Two-dimensional structure analysis of hemifacial spasms and surgical outcomes of microvascular decompression

ABSTRACT

Background

Although studies have indicated that the small posterior fossa plays a role in hemifacial spasm (HFS), few studies have denoted the correlations between local measurements of the cerebellopontine angle and the incidence of HFS and surgical outcomes.

Methods

We retrospectively analyzed the demographic and clinical data of HSF patients who underwent microvascular decompression at our institution. Healthy controls were recruited. The divergent prognosis of HFS was defined as an ordinal variable. A multivariable ordinal regression model was generated to estimate the relationship between the variables and outcomes of HFS.

Results

Between 2013 and 2018, 180 patients who were enrolled in our study met the inclusion criteria. Compared with the control group (n = 94), HFS patients had a smaller internal acousticmeatus-brainstem distance (P < 0.001) on the unaffected side and a larger facial nerve-brainstem angle (P < 0.001). The regression analysis demonstrated that subgroups with more severe facial nerve compression (mild vs severe, OR = 0.269, P = 0.018; moderate vs severe, OR = 0.215, P < 0.001) and a thinner brainstem (OR = 2.368, P = 0.014) were more likely to experience better short-term outcomes, while subgroups with a thinner brainstem (OR = 5.583, P = 0.007) were more likely to experience better long-term outcomes.

Discussion

Structural changes occurring in patients are risk factors for HFS. The patient’s local neurovascular structure and brainstem volume are factors that significantly influence short-term and long-term surgical outcomes.

KEYWORDS:

• Hemifacial spasm
• root exit zoom
• cerebellopontine angle
• microvascular decompression
• surgical outcomes

Disclosure of Interest

The authors report no conflicts of interest.

Additional information

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Notes on contributors

Shiyuan Han

Shiyuan Han is a resident in neurosurgery at Peking Union Medical College Hospital in Beijing, China.

Yongning Li

Yongning Li is a Professor of neurosurgery and Chair of the Department of International Medical Service at Peking Union Medical College Hospital in Beijing, China.

Zhimin Li

Zhimin Li is a resident in neurosurgery at Peking Union Medical College Hospital in Beijing, China.

Xin Wang

Xin Wang is a resident in neurosurgery at Peking Union Medical College Hospital in Beijing, China.

Jun Gao

Jun Gao is an Associate Professor of neurosurgery at Peking Union Medical College Hospital in Beijing, China.