Otology Flashcards
Describe the sensory supply to the upper lateral surface of the pinna.
CN V3 – Auriculotemporal nerve.
(NOTE: The auriculotemporal nerve is a branch of the mandibular nerve (V3) that runs with the superficial temporal artery and vein.)
Describe the sensory supply to the lower lateral surface and medial surface of the pinna.
C3 – Greater auricular nerve
Describe the sensory supply to the superior medial surface of the pinna.
C2/C3 – Lesser occipital nerve
Describe the sensory supply to the External Auditory Meatus.
Auricular branch of vagus (CN 10).
NOTE: often termed the Alderman’s nerve or Arnold’s nerve.
Describe how you manage an external ear laceration.
Clean and allow simple primary closure of the skin with sutures, ensuring that any exposed cartilage is covered with skin.
Describe how you manage an external ear bite.
- Appropriate history (to ascertain likely organism for potential infection)
- Irrigate the wound
- Leave wound open
- Prescribe appropriate antibiotics
Describe how you manage an external ear haematoma.
- Urgent drainage
2. Apply a pressure dressing (to prevent reoccurrence)
Describe the pathology behind a cauliflower ear deformity.
There is trauma to the external ear leading to a pinna haematomas.
This causes disruption in the blood supply to the cartilage. Normally, the cartilage obtains nutrients via diffusion from vessels in the overlying perichondrium, and a disruption can therefore lead to a vascular necrosis and a subsequent cauliflower appearance to the ear.
What symptoms will a patient with tympanic membrane perforation present with?
- Pain
- Potential conductive hearing loss
Describe how you would manage a patient with an acute tympanic membrane perforation.
- Watch and wait (most perforations will heal by themselves)
- Advise patients to follow water precautions
Describe how you would manage a patient with a chronic (after a period of 6 months or more) tympanic membrane perforation.
Myringoplasty to repair the tympanic membrane
Name 2 causes of tympanic membrane perforation.
- Direct or indirect trauma
2. Otitis media
What is a haemotympanum?
Blood in the middle ear
Trauma to which cranial bone would result in a haemotympanum?
Temporal
What type of hearing loss is a haemotympanum associated with?
Conductive
How would you manage a patient with a haemotympanum?
- Conservatively
- Follow- up to ensure that there is no residual hearing loss from damage to the ossicles
How do patients with otitis external present?
- Painful ear
- Discharge from the ear
- Itchy ear
- Hearing loss ( from the discharge present in the ear canal)
What is malignant otitis externa?
A particularly aggressive infection where the infection spreads from the soft tissue of the ear canal into the bone.
Name 2 groups of patients that suffer from malignant otitis externa.
- Diabetics
2. Immunocompromised
Describe how patients with malignant otitis externa present.
- Chronic ear discharge despite topical treatment
- Severe ear pain
- Sometimes cranial nerve palsies (most commonly CNVII).
What is the mortality rate of malignant otitis externa?
10%
Describe how you would manage patients with malignant otitis externa.
- Swab discharge
- Microsuction of pus/debris which enables the drops to get to the source of the
infection - In severe infection, a wick may be used to help hold the canal open and to allow
topical treatment to diffuse through - Aggressive treatment with iv antibiotics as
well as topical treatment for an extended period of time to eradicate infection
Name a topical ear drop.
Gentamicin
Describe the epithilial lining of the middle ear.
Pseudostratified columnar epithelium
Name 3 common causative organisms of acute otitis media.
- Streptococcus pneumoniae
- Haemophilus influenza
- Moraxella
Describe how a patient with acute otitis media may present.
- Ear Pain (in young children this may be
evident by ear pulling) - Discharge (the tympanic membrane may rupture with the pus from the middle ear
discharging into the ear canal) - Fever
Describe how you would manage a patient with acute otitis media.
- Conservative: Most patients can be managed conservatively with analgesia
- Medical: In severe or persistent cases oral antibiotics may be required
- Surgery: Recurrent AOM may be helped by grommet (ventilation tube)
insertion
What is meant by squamous, active, chronic otitis media?
Active (discharging) squamous disease is also known as cholesteatoma.
