[Microvascular decompression in hemifacial spasm: functional outcome].

Introduction: Hemifacial spasm (HFS) is a rare condition, characterized by unilateral, paroxysmal and involuntary contraction of the muscles innervated by the facial nerve (FN). The most common cause is a vascular conflict in the exit zone of the FN. The objective of this work is to demonstrate the efficacy and safety of neurovascular decompression (NVD).

Materials and methods: Retrospective analytical study, patients operated on for NVD due to HFS (n: 48), from June 2005 to December 2023, using a retrosigmoid approach and clinical-radiological follow-up, whose intraoperative recording was with a 2D or 3D video system. Age, gender, time of evolution, side of the condition, use of botulinum toxin, intraoperative findings, postsurgical results and complications were evaluated.

Results: The average age was 50 years, with 60% women. The right side was affected in 23 cases. The vessel most identified as causing the neurovascular conflict was the anterior inferior cerebellar artery in 48% of the cases. The clinical response was complete (disappearance of HFS) in 41 patients (85%), partial in 5 cases and null in 2 cases. Complications included transient deficits in 11 cases and permanent deficits in 2 cases.

Discussion: Most of our patients with HFS (85%) obtained a total improvement, along with a low rate of permanent morbidity (4%) and no cases of mortality. NVD should be considered as the first line of treatment in patients with primary HFS with evidence of neurovascular conflict on MRI.