›› 2012, Vol. 32 ›› Issue (3): 326-.doi: 10.3969/j.issn.1674-8115.2012.03.019

• Original article (Clinical research) • Previous Articles     Next Articles

Electrophysiological research on mechanism of formation of abnormal muscle response

SHANG Ming, ZHENG Xue-sheng, TANG Yin-da, LI Xin-yuan,WANG Xu-hui, JIAO Wei, YANG Xiao-sheng, LI Shi-ting   

  1. Department of Neurosurgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China
  • Online:2012-03-28 Published:2012-03-28

Abstract:

Objective To explore the mechanism of formation of abnormal muscle response (AMR) by electrophysiological methods. Methods The clinical data of 15 patients with idiopathic hemifacial spasm undergoing microvascular decompression were collected. Myoelectricity response (i.e.AMR) was recorded from the orbicularis oculi muscles when the mandibular branch of the facial nerve was electrically stimulated. Conduction potential and myoelectricity response were recorded respectively from the orbicularis oculi muscles and the mandibular branch of the facial nerve when the compression positions of facial nerve were electrically stimulated. The latencies and changes of responses after microvascular decompression were analysed. Results The mean latency of AMR recorded from orbicularis oculi muscles was (10.49±0.35) ms when the mandibular branch of the facial nerve was electrically stimulated. The mean latency of responses recorded from the mandibular branch was (3.99±0.18) ms, and the mean latency of responses recorded from the orbicularis oculi muscles was (4.62±0.32) ms when the compression positions were electrically stimulated. The mean latency of AMR was significantly longer than the sum of the mean latency of responses recorded from the marginal mandibular branch and that recorded from the orbicularis oculi muscles when the compression positions of facial nerve were electrically stimulated (P<0.05). AMR completely disappeared in 14 (93.3%) patients after decompression. Conclusion Offending vessels may participate in the abnormal electrical transmission circuit of hemifacial spasm, which is one of the necessary factors leading to hemifacial spasm.

Key words: hemifacial spasm, microvascular decompression, offending vessels, abnormal muscle response