Audio Final Exam Flashcards
Les mesures électrophysiques permettent d’évaluer:
1) la qualité de ______
2) l’intégrité de ____
1) la qualité de la transmission entre le cerveau et les organes ciblés
2) l’intégrité de certains organes
Vrai ou Faux: la diagnostique fait partie du rôle de l’audiologiste pendant les mesures électrophysiologiques
Faux
Vrai ou Faux: Le système auditif central utilise une transmission électrique
FAUX - électro-chimique
The cochlear duct is also called the ____
Rampe médiane
What type of fluid is in the rampe médiane?
Endolymphe (rich in K+)
From the basilar membrane and moving upwards, you have the CCE, then _____ then _____
Cellules ciliées externes
Stéréocils
Kinocils
Vrai/Faux: La membrane tectoriale est rigide/ne bouge pas.
Vrai
Describe the sequence of events creating action potentials in the cochlea
- From the vibration of the oval window, waves propogate through the cochlea, causing the basilar membrane to move with them
- The movement of the cilia at the top of the hair cells against the rigid tectoral membrane opens K+ selective channels
- Since the surrounding fluid (endolymphe) is rich in K+, it enters the channels
- Depolarisation occurs, ++neurotransmitters, and the action potential leaves via the auditory sensory cells that travel via auditory nerve
- This “danse” of the cilia” occurs rythmically and at different frequencies
When was the first hypothesis about the presence of emissions in the cochlea?
1940
When was the technology for measuring cochlear emissions available in clinics?
1990s
Vrai/Faux: Les ÉOAs sont des sons peu intenses générés par le mvmt des CCEs
Vrai
What level of intensity are ÉOAs?
1-2dB
In general, ÉOAs are present if the person’s hearing threshold is better than __dB
40dB
ÉOAs can be affected by (4)
- State of the middle ear
- Background noise
- Noise from the person
- State of the CAE
The stimulus for ÉOAs is presented at about __dB SPL
80dB SPL
The difference in the level of the sound produced and the level of the stimulus should be _dB or higher (RSB)
6dB
Name 4 advantages of ÉOAs
- Fast to administer, non-invasive, objective
- Able to perform differential diagnosis (cochlear vs. retrocochlear problem)
- Able to detect hearing loss above moderate degree right from birth
- Able to test each ear separately
Vrai/Faux: Les ÉOAs peuvent détecter des dommages cochléaires avant qu’elles soient perceptibles sur l’audiogramme
Vrai
What populations are ÉOAs especially advantageous for?
- Malingering
- Children/adults on the spectrum
- Chemotherapy patients
- Those with cognitive issues/post-stroke/aphasia (who can’t respond verbally)
Les PÉATC should be completed within _ to _ ms
1.5 - 10ms
PÉALM should be completed in _ to _ ms
10 - 80 ms
PÉALL should be completed within _ ms
> 100+ms
Les PÉATC correspond to what part of the brain?
Hindbrain (bulbe rachidien)
- includes cochlea, auditory nerve, superior olives, cochlear nuclei
Les PÉALM correspond to what part of the brain?
Midbrain (mésencéphale)
- includes inferior colliculus
Les PÉALL correspond to what part of the brain?
Forebrain (cortex auditif)
- Medial Geniculate nucleus (thalamus)
- Primary Auditory Cortex
- Lateral Fissure
- Longitudinal fissure
Onde I - 1.5 - 2ms
II - 2.5 - 3ms
III - 3.5 - 4ms
IV - 4.5 - 5ms
V - 5.5 - 6 ms
In what population would you expect to see waves that appear late?
Premature infants
Name the generators of each wave in the PÉATC (5)
I - partie distale du nerf auditif
II - partie proximale du nerf auditif
III - noyau cochléaire + complexe olivaire supérieur
IV - lémnisque latéral
V - lémnisque latéral + colliculus inférieur
What is latence absolue?
Interval between the beginning of the presentation of the stimulus and the peak of any given wave
- this is the most reliable/robust
What is an interlatence?
Time between the peaks of two waves
Which wave do we use for the différence de latence interaurale?
Onde V (la plus solide)
What might PÉATCs help diagnose? (70-80dB click, supra-seuil)
Neurinome acoustique (8e nerve) or neuropathie auditive (problem with the synchronisation of nerve fibers - causes issues with understanding)
How can we use PÉATC for la recherche des seuils auditifs?
- 30 - 50dBHL click
- Looking for the lowest level that wave V will show up
Who might be a good candidate for recherche de seuil by PÉATC?
a child who failed their screening at birth;
someone in a coma; non-verbal patients;
some other medical state where they can’t participate in a normal audiogram
If PÉATC isn’t a test of hearing, what kind of test is it?
Test électrophysique
Name 5 clinical applications of PÉATC
- Prediction of auditory sensitivity
- Screening of newborns
- Evaluation of hearing with young children and babies
- Evaluation of central auditory pathway (e.g. screening for retrocochlear issues like a neurinome)
- Peri-opératoire assessment of the function of the auditory nervous system (e.g. during cochlear implant)
Describe where the electrodes go for PÉATC
- Active (+) on the forehead
- Reference (-) on the ear lobe or mastoid ipsilateral to the stimulated ear
- Ground electrode on the contro ear lobe
Vrai/Faux: Les PÉATC are looking at the function of the CCI
Faux - au delà du ganglion spiral; on cherche la réponse du nerf auditif
Vrai/Faux: Si possible, l’évaluation va utiliser la même batterie de tests qu’une évaluation typique (audiométrie tonale, vocale et mesures objectives)
Vrai
