Otology Flashcards
Which landmarks should you know of the pinna?
concha
helix
antihelix
tragus
Why is pinna haematoma treated as an emergency?
?? haematoma formation between perichondrium and cartilage, where cartilage has poor vascular supply- Avascular necrosis risk
Which part should you straighten out before performing ear exam for the ear canal
posterior part of external ear
is the lateral tympanic membrane middle or outer ear?
outer
What are the layers of the pinna?
?
What is the cone of light?
anteroinferior quadrant- when performed otoscopy
What are the bones of the middle ear? /auditory ossicles
malleus, incus, stapes
What is the oval window?
membrane-covered opening from the middle ear to the cochlea of the inner ear. Sound waves cause vibration of the tympanic membrane and the ossicles transmit those vibrations to the oval window, which leads to movement of fluid within the cochlea and activation of receptors for hearing.
What is the round window?
membrane-covered opening in the cochlea that bulges outward in response to pressure placed on the oval window by the ossicles.
Which nerve travels alongside vestibulocochlear nerve?
facial nerve
Which nerve travels between the auditory ossicles that can be damaged in surgery?
chorda tympani- supplies ant 2/3 taste?
Which cells are found in the inner ear?
hair cells- cochlear nerve
What is normal tympanometry?
type A
WHat does tympanometry assess?
middle ear
What is the cause of pinna haematoma?
trauma
can be sponatneous- anticoagulant
List two complications of pinna haematoma
abscess
cauliflower ear
What is the treatment of pinna haematoma?
immediate drainage and resection if AVN
WHy is pinna haemtoma an emergency?
cartilage has no blood supply
blood clot accumulates in subchondral layer- avascular necrosis
What are the layers of the pinna
epidermis
dermis
perichondrium
subcutaneous tissue
cartilage
Which organisms cause of otitis externa? acute
aeruginosa
staph aureus
pseudomonas
(Swimmer’s ear)
What are causes of chronic otitis externa?
eczematous ear canal
itchy
Who gets necrotising otitis externa?
elderly
diabetic
immunocompromised
What is the treatment for acute otitis externa?
antibiotic drops
aural toilet?
What is a complication of necrotising otitis externa?
cranial nerve palsy
What is necrotising otitis externa?
skull base osteomyelistis
What is the causative agent of necrotising otitis externa?
pseudomonas aeruginosa
What is the treatment for necrotising otitits externa?
6-8 weeks of IV antibiotics
What are the investigations for necrotising otitits externa?
CT
swabs
How is chronic otitis media divided?
mucosal- tymphanic membrane perforation
Squamous- cholestoma ?
Treatment for simple tympanic membrane perforation?
no swimming, water sports
no treatment really
Indications for repair perforation?
recurrent perforations
suppurative perforation
What are the causes of cholesteatoma?
iatrogenic- e.g. from previous tympanic membrane repair
tympanic membrane retraction
What is the treatment for cholesteatoma?
=erosion
surgery tympanomastoidectomy
List two complications of cholesteatoma
hearing loss
erosion into facial canal- facial weakness
meningitis, brain abscess
What is cholesteatoma?
squamous epithelium and keratin debris in middle ear and mastoid. Benign but erosive process
Name another middle ear condition
otosclerosis= fixation of stapes footplate
progressive conductive hearing loss
Treatment for otosclerosis
stapedectomy surgery
hearing aid
What are the causes of sudden sensironeural hearing loss?
viral or bacterial infection
ototoxicity
autoimmune conditions
noise exposure
trauma
What is the treatment of sudden inner ear hearing loss
steroid injections
What are the three vestibular conditions you need to know?
vestibular neuritis/acute labyrinthitis
BBPV
merniere’s disease
What are the features of vestibular neuritis?
preceding URTI
acute onset, lasts days to week
disabling vertigo nausea and vomiting
What is the test for diagnosing BBPV?
Dix Hallpike
What is the treatment for BPPV?
Epley manouvre
Which is the semicircular canal that is most commonly affected in BBPV
posterior
What are the features of merniere’s disease
tinnitus, aural fullness, hearing loss, episodic vertigo
List three causes for sensorineural hearing loss
age related
congenital hearing loss
infection- e.g. meningitis
trauma/noise exposure
drugs
List two drugs that are ototoxic
aminoglycosides
chemotherapeutic agents
List two causes of conductive hearing loss
otitis media with effusion= glue ear
perforation of tympanic membrane
cholesteatoma= retention of squamous debris within middle ear space
otosclerosis
congenital anomalies of external ear/middle
Three differentials for tinnitus?
