A clinical analysis on microvascular decompression surgery in a series of 3000 cases

Objective

Despite the microvascular decompression (MVD) has become a definitive treatment for trigeminal neuralgia (TN) and hemifacial spasm (HFS), not all of the patients have been cured completely so far and this sort of operation is still with risk because of the critical operative area. In order to refine this surgery, we investigated thousands MVDs.

Methods

Among 3000 consecutive cases of MVDs have been performed in our department, 2601 were those with typical TN or HFS, who were then enrolled in this investigation. They were retrospectively analyzed with emphasis on the correlation between surgical findings and postoperative outcomes. The differences between TN and HFS cases were compared. The strategy of each surgical process of MVD was addressed.

Results

Postoperatively, the pain free or spasm cease occurred immediately in 88.3%. The symptoms improved at some degree in 7.2%. The symptoms unimproved at all in 4.5%. Most of those with poor outcome underwent a redo MVD in the following days. Eventually, their symptoms were then improved in 98.7% of the reoperative patients. The majority reason of the failed surgery was that the neurovascular conflict located beyond REZ or the offending veins were missed for TN, while the exact offending artery (arteriole) was missed for HFS as it located far more medially than expected.

Conclusion

A prompt recognition of the conflict site leads to a successful MVD. To facilitate the approach, the craniotomy should be lateral enough to the sigmoid sinus. The whole intracranial nerve root should be examined and veins or arterioles should not be ignored. For TN, all the vessels contacting the nerve should be detached. For HFS, the exposure should be medial enough to the pontomedullary sulcus.     

The Effect of Microvascular Decompression for Hemifacial Spasm Caused by Vertebrobasilar Dolichoectasia

Objective

Hemifacial spasm (HFS) caused by vertebrobasilar dolichoectasia (VBD) is very rare, and in theses cases, it is difficult to decompress the nerve from its vascular compression. The objective of this study was to investigate the outcome of microvascular decompression (MVD) for HFS caused by VBD.

Methods

There were 10 patients of HFS caused by VBD at our hospital between September 1978 and September 2008. We evaluated magnetic resonance angiography (MRA) and time of flight magnetic resonance imaginge (TOF MRI) findings using the criteria for VBD. We compared the clinical outcomes of MVD for the 10 patients with VBD with the overall outcomes of the total 2058 MVDs performed for HFS.

Results

The results of MVD for HFS caused by VBD were successful in 90.9% of cases. The postoperative complication rate in VBD was 45.5%. Offending vessels in patients with VBD were identified visually during surgery. Adverse effects after MVD were found in 4 patients. We found that the diameter of VBD was significantly greater in patients with complications than in those with no complications (p=0.028).

Conclusion

Our data shows that MVD may be a good treatment modality for HFS caused by VBD but care must be taken to avoid adverse effects from the procedure. It is important to detach the dolichoectatic artery from its surrounding structures sufficiently to allow it to be easily movable. In addition, attempts should be made to lessen the retraction of the cerebellum during release of the dolichoectatic artery.     

Microvascular Decompression for Hemifacial Spasm Associated with Vertebrobasilar Artery

Objective

Hemifacial spasm (HFS) is considered as a reversible pathophysiological condition mainly induced by continuous vascular compression of the facial nerve root exit zone (REZ) at the cerebellopontine angle. As an offending vessel, vertebrobasilar artery tends to compress much more heavily than others. The authors analyzed HFS caused by vertebrobasilar artery and described the relationships between microsurgical findings and clinical courses.

Methods

Out of 1,798 cases treated with microvascular decompression (MVD) from Jan. 1980 to Dec. 2004, the causative vessels were either vertebral artery or basilar artery in 87 patients. Seventy-nine patients were enrolled in this study. Preoperatively, computed tomography (CT) or brain magnetic resonance (MR) imaging with 3-dimentional short range MR technique was performed and CT was checked immediately or 2-3 days after anesthetic recovery. The authors retrospectively analyzed the clinical features, the compression patterns of the vessels at the time of surgery and treatment outcomes.

