ENT

Question 1

Mechanism of hearing

Answer 1

Pinna of ear —> auditory canal —> tympanic membrane —> ossicles to amplify sound (malleus, incus, stapes) —> cochlear —> cochlear nerve

Question 2

What do the semicircular canals do?

Answer 2

Sense head movement

Question 3

What does the cochlea do?

Answer 3

Convert sound vibration to nervous signal

Question 4

Explain results of Weber’s test

Answer 4

(Shooting a web in the middle of someone’s face)
Normal = equal in both ears
Sensioneural = louder in normal ear
Conductive = louder in affected ear as volume has been “turned up”

Question 5

Explain results of rinnes test

Answer 5

Normal = air > bone
Conductive = bone > air

Question 6

Sensioneural Weber’s and rinnes?

Answer 6

Weber’s - heard louder in normal ear
Rinnes - normal ie air > bone

Question 7

Conductive Weber’s and rinnes

Answer 7

Weber’s = louder in affected ear
Rinnes = bone > air

Question 8

What does otosclerosis affect

Answer 8

Ossicles - mostly the stapes. A growth/stiffening of the ossicles which leads to an inability to amplify sound

Question 9

What is the range of normal hearing ?

Answer 9

-10 to 20 decibels (dB)

Question 10

What does the vestibulocochlear nerve do?

Answer 10

transmits nerve signals from the semicircular canals and cochlea to the brain

Question 11

What are the small bones of the middle ear called, function?

Answer 11

malleus, incus and stapes

connect the tympanic membrane to the structures of the inner ear

Question 12

What does the Eustachian tube do?

Answer 12

Connects the middle ear with the throat to equalise pressure

Question 13

What is sudden sensioneural hearing loss?

Answer 13

hearing loss over less than 72 hours, unexplained by other causes.

This is considered an otological emergency and requires an immediate referral to the on-call ENT team.

Question 14

When is a diagnosis of sudden sensioneural hearing loss made?

Answer 14

when someone rapidly (<72 hours) loses their hearing, and no conductive cause can be found

Question 15

Causes of SSNHL?

Answer 15

Most cases (90%) of SSNHL are idiopathic, meaning no specific cause is found.

Other causes of SSNHL include:

Infection (e.g., meningitis, HIV and mumps)
Ménière’s disease
Ototoxic medications
Multiple sclerosis
Migraine
Stroke
Acoustic neuroma
Cogan’s syndrome (a rare autoimmune condition causing inflammation of the eyes and inner ear)

Question 16

Investigations SSNHL?

Answer 16

Audiometry is required to establish the diagnosis. A diagnosis of SSNHL requires a loss of at least 30 decibels in three consecutive frequencies on an audiogram.

MRI or CT head may be used if a stroke or acoustic neuroma are being considered.

Question 17

Management of SSNHL?

Answer 17

1. Urgent referral to ENT

If underlying cause, treat that

If idiopathic
1. Steroids initiated by ENT team - oral or intratympanic

Question 18

Presentation Presbycusis

Answer 18

age-related sensioneural hearing loss.

It tends to affect high-pitched sounds first and more notably than lower-pitched sounds.

The hearing loss occurs gradually and symmetrically.

May have associated tinnitus

Question 19

Pathophysiology presbycusis

Answer 19

loss of the hair cells in the cochlea, loss of neurones in the cochlea, atrophy of the stria vascularis and reduced endolymphatic potential.

Question 20

Risk factors for presbycusis

Answer 20

Age
Male gender
Family history
Loud noise exposure
Diabetes
Hypertension
Ototoxic medications
Smoking

Question 21

Investigations presbycusis

Answer 21

Audiometry

Question 22

Management presbycusis

Answer 22

Optimising the environment, for example, reducing the ambient noise during conversations

Hearing aids

Cochlear implants (in patients where hearing aids are not sufficient)

Question 23

Triad of symptoms Ménière’s disease

Answer 23

Hearing loss
Tinnitus
Vértigo

Question 24

Pathophysiology menieres

Answer 24

excessive buildup of endolymph in the labyrinth of the inner ear, causing a higher pressure than normal and disrupting the sensory signals. This increased pressure of the endolymph is called endolymphatic hydrops.

Question 25

The typical patient is 40-50 years old, presenting with unilateral episodes of vertigo, hearing loss, and tinnitus.

Answer 25

Menieres