14 Ear Flashcards
What is Hitzelberger’s sign
Hypoesthesia of the postauricular area a/w CN 7 compression 2/2 vestibular schwannoma
“How can one differentiate between relapsing polychondritis involving the ear and other causes of external otitis?
RP will spare the lobule
“What is the likely diagnosis for someone who presents with vesicles on the pinna and external auditory canal (EAC), facial nerve weakness, and sensorineural hearing loss (SNHL)?”
Ramsay Hunt syndrome
What is lobule colobomata
Bifid lobule
What is cryptotia
Absence of the retroauricular helix
What is cockleshell ear
Type III cup ear where the ear is malformed in all directions
Why is it particularly difficult to assess the auditory fnc in pts with bilateral aural atresia
Masking dilemma (so you should use ABR)
What is Brown sign
Seen with glomus tympanicum tumors where the TM blanches when pressure is applied from the pneumatic otoscope
What is the definition of auditory threshold
Lowest level at which the pt can detect sound 50% of the time
Where is bone-conducted sound transmitted
directly to the cochlea
Which part of the auditory system is assessed by air conduction tests
The entire auditory system
What is the significance of a negative Rinne at 256 Hz, 512 Hz, and 1024 Hz?
At least a 15 dB CHL, 25-30 CHL, and 35 CHL respectively
What percent of the time will the Rinne test miss and air bone gap < 30 dB
50%
“A patient has a negative Rinne at 256 Hz AS. At 512 and 1024 Hz, it is positive as it is at all three frequencies AD. The Weber test lateralizes to the left at all three frequencies. He hears a soft whisper AD and a soft to medium whisper AS. What is his hearing loss?”
15 dB CHL AS
“What is the significance of the ability to hear a tuning fork placed on the teeth?”
Indicates that cochlear reserve is present and surgery may be beneficial
How are air and bone thresholds measured?
By first obtaining a positive response, then lowering the intensity by 10 dB increments until no response is obtained
What are the stimuli used to obtain a speech reception threshold (SRT)
Spondees - 2 syllables with equal emphasis on both syllables
How is SRT measured
“By starting at minimal intensity and ascending in 10 dB increments until the correct response is identified.”
What is the definition of SRT
The lowest hearing level at which half of the words are heard and repeated correctly, followed by at least two correct ascending steps
“SRT should be within ___ dB of pure tone average (PTA).
10 dB
What is the speech detection threshold (SDT)?
Hearing level at which 50% of the spondaic words are detected; usu 6-7 dB lower than the SRT
How is speech discrimination testing performed
Phonetically balanced monosyllabic word lists (50) are administered 30-50 dB above threshold and the correct percentage is identified
What is a nl word recognition score
90-100%
What is the significance of speech discrimination scores?
Pts w/ cochlear and retrocochlear pathology will have poor to very poor scores, respectively. Those with only CHL will have nl scores when the intensity level is sufficiently loud.
What is rollover
A decrease in speech discrimination scores when presented at higher intensities; suggestive of a retrocochlear lesion.
“A patient with an SRT of 55 dB HL and a speech discrimination score of 64% at 75 dB HL has what kind of hearing loss?
SNHL
What is interaural attenuation
The reduction of sound when it crosses from one ear to the other
What is nl interaural attenuation of air-conducted tones
40-80 dB depending on whether ear inserts or headphones are used and also on the freq being tested
What is the nl interaural attenuation value for bone conduction
0 dB
When should masking be used
When the air conduction threshold of the test ear exceeds the bone conduction threshold of the nontest ear by a value greater than interaural attenuation
What should you mask with
Narrow band around the frequency you are testing***
What is crossover
The attained responses represent the performance of the nontest ear rather than the test ear due to a large sensitivity difference b/w the ears
When does the masking dilemma occur
Bilateral 50 dB or greater air-bone gaps
What is the Stenger’s test
Test to see if the patient is malingering; appropriate to administer if there is a >20 dB difference b/w ears in voluntary thresholds
Where is the peak pressure point in a nl tympanogram in an adult
Between -100 and +40 daPa
What would the tympanogram look like in an ear with an interrupted ossicular chain
Very steep amplitude, high peak (type Ad)
What is the acoustic reflex threshold
The lowest stimulus level that elicits the stapedial reflex
In the nl middle ear, contraction of middle ear muscles occurs at which pure tones
65-95 dB HL