Surgical Treatment of Secondary Hemifacial Spasm: Long-Term Follow-Up.

Background: Hemifacial spasm (HFS) is generally caused by the root exit zone of the facial nerve compressed by an overlying arterial loop. HFS can also be caused by various types of tumor, aneurysm, or arteriovenous malformation. We retrospectively analyzed patients to evaluate possible differences in the demographic and clinical features between primary and secondary HFS.

Methods: A retrospective study of 3140 cases of HFS treated in our department between January 2009 and June 2016. Among the 3140 total cases, 26 patients had secondary HFS.

Results: The 26 tumors of secondary HFS included 11 meningiomas, 8 epidermoid cysts, and 7 vestibular schwannomas. Compared to those with idiopathic HFS, those patients with tumor-induced HFS were significantly younger (P < 0.05). Secondary HFS tended to have responsible vessels, and were observed in 20 (76.92%) of these 26 patients. The long-term effective rate of operation was 84% in the secondary HFS group and was 96.45% in the primary HFS group (P < 0.05); the incidence rate of complication was 12% in the secondary HFS group and was 3.06% in the primary HFS group (P < 0.05).

Conclusions: In cases of secondary HFS, facial nerves of most patients were compressed by blood vessels, so microvascular decompression after tumor resection plays an important role. We should examine the entire nerve root for possible vascular compression.