HSC Section 8_April 2017

The type of surgery performed varies depending on the

site of temporal bone fracture and the likely site of facial

nerve injury. The perigeniculate region is the site in-

which the facial nerve is most often damaged and the

meatal foramen and labyrinthine segment are the nar-

rowest portion of the bony facial canal. These areas are

most commonly accessed through a MF approach, if

hearing preservation is desired (8,17,16). MF decom-

pression and repair of the facial nerve has been offered to

patients at risk for a poor long-term outcome with good

results in published series, 66.7 to 100% of patients

improved to normal or near normal facial function

(HB I or II) (3,9,10,22–29), compared with a 53% rate

of recovery for patients who were observed (40).

Data on patient’s recovery without surgery in the

setting of traumatic paralysis with poor prognosis on

electrical testing is lacking, but our results demonstrate 7

of 18 patients (38.9%) meeting electrodiagnostic criteria

were diagnosed intraoperatively with irreversible facial

nerve injuries. This shows that these patients, who are at

high-risk of having a nerve transection and long-term

complete paralysis (HB V or VI), therefore, surgical

treatment is recommended in every case and definitely

appropriate. Designing a study with matched controls to

test these patients’ recovery without surgery would be

unethical because it would involve withholding a treat-

ment that is known to be effective.

The current study supports MF facial nerve decom-

pression and repair in patients with traumatic facial

nerve paralysis who are at high-risk for a poor long-

term facial nerve outcome. In this group of patients that

met the electrodiagnostic criteria for severe dysfunction

and were surgically decompressed within 14 days from

their trauma, the course of the facial nerve was eval-

uated. Those patients with an intact facial nerve (n

11)

had a 72.7% rate of regaining normal or near normal

facial function (HB I or II) within 1 year after surgery.

For those patients with irreversible injuries (n

7),

nerve grafting was performed and all of these patients

achieved a HB III, which is consistent with the reported

literature (33,41).

Timing from the onset of facial paralysis to

decompression surgery was important for patients in

the current study. Regression analysis showed a

statistically significant improvement in final HB grade

the earlier the decompression was performed. All

patients in the current study underwent decompression

surgery within 14 days and those who were operated

on earlier had the best long-term outcomes. Fisch

initially recommended immediate decompression

within 6 to 10 days, if electrical criteria were met

(10,30). Hato et al. (31) also looked at timing of

surgery for a traumatic facial nerve paralysis and dem-

onstrated there was a 93% rate of a good recovery (HB I

and II) if they underwent decompressive surgery within 2

weeks versus only a 63% rate of achieving good recovery

if they underwent surgery after 2 weeks. Other studies

have not supported these findings (22,23). Thus, there is

controversy regarding the timing for decompression

surgery and facial nerve repair, however, surgical

intervention for traumatic facial nerve paralysis is

recommended within 14 days of the injury if surgical

criteria is met, but, patients who present after this time

frame and meet surgical criteria, may still benefit from

decompression.

Our results are limited due to an absence of control

patients and that reported data to indicate how these

patients with poor prognosis on electrical testing would

do without decompressive surgery is limited. Patients

with irreversible injuries would likely have devastating

long-term facial paralysis with little to no recovery of

facial function, however, the remaining patients may

improve with conservative measures and the rate of

recovery is not well known. In addition, there may be

selection bias in our study, because patients medically

stable enough to be worked-up and undergo early decom-

pression surgery within 14 days may have less severe

skull base trauma and facial nerve injuries.

Reviewing one’s own results can be quite educational

(and sometimes humbling). The senior author (CS) pre-

viously felt that the timing of the treatment of traumatic

facial paralysis was not critical. His previous primary

surgical goal was to identify and treat neural injury,

rather than perform facial nerve decompression, as is

done in Bell’s palsy. Based on the results of this study, we

will now manage patients with a complete immediate

facial paralysis from temporal bone fracture and who

meet electrical testing result criteria, with the goal to

operate as soon as they are medically stable.

For patients who experience facial nerve paralysis

secondary to temporal bone trauma and have poor

FIG. 2.

Final facial nerve HB grade based on the day of decom-

pression after traumatic paralysis for patients that did not require

nerve grafting.

TABLE 3.

Results of patients’ hearing tests

Average

Range

Difference in preop

to postop

Preop air PTA 57.9 dB 25–100 dB

–

Preop bone PTA 20.4 dB 4–39 dB

–

Postop air PTA 23.3 dB 5–55 dB

2.9 dB (

0.44)

Postop bone PTA 21.2 dB 5–40 dB

0.8 dB (

0.63)

Preop WRS

88.1% 12–100%

–

Postop WRS

91.4% 12–100%

3.3% (

0.74)

R. B. CANNON ET AL.

Otology & Neurotology, Vol. 37, No. 6, 2016

193