Microvascular decompression to treat hemifacial spasm: long-term results for a consecutive series of 143 patients

OBJECTIVE: The concept of neurovascular decompression for the treatment of hemifacial spasm is now widely accepted. In this study, we report our long-term results for 145 cases treated with this procedure. METHODS: The results of 145 microvascular decompressions to treat hemifacial spasm (performed between 1980 and 1998) among 143 patients (62.2% female patients and 37.8% male patients; mean age, 54.5 yr) are presented. The onset of symptoms was typical in 95.9% of cases and atypical in 4.1%. Platysma muscle involvement was observed for 24.5% of patients, with a higher incidence among female patients (74.3%). Patients were monitored with annual questionnaires. Twenty-six patients were lost to follow-up monitoring, and 117 are still undergoing follow-up monitoring, with an average period of 9.6 years (range, 1-17.6 yr). RESULTS: At discharge, 69 patients (59%) were spasm-free and 48 patients (41%) experienced further spasm. At 6 months, the number of spasm-free patients had increased to 108 (92.3%), whereas only 9 patients (7.7%) complained of hemifacial spasm; 44 patients were spasm-free at an average time of 15 weeks. In follow-up examinations (average period, 9.4 yr), 106 patients were spasm-free. Seven patients experienced only temporary relief, with recurrence after 4.5 years. Two patients were spasm-free after 4 or 6 weeks, and the recurrence of spasm was observed 1 year later. Two patients were never completely spasm-free. Among the patients who did not undergo previous surgery elsewhere, only two experienced recurrence. CONCLUSION: Deafness was the main postoperative complication (8.3%); most of those cases (66%) occurred before the routine use of intraoperative evoked potential monitoring. Analysis of our series demonstrates that this surgical procedure involves very low risk, is well tolerated by elderly patients, is associated with very low recurrence rates, and is a definitive treatment for more than 90% of cases.     

Microvascular decompression for hemifacial spasm: long-term outcome and prognostic factors, with emphasis on delayed cure

The postoperative course of microvascular decompression (MVD) for hemifacial spasm (HFS) is variable, and the optimal time for assessing the results is unclear. From April 1997 to October 2007, MVD for HFS was performed in 801 patients. Patients were divided into two groups (cured or failed) according to subjective patient assessments over a 3-year period. We analyzed patient characteristics and surgical findings to determine prognostic factors. Medical records were analyzed retrospectively over the 3-year follow-up period. Of the 801 patients who underwent surgery, 743 (92.8 %) appeared to be cured, 70 (8.7 %) had residual or recurrent spasms more than 1 year after surgery, 11 (1.3 %) had gradual improvement over 3 years, and 1 (0.1 %) had delayed improvement more than 3 years after surgery. Fifty-eight patients (7.2 %) had residual or recurrent spasms more than 3 years after surgery, of which 19 (2.4 %) had recurrence after initial relief. The mean time to spasm recurrence was 18.9 months. Intraoperative resolution of the lateral spread response (LSR) after decompression (p?=?0.048) and severe indentation (p?=?0.038) were significant predictors of good long-term outcome after MVD for HFS. In our series, 70 patients (8.7 %) had residual or recurrent spasms more than 1 year after surgery, of which 12 (17.1 %) improved gradually after 1 year. If the surgeon can confirm intraoperative resolution of the LSR and severe indentation, reoperation can be delayed until 3 years after MVD.     

