Delayed Resolution of Hemifacial Spasm after Microvascular Decompression

Abstract

Objective: In a proportion of patients of hemifacial spasm (HFS) after microvascular decompression (MVD), the symptom was not relieved immediately after MVD. We aimed to investigate the incidence and factors related with delayed resolution of HFS after MVD. Methods: This study was based on the clinical data of 415 patients with HFS treated using MVD who had been followed up for 2 to 6 years. Multivariate analysis, two-variable correlative test, and linear regression analysis were applied to identify the factors related with delayed resolution after MVD. Results: In 415 patients, 115 did not achieve resolution of HFS immediately after MVD. The symptom was gradually resolved from 7 days to 8 months (mean duration: 6 weeks) in 106 patients (25.5%). Comparing patients with delayed resolution of HFS after MVD with those who had immediately complete resolution, the occurrence of delayed resolution was correlated significantly with the illness duration, severity of HFS, sclerosis of offending arteries, and intraoperative abnormal muscle response (AMR) findings. The persisting period of HFS in patients with delayed resolution was positively correlated with the preoperative illness duration. Conclusions: The occurrence of delayed resolution could be related with illness duration, severity of HFS, sclerosis of offending arteries and intraoperative AMR findings. The effect of MVD for HFS should be evaluated after at least 1 year of follow-up.