6 Ear Disorders

Question 1

What is the innervation of the auricle?

Answer 1

Anterior part: Auriculotemporal branch of CNV3

Posterior/lower 1/2 anterior: Greater auricular nerve (C2,C3)

Question 2

What is the innervation of the EAM

Answer 2

Anteroinferior part:
Auriculotemporal branch of CNV3

Posteroinferior part:
Auricular branch of CNX

Some from CNVII

Question 3

What is the innervation of the tympanic membrane

Answer 3

External:
Auriculotemporal of CNV3
Auricular of CNX

Internal:
CNIX (Tympanic plexus)

Question 4

What is the innervation of the inner ear?

Answer 4

Vestibulocochlear nerve CNVIII
Cohclear nerve –> organ of corgi
Vestibular nerve –> saccule, utricle and semilunar canal ampullae

Question 5

What nerves can refer pain to the ear? From where?

Answer 5

CNV Oral cavity
CNVII - Teeth, TMJ, PArotid
CNIV Oroharynx/tonsills
CNX - Laryngopharynx

Question 6

What is cauliflower ear? How does it happen? What happens if it is not drained quickly?

Answer 6

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.

Question 7

What is acute otitis externa? Who often get it? How does it present?

Answer 7

Infection of the EAM
Swimmers who do not dry their ears properly often get it.
Presents with otalgia, pruritus
Pain worse on pulling auricle

Question 8

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?

Answer 8

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.

Question 9

What cases perforation of the tympanic membrane?
What does this lead to?
How is it healed?

Answer 9

Infection
Trauma
Excess pressure
Foreign body

May cause middle ear deafness

Minor rupture - heals spontaneously
Major rupture - requires surgical repair.

Question 10

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?

Answer 10

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.

Question 11

What is otitis media with effusion? Why does it occur? How does the tympanic membrane present?

Answer 11

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.

Question 12

What causes blockage of the eustachian tube? Where does residual air in the tympanic cavity go?

Answer 12

Swelling of mucous membrane.

Mucosa of tympanic cavity absorbed resiual air into blood vessels.

Question 13

What is cholesteatoma? How is it caused? How can middle ear structures be damaged?

Answer 13

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.

Question 14

Why are children more likely to get glue ear?

Answer 14

Adenoidal hypertrophy is more common in 3-8yo due to Eppstein Barr Virus.
This blocks the eustachian tube.

Question 15

What is benign paroxysm positional vertigo?

Answer 15

Spinning sensation caused by changes in head position
Vommiting, nausea
Sudden onset
Short duration
Calcium crystals in endolymph displace fluid in semicircular canals.

Question 16

What are three signs of injuries to the peripheral auditory system.

Answer 16

1. Hearing loss (conductive)
2. Vertigo (indicates semilunar canals)
3. Tinnitus (Buzzing/ringing)

Question 17

What does conductive hearing loss result from?
How do people with conductive hearing loss speak?
What treatments?

Answer 17

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

Question 18

What does sensorineural hearing loss result from? How can it be treated?

Answer 18

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.

Question 19

What is Meniere’s syndrome? Symptoms?

Answer 19

Blockage of the cochlear aqueduct.
Leads to:
Hearing loss
Tinnitus
Vertigo
Sense of pressure in ear, distortion of sound and sensitivity to noise

Question 20

Describe Weber’s and RInne’s tests.

Answer 20

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.

Question 21

What is otalgia?

Answer 21

Pain in ear
Infection/Inflammation
Referred pain from teeth pharynx, C-spine

Question 22

What is pruritus? What can it result from?

Answer 22

Itchiness in ear

May result from primary discharge

Question 23

What is otorrhoea? What does it indicate?

Answer 23

Discharge from ear.
Acute/chronic infection
If blood/CSF –> skull fracture

Question 24

Where might mastoiditis spread to in children?

Answer 24

Middle cranial fossa via petrosquamous fissure leading to meningitis or osteomyelitis.