HSC Section 8_April 2017

R. B. CANNON ET AL.

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 ¼ 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 ¼ 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.

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

TABLE 3.

Results of patients’ hearing tests

Difference in preop to postop

Average

Range

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 Postop bone PTA 21.2 dB 5–40 dB

– –

þ 2.9 dB ( p ¼ 0.44) þ 0.8 dB ( p ¼ 0.63)

Preop WRS Postop WRS

88.1% 12–100% 91.4% 12–100%

–

þ 3.3% ( p ¼ 0.74)

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