Neurophysiological Monitoring In Microvascular Decompression For The Treatment Of Facial Spasm

ObjectiveTo explore the value of neurophysiological monitoring in microvascular decompression in the treatment of primary hemifacial spasm(HFS). Materials and Methods1?71 cases with primary hemifacial spasm were collected, who were treated and received microvascular decompresslon from January 2010 to January 2016. In the department of neurosurgery at the second clinical hospital of Zhengzhou university, they were divided into two groups.2? 43 cases of the primary hemifacial spasm patients from September 2013 to January 2016 as the monitoring group, 28 cases of patients who were treated from January 2010 to September 2013 as the control group. The monitoring group, with electrophysiological monitoring of LSR(lateral spread response) and BAEP(brainstem auditory evoked potential). Electrical stimulation for the marginal mandibular branch of facial nerve were made before surgery, after released of cerebrospinal fluid, the sharp separation of the subarachnoid, after the facial nerve and the responsible blood vessels were separated and the Teflon gasket was placed, the closure of the dura mater. The EMG responses of the orbicularis oculi muscle were recorded, and the disappeared time of LSR wave was also recorded at the same time. Analyzed and compared the effect of surgical treatment and the disappearance of LSR. The changes of amplitude and latency of wave ?were observed especially, Set volatility fell 50% as early warning signs. Electrophysiological monitoring was not performed in the control group during the operation.3?The monitoring group contained 12 male patients, 31 female patients, aged between 30 to 65 years old, the average age was(38 ±12.6) years old, the course of disease was 3.2 to 7.5 years, the average course of disease was(4.7 ± 1.5) years. There were 9 male patients, 19 female patients in control group, aged between 27 to 62 years old, the average age was(34 ±15.5) years old, the course of disease was 5.4 to 7.7 years, the average course of disease was(5.8 ± 2.5) years. SPSS 19.0 statistical software was used, and the test of ?2 was included. Set p<0.05 with statistical significance. Results1? There were 36 cases of the monitoring group, whose LSR waves were disappeared at the end of surgery. 2 cases were disappeared after released the cerebrospinal fluid fully. 3 cases' LSR were disappeared after release the arachnoid, 31 cases' LSR were disappeared after the offending vessels were found and separated, and the Teflon gasket was placed. 7 cases were not disappeared after decompression, 3 cases of patients were found that, there was a nerve pressure points at the distal end of the facial, after exploration used by nerve endoscope. 4 cases were not disappeared after depressurized fully. There were two cases' amplitude decreased more than 50% of the V wave of BAEP, Both of them appeared hearing loss after postoperative, but recovered in 3months.2?The short-term efficiency(postoperative 1d) of the monitoring group was 90.69%(39 cases), which was higher than 82.14%(23 cases) of the control group, the difference was statistically significant(p<0.05). The long-term efficiency(postoperative 1m) was 95.35%(41 cases) in the monitoring group still higher than 89.29% in the control group(25 cases).The complication rate of the monitoring group(13.96%) was significantly lower than the control group(35.71%), the difference was statistically significant(p<0.05). Conclusion1?The lateral spread response(LSR) is the characteristic performance of the primary HFS. The disappeared LSR is usually closely related to the removal of the responsible vessels during the operation of MVD. Furthermore, patients' hemifacial spasm symptoms will be significantly improved after MVD.2?The brainstem auditory evoked potentials(BAEP) is more sensitive and objective indicators for monitoring brain stem damage, and it can not only better protect the patient's auditory nerve from damage during the surgery, but also can reduce the incidence of postoperative complications. The V wave' change in volatility can predict of hearing-impaired patients effectively after the operation.3?The combination of LSR and BAEP can greatly improve the operation efficiency and reduce the incidence of surgical complications in microvascular decompression surgery.