w5

Question 1

types of temporal bone traumas

Answer 1

• blunt trauma (strike to head)
• penetrating (injury penetrates skull ex., gunshot wound)
• compressive (slow skull compression)
• Barotrauma (scuba diving)

Question 2

how do ontario trauma centers work

Answer 2

identified by specialized equipment and staff
– “Level” designation: Level I (highest) to Level III (lowest)

Question 3

Structures at risk from temporal bone fracture

Answer 3

cranial nerve, cochlea, ossicles, TM, carotid artery, jugular vein

Question 4

physical examination of TB fracture

Answer 4

External ear: lacerations, hematoma (bruise), bony deformity, battle sign-bruising around temporal bone
Fractures can be open to middle ear or cranium: is the CSF leaking out of ear, eustachian tube, otorrhea- clear (CSF), blood (issue elsewhere)
Periorbital hematoma (raccoon eyes)

Question 5

TB fracture Audiology:

Answer 5

standard audiometric assessment, otoscopy to determine status of OAM & TM,
Immittance: variety depending on pathology (reduced with fluid in ME, hypermobile with ossicular disarticulation)

Question 6

indications for high resolution CT of temporal bones

Answer 6

– facial paralysis
– Cerebral spinal fluid leak
– disruption of superior wall of EAC
– vascular injury

Question 7

Classification of temporal bone fractures:

Answer 7

Traditional: longitudinal, transveres, mixed (complex)
Newer classification: sparing of optic capsule (Bony labyrinth surrounding cochlea), disruption of otic capsule

Question 8

Longitudinal fracture

Answer 8

(otic capsule sparing)
Structures Involved: EAC, TM, ME, ossicles, Facial Nerve

Question 9

Longitudinal fracture presentation

Answer 9

conductive component (tympanic disruption, ossicular derangement, hemorrhage into ME), FN paresis

Question 10

traumatic force can also

Answer 10

injure oval window
» produce forceful fluid wave with mechanical damage to hair cells
» causes a piston-like movement of the stapes which can penetrate inner ear & damage structures

Question 11

– Hemotympanum

Answer 11

• Serial monitoring
• Often resolves spontaneously (≈ 1 month)

Question 12

– TM perforation

Answer 12

• Serial monitoring
• Often resolves spontaneously (≈ 3 months)
  – Tympanoplasty if not

Question 13

longitudinal fracture medical management

Answer 13

80% CHL resolves spontaneously
Ossicular damage suggested by residual CHL following resolution of hemotympanum
Exploratory tympanotomy
- 30dB CHL persisting > 2m after injury
- contraindications: CHL in only hearing ear

Question 14

common ossicular injuries

Answer 14

• Incudostapedial joint
• dislocation of incus
• Fracture of stapes crura

Question 15

Ossiculoplasty

Answer 15

Surgical repair of disarticulation. stapes intact- rate of hearing recovery is about 75% stapes not intact - the rate of hearing recovery is about 50%

Question 16

Transverse temporal bone Fracture
Structures involved:

Answer 16

otic capsule, IAC, FN

Question 17

Transverse temporal bone Fracture presentation

Answer 17

sensorineural HL, vestibular dysfunction , FN paresis
* Perpendicular to long axis of temporal bone
* Impact often at frontal or occipital area
* Usually involves otic capsule with SNHL & vestibular symptoms
* Less common: middle ear involvement (with conductive component)

Question 18

audiological management

Answer 18

Varies with outcome
Monitoring: spontaneous recovery; pre & post intervention
With temporary or permanent residual hearing loss:
– Amplification
– Assistive devices
– Cochlear implantation
– Aural rehabilitation (including vocational depending on severity/nature of residual activity and participation limitations)

Question 19

prognosis of SNHL for TB fractures

Answer 19

• Prognosis
  – Profound SNHL has poor prognosis
  – Moderate SNHL may have some recovery