Otology Flashcards
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
What are the sings and symptoms of cholesteatoma?
foul smelling discharge (if CSOM)
a conductive hearing loss
attic aural polyps (a proliferation of chronic inflammatory cells)
What bacteria is thought to cause cholesteatoma?
Pseudomonas
What are thought to predispose a pt to cholesteatoma?
genes i.e. congenital
What are the risks of cholesteatoma?
It can essentially erode anything including: (it takes years)
ossicles - 50db conductive hearing loss
lateral semicircular canal - vertigo
CN7 - facial palsy
cochlea - sensorineural heaing loss
roof of middle ear into brain - sepsis
sigmoid sinus - thrombosis
How is cholesteatoma treated?
Surgical removal
What are the types of otitis media?
Otitis media with effusion (sterile fluid aka glue ear)
Acute (suppurative) otitis media (has a suppurative fluid and is due to infection)
Chronic suppurative otitis media (CSOM)
What occurs if there are repeated attacks of acute otitis media?
The repeated attacks weaken the tympanic membrane.
This eventually causes perforation
which does not heal
This is now chronic suppurative otitis media (CSOM)
Which demographic commonly get otitis media?
Children with URTI (these track up and cause OME)
What does the infection cause in acute otits media?
The infection in the middle ear causes pus accumulation
This leads to pressure on the tympanic membrane, thus pain.
This can then rupture causing otorrhoea and reduction in otalgia.
What are the symptoms of AOM?
Otalgia
Otorrhoea (one perforated)
Conductive hearing loss
Pyrexia
What is the treatment for AOM?
antibiotics (amoxycillin + clavulanic acid = Augmentin)
analgesia
Myringotomy (tiny incision is created in the eardrum) if condition fails to resolve or is having serious side-effects
How must a perforated ear be managed?
It should be kept dry until healed.
What is otitis media with effusion colloquially known as?
Glue ear
What is the essential cause of otitis media with effusion (Glue ear)
Poor ventilation of the middle ear due to narrowing of the eustachian tube.
How common is glue ear and what is the normal prognosis?
75% of children will have it at some point
most resolve spontaneously
How long can chronic otitis media with effusion last?
months or even years.
What are the issues with long term glue ear?
can cause a hearing loss of ~25dB which can affect
schooling/development
It can predispose to acute supperative otitis media
What is the consistancy of the liquid in otitis media with effusion?
Thick and sticky (however it is NOT purulent)
What are the possible causes of eustachian tube narrowing (that leads to glue ear)?
infection or allergy of middle ear mucosa
eustachian tube dysfunction
as a sequale of acute supperative otitis media
What is the treatment for glue ear?
50% resolve spontaneously in 3 months (so wait 3mnths 1st)
after which if not resolving treatment is indicated:
grommets
OR
hearing aid
for a few years as kids tend to grow out of it
What degree of hearing loss can be expected in CSOM?
15dB normally
60dB if the ossicles are disrupted
What is the treatment for CSOM?
aural toilet
and
antibiotic + steroid drops
Myringoplasty may help
What is otosclerosis?
Spongy bone formation around the oval window and as it grows it fuses with the stapes
What is the mechanism by which otosclerosis causes sensorineural hearing loss?
the compact bone (of the otic capsule/bony labyrinth) is replaced by spongy bone
which produces toxins
which destroy the cochlear
causing senirneural hearing loss
What is the mechanism by which otosclerosis causes conductive hearing loss?
more commonly
the bony overgrowth affects the footplate of the stapes
which results in its fixation
and leads to conductive hearing loss
What increases your risk of developing otosclerosis?
family history
How common is otosclerosis?
1/100 but very few are symptomatic
What are the symptoms/signs of otosclerosis?
Bilateral hearing loss
Paracusis willisii (background hearing is better)
Tinnitus
Positional vertigo
What is the usual age otosclerosis become symptomatic?
30
How is otosclerosis diagnosed?
Clinically: normal ear drum w/
conductive hearing loss
Definitively:
surgical examination of the stapes footplate (fixation being the most common cause of deafness in otosclerosis)
What is the treatment for otosclerosis?
hearing aid (if required)
if severe then surgically replace the stapes with a Teflon piston (small risk of sensorineural deafness)
What are the classical signs of noise induced hearing loss?
Tinnitus is very common
Classical 4 or 6kHz dip on audiogram
Genuine Hx of noise exposure
What is the treatment for noise induced hearing loss?
Councelling for tinnitus
and provision of a hearing aid
What is the usual cause of tinnitus?
Sensorineural hearing loss
What is the classical presentation of Meniere’s disease?
