Role of monitoring abnormal muscle responses during microvascular decompression for hemifacial spasm

Objective: To investigate the significance of monitoring abnormal muscle responses during microvascular decompression for hemifacial spasm. Methods: 32 patients of hemifacial spasm underwent microvascular decompression under monitoring of intraoperative abnormal muscle responses. Relationships between disappearance of intraoperative abnormal muscle responses and curative effect were observed. Results: In 27 patients, the abnormal responses disappeared when the blood vessel was separated from the facial nerve in operation, and in 26 of them, facial spasm immediately disappeared after operation, and in 1 of them, facial spasm disappeared during follow-up phase. In another 5 patients, the abnormal responses did not disappear when the blood vessel was separated from the facial nerve, and in 1 of them, facial spasm immediately disappeared after operation, and in 2 of them, facial spasm eased during follow -up phase. Conclusion: The monitoring intraoperative abnormal muscle responses are useful to judge the effectiveness of the decompression and improve the recovery rate.