Microsurgical treatment of trigeminal neuralgia. Results and prognostic factors of microsurgical vascular decompression

The authors have reviewed 100 cases of trigeminal neuralgia operated upon at the cerebello-pontine angle using microsurgical techniques, i.e. 20% of their total series of 513 patients with tic douloureux, 413 of them having been submitted to percutaneous R.F.--thermocoagulation. In 10 of the above 100 patients, a tumour or an angioma have been found and with its removal a total relief of pain has been obtained. In all but three of the other 90 patients, a neurovascular conflict has been revealed. In 17 of them a selective section of the trigeminal root had to be performed, as its cross-compression could not be eliminated. A total cure was achieved in all but three cases in which the result was only partial. In 70 patients a microvascular decompression (MVD) was performed and in 68 of them a follow-up of 1 to 5 years has been analyzed. In 82.4% the results were excellent. Further 7.3% thought to be benefited by the operation; although they still had some pain, they were well controlled by medical treatment. In 10.3% an unsatisfactory improvement, failure or recurrence were noted. Then a critical study of the whole material has been made in search for the causes of unsatisfactory results and for the possibilities of making the efficacity of MVD ascertained in a higher percentage of patients. The results of this study lead to definite conclusions, a part of which is quoted below: Some of clinical findings showed to be of paramount importance for the prognosis. The most evident has been a highly significant difference in the percentage of a total cure in patients with attacks of tic douloureux only (94.5%) and in those with the same type of attacks, but associated with permanent pain (58.3%). The analysis of the operative findings and of the details of the surgical procedure indicated to a necessity of restitution of the normal shape and course of the trigeminal root from the petrous ridge up to the entry-zone and of an adequate root protection (for instance with Dacron), after the Vth nerve had been detached from the conflicting vessel. A correlation of the above findings with the angiographic ones has been made. A measurable method has been used to make available data which could be informative as to the presence of a conflict, as well as to its anatomical cause. But this still needs a further critical elaboration.     

Microvascular decompression for hemifacial spasm: a long-term follow-up of 1,169 consecutive cases

We analyzed the records of 1,169 patients with hemifacial spasm (HFS) who underwent microvascular decompression (MVD) and were followed up for more than 6 months from January 1987. The mean follow-up duration was 23.8 months (6-145 months). Excellent surgical outcome was obtained in 90.5% and good in 4.5%, giving an overall success rate of 95.0%. There was statistically significant relationship between vertebral artery (VA) shift and side of symptom. Permanent facial weakness and hearing impairment were 1.4% and 2.3%, respectively. There were no anatomical differences at the root entry zone (REZ) and significant differences of surgical outcome in young HFS (34 patients). Factors such as type of offender, severity of compression on the facial nerve root, and the degree of decompression of the REZ on postoperative MRI did not correlate with surgical outcome.     

Microvascular decompression for hemifacial spasm. Patterns of vascular compression in unsuccessfully operated patients

To determine the causative factors of unsuccessful microvascular decompression for hemifacial spasm, the follow-up results in 53 patients were assessed retrospectively. The mean follow-up period was 36 months. There were 32 patients who had compression of the seventh cranial nerve ventrocaudally by an anterior inferior cerebellar artery (AICA) or a posterior inferior cerebellar artery. Of these 32 patients, 30 (94%) had excellent postoperative results. Of 14 patients with more severe compression by the vertebral artery, nine (64%) had excellent results, three (21%) had good results, and two (14%) had poor results; in this group, three patients with excellent results experienced transient spasm recurrence. There were seven patients in whom the meatal branch of the AICA coursed between the seventh and eighth cranial nerves and compressed the dorsal aspect of the seventh nerve; this was usually associated with another artery compressing the ventral aspect of the nerve ("sandwich-type" compression). Of these seven patients, five (71%) had poor results including operative failure in one and recurrence of spasm in four. The authors conclude that the clinical outcome was closely related to the patterns of vascular compression.     

Microvascular decompression for hemifacial spasm: analyses of operative findings and results in 310 patients.

