1- Ears (Conductive hearing loss)

Question 1

Conductive hearing loss causes

Answer 1

• Ear wax
• Infection (otitis media/externa)- see infection
• Fluid in the middle ear (effusion)- see infection
• Eustachian tube dysfunction
• Perforated tympanic membrane
• Otosclerosis
• Cholesteatoma
• Exostoses
• Tumours

Question 2

examination findings of conductive hearing loss

Answer 2

Webers
- The “louder” ear may be due to conductive hearing loss in that ear

Rinnes
- When position 2 is quieter than position 1, (Negative Rinne), this indicates external or middle ear disease affecting the air conduction

Question 3

Ear wax
Background

Answer 3

• Also called cerumen
• Normally produced in small amounts in the external ear canal

Made up of
- Dead skin
- Secretions
- Substances that enter the ear
- Protective role -> prevents infections

Question 4

Impacted ear wax

Answer 4

Ear wax can build up and become impacted and stuck to the tympanic membrane. This can result in:
* Conductive hearing loss
* Discomfort in the ear
* A feeling of fullness
* Pain
* Tinnitus

Ear wax can be seen on examination with an otoscope. It may completely cover the tympanic membrane, preventing assessment of the tympanic membrane and inner ear.

Question 5

Management of ear wax

Answer 5

• Doesn’t require any intervention in most cases

AVOID
- Cotton buds -> impact wax

Three main methods of removing wav
- Ear drops – usually olive oil or sodium bicarbonate 5%
- Ear irrigation – squirting water in the ears to clean away wax
- Microsuction

Question 6

Otosclerosis
Background

Answer 6

• Fusion of ossicles
• One of the most common causes of acquired hearing loss in young adults
• Conductive

Question 7

Pathophysiology of otosclerosis

Answer 7

• Ossicles (malleus, incus, stapes) fused at articulations due to abnormal bone growth particularly between base plate of stapes and oval window
• Therefore sound vibrations cannot be transmitted effectively to cochlea

Question 8

RF for otosclerosis

Answer 8

• <40yo
• Family history

Question 9

Causes of otosclerosis

Answer 9

• Both genetic and environmental
• Can be inherited in autosomal dominant pattern
• Exact cause unknown

Question 10

Presentation of otosclerosis

Answer 10

• Gradual unilateral or bilateral conductive hearing loss
• Lower pitched sounds harder i.e. female speech easier
• Experience their own voice as loud
• Tinnitus

Question 11

Investigations of otosclerosis

Answer 11

• Audiometry
• Otoscopy normal
• Tympanometry – reduced admittance of sound
• CT scan

Question 12

Management of otosclerosis

Answer 12

• Hearing aid
• Surgery -> stapedectomy ->removal of stapes and replacement with prosthetic device in middle ear to bypass abnormal bone and permit sounds waves to travel to inner ear and restore hearing

Question 13

Dry tympanic perforation
Background

Answer 13

• Hole in the eardrum, usually heals in a few weeks and might not need any treatment
• Conductive hearing loss

Question 14

causes of dry tympanic perforation

Answer 14

Causes
- Ear infection
- Injury to eardrum such as foreign body
- Changes in pressure
- Loud noise e.g. explosion

Question 15

Presentation of dry tympanic perforation

Answer 15

• Hearing loss
• Earache
• Itching
• Fluid leaking
• High temp
• tinnitus

Question 16

Investigations for dry tympanic perforation

Answer 16

otoscopy

Question 17

Management of dry tympanic perforation

Answer 17

• Infection caused by perforated eardrum -> antibiotics
• Usually self limiting if small
• If big hole -> surgery for perforated eardrum

Question 18

eustachian tube dysfunction background

Answer 18

• When the tube between the middle ear and throat is not functioning properly.
• The Eustachian tube is present mainly to equalise the air pressure in the middle ear and drain fluid from the middle ear.
• When the Eustachian tube is not functioning correctly or becomes blocked, the air pressure cannot equalise properly and fluid cannot drain freely from the middle ear.
• The air pressure between the middle ear and the environment can become unequal. The middle ear can fill with fluid.
• Eustachian tube dysfunction may be related to a viral upper respiratory tract infection (URTI), allergies (e.g., hayfever) or smoking.

Question 19

Presentation of eustachian tube dysfunction

Answer 19

• Reduced or altered hearing
• Popping noises or sensations in the ear
• A fullness sensation in the ear
• Pain or discomfort
• Tinnitus

otoscopy may appear normal

Question 20

Investigations for eustachian tube dysfunction
tympanic membrane
o Plotting a tympanogram (graph) of the sound absorbed (admittance) at different air pressures
- Audiometry
- Nasopharyngoscopy
- CT scan

Answer 20

Only if persistent, problematic or severe symptoms
- Tympanometry
- Audiometry
- Nasopharyngoscopy
- CT scan

Question 21

Tympanometry presures

Answer 21

• air pressure in middle ear when there is eustachian tube dysfunction is lower than ambient air pressure (usually the same)- new air cannot get in through tympanic membrane to equalise the pressure -> tympanogram will show peak admittance (most sound absorbed) with negative ear canal pressures
  o Inserting a device into the external auditory canal (ear canal)
  o Creating different air pressures in the canal
  o Sending a sound in the direction of the tympanic membrane
  o Measuring the amount of sound reflected back off the tympanic membrane
  o Plotting a tympanogram (graph) of the sound absorbed (admittance) at different air pressures

Question 22

management of eustachian tube dysfunction

Answer 22

Management

• No treatment e.g. if viral URTI
• Valsalva manoeuvre -> holding the nose and blowing into it to inflate eustachian tube
  o Otovent is an over counter device where patient blows into a balloon using a single nostril- helps to inflate estuation tube
• Decongestant nasal sprays
• Antihistamine and steroid nasal spray
• Surgery if persistent
  o Adenoidectomy
  o Grommets
  o Balloon dilation eustachian tuboplasty

Question 23

Cholesteatoma

Background

Answer 23

• Abnormal collection of squamous epithelial cells in the middle ear
• Rare- should not be missed
• Not a tumour or related to cholesterol
• Potentially serious- not malignant but slowly grows and expands
• Can erode ossicles, mastoid/petrous bone, cochlea via enzymatic action

Question 24

cholesteoma pathophysiology

Answer 24

• If chronically increased negative ear pressure in the middle ear – the pars flaccida will start to retract forms a sac/pocket
• Trapping stratified squamous epithelium and keratin -> collecting in the retraction pocket
• Proliferates forming cholesteatoma
• Usually secondary to chronic eustachian tube (ET) dysfunction

Question 25

cholesteatoma presentation

Answer 25

Presentation

• Painless,
• Often foul smelling otorrhea ear discharge
• +/- unilateral conductive hearing loss
• As the cholesteatoma expands
  o Infection
  o Pain
  o Vertigo
  o Facial nerve palsy

Question 26

cholesteoma managemet

Answer 26

Management
- CT head
- MRI to assess invasion and damage to local soft tissues
- Surgical removal of cholesteatoma

Question 27

infectious causes of conductive hearing loss

Answer 27

otitis media

Question 28

Conductive vs sensorineural hearing loss

Answer 28

Conductive hearing loss occurs when sound is unable to effectively transfer at any point between the outer ear, external auditory canal, tympanic membrane and middle ear (ossicles).
Causes of conductive hearing loss include
- excessive ear wax
- otitis externa
- otitis media
- perforated tympanic membrane
- otosclerosis.

Sensorineural hearing loss problem with inner ear or vestibulocochlear nerve