Otology Flashcards
(98 cards)
What frequency of tuning forks should one use to peroform Rinnes and Webers tests?
512Hz
What does a Weber’s test lateralising to the right mean?
A conductive hearing loss in the R ear
Or
A sensorineural hearing loss in the L ear
If you get a senorineural loss in the L ear where will Webers test lateralise to?
The pt will have better hearing in the R ear.
If Rinne’s test is positive then is BC>AC or is AC
AC it better than (>) BC.
This is normal
If Rinne’s test is negative what does this mean?
That BC is better than AC.
This is abnormal and indicates a conductive hearing loss
What causes a false negative Rinne’s test?
The ear you are testing has profound sensorineural hearing loss (i.e. its dead)
So when testing BC the other ear picks up the sound giving the picture that BC>AC however BC and AC from that ear will not actually occur as it is dead.
Do pure tone audiograms test BC or AC?
They test both.
How are the L and R ears BC and AC noted down on a pure tone audiogram?
R - AC –> O RED
R - BC –> [ RED
L - AC –> X BLUE
L - BC –> ] BLUE
Under what volume should normal pt be able to hear and at what frequencies
Normal hearing is to be able to hear:
All frequencies
At at least 20dB or less
What indicates normal age-related hearing loss (presbycusis)?
A sloping off of hearing above 4000hz
What does tympanometry measure?
The compliance/stiffness of the eardrum
What is tympanometry also known as?
Impedance audiometry
In tympanometry the probe has a number of channels, what are these?
A speaker to send the sound wave
A microphone to receive the sound wave
A device to vary the pressure
What is a Type B tympanogram?
A flat line
What is a Type C tympanogram?
A normal shape graph BUT further towards the Y-axis
What does a Type C tympanogram indicate?
The drum is retracted, as there is a negative pressure in the middle ear.
What does a Type B tympanogram indicate?
There is fluid in the middle ear
What can an excessively tall peak on a tympanogram indicate?
A hyper mobile drum
such as in ossicular discontinuration
What is presbyacusis?
the degenerative loss of hearing in old age (>50yrs)
What are the characteristics of presbyacusis?
Bilateral high frequency hearing loss
With or without tinnitus
How is presbyacusis treated?
Hearing aids
to help with hearing loss and mask tinnitus
What causes presbyacusis?
Atrophy of the outer hair cells in the cochlea
What is a cholesteatoma?
a cyst or sac
of keratinizing squamous epithelium
in the middle ear and/or mastoid process
Where do cholesteatomas most commonly occur?
in the attic aka epitympanic part of the middle ear