Objective:To study whether the excitability of facial nerve motor nucleus is increased in patients with facial spasm to further study the mechanism of facial spasm.Methods:Thirty patients with HFS underwent MVD in our hospital from April 2018 and March 2019 were chosen in our study. The amplitude and threshold voltage of facial nerve motor evoked potential (FNMEP) of the affected side and healthy side were monitored and compared by using monopulse stimulation and multi-pulse stimulation. The changes of FNMEP amplitude in patients before and after sevoflurane inhalation were monitored.Results:Stable facial motor evoked potential could be stimulated by monopulse in 26 patients (89.7%) on the affected side, while only 5 patients (17.2%) on the healthy side, showing statistical difference between the two sides ( P<0.05); there was no significant difference in FNMEP amplitude between the affected side and the healthy side ([207.2±62.1] μV vs. [180.2±55.0] μV, P>0.05); the average threshold voltage of neuromotor evoked potential on the affected side was (140.3±26.8) V, which was significantly lower than that in the healthy side ([177.0±23.2] V, P<0.05). The amplitude of FNMEP on the affected side was (207.2±62.1) μV, (133.0±36.5) μV, and (70.4±40.2) μV, respectively, before sevoflurane inhalation, and at 0.5 fold of minimun alveolar concentration (MAC) and 1.0 fold of MAC concentrations, with significant differences ( P<0.05). Conclusion:In patients with hemifacial spasm, there is increased excitability of facial nerve motor nucleus on the affected side, which to a certain extent supports the central theory of hemifacial spasm pathogenesis.

Objective To evaluate the efficacy and safety of nerve combing for trigeminal neuralgia without neurovascular decompression.Methods A retrospective review of clinical data of 281 patients with trigeminal neuralgia,admitted to our hospital from January 2008 to January 2016,was performed.The patients were divided into two groups:patients from group A were treated by nerve combing (n=32),and patients from group B were treated by microvascular decompression (n=249).The two groups were compared in terms of surgical outcomes and postoperative complications.Results The pain was completely relieved in 90.6％ patients of group A (29/32) and 94.4％ patients of group B (235/249),respectively;the mean follow-up duration was 62.5 months in group A,and 78.1％ patients (25/32) were completely relieved;the mean follow-up duration was 59.8 months in group B,and 84.1％ patients (201/239)were completely relieved;no statistically significant differences existed in the surgical outcomes and long-term outcomes between the two groups (P＞0.05).No complications related to severe disability or death were noted in the two groups.The rate of facial numbness in patients from group A (71.9％) was significant higher than that in group B (2.5％,P＜0.05).Conclusions Nerve combing is a safe and effective treatment for trigeminal neuralgia without neurovascular decompression.Most patients treated with nerve combing experienced some degrees of facial numbness.