Yinda Tang

Re-operation for persistent hemifacial spasm after microvascular decompression with the aid of intraoperative monitoring of abnormal muscle response.

Background and objectivesMicrovascular decompression (MVD) is the only solution that can effectively control hemifacial spasm (HFS). Regarding treatment of the patients who failed the first operation, it is still controversial. We tried to evaluate the safety and efficiency of the early re-exploration for such kinds of patients.MethodsThirteen patients failed the first MVD and received a second MVD procedure. The spasm was not resolved at all or became even more severe after the first MVD. Abnormal muscle response (AMR) persisted during the first MVD operation or disappeared once but emerged again. The patient had a strong will to do the re-operation and was aware of the high risks of operative complications.ResultsAll the 13 patients got good or excellent spasm resolution immediately after the re-operation, which involved whole-range exploration and intraoperative AMR monitoring; however, there were two cases (15.4%) of permanent facial weakness and three cases (23.0%) of transient facial weakness.ConclusionsOur experience on early repeat MVD is whole-range exploration and intraoperative AMR monitoring; in other words, re-operation cannot rely too much on experience.

Factors Promoting a Good Outcome in a Second Microvascular Decompression Operation When Hemifacial Spasm is Not Relieved After the Initial Operation

BACKGROUND Microvascular decompression (MVD) has become the best treatment for hemifacial spasm (HFS); however, some patients do not obtain complete relief after the initial MVD. We analyzed a group of patients who underwent a second MVD, to identify the factors that prevented relief after the initial MVD and those that promote the success of the second procedure. METHODS Of a group of 1400 patients with typical primary unilateral HFS treated with MVD between January 2014 and October 2015, we focused on 42 patients with poor postoperative outcomes. All patients underwent abnormal muscle response (AMR) monitoring again the day after surgery. Of those patients, 35 underwent a second MVD surgery within a week. We analyzed their AMRs after each operation. RESULTS After the first operation, AMR was positive in 40 patients and negative in 2 patients. The latter 2 patients reported spontaneous relief within 1 week. Among the 40 positive patients, 35 and 4 patients underwent a second MVD within a week and 6-11 months, respectively. Thirty-nine patients reported relief after the second MVD; 1 patient remained unchanged at follow-up (<12 months). CONCLUSIONS When initial MVD does not provide relief, a repeat MVD should be performed as soon as possible. In 2/42 cases, relief was delayed enough that AMR had a false-negative result. Combinative monitoring of AMR and Z-L responses was important in identifying the real cause of HFS.

Microvascular Decompression for Idiopathic Primary Trigeminal Neuralgia in Patients Over 75 Years of Age.

Objective:In the present study, the authors appraised the results of microvascular decompression in patients over 75 years of age. Methods:From June 2009 to June 2013, a number of 108 aged patients with primary trigeminal neuralgia experienced microvascular decompression. The authors present a retrospective review of medical records and compared the results with those of a control group of 302 younger patients. Results:The mean follow-up period was 3 years. No statistically marked differences were observed between the 2 groups in terms of rate of pain control, recurrences, complications. The duration of operation in the elderly group was markedly shorter than that in the younger group. Conclusion:Microvascular decompression is a liable and safe surgical method for aged patients with primary trigeminal neuralgia. Unless the aged patients cannot bear general anesthesia, they should have the chance to select microvascular decompression.

Microvascular Decompression for Glossopharyngeal Neuralgia: Long-Term Follow-Up

OBJECTIVE To examine operative findings and outcome of microvascular decompression (MVD) for glossopharyngeal neuralgia (GPN). This research displayed the long-term outcomes of a large series of 35 cases with GPN treated with MVD. METHODS From January 2004 to June 2006, 35 consecutive patients were diagnosed with GPN. All of them underwent MVD. Demographic data, clinical presentation, operative findings, clinical results, operative complications were reviewed. RESULTS A total of 33 patients (94.3%) experienced complete pain relief immediately after MVD. Long-term follow-up was available for 30 of these 35 patients, and 28 of these 30 patients continued to be pain-free. There was no long-term operative morbidity in all cases. One patient had a cerebrospinal fluid leak and 1 case presented with delayed facial palsy. CONCLUSIONS Classic GPN is usually caused by pulsatile neurovascular compression of the glossopharyngeal and vagus rootlets. MVD is a safe, effective, and durable operation for GPN.

