What is the management of traumatic facial nerve palsy?

Management of Traumatic Facial Nerve Palsy

Immediate Assessment and Imaging

For traumatic facial nerve palsy with immediate-onset complete paralysis, CT of the temporal bone is the essential first imaging study to identify fractures and guide surgical decision-making, followed by surgical exploration if a fracture line crosses the fallopian canal. 1, 2

• CT temporal bone with thin sections is the primary imaging modality for traumatic facial palsy to evaluate fracture patterns, osseous anatomy, and nerve involvement 1
• MRI with and without contrast should be obtained if CT is negative but clinical suspicion remains high, or for delayed-onset paralysis 1, 3
• Document the timing of paralysis onset (immediate vs. delayed) as this fundamentally determines management 4, 2, 5
• Assess completeness of paralysis using House-Brackmann grading scale (I-VI) 4, 5
• Evaluate all facial nerve branches to determine level of injury 5

Medical Management Algorithm

Incomplete traumatic facial palsy should be managed medically with high-dose corticosteroids (prednisolone 1 mg/kg/day, maximum 60 mg) for 2 weeks followed by taper, combined with aggressive eye protection. 6

• Initiate prednisolone 1 mg/kg/day (maximum 50-60 mg daily) within 72 hours if possible, though benefit may extend beyond this window in trauma 3, 6
• Continue for 10-14 days, then taper over 5 days 3, 6
• Implement eye protection immediately: lubricating drops every 1-2 hours while awake, ophthalmic ointment at bedtime, eye taping at night, and sunglasses outdoors 3
• Refer to ophthalmology urgently if complete inability to close eye or signs of corneal exposure 3

Surgical Management Indications

Immediate-onset complete facial paralysis with a temporal bone fracture crossing the fallopian canal requires surgical decompression, ideally within 2-3 weeks but potentially beneficial up to 3 months post-injury. 4, 2, 7

Absolute Surgical Indications:

• Immediate-onset complete paralysis (House-Brackmann VI) with fracture line through fallopian canal on CT 2
• >90% amplitude reduction on electroneurography (ENoG) compared to contralateral side 1
• Absent voluntary motor unit potentials on electromyography (EMG) 2, 7

Surgical Approach Selection:

• Transmastoid approach for fractures involving mastoid and tympanic segments, especially with hearing preservation 4, 2
• Middle fossa approach for fractures involving geniculate ganglion and labyrinthine segment with serviceable hearing 2
• Translabyrinthine approach for patients with profound sensorineural hearing loss 2

Surgical Timing:

• Optimal timing: 2-3 weeks post-injury when patient is medically stable 4, 2
• Acceptable window: up to 3 months - delayed decompression can still yield good recovery even at 14 months 4, 7
• Patients with severe polytrauma requiring ICU care can safely undergo delayed surgery 4

Electrodiagnostic Testing Protocol

Perform ENoG and EMG at 3-14 days post-injury in patients with complete paralysis to guide surgical decision-making. 1, 2, 5

• ENoG showing >90% amplitude reduction indicates severe nerve injury requiring surgery 1
• EMG showing complete denervation supports surgical intervention, though recovery is possible even with these findings 7
• Testing before 3 days is unreliable as Wallerian degeneration has not occurred 1
• Testing after 14 days may miss the optimal surgical window 1

Expected Outcomes

Surgical decompression for immediate-onset complete paralysis achieves House-Brackmann grade I-III recovery in 92% of patients at 2 years. 2

• Medically managed incomplete paralysis: 100% recovery expected 6, 2
• Surgically managed complete paralysis: 92.3% achieve grade I-III (good to excellent) function 2
• Delayed surgery (up to 14 months): good recovery still possible within 6 months of decompression 7
• Most common lesion location: geniculate ganglion area 2
• Nerve transection requiring grafting: only 13.5% of surgical cases 2

Critical Pitfalls to Avoid

• Do not delay CT imaging - fracture identification is essential for surgical planning 1, 2
• Do not rely solely on ENoG/EMG - these tests may underestimate recovery potential, especially in delayed presentations 7
• Do not dismiss delayed-onset paralysis - this may indicate progressive edema and still requires close monitoring 2, 5
• Do not assume late surgery is futile - decompression up to 14 months post-injury can yield good outcomes 7
• Do not perform routine decompression for incomplete paralysis - medical management achieves 100% recovery 6, 2
• Do not neglect eye protection - corneal exposure is the most immediate threat to quality of life 3, 6

Follow-Up Protocol

• Reassess at 3 months - if no recovery, refer to facial nerve specialist for reconstructive options 3
• Ophthalmology referral for persistent lagophthalmos beyond 3 months 3
• Consider reconstructive surgery (eyelid weights, nerve transfers, facial slings) for incomplete recovery at 6-12 months 1, 3
• Screen for depression in patients with persistent paralysis affecting quality of life 3