordings |
|
Definition
| Active or noninverting electrode |
|
|
Term
| electrode attached to the side of a differential amplifier that inverts the input by 180°; reference or earlobe electrode in conventional ABR recordings |
|
Definition
|
|
Term
| the electrode that attaches the patient to ground |
|
Definition
|
|
Term
| What type of electrodes are the Fz, Fpz, and A1 and A2? |
|
Definition
Fz-noninverting
Fpz-common electrode
A1 and A2-inverting electrodes |
|
|
Term
| What are some advantages of the 2 channel recording? |
|
Definition
| Contra recordings yield better separation of waves 4 and 5. May also allow tester to determine ear that is responding |
|
|
Term
| Sing-channel recordings only yield what kind of results? |
|
Definition
|
|
Term
| Describe patient preparation techniques for ABR testing |
|
Definition
-Clean sites with alcohol pads &/or abrasive liquid
-May put conductive gel or paste on electrodes to enhance connection between electrodes & skin
-Tape disc-type electrodes to skin
-“clip-trodes” clip on ear lobes
-Check impedance before starting test & throughout test session if “electrical noise levels” increase
-If impedance is too high, re-prep skin then re-attach electrodes |
|
|
Term
| arrangement of electrodes in evoked potential measurement |
|
Definition
|
|
Term
| What are some advantages of using insert ear phones? |
|
Definition
| Reduce ambient noise, Increase inter-aural attenuation of the stimulus, Reduce ear canal collapse, Stay in place better, Deliver sound to ears accurately & consistently, Make infection control procedures time-efficient and more |
|
|
Term
|
Definition
|
|
Term
Stimulus Types:
-A ___ is a rapid-onset, short-duration, broadband sound, produced by delivering an electric pulse to an earphone; used to elicit an ABR and transient-evoked optoacoustic emissions
-A _______ is a brief pure tone that has a rapid rise & fall time, the duration if long enough to be perceived as having tonality. Yields a greater frequency-specificity. |
|
Definition
|
|
Term
| What is the rationale for the use of click stimuli? |
|
Definition
| Neurons are MOST responsive to stimulus ONSET |
|
|
Term
-Frequency content of a stimulus is ___ proportional to the duration
-Clicks: ___ duration (___ ms = 100 microseconds)
-Clicks primarily stimulate the cochlea at __-__ kHz region |
|
Definition
| inversely; brief; 0.1; 1-4 |
|
|
Term
| ___ is Not Determined Adequately with Click-Evoked ABR Alone |
|
Definition
|
|
Term
| What is the rationale for using tone bursts? |
|
Definition
| Tone-burst stimuli yield greater frequency-specificity than clicks |
|
|
Term
Toneburst Durations:
-Rise/fall times are longer for ___ freqs & shorter for ___ freqs
-Duration: rise/fall and plateau times vary depending on ___
-Use ___ times for lower frequencies to include more cycles to increase likelihood that stimuli sound like tones (not clicks) |
|
Definition
| lower; higher; frequency; LONGER |
|
|
Term
Stimulus Polarity Options:
-____: in the propagation of sound waves, the time during which the density of air molecules is INCREASED above its static value
-____: in the propagation of sound waves, the time during which the density of air molecules is DECREASED below its static value
-___: characteristic of AEP stimuli in which the rarefaction and condensation polarity of a click or tone burst are alternated successively |
|
Definition
| Condensation; Rarefaction; Alternating |
|
|
Term
-____ click: rapid-onset, short-duration, broad-band sound produced by delivering a positive-polarity electric pulse to an earphone
-___ ___: rapid-onset, short-duration, broad-band sound produced by delivering a negative-polarity electric pulse to an earphone |
|
Definition
| Condensation; Rarefaction click |
|
|
Term
-Rarefaction moves the transducer diaphragm ___ first, causes the basilar membrane to move ___ and ___ hair cells
-Condensation moves the transducer diaphragm ___ first and causes basilar membrane to move ___ and ___ hair cells initially the ___ hair cells in the next phase |
|
Definition
| inward; upward; excites; outward; downward; inhibits; excites |
|
|
Term
Dr. Hall Recommends Using Rarefaction Polarity First:
-Rarefaction: best for activating the ___ & ___ pathways and yields ___ amplitudes of waveforms
-Change to condensation if waveform morphology is ___ with rarefaction clicks |
|
Definition
| cochlea; auditory; larger; poor |
|
|
Term
Stimulus Rate-More than 20 clicks/sec
-Choose as fast as possible without ___ the response
-May be used to evaluate ___ integrity
-Can use faster rates with ___ (20-80 clicks/sec) than later AEPs |
|
Definition
|
|
Term
-A high stimulus intensity is used for ___ ABR
-For a dual purpose ABR there will be ___ intensity levels |
|
Definition
|
|
Term
Stimulus Repetitions:
-Variable, depends on _______
-Complete ___ sweeps/repetitions when more noise is present (to increase the signal relative to the noise)
-Equipment may have “___” # of sweeps |
|
Definition
|
|
Term
| Signal averaging takes advantage of the fact that responses are ___ over time, but ongoing EEG activity & electrical interference is ___ in respect to the stimulus |
|
Definition
|
|
Term
Signal averaging 1:
-Response is ___-__ to the stimulus |
|
Definition
|
|
Term
Signal Averaging 2:
-System records ___
-AER voltages are ___ at a given time following successive stimuli
-Noise is ___
-After multiple “sweeps,” AER stays at ___ voltage, while the noise reduces toward ___ |
|
Definition
| voltages (“snapshots”); identical; random; characteristic; zero |
|
|
Term
| As INCREASE # of Sweeps, Noise ___ |
|
Definition
|
|
Term
Masking:
-Requires __-channel recording (e.g. “ipsilateral” & “contralateral” waveforms)
-Masking is needed only if Wave __ is absent in the ipsilateral recording |
|
Definition
|
|