The operative findings and results of microvascular decompression (MVD) on 310 Chinese patients with hemifacial spasm are analyzed in this report. The operations were performed at the Neurological Institute of the Veterans General Hospital-Taipei between January 1983 and June 1990. The length of follow-up ranged from 6 months to 8 years (mean, 4.3 years); 273 patients (88%) had complete relief of spasm within 3 days after one MVD, and the remaining 37 patients (12%) showed no immediate postoperative improvement. Sixteen (5.2%) of these 37 initially unresponsive patients subsequently experienced complete relief, which occurred from 4 days to 22 months (median, 21 days) after one MVD; 13 others (4.2%) had complete relief immediately after the second MVD; another 3 (1%) had delayed complete relief 6, 9, and 11 months after the second MVD, respectively; and the remaining 5 (1.6%) only had delayed partial relief, which occurred 2 to 9 weeks after one MVD. Late recurrence occurred in three patients (1%). These immediate and long-term results lend support to the conclusion that the timing of reoperation can be postponed for a period of 3 to 4 weeks in the event of an initial failure to get improvement, and that a second MVD may be of value.     

Microvascular decompression for hemifacial spasm: Outcome on spasm and complications. A review

Over the last decades microvascular decompression (MVD) has been established as the curative treatment of the primary Hemifacial Spasm (HFS), proven to be linked in almost all cases to a neurovascular compression of the facial nerve. Because the disease is not life-threatening and MVD not totally innocuous, efficacy and safety have to be weighted before decision taken of indicating surgery. The authors have been charged by the French Speaking Society of Neurosurgery to conduct a detailed evaluation of the probability of relief of the spasm that MVD is able to obtain, together with its potential complications. For the review, the authors have gone through the reports available from the Pubmed system. Eighty-two publications have been read and analysed, totalizing more than 10,000 operated cases. In most series, the percentage of patients with total relief ranged between 85% and 90%. Relief was obtained after a certain delay in as many as in 33% ± 8% of the patients in many series. For those, delay lasted around one year in 12% of them. When effect of MVD was considered achieved, relief remained permanent in all but 1%–2% of the long-term followed patients. As regards to complications, risk of permanent cranial nerve deficit was evaluated at 1%–2% for facial palsy, 2%–3% for non-functional hearing loss, 0.5%–1% for lower cranial nerve dysfunction. Risk of stroke was at 0.1% and mortality at 0.1%. CSF leakage and related complications could be reduced at less than 2% in most series provided careful closing techniques be applied. Complications were at a higher rate in repeated MVD. MVD is an effective curative method for almost all the patients affected with primary HFS. Because MVD for HFS is functional surgery, scrupulous consideration of its potential risks, together with the ways to avoid complications are of paramount importance. When MVD is estimated to have failed, it is wise to wait one year before considering to repeat surgery, as number of patients may benefit from delayed effect. This is the more so as important as repeated surgery entails a higher rate of complications.     

Abnormal muscle response monitoring during microvascular decompression for hemifacial spasm and long term results

OBJECTIVE: There is some debate over the reliability of intraoperative abnormal muscle response (AMR) monitoring as an indicator of postoperative long-term outcome in patients with hemifacial spasm (HFS). We investigated whether AMR findings obtained during microvascular decompression reflect postoperative long-term outcome. MATERIAS AND METHODS: Subjects were 51 HFS patients who underwent AMR monitoring during surgery. AMR recordings were obtained from the mentalis muscle by electrical stimulation of the temporal branch of the facial nerve and from the orbicularis oculi muscles by stimulation of the marginal mandibular branch. Postoperative follow-up was more than 5 years (range 61-118 months, mean 87 months). RESULTS: In 37 patients, AMR disappeared after vascular decompression. Among those patients, only one presented with spasm at the final follow-up examination. In 6 of 7 patients with AMR that disappeared early before the completion of decompression, hemifacial spasm resolved completely. Five of six patients in whom AMR still remained but with decreased amplitude at the end of surgery experienced complete resolution. CONCLUSIONS: Our findings suggest that intraoperative cessation including prior to decompression or decreased amplitude of AMR at the end of surgery indicates a high likelihood of postoperative long-term relief of HFS. We believe that intraoperative AMR monitoring is useful in MVD surgery for HFS.     

