2017-18 HSC Section 3 Green Book

P. Xu et al. / American Journal of Otolaryngology – Head and Neck Medicine and Surgery 38 (2017) 269 – 271

N 6 months (surgery was performed 6 months later after paralysis onset). The outcomes of facial nerve between different groups were compared.

2.3. Surgery and preoperative fi ndings

Electroneurography (ENoG) was performed within 2 – 3 weeks after facial paralysis, and electromusculography (EMG) was performed if pa- tients were admitted after 3 weeks. N 90% neural degeneration on ENoG or absence of regeneration potentials on EMG was considered as indica- tion of facial nerve exploration and decompression. The facial nerve was decompressed from stylomastoid foramen till labyrinthine segment of facial nerve through mastoid approach, including vertical segment, tympanic segment, geniculate ganglion and labyrinthine segment. The surgical details had been described suf fi ciently before, and this ap- proach can avoid opening the skull and the subsequent possible compli- cations [7 – 11] . High-resolution CT of temporal bone was performed before surgery for each patient.

In addition, another 4 cases met the surgical indication but refused surgery (conservative treatment was provided), among which HRCT re- vealed no clear fracture lines in one case and longitudinal type of tem- poral fractures in 3 cases. Finally, none of the 4 cases recovered to Grade II or better (0%). When compared with the patients in the 3 – 6 months group or N 6 months group, there was no signi fi cant differ- ence in the good recovery rate ( p N 0.05), but there was signi fi cant dif- ference when compared with the those in the b 1 month group or 1 – 2 months group or 2 – 3 months group ( p b 0.05). It has been widely accepted that surgical facial nerve decompression is recommended if ENoG shows N 90% degeneration of nerve fi bers within the fi rst 2 – 3 weeks after paralysis or EMG shows no regeneration signs after 3 weeks [13 – 15] . However, surgical timing of facial paralysis after temporal bone trauma is still controversial. Some authors recom- mend surgical decompression within 2 weeks or one month of paralysis onset, while others claim that facial nerve decompression between 1 month and 3 months still has bene fi cial effects [6,16,17] . In our study, the good recovery rate of facial paralysis after temporal bone trauma declined gradually as prolongation of the interval between pa- ralysis onset and surgical intervention, and the good recovery rate of the b 1 month was signi fi cantly higher than that of the 3 – 6 months group or the N 6 months group ( P b 0.05). The above facts indicated that outcomes of facial nerve would be better if surgical intervention was performed during the fi rst month. Whereas there was no signi fi - cant difference between the b 1 month group and the 1 – 2 months group or the 2 – 3 months group ( P N 0.05), although the good recovery rate declined from 84.2% to 73.1% and 66.7%. It indicated that facial nerve decompression between 1 month and 3 months was still recom- mended, if it was impossible to perform surgery within 1 month due to severe head trauma. The viewpoints above were similar to Chang and Cass's conclusion [2] . Since the largest case series were involved in our study and the follow-up was one year, a relatively more solid conclusion was drawn. Of course, a well designed double-blinded controlled clini- cal trial was more convincing. Surgical decompression on the patients with facial paralysis due to temporal bone trauma over 3 months was rarely reported before. In Hato N et al. ’ s report [17] , only 8 cases accepted surgical decompression when facial paralysis lasted for over 3 months, which had a good recov- ery rate of 37.5%, similar to 38.5% among the patients accepting surgery between 3 and 6 months in our study. Of note, we even performed Fig. 1. The good recovery rate among patients who underwent surgical decompression with different interval between facial paralysis and surgery. There was no signi fi cant difference in the good recovery rate between the b 1 month and the 1 – 2 months group or the 2 – 3 months group ( P N 0.05), but the good recovery rate of the b 1 month group was signi fi cantly higher compared to the 3 – 6 months group or the N 6 months group ( P b 0.05). 4. Discussion

2.4. Facial nerve function evaluation

House-Brackmann (HB) grading system [12] was introduced to eval- uate facial nerve function. Facial nerve recovery to Grade I or II was deemed as good recovery.

2.5. Statistical analysis

SPSS 16.0 software was employed for data analysis. The good recov- ery rate between two groups was compared by the chi-square test, if normal distribution and homogeneity of variance as well as the sum of case number ≥ 40 were met. Or else, Fisher's exact test was used for the comparison. P b 0.05 indicated signi fi cant difference.

3. Results

Eighty of eighty eight cases meeting the criteria were enrolled in data analysis, and the remaining eight cases lost one-year follow-up. There were 53 males and 27 females. There were 44 cases of traf fi c ac- cident, 10 cases of high falling, 11 cases of fi ghting, 10 cases of tumble, 3 cases injured by crashing objects, and 2 cases of machine work. 49 cases had paralysis at the left side and 31 at the right side. Their age ranged from 2 to 65 years, and interval between facial paralysis and sur- gery ranged from 4 days to 9 months. High-resolution CT of temporal bone suggested clear fracture lines in 68 cases and absent fractures in 12 cases. Among the 68 cases with clear fracture lines, 49 cases (72.1%) belonged to the longitudinal type of tem- poral fractures, 13 cases (19.1%) belonged to the transverse type and the rest 6 cases (8.8%) belonged to the mixed type. The number of patients who achieved recovery of Grade I in 22 cases, Grade II in 30, Grade III in 15, Grade IV in 8 and Grade V in 5. 52 of 80 patients (65.0%) achieved good recovery (Grade I or II). 43 of 66 cases (65.2%) in the younger group had good recovery of facial nerve in con- trast to 9 of 14 cases (64.3%) in the elder group, without signi fi cant dif- ference ( p N 0.05). 9 of 13 cases (69.2%) in the delayed onset group had good recovery, while 43 of 67 cases (64.2%) in the immediate onset group had good recovery, without signi fi cant difference ( p N 0.05). Among subgroups of surgical time, the number of patients with good re- covery was 16 of 19 cases (84.2%) in the b 1 month group, 19 of 26 cases (73.1%) in the 1 – 2 months group, 10 of 15 cases (66.7%) in the 2 – 3 months group, 5 of 13 cases (38.5%) in the 3 – 6 months group and 2 of 7 cases (28.6%) in the N 6 months group ( Fig. 1 ). There was no signi fi cant difference in the good recovery rate between the b 1 month and the 1 – 2 months group or the 2 – 3 months group ( P N 0.05), but the good recovery rate of the b 1 month group was signif- icantly higher than that of the 3 – 6 months group or the N 6 months group ( P b 0.05).

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