6 Ear Disorders Flashcards
What is the innervation of the auricle?
Anterior part: Auriculotemporal branch of CNV3
Posterior/lower 1/2 anterior: Greater auricular nerve (C2,C3)
What is the innervation of the EAM
Anteroinferior part:
Auriculotemporal branch of CNV3
Posteroinferior part:
Auricular branch of CNX
Some from CNVII
What is the innervation of the tympanic membrane
External:
Auriculotemporal of CNV3
Auricular of CNX
Internal:
CNIX (Tympanic plexus)
What is the innervation of the inner ear?
Vestibulocochlear nerve CNVIII
Cohclear nerve –> organ of corgi
Vestibular nerve –> saccule, utricle and semilunar canal ampullae
What nerves can refer pain to the ear? From where?
CNV Oral cavity
CNVII - Teeth, TMJ, PArotid
CNIV Oroharynx/tonsills
CNX - Laryngopharynx
What is cauliflower ear? How does it happen? What happens if it is not drained quickly?
Auricular haematoma
Trauma induces bleeding.
Blood collects between perichondrium and cartilage of auricle.
Cartilage is avascular and so relies on diffusion of oxygen and nutrients from the overlying CT.
Blood accumulation disrupts the blood supply to the cartilage of the ear.
Cartilage begins necrosis.
If it is not drained quickly, fibrosis of overlying skin occurs leading to gross deformity.
What is acute otitis externa? Who often get it? How does it present?
Infection of the EAM
Swimmers who do not dry their ears properly often get it.
Presents with otalgia, pruritus
Pain worse on pulling auricle
What is otitis media? How does the tympanic membrane present? Why?
Why is it more common in children?
Why can it lead to otitis media with effusion?
Otitis media is infection of the middle ear.
The tympanic membrane appears bulging and red due to pus/fluid in the middle ear.
It is often secondary to URTI spread via Eustachian tube and so more common in children who have, straighter, shorter, more horizontal Eustachian tube making it easier for organisms to climb and harder to drain fluid.
It can lead to otitis media with effusion as inflammation of the tympanic cavity mucosa can block the Eustachian tube.
What cases perforation of the tympanic membrane?
What does this lead to?
How is it healed?
Infection
Trauma
Excess pressure
Foreign body
May cause middle ear deafness
Minor rupture - heals spontaneously
Major rupture - requires surgical repair.
What is mastoiditis? Why does it occur? What is a presenting sign? What must be done if it is suspected? What nerve is at risk?
Mastoiditis is infection and inflammation of the mastoid air cells/antrum.
Porous nature of mastoid air cells are ideal for pathogenic replication.
Spread from otitis media.
Mastoid process can be infected and so present with swollen, red mastoid process.
If suspected, mastoid air cells must be drained.
Facial CNVII nerve is at risk of damage.
What is otitis media with effusion? Why does it occur? How does the tympanic membrane present?
Otitis media with effusion is chronic inflammation of the middle ear with build up of fluid.
Results from Eustachian tube dysfunction.
Blocked Eustachian tube cannot equalise pressure in middle ear.
Tympanic cavity mucosa absorb air continuously. This results in the generation of a negative pressure.
Negative pressure draws out transudate from mucosa causing fluid build up and pathogenic replication.
Tympanic membrane is inverted/retracted due to the negative pressure sucking it in.
What causes blockage of the eustachian tube? Where does residual air in the tympanic cavity go?
Swelling of mucous membrane.
Mucosa of tympanic cavity absorbed resiual air into blood vessels.
What is cholesteatoma? How is it caused? How can middle ear structures be damaged?
Blockage of the eutachian tube leads to reduced pressure in the tympanic cavity.
This leads to retraction pockets.
Dead skin cell accumulate in the pockets.
Necrotic mass of dead skin = cholesteatoma.
Lytic enzymes can erode middle ear structures.
Why are children more likely to get glue ear?
Adenoidal hypertrophy is more common in 3-8yo due to Eppstein Barr Virus.
This blocks the eustachian tube.
What is benign paroxysm positional vertigo?
Spinning sensation caused by changes in head position
Vommiting, nausea
Sudden onset
Short duration
Calcium crystals in endolymph displace fluid in semicircular canals.
What are three signs of injuries to the peripheral auditory system.
- Hearing loss (conductive)
- Vertigo (indicates semilunar canals)
- Tinnitus (Buzzing/ringing)
What does conductive hearing loss result from?
How do people with conductive hearing loss speak?
What treatments?
Results from anything in external or middle ear interfering with the conduction of sound or the movement of the oval or round windows.
Usually speak with soft voice
Hearing aid/surgically
What does sensorineural hearing loss result from? How can it be treated?
Results in defect in pathway from cochlear to brain.
Cochlea, cochlear nerve, brain.
Implants with external microphone transmitting to implanted receiver that sends impulses to the cochlea.
What is Meniere’s syndrome? Symptoms?
Blockage of the cochlear aqueduct. Leads to: Hearing loss Tinnitus Vertigo Sense of pressure in ear, distortion of sound and sensitivity to noise
Describe Weber’s and RInne’s tests.
Rinne: mastoid then air
AC>BC = normal or sensor neural hearing loss
BC>AC = conductive hearing loss (infection/wax/ punctured TM)
Weber’s: on head
Same in both ears = normal
Sensorineural - lateralise to good ear (louder on opposite side)
Conductive - louder in affected ear (less competition from external sound.
What is otalgia?
Pain in ear
Infection/Inflammation
Referred pain from teeth pharynx, C-spine
What is pruritus? What can it result from?
Itchiness in ear
May result from primary discharge
What is otorrhoea? What does it indicate?
Discharge from ear.
Acute/chronic infection
If blood/CSF –> skull fracture
Where might mastoiditis spread to in children?
Middle cranial fossa via petrosquamous fissure leading to meningitis or osteomyelitis.