(NOTE: Inactive (not discharging) squamous COM is a retraction pocket which may develop into active disease.)
What is meant by active mucosal chronic otitis media?
Chronic discharge from the middle ear travels through a tympanic membrane perforation.
(NOTE: inactive mucosal disease is where there is a tympanic membrane perforation but no active infection/discharge)
Describe the pathology behind active, mucosal, chronic otitis media.
It is thought to develop from an episode of acute otitis media.
After rupturing of the tympanic membrane there is a failure to heal.
Describe the pathology behind active, squamous, chronic otitis media.
This is thought to develop when keratinised squamous cells are introduced into the middle ear from a retraction pocket or a perforation.
Describe how you would manage a patient with a cholesteatoma.
Mastoidectomy.
Describe how you would manage a patient with mucosal, chronic otitis media.
- Topical antibiotic drops
- Aural toilet
Name some complications of mastectomy.
- Facial nerve palsy
- Altered taste from damage to the chorda typani
- CSF Leak
- Tinnitus
- Vertigo
- Deafness
What is glue ear?
Otitis media with effusion. This is when fluid is present in the middle ear with an intact tympanic membrane and is related to eustachian tube dysfunction.
Is otitis media with effusion painful?
No
What type of hearing loss is associated with otitis media with effusion?
Conductive
Describe the tympanogram of a patient with otitis media with effusion.
Flat (Type B) Tracing with normal canal volume
Describe the pure tone audiogram of a patient with otitis media with effusion.
Conductive hearing loss
Describe how you would manage a patient with otitis media with effusion.
- Conservative: most cases settle within 3 months
- Hearing aid
- Surgery: Grommets +/- Adenoidectomy
Describe the genetic transmission of otosclerosis.
Autosomal dominant
Describe the pathophysiology behind otosclerosis.
Mature bone is gradually replaced with woven bone, and symptoms develop as the stapes footplate becomes fixed to the oval window.
Which gender if affected most with otosclerosis?
Twice as many females are affected compared with males.
Otosclerosis causing symptoms is thought to occur in 1-2% of the population.
What percentage of these patients will develop bilateral disease?
85%
Describe how a patient with otosclerosis will present.
- Progressive hearing loss
- Tinnitus
- Improved hearing in noisy surroundings during early stages of disease
- Family History
What is Schwartze’s sign?
A pink hue to the tympanic membrane that is rarely seen in otosclerosis.
Describe the tympanogram of a patient with otosclerosis.
Normal type A trace
Describe the pure tone audiogram of a patient with otosclerosis.
- Conductive hearing loss
- A characteristic “Carhart notch” at 2kHz (a depression in the bone-conduction)
Describe how you would manage a patient with otitis media with otosclerosis.
- Conservative: hearing aid
- Surgery: stapedectomy
What part of the temporal bone does the inner ear reside?
Petrous
Name the 2 functional components of the inner ear.
- The vestibule and semicircular canals
2. The cochlea
Describe the 3 components of the vestibular system.
- Semicircular canals
- Utricle
- Saccule
Describe the normal physiology of the cochlear beginning at the stapes.
- The stapes articulates with the oval window, causing movement of perilymph, and
a pressure change, compensated by the round window. - Vibrations are transmitted through the endolymph to the tectorial membrane.
- Movement of the tectorial membrane causes movement of hair cells, and
subsequent depolarisation of neuronal fibres allowing perception of sound. - Transmission of information occurs via the cochlear nerve.
Where are low frequency sounds detected?
The apex of the cochlea
Define vertigo.
The hallucination of movement
Describe how a patient with BPPV would present.
Vertigo occurring with particular head movements which typically last for seconds
Describe the pathophysiology of BPPV.
Otoliths (crystals) in the semicircular canals (most commonly posterior) causing abnormal stimulation of the hair cells giving a hallucination of movement
What test is used to diagnose BPPV?
Dix-hallpike
What test is used to treat BPPV?
Employ Manoeuvre
Describe the pathophysiology of ménière’s disease.
Endolymphatic hydrops (increased fluid in the endolymphatic compartment)
Describe how a patient with ménière’s disease would present.
