w5 Flashcards
types of temporal bone traumas
- blunt trauma (strike to head)
- penetrating (injury penetrates skull ex., gunshot wound)
- compressive (slow skull compression)
- Barotrauma (scuba diving)
how do ontario trauma centers work
identified by specialized equipment and staff
– “Level” designation: Level I (highest) to Level III (lowest)
Medical: Neuro-otologic exam for temporal bone trauma
Subjective: assess patient for disequilibrium, hearing loss, vertigo or prior otologic history
Mechanism of injury: direction of force site of inpact
Cranial nerve assessment (any trauma?)
Tuning forks (crude assessment of hearing)
Radiology: CT high resolution
Structures at risk from temporal bone fracture
cranial nerve, cochlea, ossicles, TM, carotid artery, jugular vein
physical examination of TB fracture
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)
TB fracture Audiology:
standard audiometric assessment, otoscopy to determine status of OAM & TM,
Immittance: variety depending on pathology (reduced with fluid in ME, hypermobile with ossicular disarticulation)
TB fracture sex
Sex: 3 male: 1 female
TB fracture age
3rd and 4th decade
TB fracture imaging
- Imaging follows acute stabilization of life-threatening injuries
- Screening head CT to rule out intracranial injuries
- High-resolution CT scan of temporal bones if fracture suspected
indications for high resolution CT of temporal bones
– facial paralysis
– Cerebral spinal fluid leak
– disruption of superior wall of EAC
– vascular injury
Classification of temporal bone fractures:
Traditional: longitudinal, transveres, mixed (complex)
Newer classification: sparing of optic capsule (Bony labyrinth surrounding cochlea), disruption of otic capsule
Longitudinal fracture
(otic capsule sparing)
Structures Involved: EAC, TM, ME, ossicles, Facial Nerve
Longitudinal fracture presentation
conductive component (tympanic disruption, ossicular derangement, hemorrhage into ME), FN paresis
traumatic force can also
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
– Hemotympanum
- Serial monitoring
- Often resolves spontaneously (≈ 1 month)
– TM perforation
- Serial monitoring
- Often resolves spontaneously (≈ 3 months)
– Tympanoplasty if not
longitudinal fracture medical management
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
common ossicular injuries
- Incudostapedial joint
- dislocation of incus
- Fracture of stapes crura
Ossiculoplasty
Surgical repair of disarticulation. stapes intact- rate of hearing recovery is about 75% stapes not intact - the rate of hearing recovery is about 50%
Transverse temporal bone Fracture
Structures involved:
otic capsule, IAC, FN
Transverse temporal bone Fracture presentation
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)
audiological management
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)
prognosis of SNHL for TB fractures
- Prognosis
– Profound SNHL has poor prognosis
– Moderate SNHL may have some recovery
