Surgical Specialties - ENT: ear.

Question 1

Otological causes of imbalance?

Answer 1

• Middle ear disease.
• Trauma involving labyrinth, stapedectomy, temporal bone fracture etc.
• Meniere’s disease.
• Labyrinthitis.
• Otosclerosis.
• Syphilis.
• Ototoxic drugs e.g. aminoglycosides.
• Acoustic neuroma.
• Impacted wax in eardrum.
• BPPV.

Question 2

Episodes of vertigo + fluctuant hearing loss + aural fullness which are often preceded by tinnitus makes a diagnosis of what likely?

Answer 2

Meniere’s disease.

Question 3

How might Meniere’s be treated?

Answer 3

• Reduce smoking, caffeine, salt.
• Betahistine (vasodilator) + diuretics to reduce endolymphatic fluid imbalance of inner ear.
• Surgery to drain endolymphatic sac (decompress inner ear) / vestibular neurectomy ( disconnect labyrinth) / labyrinthectomy ( destroy labyrinth).

Question 4

Symptoms of labyrinthitis?

Answer 4

• Acute onset of vertigo.
• Nystagmus.
• Hearing loss (if cochlear involvement).
• Patient feels v unwell for first 24 hours with improvement after central compensation.

Question 5

Failure of both labyrinths will cause?

Answer 5

• Bobbling oscillopsia (world shakes up & down when walking due to loss of normal eye control).

Question 6

What is likely to be the cause of imbalance in children?

Answer 6

Otitis media with effusion i.e. glue ear.

Question 7

Symptoms / signs of acute otitis media?

Answer 7

• Imbalance / vertigo.
• Otalgia (severe in children).
• Congested, bulging eardrum +/- rupture with bloody discharge.
• Systemic illness e.g. tachycardia, fever.

Question 8

What is presbyacusis?

Answer 8

Progressive loss of hair cells in cochlea associated with ageing.

Question 9

From which age is presbyacusis typically clinically noticeable?

Answer 9

60-65 y/o.

Question 10

How might perforations from simple chronic otitis media without mastoid disease be treated?

Answer 10

• Tympanoplasty using a graft from temporalis fascia.

Question 11

How are traumatic perforations of the tympanic membrane treated?

Answer 11

• Typically heal spontaneously so long as the ear is kept dry.

Question 12

In adults who present with middle ear effusions investigations should be carried out to rule out what?

Answer 12

• Sinusitis.

- Nasopharyngeal tumours blocking eustachian tube.

Question 13

What structures make up the external ear?

Answer 13

• Pinna.
• External auditory meatus.
• Tympanic membrane.

Question 14

The eardrum is divided into which structures?

Answer 14

• Pars tensa.

- Pars flaccida.

Question 15

What is the main landmark of the eardrum?

Answer 15

• Malleus handle.

Question 16

Describe the middle ear.

Answer 16

Air filled space connecting nasopharynx to eustahian tube.

Question 17

Function of the middle ear.

Answer 17

Transfers sound energy from air to the fluid medium in the cochlea.

Question 18

The middle ear space - including mastoid air cells - is closely related to which structures?

Answer 18

• Temporal lobe.
• Cerebellum.
• Jugular bulb.
• Labyrinth of inner ear.

Question 19

The middle ear contains how many ossicles? Name them.

Answer 19

Three.

• Stapes.
• Malleus.
• Incus.

Question 20

What is the function of the ossicles?

Answer 20

Transmit sound vibrations from eardrum to cochlea.

Question 21

What traverses the middle ear before exiting the skull?

Answer 21

Facial nerve.

Question 22

What is contained within the inner ear?

Answer 22

Dense bony capsule containing a labyrinth forming the:

• Cochlea.
• Vestibule.
• Semicircular canals.

Question 23

The membranous part of the inner ear is surrounded externally by?

Answer 23

Perilymph.

Question 24

How is the inner ear sealed off from the middle ear?

Answer 24

By the stapes footplate and round window membrane.

Question 25

The membranous part of the inner ear contains what?

Answer 25

Endolymph.

Question 26

How is the cochlea connected to the brainstem?

Answer 26

By the auditory nerve.

Question 27

How is sound perceived by the cerebral cortex?

Answer 27

• Displacement of basilar membrane and movement of hair cells > organised electrical discharge of vestibulocochlear nerve > sound perceived by cortex.

Question 28

What comprises the peripheral balance organ?

Answer 28

• Vestibule + semi circular canals.

Question 29

What is the important function of the peripheral balance organ i.e. the vestibule and semi circular canals?

Answer 29

• Connect to cerebellum and eyes.

- Important in maintaining posture and maintaining fixed eye position on head movement.

Question 30

Conductive deafness arises as a result of?

Answer 30

• Disease affecting the outer or middle ear.

Question 31

Sensorineural deafness arises as a result of?

Answer 31

Damage to the cochlea or vestibulocochlear nerve.