Chronic OM, Mastoiditis, Petrositis

Question 1

Leading cause of childhood hearing loss

Answer 1

Persistent OM with effusion

Question 2

Infectious complications of OM (3)

Answer 2

Acute and chronic mastoiditis, petrositis, intracranial infection

Question 3

Noninfectious complications of OM (4)

Answer 3

TM perforation, Ossicular erosion, labyrinthine erosion, tympanosclerosis

Question 4

Patients with history of chronic OME: Hereditary theory

Answer 4

Hypoaeration of the mastoid is more prone to OME

Question 5

Patients with history of chronic OME: Environmental theory

Answer 5

Chronic OME resulrs in hypopneumatization of the mastoid

Question 6

Pathophysiology of decreased size of mastoid air cells in OM

Answer 6

Chronic inflammation in early childhood leads to new bone formation within the middle ear and mastoid leading to decrease size of mastoid air cells

Question 7

A) Atelectasis vs B) Adhesive OM: 1) Middle ear space, 2) TM status, 3)Mucosal surfaces

Answer 7

A1 partially or completely obliterated 2 not adherent to medial wall of middle ear 3 intact mucosa; B1 totally obliterated, adherent to medial wall of the middle ear, mucosal surfaces not present

Question 8

Pathophysiology of atelectasis

Answer 8

Repeated bouts of AOM leads to weakness and thinning of the membrane, allowing atelectasis

Question 9

Severe retraction of the TM can erode: (2)

Answer 9

Long process of incus, stapes superstructure

Question 10

Sade and Berco 4 stages of TM retraction

Answer 10

1) retracted, 2) attached to incus, 3) middle ear atelectasis, 4) adhesive OM

Question 11

Judicious use of these can potentially reverse middle ear atelectasis

Answer 11

Ventilating tubes

Question 12

Cholesteatoma resemble these (why it is a misnomer)

Answer 12

Cholesterol crystals * Do not contain cholesterol

Question 13

Otorrhea from infected cholesteatoma is often malodorous due to frequent infection of this kind of bacteria

Answer 13

Anaerobes

Question 14

Complications of cholesteatoma (5)

Answer 14

Vertigo, hearing loss, labyrinthine fistula, FN paralysis, intracranial infection

Question 15

Typical location of attic retraction cholesteatoma

Answer 15

Posterosuperior TM

Question 16

Differential diagnosis for aural polyp in a chronically infected ear

Answer 16

Cholesteatoma

Question 17

Origin of congenital cholesteatoma

Answer 17

Originates from areas of keratinizing epithelium within the middle ear cleft

Question 18

Pathogenesis of acquired cholesteatoma (4)

Answer 18

Invagination of TM, Basal Cell Hyperplasia, Epithelial Migration, Squamous Metaplasia of Middle ear epithelium

Question 19

How attic cholesteatomas form, pars flaccida retraction pockets deepen due to negative middle ear pressure, possibly repeated inflammation. Desquamated keratin cannot be cleared from the recess resulting in Cholesteatoma

Answer 19

Invagination Theory

Question 20

Usual area of TM affected by retraction and why?

Answer 20

Pars flaccida, less fibrous, less resistant to displacement

Question 21

Presence of these in the cholesteatoma matrix can lead to epithelial proliferation and invasion of the cholesteatoma

Answer 21

Bacterial biofilms

Question 22

Epithelium invasion to the lamina propria by proliferating columns of epithelial cells due to alterations in basal lamina

Answer 22

Basal cell hyperplasia

Question 23

Keratinizing squamous epithelium from surface of the TM invades or migrates into the middle ear from a perforation

Answer 23

Epithelial Invasion * Once in contact with a different epithelial surface, they stop migrating. Due to inflammatory damage to the innert mucosal lining of the TM, outer keratinizing epithelium migrates inward to create a cholesteatoma

Question 24

Metaplastic transformation of simple squamous or cuboidal epithelium of middle ear into keratinizing epithelium, enlarging with accumulated debris and contact with TM, causing TM lysis with subsequent perforation

Answer 24

Squamous Metaplasia

Question 25

Most common bacteria in cholesteatoma (3)

Answer 25

Pseudomonas, S. Aureus, Anaerobic cocci (Peptococcus, Peptostreptococcus)

Question 26

Goals of cholesteatoma surgery (2)

Answer 26

Eradicate disease first, then reconstruct hearing mechanism of middle ear

Question 27

Consideration and kind of ear surgery depends on (7)

Answer 27

Nature and extent of the diseade, complications, mastoid pneumatization, ET function, hearing status, patient reliability, skill and experience of surgeon

Question 28

Simple perforation manifests as what type of hearing loss (frequency? type?)

Answer 28

Low frequency conductive

Question 29

This depends on the free movement of gases from the eustachian tune into the mastoid air cells.

Answer 29

Aeration * Gases must travel around the ossicles in the epitympanum to get into the antrum

Question 30

Edema and inflammation of mucosa between these 2 corridors can lead to chronic obstruction and infection of the attic leading to irreversible mucosal and bony changes in the antrum and mastoid

Answer 30

Between tendon of tensor tympani and stapes, between short process of incus and stapedial tendon

Question 31

Aside from cholesteatoma, presence of this tissue can also lead to bony erosion

Answer 31

Granulation tissue