Methods
For groups A, B, and C, we
compared the electrical potential in response to stimulation of the
facial nerve trunk before and after tumor resection. We also compared
the electrical potential in response to stimulation of the facial nerve
trunk and stimulation of each branch after tumor resection. From these
results, we calculated the amplitude response ratio (ARR) for each
patient and compared each group. In other words, the ratio of electrical
potential in response to trunk stimulation before and after tumor
resection (after / before resection) was determined as ARR1, and the
ratio of electrical potential in response to trunk stimulation and
branch stimulation after tumor resection (trunk / periphery) was
determined as ARR2. Furthermore, in group C, the time to recovery of
paralyzed branches and ARR1 and ARR2 were compared. The House-Brackmann
scale was used to assess paralysis.
Statistical processing was carried out using the Chi-squared test,
Wilcoxon signed-rank sum test, and the Mann-Whitney U test, with p
< 0.05 considered statistically significant. We used
Spearman’s rank correlation coefficients to examine correlations.