Delayed Facial Palsy After Microvascular Decompression for Hemifacial Spasm.

To explore the risk factors of delayed facial paralysis (DFP) after microvascular decompression (MVD) for hemifacial spasm (HFS) METHODS: :A retrospective study was conducted on 636 patients who had undergone MVD for HFS by the same neurosurgery department of China-Japan Friendship Hospital from January 2006 to May 2016. Of all patients, 7.9% (50 of 636) presented DFP, which occurred from the 2nd day to the 60th day after operation, with an average of 12.9 days (SD = 10.0005). All of 50 patients with DFP recovered completely from 10 to 300 days after the onset of DFP, with an average of 88.7 days (SD = 61.389). We randomly selected 100 patients from 586 patients without DFP as the control group. Univariate and multivariate logistic analysis was used to analyze the risk factors involved in the occurrence of DFP RESULTS: : Univariate analysis showed that course of disease was the only factor associated with DFP (P = 0.003). Furthermore, in the multivariate logistic analysis,the course of HFS was the only risk factor associated with DFP (P = 0.01). Additionally, Spearman test revealed a positive correlation between the time of DFP onset and the duration of DFP symptoms (rs = 0.682, P < 0.001) CONCLUSION: Although DFP frequently occurred after MVD, it can recover spontaneously. The longer the course of HFS lasts, the more frequently DFP will occur after MVD. The earlier DFP occurs, the shorter it takes to recover. Hemifacial spasm (HFS) is characterized by involuntary paroxysmal convulsions of one side facial muscles. The main cause of HFS is vascular compression of the root exit zoon (REZ) of facial nerve. ^1-3 Microvascular decompression (MVD) is the only effective method to cure HFS. Complications of MVD includes hearing impairment, facial paralysis, meningitis, intracranial hemorrhage, intracranial infection, and delayed facial paralysis (DFP). ^4,5 DFP refers to the facial paralysis which occurs more than 24 hours after MVD,and it can generally recover spontaneously. ⁶ It is common in the clinical observation and its mechanism is still unclear.^7-9 To study the risk factors of DFP after MVD for HFS is of great significance for exploring the mechanism of DFP and further understanding the intrinsic pathophysiological process of cranial nerve diseases.