Clinical Trial: Observe Abnormal Potential From the Offending Vessel to the Facial Muscles of HFS Patients

Study Status: Completed
Recruit Status: Unknown status
Study Type: Observational

Official Title: Observation of the Abnormal Potential From the Offending Vessel to the Facial Muscles of Hemifacial Spasm Patients

Brief Summary: The pathophysiologic basis of hemifacial spasm is cross-transmission between different branches of the facial nerve. The hypothesis is that the cross-transmission is mediated by the sympathetic nerve fibers on the surface of the offending artery. The abnormal potential from the offending vessel to the facial muscles will be detected on hemifacial spasm patients, so as to determine if the sympathetic nerve fibers take part in the circuit of cross-transmission.

Detailed Summary: It's hypothesized that at the location where the facial nerve is compressed by an artery, ephaptic cross-transmission takes place between the nude facial nerve fibers and the sympathetic nerve fibers on the arterial surface. Thus action potentials could spread indirectly from one facial nerve fiber to several other facial nerve fibers (via the "bridge" of sympathetic fibers), or directly from the sympathetic fibers to facial nerve fibers. The investigators assume this is the electrophysiological basis of hemifacial spasm and its characteristic sign abnormal muscle response (AMR). If an abnormal potential from the offending artery to the facial muscles similar to AMR can be recorded, the hypothesis will be verified.
Sponsor: Shanghai Jiao Tong University School of Medicine

Current Primary Outcome: Abnormal Potential From the Offending Vessel to the Facial Muscles [ Time Frame: up to 4 months ]

Original Primary Outcome: Same as current

Current Secondary Outcome: Latency from the root entry zone of facial nerve to the facial muscles [ Time Frame: up to 4 months ]

Original Secondary Outcome: Same as current

Information By: Shanghai Jiao Tong University School of Medicine

Dates:
Date Received: January 5, 2011
Date Started: January 2011
Date Completion: December 2011
Last Updated: July 22, 2011
Last Verified: July 2011