Neurovascular Mechanisms and Clinical Imaging Correlates in Hemifacial Spasm: A Prospective Observational Study with Surgical Outcome Evaluation

This prospective observational study evaluated the neurovascular mechanisms and imaging correlates of hemifacial spasm (HFS), with surgical outcome assessment following microvascular decompression (MVD). A total of 1,670 patients with primary HFS were enrolled and underwent clinical, radiological, and surgical evaluation over 24 months. Clinical severity was assessed using the Jankovic Rating Scale (JRS) and 36-Item Short Form Health Survey (SF-36) quality-of-life measures. High-resolution magnetic resonance imaging (MRI) (Fast Imaging Employing Steady-State Acquisition [FIESTA] and Constructive Interference in Steady State [CISS] sequences) identified neurovascular compression (NVC) in 94.7% of cases, predominantly involving the anterior inferior cerebellar artery (AICA) (51.2%). Compression at the root exit zone (REZ) was observed in 87.5%. Imaging severity correlated significantly with clinical severity (r = 0.52, p < 0.001) and quality-of-life impairment (r = –0.44, p < 0.001). Among 964 patients undergoing MVD, 56.1% achieved complete relief, and 31.6% had partial improvement. Severe compression predicted better outcomes (74.2% relief rate). Longer symptom duration (>5 years) was associated with reduced surgical benefit (p = 0.008). Recurrence occurred in 11.1% overall, most frequently among patients with venous or multiple vessel compression. Logistic regression failed to identify age, sex, or imaging score alone as significant predictors of poor outcome. However, subgroup analysis confirmed that shorter duration, high imaging severity, and REZ involvement improved surgical prognosis. Health-related quality of life (HRQoL) improvements were greatest among patients with complete symptom relief. These findings support the utility of neuroimaging in diagnosis, prognostication, and surgical planning, emphasizing the importance of early intervention and anatomical characterization of NVC.