Middle Ear Pathologies, Bony Diseases and Cholesteatoma

Question 1

What are the important parts of the ME?

Answer 1

• Some of the ossicles will not be seen through the eardrum
• Stapes is posterior to malleus

Question 2

What is the orientation of the ME parts in the Anterior view?

Answer 2

The shape of the eardrum looks like a dish or bowl not flat

Question 3

What are the 3 layers of the pars Tensa?

Answer 3

Composed of 3 layers
1. Outer-squamous: epithelium/skin same cells
2. Middle-fibrous: gives rigidity to the membrane
3. Inner-mucosa: same as skin in nose

Question 4

How big are the ossicles?

Answer 4

Smaller than a dime

Question 5

What is the bulk of the TM called?

Answer 5

Pars tensa

Question 6

What is the name of the section of the TM over the lateral process of the malleus?

Answer 6

Pars Flaccida (doesn’t have fibrous layer)

Question 7

What are the three main Physiology aspects of the ME?

Answer 7

• Aerated space
• Eustachian tube
• Mastoid space

Question 8

Why does the ME need to be aerated and why do the ossicles look this way?

Answer 8

Transfer of sound energy from low-impedance air to the high-impedance cochlear fluid

Question 9

Which way does the ME match the impedance?

Answer 9

Lever effect 2.5 dB Longer malleus to shorter incus transfer of energy

Area effect 25 dB high area eardrum to a low area stapes footplate

Question 10

What are the typical causes of TM perforation? (6)

Answer 10

Trauma
Infection (most common)
Cholesteatoma
Tympanostomy tubes
Tympanosclerosis
Spontaneous

Question 11

What is the difference between both these TM perforation?

Answer 11

Marginal and central perforation (worst)

Question 12

How do you treat small perforations of the TM?

Answer 12

With time it heals by itself

Question 13

What problems can be caused by a perforated TM? (2)

Answer 13

Recurrent infections/otorrhea
CHL (reduced immittance/energy transfer mechanism)

Question 14

How do you manage the TM perforations? (2)

Answer 14

1. Monitor (most heal with time)
2. Tympanoplasty

Question 15

What is Tympanosclerosis?

Answer 15

1. Scarring of the tympanic membrane Aka myringosclerosis
2. CHL is rare

Question 16

What can cause tympanosclerosis? (3)

Answer 16

1. Otitis media
2. Tympanostomy Tubes
3. TM perforation

Heals by itself

Question 17

What is this condition?

Answer 17

TM Granulation: causes by foreign bodies being fought off by the immune system most of the time

Question 18

What is this condition?

Answer 18

Hemotympanum

Question 19

What is this condition

Answer 19

Retraction Pockets

Question 20

What is this condition?

Answer 20

Middle Ear Atelectasis/Collapse

Question 21

What is Bullous Myringitis?

Answer 21

• Inflammatory condition of TM
• Fluid-filled vesicles
• Sudden onset of severe otalgia
• Often follows AOM
• Treat with antibiotics, analgesics and drainage

Question 22

What is otosclerosis?

Answer 22

Oto = ear
Sclerosis = hardening or fibrosis of the bone

A metabolic bone disease of the otic capsule (embryological origin of some of our ear structure)

Question 23

What is the epidemiology of Otosclerosis?

Answer 23

• Typically present in the 2nd-4th decades of life
• Rarely in children (congenital fixation of stapes)
• More common in females (2:1)
• Mostly Caucasians (non-existent in First * Nations/Indigenous)
• 10% of all temporal bones showed histological changes of otosclerosis in one study
• Becoming less common

Question 24

What causes Otosclerosis?

Answer 24

Idiopathic: tends to just appear
* Genetic
- Family history present in 50-70%
- AD with incomplete penetrance
* Hormonal
- F > M almost 2 to 1
- Accelerated during pregnancy
* Viral
- Reduced after measles vaccination

Question 25

What are the two pathophysiology phases of Otosclerosis?

