Neuroimaging Markers for Diagnosis and Management of Hemifacial Spasm: A Systematic Review

Abstract

Background Hemifacial spasm (HFS) is a neurological disorder characterized by involuntary, rhythmic contractions of the facial muscles, often caused by neurovascular compression of the facial nerve. Traditional diagnosis relies on clinical evaluation, but neuroimaging plays an increasing role in identifying underlying causes and guiding treatment, particularly in cases where surgery is considered. This systematic review aims to evaluate the effectiveness of neuroimaging markers in the diagnosis and management of HFS, focusing on the role of MRI, Diffusion Tensor Imaging (DTI), and other advanced imaging modalities.

Objective To assess the role of neuroimaging techniques in diagnosing HFS, identifying vascular compression, and predicting treatment outcomes.

Methods A systematic review was conducted by analyzing studies published from 2000 to 2024. Articles were selected based on their use of neuroimaging techniques, including MRI, DTI, and functional MRI (fMRI), in the diagnosis and management of HFS. Studies were screened for relevance, and data were extracted on sample size, imaging methods, and key findings. The quality of the studies was assessed using appropriate tools for observational studies.

Results Eight studies were included in the review, involving a total of 320 HFS patients. Key findings indicated that vascular compression of the facial nerve at the root exit zone (REZ) was a prevalent imaging marker, particularly in MRI studies. Advanced imaging techniques like DTI and fMRI provided additional insights into nerve tract integrity and brain activity patterns, which correlated with disease severity. Several studies showed that neuroimaging findings, particularly vascular compression, were predictive of successful surgical outcomes, especially after microvascular decompression (MVD). However, variability in imaging findings was noted, with some patients exhibiting vascular compression without symptomatic HFS.

Conclusions Neuroimaging, particularly MRI, plays a crucial role in diagnosing HFS and guiding treatment decisions. Advanced imaging techniques, such as DTI and fMRI, provide additional valuable information about brain structure and function, contributing to a more comprehensive understanding of the disorder. While vascular compression remains the primary imaging marker, future research should focus on refining imaging protocols and exploring the role of central nervous system changes in HFS. A multimodal imaging approach is recommended for a more accurate diagnosis and personalized treatment strategies.