Good Surgical Outcomes of Hemifacial Spasm Patients with Obvious Facial Nerve Indentation and Color Change.

OBJECTIVES: Hemifacial spasm results from vascular compression of the facial nerve. It remains controversial whether severe compression and subsequent nerve indentation predict a good or a poor surgical outcome. Here, to illustrate the relationship between the degree of neurovascular compression and surgical outcome, we conducted a retrospective case-cohort study focused on patients whose facial nerve was seriously compressed. METHODS: This study included 2 groups. The nerve-indentation group included 48 patients with hemifacial spasm whose facial nerves had obvious indentation and color change at the site of neurovascular conflict. The control group included 48 randomly selected patients with hemifacial spasm without facial nerve indentation or color change who were surgically treated by the same team during the same period. The surgical findings, intraoperative lateral spread response results, and clinical outcomes were compared. RESULTS: Single-vessel compression was found more frequently in the nerve-indentation group (87.5%) than in the control group (60.4%, P < 0.05). The lateral spread response (LSR) resolution rate of the nerve-indentation group was 91.7%, and that of the control group was 87.5% (P > 0.05). The rates at which the microvascular decompression procedure was successful were equal in the nerve-indentation and the control groups (93.8% vs. 91.7%, P > 0.05). CONCLUSIONS: Severe vascular compression and subsequent nerve indentation were correlated with a greater possibility of single compression and a lower incidence of multiple neurovascular conflicts in patients with hemifacial spasm, making the microvascular decompression procedure more accurate and easier. Therefore nerve indentation might predict good surgical outcomes.