Utility of intraoperative electromyography in microvascular decompression for hemifacial spasm: A meta-analysis

Abstract

Object: In this paper, the authors' goal was to determine the utility of monitoring the abnormal muscle response (AMR) or "lateral spread" during microvascular decompression surgery for hemifacial spasm. Methods: The authors' experience with AMR as well as the data available in the English-language literature regarding resolution or persistence of AMR and the resolution or persistence of hemifacial spasm at follow-up was pooled and subjected to a meta-analysis. Results: The pooled OR revealed by the meta-analysis was 4.2 (95% CI 2.7-6.7). The chance of a cure if the AMR was abolished during surgery was 4.2 times greater than if the lateral spread persisted. Conclusions: The AMR should be monitored routinely in the operating room, and surgical decision-making in the operating room should be augmented by the AMR.