Answer 25

Active Phase Mature Phase

Question 26

Describe the Active phase in Otosclerosis Pathophysiology:

Answer 26

“Otospongiosis” Osteoclasts more active Resorption of bone Schwartze’s sign

Question 27

Describe the Mature phase in Otosclerosis Pathophysiology:

Answer 27

Osteoblasts more active Deposition of new bone

Question 28

What are the common sites of involvement of Otosclerosis? (4)

Answer 28

Fissula ante fenestrum (anterior part of footplate) Round window The anterior wall of IAC Inner ear “cochlear otosclerosis”

Question 29

What are the common places of Otosclerosis?

Answer 29

* STAPES footplate fixation - CHL - Better understanding in noise (paracusis of Willis) * Inner ear involvement  SNHL * HL progresses from low to high frequencies * Low-frequency tinnitus Bilateral in 70% of patients

Question 30

What are the signs in the audiogram that indicates Otosclerosis?

Answer 30

- Air-bone gap (CHL) - Carhart’s notch - Normal discrimination - Tympanograms (normal or As)

Question 31

What is a Cahart's Notch?

Answer 31

* At 2000 Hz, air and bone conduction come together to appear as a SNHL * Theories - Disrupted ossicular resonance/perilymph immobility - Mechanical artifact * Reverses with stapedotomy

Question 32

How do you manage Otosclerosis? (4)

Answer 32

Depends on the degree of Hearing loss * Conservative (for mild cases) * Audiological - Amplification * Medical - Sodium fluoride - Vitamin D and calcium carbonate * Surgical

Question 33

Why is Otolsclerosis amplification a good option? (2)

Answer 33

For Poor surgical candidates For Patients who don’t want surgery

Question 34

What are Otosclerosis Amplification problems? (5)

Answer 34

Canal occlusion effect Sound quality No amplification at night Cost Cosmetic

Question 35

What is the surgical device we use in Otosclerosis?

Answer 35

Bone-anchored hearing aids (BAHA)

Question 36

How does BAHA work? (3)

Answer 36

* Titanium screw placed in the temporal bone * Sound processor connected to the screw causes vibrations * Sound energy bypasses the external and middle ears

Question 37

What is Stapedectomy?

Answer 37

A surgical management option against Otosclerosis

Question 38

What is superior semicircular canal dehiscence (SSCD)?

Answer 38

Bony defect of superior semicircular canal

Question 39

What are clinical features of SSCD?

Answer 39

Autophony (own voice echoes in your head) Dizziness CHL (low-freq) Hyperacusis Tullio phenomenon

Question 40

What is cholesteatoma? (3)

Answer 40

* A collection of squamous keratin * Produced from squamous epithelial cells (not normal outside of EAC) mostly appears on top of ossicles or pars flaccida * Exhibits independent growth and locally aggressive * Should really be called keratoma

Question 41

What are the two ways to develop cholesteatoma?

Answer 41

* Congenital (Left) Gradual growth over time Presents early in life * Acquired Primary acquired (retraction pocket) Secondary acquired (TM perforation)

Question 42

What is acquired cholesteatoma associated with?

Answer 42

Associated with chronic ETD and recurrent OMs - TM is weakened resulting in retraction pockets or perforations Presents later in life

Question 43

Describe Primary Acquired cholesteatoma (3) :

Answer 43

1. Chronic ETD 2. Deep retraction pocket (pars flaccida) 3. Collection of keratin within the retraction pocket

Question 44

Describe Secondary Acquired cholesteatoma:

Answer 44

Secondary acquired 1. Chronic ETD 2. Recurrent OMs 3. Chronic TM perforation In-growth of keratin via the TM perforation

Question 45

What are the clinical presentations of Cholesteatoma? (3)

Answer 45

* History Otorrhea, hearing loss, otalgia, aural fullness, dizziness, tinnitus * Past medical history OMs, TM perforations, trauma, ear surgery * Most common presentation involves unilateral chronic otorrhea and hearing loss

Question 46

What can we see in this Otoscopic Evaluation?

Answer 46

1. Pars flaccida (attic) crusts and CHL -> suspect cholesteatoma 2. This isn’t just wax-suspect underlying pocket and cholesteatoma

Question 47

What are the causes of Hearing loss due to Choleosteoma? (2)

Answer 47

1. Ossicular erosion (mostly CHL) 2. Labyrinthine fistula (SNHL, vertigo)