Temporal bone path

Question 1

Tumors (of temporal bone)
Rhabdomyosarcoma (common)

At petrous apex

Question 2

Ossicular discontinuity (TRAUMA)

Answer 2

Ossicular dislocation especially incus-stapes

Can be caused byErosions can occur in CSOM from infection/ cholesteatoma

CHL

Ossiculoplasty: ossicular chain reconstruction using prosthesis replacement
- PORP partial
-TORP total (use of cartilage on TM)

Question 3

Perilymph fistula
(head injury, barotrauma, ossiculoplasty, stapedectomy)

Answer 3

Perilymph leaks from inner to middle ear

CHL

Graft placed on oval and round window to prevent leaks

Question 4

Otic capsule sparing fracture (from direct blow to side of head)

Answer 4

Pass thru mastoid air cells & roof of ME, may involve facial nerve

Mixe

CHL: TM perforation & ossicular chain disruption (damage malleus)

Need ossiculoplasty

Question 5

Otic capsule disrupting fracture (from blow to (occiput) back of head )

Answer 5

Cochlea damage, higher risk of facial paralysis

No ossicular chain/ EAC involved

SNHL

Question 6

Osteogenesis imperfecta

Answer 6

Disorder of connective tissue (Type 1 collagen)
- blue eyes
- fragile bones

SNHL, mixed,
CHL (if ossicular fracture)

Surgery may be performed for stapes fixation or ossicular fractures (ossiculoplasty?)

Question 7

Sclerosing bone dysplasia

Answer 7

Genetic disorder: overgrowth & increased radiological density of skeleton (in temporal bone)

CHL
Closure of EAC
Entrapment of cochlear nerves - SNHL?

Question 8

Paget disease

Answer 8

Chronic disorder of bone metabolism with overgrowth (temporal bone)

SNHL, mixed, CHL (not amenable to surgery)
- change in bone change mecha

Question 9

otosclerosis

Deposits of abnormal bone of the otic capsule (bony labyrinth) on oval window

Answer 9

Limits movement of stapes footplate/affect cochlea- genetic

-flamingo flush, Schwartze sign

-can have tinnitus

–paracusis of willis: hear better in noise especially CHL without SNHL

CHL, mixed, SNHL

-ABG widen f

CHL, SNHL, mixed

stapedotomy/
Stapedectomy:
(For CHL without another reason)

1.at least small part of stapes footplate cut
2.prosthesis to connect incus & cochlear fluid
3.seal made to prevent leakage of perilymph

Can cause overclosure of ABG (reverse)