The patterns and risk factors of hearing loss following microvascular decompression for hemifacial spasm

Objective  

The aim of this study was to reveal the risk factors including intraoperative brain stem auditory evoked potential (BAEP) changes and to define parameter and warning values of BAEP beyond which the probability of hearing impairment rises significantly.     

Loss of auditory function in microvascular decompression for hemifacial spasm. Results in 143 consecutive cases

Auditory function was studied before and after surgery in 143 consecutive patients who were operated on for hemifacial spasm by microvascular decompression of the intracranial portion of the facial nerve. The acoustic middle ear reflex was abnormal preoperatively in 41% of the patients, indicating that the vascular abnormalities that caused the hemifacial spasm also affected the auditory nerve. Three patients suffered a profound hearing loss in the ear on the operated side, and one lost hearing function totally. In addition, 24 patients had a moderate elevation in the pure-tone threshold at one or more octave frequencies. Of these, 16 patients experienced a hearing loss at only one frequency (8000 Hz), while eight had a threshold evaluation of no more than 20 dB in the speech frequency range (500, 1000, and 2000 Hz). Two patients were deaf on the side of the spasm before the operation. Three patients were not tested postoperatively, and one patient was tested only after surgery. Thus, in this series of 143 patients, only 2.8% suffered a significant hearing loss as a complication of facial nerve decompression to relieve hemifacial spasm.     

Delayed hearing loss after microvascular decompression for hemifacial spasm: report of two cases

We report two unusual cases of delayed hearing loss after microvascular decompression (MVD) for hemifacial spasm. In the first case, A 59-year-old female noted left hearing loss one week after receiving MVD for left hemifacial spasm. In the second case, A 39-year-old male also noticed ipsilateral hearing loss on the 7th day after MVD for right hemifacial spasm. Both cases were treated by steroid. Two months after the onset, their hearing function improved dramatically. These cases indicated that the delayed hearing loss after MVD for hemifacial spasm can occur, even when gentle microsurgical technique is used, but the prognosis for this condition is fairly good.     

Microvascular decompression for primary hemifacial spasm. Importance of intraoperative neurophysiological monitoring

Summary There is considerable evidence that primary Hemi-Facial Spasm (HFS) is in almost all cases related to a vascular compression of the facial nerve at its Root Exit Zone (REZ) from brainstem, and that Micro-Vascular Decompression (MVD) constitutes its curative treatment. Clinical as well as electrophysiological features plead for mechanisms of the disease in structural lesions at the neural fibers (putatively: focal demyelination at origin of ephapses) and functional changes in the nuclear cells (hyperactivity of the facial nucleus). Lateral Spread Responses (LSRs) elicited by stimulation of the facial nerve branches testify of these electrophysiological perturbations. Monitoring LSRs during surgery is feasible; however the practical value of their intraoperative disappearance as control-test of an effective decompression remains controversial. MVD allows cure of the disease in most cases. Because the VIIIth nerve is at risk during surgery, intraoperative monitoring of Brainstem Auditory Evoked Potentials (BEAPs) is of value to reduce occurrence of hearing loss. Increase in latency of Peak V and decrease in amplitude of Peak I are warning-signals of an excessive stretching of the the cochlear nerve and impairment of the cochlear vascular supply, respectively.     

A proposal for standardized analysis of the results of microvascular decompression for trigeminal neuralgia and hemifacial spasm

Background

The purpose of this study was to evaluate and analyze overall postoperative results from microvascular decompression (MVD) by combining the cure rate of symptoms with the complication rate. A new scoring system for obtaining objective surgical results from MVD for trigeminal neuralgia (TN) and hemifacial spasm (HFS) is proposed to document treatment results using consistent criteria in a standardized manner.

