Intraoperative Electrophysiological Monitoring In Microvascular Decompression For Hemifacial Spasm

Objective: to investigate the value of intraoperative facial muscles lateral spreadresponse (LSR)and brainstem auditory evoked potential(BAEP) in the microvasculardecompression(MVD) for hemifacial spasm(HFS).Methods:from January2011toDecember2011,33patients affected with hemifacial spasms were treat downsideMVD,during which LSR and BAEP were monitoring synchronously.Analysis therelationship between the monitoring result and the outcomes. Results: LSR waveform canbe recorded in all of the33patients intraoperatively.LSR disappeared during28patients,and sustained in5patients.All of the28patients in the group of LSR disappearingwere cured,and only4patients cured in the group of LSR sustained.Statistical analysiswere made between two groups,there were dignificant difference between them(P＜0.05).It suggests that the disappearing of LSR response indicate the facial spasm symptomwill disappear after operation.The outcome of the group that LSR response persisted afterMVD were much more than the contrast group.It suggests that the disappearing of LSRresponse can prognosticate the effect of MVD.Intraoperative BAEP waveform in V wavereduced by50%or more or disappear in4patients,of which3patients were found hearingloss with obvious symptom after operation. Conclusion:intraoperative monitoring of LSRand BAEP during MVD benefits to enhance the effective rate,forecast the outcome duringthe operation,and protect the audio function.