Nimodipine-mediated re-myelination after facial nerve crush injury in rats

This study aimed to investigate the mechanism of nimodipine-mediated neural repair after facial nerve crush injury in rats. Adult Sprague-Dawley rats were divided into three groups: healthy controls, surgery alone, and surgery plus nimodipine. A facial nerve crush injury model was constructed. Immediately after surgery, the rats in the surgery plus nimodipine group were administered nimodipine, 6 mg/kg/day, for a variable numbers of days. The animals underwent electromyography (EMG) before surgery and at 3, 10, or 20 days after surgery. After sacrifice, nerve samples were stained with hematoxylin and eosin (H&E) and luxol fast blue. The EMG at 20 days revealed an apparent recovery of eletroconductivity, with the surgery plus nimodipine group having a higher amplitude and shorter latency time than the surgery only group. H&E staining showed that at 20 days, the rats treated with nimodipine had an obvious recovery of myelination and reduction in the number of infiltrating cells, suggesting less inflammation, compared with the rats in the surgery only group. Luxol fast blue staining was relatively even in the surgery plus nimodipine group, indicating a protective effect against injury-induced demyelination. Staining for S100 calcium-binding protein B (S-100β) was not evident in the surgery alone group, but was evident in the surgery plus nimodipine group, indicating that nimodipine reversed the damage of the crush injury. After a facial nerve crush injury, treatment with nimodipine for 20 days reduced the nerve injury by mediating remyelination by Schwann cells. The protective effect of nimodipine may include a reduction of inflammation and an increase in calcium-binding S-100β protein.

Outcome of Biomedical Glue Sling Technique in Microvascular Decompression for Hemifacial Spasm Involving the Vertebral Artery

BACKGROUND Microvascular decompression (MVD) is the most useful treatment for hemifacial spasm (HFS). In cases of vertebral artery (VA) compression of the facial nerve, MVD is often difficult. In this study, we compared the outcome of the biomedical glue sling technique with the traditional technique in MVD for HFS involving the VA. METHODS A retrospective study of patients with HFS treated by MVD was conducted between January 2013 and December 2015. A total of 327 patients with VA-associated HFS underwent their first MVD at our institution. Among them, the traditional technique was performed in 153 patients and the biomedical glue sling technique was performed in 174 patients. We measured effectiveness at 1 day, 7 days, 1 month, 3 months, and 1 year after MVD surgery. RESULTS In the traditional technique group, the effective rates of MVD were 89.54%, 88.89%, 89.40%, 88.44%, and 86.71%, and the incidence rates of complication were 5.23%, 4.58%, 3.97%, 2.72%, and 0.70%. In the biomedical glue sling technique group, the effective rates of operation were 96.55%, 96.55%, 97.66%, 95.86%, and 95.76% (P < 0.05), and the incidence rates of complication were 8.62%, 8.62%, 7.60%, 4.73%, and 2.42% (P > 0.05). CONCLUSION When the HFS were associated with the VA, the effective rate of biomedical glue sling technique of MVD was higher than the traditional technique, and there was no statistical difference between the 2 groups about the incidence of complication.

Long-Term Efficacy of Nerve Combing for Patients with Trigeminal Neuralgia and Failed Prior Microvascular Decompression

BACKGROUND Microvascular decompression (MVD) of the trigeminal nerve is the most effective treatment for trigeminal neuralgia (TN). However, many patients respond poorly to initial MVD. For these patients, redo MVD is commonly done. There has been no research regarding the effectiveness of nerve combing (NC) plus MVD in patients with TN and failed prior MVD. We compared the clinical outcome of NC plus MVD and simple redo MVD in patients with TN and failed prior MVD. METHODS We performed a retrospective analysis of 148 patients with recurrent or persistent TN symptoms who underwent surgery between January 2007 and December 2015. Simple MVD was performed in 62 patients, and NC plus MVD was performed in 86 patients. RESULTS For simple MVD, success rates at 1 day, 7 days, 1 month, 3 months, and 1 year after surgery all were approximately 80%. Success rates of NC plus MVD were significantly (P < 0.05) higher than success rates of simple MVD, by 17.02%, 18.64%, 16.47%, 17.21%, and 14.80% at 1 day, 7 days, 1 month, 3 months, and 1 year. The incidence rates of facial numbness in the simple MVD group were 48.39%, 45.16%, 36.67%, 16.95%, and 1.75% at 1 day, 7 days, 1 month, 3 months, and 1 year; the incidence rates in the NC plus MVD group were 60.47%, 55.81%, 48.24%, 21.69%, and 3.75% (P > 0.05). CONCLUSIONS In patients with TN who failed prior MVD, NC plus MVD significantly improved the success rate of the operation compared with simple redo MVD. We obtained good short-term and long-term surgical outcomes with NC combined with MVD.