Method

Surgical results combining complications , if any, were obtained from a questionnaire sent to patients who had undergone surgery for TN or HFS in recent years and had been followed-up for more than 1?year after surgery (TN patients, n?=?54; HFS patients, n?=?81) When surgical outcome is complete resolution of symptoms, the efficacy of surgery (E) is designated E-0, but when moderate symptoms are still persist postoperatively, the score is designated E-2. When no complications are seen after surgery, the complication score (C) is C-0, while the score is C-2 if troublesome complications remain. In addition, total evaluation of the results (T) is judged by combining the E and C scores. For example, when E is 0, and C is C-2, the total evaluation is scored as T-2, which is diagnosed as fair.

Findings

The response rate of the questionnaire was 80.7% (109/135). Overall surgical data were evaluated and analyzed using our new scoring system. Analysis of the collected data revealed an outcome of T-0 was 70% (35/50 patients) and T-1 was 24% (12/50) and T-2 was 6% (3/50) in TN, whereas in HFS, T-0 was 61% (36/59) and T-1 was 27.1% (16/59) and T-2 was 6.8% (4/59) and T-3 was 5.1% (3/59).

Conclusion

The total results of MVD should be evaluated and analyzed by combining the cure rate of symptoms together with the complication rate. This new scoring system could allow much more objective analysis of the results of following MVD. Adopting this scoring system to objectively judge treatment results for TN and HFS, individual surgeons can compare their own overall surgical results with those of other institutes. Comparative results of MVD can also be provided to patients considering therapy to allow informed decision-making on the basis of good quality evidence.     

Relationship between angiographical manifestations and operative findings in 100 cases of hemifacial spasm

Relationship between angiographical manifestations and operative findings of hemifacial spasm was studied in 100 cases. Vertebral angiography was performed, and Towne, straight AP, and lateral projections were routinely studied. The anterior inferior cerebellar artery (AICA) directly compressed the facial nerve root exit zone in 54 instances, the posterior inferior cerebellar artery (PICA) in 38, and the vertebral artery (VA) in 11. Compressions by multiple vessels were observed in 3 cases. Anatomical variations of the AICA and the PICA were classified into 3 groups according to their origins and their distributions of blood supply: Type I, normal distribution of AICA and PICA; Type II, common trunk anomaly with dominant AICA (basilar artery origin); and Type III, common trunk anomaly with dominant PICA (vertebral artery origin). In our cases, 35% of them showed normal distribution, 34% dominant AICA, and 35% dominant PICA. Analyses of the angiograms revealed significantly increased numbers of common trunk anomalies when compared with normal angiograms studied by Takahashi. In 60 of the 65 cases with common trunk anomalies, facial nerves were compressed by the main trunk or the branches of the dominant artery. There were 35 cases which belonged to Type I anatomical classification. They were subdivided into 2 groups according to the size of the AICA and PICA: 1. AICA greater than PICA, and, 2. PICA greater than AICA. In the AICA greater than PICA subgroup, the AICA was the offending artery in all but one case. In the PICA greater than AICA subgroup, the PICA was responsible in 9 of 17 cases. In 31 cases, angiograms showed a redundant VA with lateral elongation into the cerebellopontine angle.(ABSTRACT TRUNCATED AT 250 WORDS)     

The outcome of microvascular decompression for hemifacial spasm: a systematic review and meta-analysis

