Temporal Bone Trauma

Mahmoud AwadTrauma ConferenceFebruary 26, 2015

Temporal Bone

Epidemiology

• In the largest series of temporal bone fx, 31% resulted from MVAs• Reported across all age groups; >70% in 2nd, 3rd, 4th decades of life• M:F ratio of 3:1• 8-29% occur bilaterally

Classification

• Longitudinal (80%) vs. transverse (20%) in relation to the axis of petrous ridge

Tempoparietal impactFN injury in 10-25%

Fronto-occipital impactFN injury in 30-50%

Classification-Otic capsule

• Otic capsule-sparing (94.2-97.5%) vs. disrupting (2.5-5.8%)

• More predictive clinical outcome• Anatomic orientation vs. functional sequelae• Otic-capsule disrupting: SNHL, FN paralysis,

CSF leak• Otic-capsule sparing: Conductive or mixed HL,

FN paralysis and CSF leak less likely

Evaluation

• ATLS: Primary (ABCDE) and secondary surveys• Inspect auricles for lacerations, hematomas• Inspect ear canal for fx, TM perforation,

bleeding, brain herniation• Suction EAC to evaluate for CSF leak• Assess facial nerve for paralysis• Assess hearing with tuning fork• Imaging – HRCT temporal bone (cuts ≤1.5mm)

Evaluation

Complications

The primary indications for surgical intervention in temporal bone fractures are immediate complete facial paralysis with poor prognostic indicators, and persistent CSF leaks

Facial Paralysis

• Immediate – transection; Delayed – edema• Most traumatic facial palsies resolve without

surgical intervention• Indicated for immediate-onset and complete

facial paralysis• Nerve anatomically disrupted• Delayed-onset – treat conservatively

Criteria for surgical selection

• Immediate-onset paralysis with progressive decline of electrical responses on electroneuronography (ENoG) to less than 10% of responses on the normal side within the first 14 days.

• Immediate-onset paralysis with significant disruption of the otic capsule demonstrated on HRCT.

Incomplete immediate-onset facial paralysis

• Conservative management if there is partial function

• Aggressive eye care• Tapering course of systemic steroids

Algorithm for FN injury

CSF leaks

• Manifest as otorrhea, rhinorrhea, or both• Most resolve with conservative management– Strict bed rest– Head elevation– Stool softeners– No nose blowing

• After day 3, lumbar drainage is used• If drainage persists -> surgery

Prophylactic antibiotics

• Incidence of meningitis following temporal bone trauma a/w CSF leak <10%

• Risk factors:– Persistent CSF leak beyond 7 days– Concomitant infections– Lumbar drain

• May mask early signs and symptoms of meningitis if used indiscriminately

Conclusions

• Otic capsule disrupting fractures have a fourfold to fivefold higher risk of facial paralysis and a twofold to fourfold increased risk of a CSF leak when compared with otic capsule sparing fractures.

• The primary indications for surgical intervention in temporal bone fractures are immediate complete facial paralysis and persistent CSF leaks.