The Value Of 3D-TOF-MRA Combined With Neurophysiological Monitoring During Microvascular Decompression For Hemifacial Spasm

Objective:To investigate the value of 3D-TOF-MRA combined with electrophysiological monitoring during microvascular decompression for hemifacial spasm.Methods: The clinical data of 143 patients with hemifacial spasm in Guizhou Provincal People’s Hospital from March 2013 to March 2016 was retrospectively reviewed.All the patients performed microvascular decompression by the same group of surgeons,were divided into two groups.The control group including 61 patients was examined by MRI scan before surgery from March 2013 to May 2014 and June 2014 to March 2016.Expect for MRI scan,the test group including 82 patients accepted preoperative 3D-TOF-MRA and intraoperative electrophysiological monitoring from June 2014 and March 2016.The accuracy of 3D-TOF-MRA was verified by observing the blood vessels and nerves intraoperatively.The efficacy and the incidence of postoperative nerve injury were compared between the two groups.Results: 1.All patients were detected neurovascular compression(NVC)introperatively,including 53 cases with vertebral basilar artery compression(about 37.1%),and 90 cases with small vessels compression(about 62.9%).In test group,preoperative 3D-TOF-MRA showed that the findings of facial nerve roots compressed by or adjacent to vessels in 73cases(about 89%)were confirmed intraoperatively.The typical waves of abnormal muscle response(AMR)were found in all test group patients.AMR in 64 cases immediately disappeared intraoperatively after microvascular decompression,and AMR in 18 cases still continued postoperatively.2.Operative effect evaluation: According to the China expert consensus on microvascular decompression for treatment of hemifacial spasm in 2014:In the control group,50 cases(about 82.0%)were judged to be effective and invalid in 11 cases(about 18.0%);In the test group,77 cases(about 93.9%)were judged to be effective,invalid in 5 cases(about6.1%).The difference between the test group and the control group was statistically significant(P<0.05).3.Nerve injury rate: The incidence of nerve injury in the test group was 7.3%(6/82),including facial nerve injury in 4 cases,auditory nerve injury in 2 cases.The incidence of nerve injury in the control group was 19.7% 12/61),including facial nerve injury in 8 cases,auditory nerve injury in 4 cases.The difference between the test group and the control group was statistically significant(P<0.05),The complication rate of the control group was higher than that of the test group.Follow-up:The patients without complications were followed up by telephone;patients with surgical complications and / or invalid,partial remission were followed up by out-patient service.In the control group,55 cases were followed up for more than 1 years and between 6 months to 48 months(averaged 28.1±10.7 months),with 6 cases lost to follow-up.In test group,75 cases were followed up for more than 1 years and between 6months to 33 months,averaged 19.4±7.9 months,with 7 cases lost to follow-up.All of the patients were cured before they were lost to follow-up without complications.All patients with facial nerve injury were cured after treatment at the last follow-up.Hearing loss was cured in 2 case,different degrees of hearing impairment in 3 cases,and permanent hearing loss in 1 case.There were no complications such as dysphagia,hoarseness and facial numbness in the two groups.Conclusion: Preoperative 3D-TOF-MRA combined with electrophysiological monitoring is useful to finding of responsible vessel.Intraoperative electrophysiological monitoring is helpful for improving efficacy,reducing the risk of posterior cranial nerve injury,and improving the quality of life.