Microvascular decompression (MVD) is the first choice of surgery for hemifacial spasm (HFS). MVD surgery for vertebral artery (VA)-associated HFS is more difficult than for non-VA-associated HFS. There is controversy about the cure rate and complication of MVD for HFS in previous studies. We searched PubMed, Web of Science, and Embase for relevant publications. Based on the search results, we compared the outcomes of MVD for VA-associated HFS and non-VA-associated HFS. At the same time, we analyzed spasm-free rates and the complications and assessed the relationship between VA-associated HFS and gender, left side, and age. For analysis, six studies that included 2952 patients in the VA-associated group and 604 in the non-VA-associated group were selected. The effective rate of MVD was not significantly different between both groups (OR?=?1.16, 95% CI 0.81–1.67, P?=?0.42). Compared to non-VA-associated group, the transient complications (OR?=?0.64, 95% CI 0.46–0.89, P?=?0.008) and permanent complications (OR?=?0.28, 95% CI 0.15–0.54, P?=?0.0001) occurred more frequently in VA-associated group. The rate of hearing loss was significantly higher in VA-associated HFS than non-VA-associated HFS (OR?=?0.35, 95% CI 0.19–0.64, P?=?0.0007); the facial paralysis after operation was not significantly different between both groups (OR?=?1.25, 95% CI 0.91–1.72, P?=?0.17). There were older patients (WMD?=?3.67, 95% CI 3.29–4.05, P?<?0.00001) and more left-sided HFS (OR?=?0.23, 95% CI 0.19???0.29, P?<?0.0002) in the VA-associated HFS group than non-VA-associated HFS group, while the non-VA-associated HFS group was female-dominated (OR?=?1.58, 95% CI 1.32???1.89, P?<?0.00001). Both groups achieved good results in MVD cure rates. In VA-associated HFS, the complication rate of decompression and the rate of hearing loss after operation were higher than in non-VA-associated HFS, but the facial paralysis after operation was similar in both groups, and most complications were transient and disappeared during follow-up. VA-associated HFS is more prevalent in older adults, less prevalent in women, and more predominantly left-sided. More clinical studies are needed to better compare the efficacy and complication of MVD between both groups.

     

Serious complications of microvascular decompression operations for trigeminal neuralgia and hemifacial spasm

Serious complications of microvascular decompression operations for trigeminal neuralgia or hemifacial spasm are reported. Among 278 patients who underwent microvascular decompression, 9 serious complications were observed: 1 intracerebellar hematoma with acute hydrocephalus, 1 cerebellar swelling with acute hydrocephalus, 1 supratentorial acute subdural hematoma, 2 status epilepticus, 1 infarction of the brain stem, 1 subarachnoid hemorrhage due to traumatic aneurysm, and 1 infarction in the territory of the posterior cerebral artery. Of the 9 patients with such complications, 2 died. The possible causes of such serious complications are discussed.     

Early permanent disappearance of abnormal muscle response during microvascular decompression for hemifacial spasm: a retrospective clinical study

The objective of this study is to explore the cause of early abnormal muscle response (AMR) disappearance during microvascular decompression for hemifacial spasm and the clinical outcomes of these patients. Three hundred seventy-two patients received microvascular decompression (MVD) under intraoperative electrophysiological monitoring in Nanjing Drum Tower Hospital in 2014; the characteristic AMR of HFS was observed in 359 patients during the operation. And the 359 patients were divided into two groups based on whether AMR had remained before the beginning of the decompression procedure for offending vessels. Thirty-three patients who showed a permanent disappearance of AMR before the beginning of decompression were regarded as group I. Dural opening and the succeeding CSF drainage produced a permanent disappearance of AMR in 13. During the dissection of lateral cerebellomedullary cistern, a permanent disappearance of AMR was found in 20 patients. Thirty-two patients were cured immediately; delayed resolution (7 days after surgery) was found in one patient. No complications were observed and no recurrence was found during the follow-up period in the 33 patients. In the other 326 patients (group II), AMR disappeared temporarily before the beginning of the decompression procedure for offending vessels in 42 patients. After decompression, AMR disappeared completely in 305 patients. Two hundred sixty-seven patients were cured immediately and 57 patients got a delayed resolution (2 days to 45 weeks after surgery). The two left did not get a complete abolition of spasm. Three cases of hearing loss, one hoarseness, and nine delayed facial paralysis were observed. The reason of early abnormal muscle response disappearance may be that the degree of neurovascular compression was not serious; these patients were more likely to get an immediate cure. Continuous intraoperative electrophysiological monitoring of AMR is necessary.