Results of Atypical Hemifacial Spasm with Microvascular Decompression: 14 Case Reports and Literature Review

BACKGROUND Few studies have examined atypical hemifacial spasm (AHFS), and the mechanism of AHFS remains unclear. In this study, we examined the etiology, prognosis, and treatment of AHFS. METHODS We retrospectively analyzed the clinical data for 14 consecutive patients that underwent microvascular decompression (MVD) for AHFS between January 2014 and December 2015. Clinical features, outcomes, and complications were evaluated. RESULTS The incidence of AHFS is 1.52%. There were no significant differences in sex, age, side and duration between the typical hemifacial spasm and AHFS. During the follow-up period, the effective rate of MVD for patients with AHFS was 92.3%. Three patients developed delayed facial nerve palsy postoperatively, 1 patient experienced occipital sensory disturbance, and 1 patient suffered hearing loss. CONCLUSIONS Most of the cases of AHFS studied here were caused by neurovascular conflict in zone IV of the facial nerve distal to the root entry zone. MVD surgery is the first choice treatment for AHFS.

Comparison of the Efficacy of Reoperation, Percutaneous Radiofrequency Thermocoagulation When Microvascular Decompression of Trigeminal Neuralgia Is Invalid.

Objective:To compare the curative effect of reoperation in short-term and percutaneous radiofrequency thermocoagulation (PRT) when trigeminal neuralgia patient after microvascular decompression (MVD) is invalid. Methods:Follow-up of 54 patients (30 patients with reoperation in the short term, 24 patients with PRT of primitive trigeminal neuralgia) when MVD is invalid between January 2008 and December 2014. To evaluate the degree of pain relief and facial numbness of patients after the treatment in short-term (1 month), in long-term (1 year). Result:One month after surgery, the authors compared the reoperation group with PRT group. The ratio of cure rate P = 0.02, the ratio of effective rate P = 0.04, the ratio of facial numbness P = 0.01; 1 year after surgery, the authors compared the reoperation group with PRT group. The ratio of cure rate P = 0.004, the ratio of effective rate P = 0.006, the ratio of facial numbness P = 0.02, the ratio of recurrence P = 0.04. The short-term and long-term clinical efficacy in reoperation group was better than PRT group (P < 0.05). Conclusion:For the patients of trigeminal neuralgia when first MVD is invalid, reoperation is better than PRT, and a significantly lower incidence of facial numbness and recurrence than PRT.

The Effects of Dual Abnormal Muscle Response Monitoring on Microvascular Decompression in Patients with Hemifacial Spasm

BACKGROUND Microvascular decompression (MVD) is the most useful treatment for hemifacial spasm (HFS). During MVD surgery, traditional abnormal muscle response (tAMR) is widely used to monitor success in decompressing the facial nerve. Dual AMR (dAMR) is a new monitoring method used during MVD for HFS. We compared the sensitivities and reliabilities of tAMR and dAMR. METHODS We performed a retrospective study of 1301 cases of HFS treated using MVD between January 2014 and March 2016. Among the 1301 cases, 587 patients underwent tAMR monitoring and 714 underwent dAMR monitoring. RESULTS Typical abnormal muscle response (AMR) waveforms were observed in 484 patients (82.5%) in the tAMR group and in 688 patients (96.4%) in the dAMR group (P < 0.05). AMR waveforms disappeared in 459 patients in the tAMR group and in 655 patients in the dAMR group during MVD. One day, 7 days, 1 month, and 3 months after MVD surgeries with AMR disappearance, the effective rate of MVD was 95.0%, 94.3%, 94.5%, and 95.0%, respectively, in the tAMR group. The corresponding rates were 97.7%, 96.9%, 97.3%, and 98.0% in the dAMR group (P < 0.05). One day, 7 days, 1 month, and 3 months after MVD surgeries with AMR persistence, the effective rate of MVD was 68.0%, 64.0%, 64.0%, and 64.0%, respectively, in the tAMR group. The corresponding rates were 90.9%, 87.9%, 87.9%, and 90.9% in the dAMR group (P < 0.05). CONCLUSIONS AMR monitoring provides valuable neurosurgical guidance during MVD for HFS. dAMR monitoring has better sensitivity and reliability than tAMR monitoring.