Temporal Bone Trauma Mahmoud Awad Trauma Conference February 26, 2015

Temporal Bone

Epidemiology In the largest series of temporal bone fx, 31% resulted from MVAs Reported across all age groups; >70% in 2 nd, 3 rd, 4 th 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 impact FN injury in 10-25% Fronto-occipital impact FN injury in 30-50%

Classification-Otic capsule Otic capsule-sparing ( %) vs. disrupting ( %) 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.