- Tinnitus
- Vertigo lasting minutes to hours
- Nausea & vomiting
- Fluctuating sensorineural hearing loss which over time becomes permanent
- Aural fullness
Describe how you would conservatively manage a patient with ménière’s disease.
Suggest dietary changes i.e. reduce salt, chocolate, alcohol, caffeine, chinese food.
Describe how you would medically manage a patient with ménière’s disease.
- Thiazide diuretics e.g. bendrofluazide
- Betahistine
- Vestibular sedatives e.g. prochlorperazine for acute attacks only
Describe how you would surgically manage a patient with ménière’s disease.
- Grommet insertion
- Dexamethasone middle ear injection
- Endolymphatic sac decompression
- Vestibular destruction using middle ear injection of gentamicin
- Surgical labyrinthectomy (rare)
Describe how a patient with vestibular neuronitis would present.
Severe incapacitating vertigo lasting several days associated with nausea and vomiting.
Describe what you would see upon examination of a patient with acute vestibular neuronitis.
Horizontal nystagmus, neurological exam is otherwise normal.
Describe how you would manage a patient with vestibular neuronitis.
Vestibular sedatives during the acute episode
What are Cawthorne-Cooksey exercises?
Vestibular rehabilitation for patients who are suffering from prolonged poor balance as a result of vestibular hypofunction in one ear from vestibular neuronitis.
What is the prognosis of vestibular neuronitis?
1/3 recovery to normal
1/3 some recovery
1/3 no recovery
During a weber test, what side will the tone be heard if the patient has sensorineural hearing loss?
The tone will be heard on the opposite side to the
hearing loss
During a weber test, what side will the tone be heard if the patient has conductive hearing loss?
The tone will be heard on the same side as the hearing
loss.
This is because the conductive loss will block out background noise so
relative to the other ear the tone will sound louder in that ear.
If a patient has sensorineural hearing loss, what would be the result of a rinnie test?
Rinne +ve if heard at all because you are still getting
the benefit of the amplification of the external and middle ear.
If a patient has conductive hearing loss, what would be the result of a rinnie test?
Rinne -ve as you are no longer getting the benefit of the
amplification from the middle and external ear.
What does a pure tone audiogram (PTA) assess?
The hearing thresholds of patients at different frequencies.
Each frequency is tested a number of times and the quietest tone that can be reliably heard is marked on the audiogram.
Describe the axises of a pure tone audiogram.
The frequency in hertz is on the x axis and the decibel scale on the y axis with 0 at the top and increasing decibels (loudness) as you descend the y axis.
True or false: the higher the line on the pure tone audiogram the better the hearing.
TRUE
The frequency in hertz is on the x axis and the decibel scale on the y axis with 0 at the top and increasing decibels (loudness) as you descend the y axis. The higher the decibel number the louder the noise.
Above what dB is considered normal on an audiogram?
20dB
When measuring a patient’s bone conduction (approximating a patient’s sensorineural hearing), why must noise be played to the contralateral ear?
Sound played through the bone conductor to one ear will not only travel to the cochlear on that side but also to the cochlear on the other side so if there is any discrepancy in the hearing between the ears the other side will need to be masked.
Describe what an audiogram will show if the patient has conductive hearing loss.
Normal bone conduction and reduced air conduction
thresholds i.e. an air bone gap
Describe what an audiogram will show if the patient has sensorineural hearing loss.
The audiogram will have reduced bone and air conduction thresholds i.e. no air
bone gap
What is the purpose of a tympanogram?
To measure the compliance of the tympanic membrane
What does the peak of a tympanogram represent?
The compliance peaks when the pressure in the canal equals that of the middle ear.
Describe the 3 classical tympanogram tracings.
Type A: Normal result, peak centred on 0 daPa on x-axis
Type B: Flat
Type C: The peak of the tracing has negative pressure
Name a pathology that would have a Type A tympanogram tracing.
None, this would be a normal result
Name a pathology that would have a Type B tympanogram tracing.
Middle ear effusion/ Perforation
Name a pathology that would have a Type C tympanogram tracing.
Eustachian tube dysfunction
