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linear regression analysis was performed to assess differences in
outcome with timing of surgical intervention (37–38).
RESULTS
There were 18 patients who met inclusion criteria. The
average patient age at the time of surgical decompression
was 28 years and 72.2% of patients were men. Temporal
bone CT scan demonstrated 94.4% of patients had otic
capsule-sparing fractures and 5.6% had otic capsule-
violating fractures. An isolated MF approach was per-
formed on nine patients, whereas, nine patients had
combined MF and transmastoid exposure. An anatomi-
cally intact facial nerve was identified in 11 patients and
an irreversible nerve injury, which required nerve graft-
ing was identified in seven patients. The average duration
of follow-up was 36 months. The mechanisms of injury
are summarized in Table 1 and the location of facial
nerve injury diagnosed intraoperatively in Table 2.
For patients who underwent MF decompression and an
intact facial nerve was identified (n
¼
11), 72.7%
regained normal or near normal facial function (HB I
or II) within 1 year after surgery. Of these patients with
intact nerves, 27.3% improved to normal (HB I), 45.5%
improved to near normal (HB II), and all remaining
patients, 27.3%, improved to a HB III (Fig. 1). At
surgery, seven patients were found to have injuries that
required nerve grafting, and all seven (100%) improved
to HB III. For all patients, facial nerve function signifi-
cantly improved after surgery (
p
<
0.01). There was no
difference in final facial nerve outcome depending on the
patient’s sex, side of paralysis, ENoG degeneration, or
type of temporal bone fracture. In the subset of patients
with an intact facial nerve at decompression, the single
patient older than 60 years had a HB III facial outcome.
The average time from onset of traumatic facial para-
lysis to MF decompression with or without nerve grafting
was 12.4 days (range: 9–14 days; median: 12 days).
Analyzing the final facial nerve grade for patients that did
not require nerve grafting based on the number of days
from the beginning of facial paralysis to surgical decom-
pression demonstrated a moderate positive correlation
(
R
2
¼
0.55;
p
<
0.01) (Fig. 2). Regression analysis with a
best-fit linear line shows a statistically significant
improvement in final HB grade the earlier the decom-
pression was performed.
Due to significant preoperative conductive hearing
losses, the preoperative bone PTA was compared with
the postoperative air PTA to illustrate their preoperative
inner ear function and their postoperative hearing result.
Results of patients’ hearing tests are summarized in
Table 3. The average difference in pure tone average
and word recognition after surgery was
þ
2.9 dB and
þ
3.3%, respectively (
p
¼
0.44;
p
¼
0.74) and 1 of 18
patients experienced a significant change in final hearing
results (
>
8 dB loss or
>
8% decrease in WRS).
According to a standardized classification of surgical
complications (39), minor complications (Grade I)
occurred in 16.7% of patients, including vertigo, autoph-
ony, and tinnitus, and all resolved by 3 months after
surgery. One patient developed a surgical wound infec-
tion and abscess, 9 days postoperatively, which required
an incision and drainage and IV antibiotics (Grade III).
There were no other major complications.
DISCUSSION
Most patients with traumatic facial paralysis can
recover normal facial function with conservative treat-
ments such as observation or steroids, however, a fraction
of patients are at increased risk for permanent facial
nerve dysfunction. Identifying these high-risk patients
requires a clinical exam with complete facial paralysis
(HB VI) identified immediately after the injury that is not
recovering, electrodiagnostic testing with ENOG show-
ing
>
90% degeneration, and EMG with absent voluntary
potentials. This subset of patients is at increased risk for a
poor long-term outcome and benefit from decompression
surgery to identify those with an irreversibly injured
facial nerve. This procedure is also therapeutic to those
patients with bony fragments and significant edema
constricting the facial nerve because alleviating this
impingement allows the facial nerve to recover.
TABLE 1.
Mechanisms of injury of the temporal bone
fracture
Motor vehicle
66.7%
Falls
11.1%
Water skiing
5.6%
ATV
5.6%
Mining
5.6%
Snowmobile
5.6%
TABLE 2.
Location of the facial nerve injury diagnosed
intraoperatively
Peri-geniculate
66.7%
Tympanic segment
22.2%
Mastoid segment
11.1%
Labyrinthine segment
5.6%
FIG. 1.
Final facial nerve HB grade in patientswith an intact facial
nerve after MF decompression compared with patients requiring
nerve grafting.
MIDDLE FOSSA APPROACH FOR TRAUMATIC FACIAL PARALYSIS
Otology & Neurotology, Vol. 37, No. 6, 2016
192