Typically 45y/o with the triad:
1) Severe recurrent attacks of vertigo lasting from 10 minutes to 24 hours
2) Tinnitus
3) Fluctuating but deteriorating sensorineural hearing loss
Is Meniere’s disease bi or unilateral?
unilateral but can progress to be bilateral
What is the character of the hearing loss in Meniere’s disease?
initially affects the lower frequencies
Recovers but does eventually permanently deteriorate
How often do attacks occur in Meniere’s disease?
In clusters or may only occur very occasionally.
How is Meniere’s disease treated?
Acutely:
-> vestibular sedative (e.g. prochlorperazine)
Long term:
- > betahistine (a vasodilator)
- > diuretics
- > avoidance of caffeine and salt
If severe:
-> Surgery - e.g. destroying the labyrinth or cutting 8th nerve.
Is otitis externa acute or chronic?
It can be both
What is otitis externa?
generalised inflammation of the external ear canal and ear
thus causing swollen + narrowed EAM
What can predispose to otitis externa?
Eczema
local trauma
commonly otitis media (this should be checked for once you can see down the ear canal)
What are the signs/symptoms of otitis externa?
Swollen ear + canal (thus causes conductive hearing loss) this can extend to the face
Tender ear + canal
Itchy ear + canal
otorrhoea
Cracking/crusting skin (can allow fungus to enter)
if chronic skin maybe thickened or fissured
Permanently moist
What is the treatment for otitis externa?
aural toilet (dry mopping or suction)
antibiotic (sytemic if severe) and/or steroid ear drops
antifungals (if indicated)
glycerine (to withdraw moisture from the ear)
Is swimming with grommets harmful?
No
How long does it take for the ear drum to heal after rupture after due to ASOM?
4-5 days
What is commonly misdiagnosed as ASOM?
Viral acute otitis media
What is a retraction pocket?
An indrawing of the tympanic membrane and is self cleansing (when not self cleansing = cholestiatoma)
What is the treatment of retraction pockets?
Just ENT follow-up
What is typanosclerosis and what are the symptoms?
Scaring of the tympanic membrane
can have no symptoms or
total obliteration of the middle ear - 50db conductive hearing loss
What is a “safe” ear infection?
There is no such thing, all are potentially dangerous
What should be done with asymptomatic perforations?
Nothing, just leave alone
Will fractured or disrupted ossicles repair themselves?
No
What should be done with intracranial sepsis of unknown cause?
ENT Hx and Ex
What are the classic ENT presentations of intracranial sepsis?
Ear sepsis or sinusitis
who develop headache, malaise and loss of concentration
What is the issue regarding unilateral presbycusis?
It doesn’t really occur so this acoustic neuroma
What is an acoustic neuroma?
Benign tumour of the auditory nerve.
What are the early signs of acoustic neuroma?
Hearing loss or
tinnitus
Who should always be screened for acoustic neuroma?
Patients with unilateral or asymmetrical
sensorineural hearing loss
What should you do with patients who have had sudden sensorineural hearing loss?
Urgent ENT referral (its a medical emergancy)
How can non-organic hearing loss be diagnosed?
Electric response audiometry
What should you suspect if a pt has a discharging ear and a VII nerve palsy?
Medical emergency - suspect cholestiatoma
What are the frequencies of the different types of temporal bone fracture and which has a worse prognosis?
Longitudinal (80%)
Transverse (20%) - worse prognosis
What are the three types of otitis externa?
diffuse
furuncle
malignant
What is diffuse otitis externa?
Normal generalised otitis externa
What must you suspect if there is otitis externa with mucus?
THIS MUST BE COMING FROM THE MIDDLE EAR via a perforation
as there are not mucus secreting glands in the ear canal
What is furuncle otitis externa?
Infection of the hair follicles in the outer 1/3 of the ear canal by staphylococcus, usually after a hair has been plucked
What is malignant otitis externa?
Agressive otitis externa NOT CANCEROUS
due to pseudomonas aeruginosa
Who is malignant otitis externa most commo in?
Immunocompromised
Diabetics
What is the most common cause of acute otitis media?
50% viral
The rest are bacterial causes
What is a common complication of AOM?
acute mastoiditis
What is the dangerous with acute mastoiditis?
The bacterial in the purulent fluid in the mastoid air cells start to erode surrounding bone
What is a worrying sign associated with acute mastoiditis?
unilateral headache as it is a sign of intracranial complications
When can the need for a nasal fracture be properly assessed?
Immediately after or 5-10 days later once the inflammation has reduced