Loud noise exposure – Bilateral, non-pulsatile, irreversible
Vestibular schwannoma – Unilateral / asymmetric, non-pulsatile – consider MRI
Drugs
Meniere’s disease – Unilateral / bilateral, increase during attacks
Vascular lesions (pulsatile) – e.g. glomus tumours, AV malformations, Carotid bruits
Name a common drug that can causes tinnitus in overdose
aspirin overdose- reversible
List two differentials for vertigo
BBPV
Merniere’s disease
Vestibular neuronitis
Non ear related/central
drugs + alcohol
Name one non ear related cause of vertigo
atypical migraine
cerebellar disease
Three differentials for otalgia
External ear – Otitis externa, furunculosis, pinna infections
Middle ear – Acute otitis media (common), Chronic otitis media (pain rare)
Temporomandibular joint dysfunction – tender over TMJ, crepitus
Referred pain from head and neck (neoplastic / inflammatory)
Neoplasm of ear (rare)
Define otorrhoea
discharge from ear
List two differentials for otorrhoea (discharge)
Otitis externa – classically serous
Acute Otitis media – when complicated by perforation classically mucoid – usually heals up
Chronic otitis media – perforation > 3 months (squamous / mucosal, active / inactive)
Foreign body – secondary infection
Neoplasm – rare e.g. SCC of EAM, Glomus tumour
What is vestibular schwannoma?
benign growth of schwann cells of vestibular nerve
What are the features of vestibular schwannoma?
unilateral hearing loss
tinnitues
balance disturbance
Which nerves can be affected with vestibular schwannoma
vestibucochlear nerve
facial nerve
trigeminal nerve
what is the management of vestibular schwannoma?
interval scanning
surgery
radiotherapy
Why do diabetic patients require special care of otitis externa?
osteomyelitis of temporal bone
what is the mode of inheritance of otosclerosis?
autosomal dominant
what is the treatment of otitis externa?
aural toilet= Aural toilet is a procedure used to clean the external auditory meatus (EAM) of the ear of wax, discharge and debris.
topical steroids and antibiotics
Name three complications of cholesteatoma
hearing loss
tinnitus
vertigo
facial palsy
intracranial infection
What is the treatment of mucosal otitis media?
microsuction
topical antibiotics and steroids
What is the difference between squamous and mucosal otitis media
squamous= squamous tissue retained in middle ear following perf
mucosal= no squamous debris in middle ear
List three organisms that cause acute otitis media
strep pneumoniae
h influenzae
moraxella catarrhalis
What are the indications for antibiotic prescription in acute otitis media?
<2 years
>49-72 hr fever
List two complications of acute otitis media
acute mastoiditis
facial nerve palsy
intracranial infection
otitis media with effusion= glue ear
What is another name for glue ear
otitis media with effusion
Why is glue ear more common in children?
due to poor eustachian tube function
When would you treat glue ear?
if bilateral hearing loss >3 months
What is the treatment for glue ear?
grommets
WHat is the medical management of merniere’s disease?
low salt/caffeine diet
diuretics
betahistine
List three classes of ototoxic drugs and one example
Aminoglycosides e.g. gentamycin
Loop diuretics e.g. furosemide
Cytotoxis agents e.g. cisplatin
Beta blockers e.g. atenolol
Salicylates e.g. asprin (reversible on withdrawing)
Three differentials for sudden onset sensorineural hearing loss
The majority of sudden-onset sensorineural hearing loss is idiopathic in nature, however it can be attributed to:
autoimmune conditions (e.g. Behcet’s or SLE)
infectious causes (e.g. bacterial meningitis, mumps, Lyme’s disease)
metabolic causes (e.g. diabetes, hypothyroidism)
neoplasm
What is the treatment for sudden onset sensorineural hearing loss
high dose oral steroids
Patient with vesicles on ear and facial paralysis. What is the diagnosis?
Ramsay Hunt syndrome
What are the causes of Ramsay hunt syndrome?
shingles
chicken pox
idiopathic
What is the most important problem with ramsay hunt syndrome?
dry eyes- patch over night and eye drops
Which nerve is affected in Ramsay Hunt syndrome?
facial nerve
List two features of otosclerosis
Onset is usually at 20-40 years - features include:
conductive deafness
tinnitus
normal tympanic membrane*
positive family history
What is the cause of otosclerosis?
replacement of normal bone by vascular spongy bone. It causes a progressive conductive deafness due to fixation of the stapes at the oval window. Otosclerosis is autosomal dominant and typically affects young adults
Why do you get vertigo?
unopposed action potentials of contralateral ear/labrinth + eye deviation
What features would you see in someone with an episode of merniere’s?
unilateral sensironeural hearing loss
Which other assessments should you do when examining a vestibular issue? / what are differentials for vertigo/light headedness
postural hypotension- lying and standing BP
cerebellar exam
visual assessment
T2DM B12
Lifestyle advice for merniere’s?
reduced salt and caffein intake
Name one pharmacological agent for merniere’s disease
beta histine
bendroflumethiazide (if taking antihistamine already)
prochlorperazine
What is the rescue medication for merniere’s?
prochlorperazine- only use for a couple of days
What are the surgical options for merniere’s?
grommets
chemical labrinthectomy
tympanic injection with steroid
What is a chemical labrinthectomy?
injection of gentamicin behind tympanic membrane to cause toxicity and death of vestibular system
What type of nystagmus do you get with a peripheral issue?
horizontal
What type of nystagmus do you get with central issue?
vertical
What is the function of HINTS?
determining whether vertigo is central or peripheral
What are the components of HINTS?
Head impulse
Nystagmus
Test of skew
List the three positive features of HINTS exam that would indicate a central problem for the cause of vertigo
Normal head test
Vertical/ bidirectional nystagmus
Vertical skew (position of iris)
How to perform head test in HINTS?
hold head in between hands, ask for pain in neck or stiffness (e.g. RA), get patient to fixate on tip of your nose, jerk head to one side randomly. If patient has to adjust eyes after you have moved their head then abnormal- peripheral cause