Results

There were 47 were male and 32 female patients. HFS developed on the left side in 52 cases and on the right side in 27. The mean age of onset was 52.3 years (range 19-60) and the mean duration of symptoms was 10.7 years. Many patients (39 cases; 49.1%) had past history of hypertension. HFS caused only by the vertebral artery was 8 cases although most of the other cases were caused by vertebral artery (VA) in combination with its branching arteries. Most frequently, the VA and the posterior inferior cerebellar artery (PICA) were the simultaneous causative blood vessels comprising 32 cases (40.5%), and in 27 cases (34.2%) the VA and the anterior inferior cerebellar artery (AICA) were the offenders. Facial symptoms disappeared in 61 cases (77.2%) immediately after the operation and 68 cases (86.1%) showed good outcome after 6 months. Surgical outcome just after the operation was poor in whom the perforators arose from the offending vessels concurrently (p<0.05).

Conclusion

In case where the vertebral artery is a cause of HFS, commonly branching arteries associated with main arterial compression on facial REZ requires more definite treatment for proper decompression because of its relatively poor results compared to the condition caused by other vascular compressive origins.     

Hearing outcomes following microvascular decompression for hemifacial spasm

Purpose

Facial nerve microvascular decompression (MVD) for hemifacial spasm (HFS) provides relief to most patients. Due to the proximity of the cochlear and facial nerves, hearing loss is a potential MVD complication, however, there is a wide range in the reported incidence of hearing loss (HL) in the literature. In order to better understand the HL incidence in our MVD population, we utilized the combination of speech discrimination scores (SDS) and air and bone pure tone threshold averages (PTA) to identify patients with no hearing change, sensorineural hearing loss, or conductive hearing loss. We also assessed the predictive value of patient-reported hearing deficits on the ultimate audiometric diagnosis of hearing loss.

Methods

One hundred and fifty one patients underwent facial nerve MVD at the University of Pittsburgh Medical Center between January 2000 and December 2007. Peri-operative audiometric data, including changes in air and bone pure tone thresholds and speech discrimination scores, were analyzed retrospectively. Criteria from the 1995 American Academy of Otolaryngology Committee on Hearing and Equilibrium consensus were used to analyze post-operative hearing loss. Patient-reported hearing disturbances obtained in the immediate post-operative period were compared to seven-day post-operative conductive and sensorineural HL status.

Results

Non-functional, non-serviceable HL (Class D) occurred in 6.6% of patients, while 10.6% developed cumulative non-functional HL (Class C and D). Twenty-nine patients (18.7%) exhibited conductive HL. While patient-reported complaints were predictive of Class C/D HL (<0.0001) with a 56.3% sensitivity and 92.6% specificity, patient-reported complaints were not strongly associated with conductive HL status (p = 0.369) with 17.2% sensitivity and 88.5% specificity.

Conclusions

Perioperative hearing evaluations, in conjunction with careful scrutiny of patient complaints and air-bone pure tone testing enables the physician to more precisely quote complication rates and rapidly distinguish potentially reversible conductive hearing pathologies from permanent sensorineural disorders.     

Delayed Cranial Nerve Palsy after Microvascular Decompression for Hemifacial Spasm

Objective

Microvascular decompression (MVD) for hemifacial spasm (HFS) is a safe and effective treatment with favorable outcomes. The purpose of this study was to evaluate the incidence of delayed cranirve ( VI, VII, and VIII ) palsy following MVD and its clinical courses.

Methods

Between January 1998 and December 2009, 1354 patients underwent MVD for HFS at our institution. Of them, 100 patients (7.4%) experienced delayed facial palsy (DFP), one developed sixth nerve palsy, and one patient had delayed hearing loss.

Results

DFP occurred between postoperative day number 2 and 23 (average 11 days). Ninety-two patients (92%) completely recovered; however, House-Brackmann grade II facial weakness remained in eight other patients (8%). The time to recovery averaged 64 days (range, 16 days to 9 months). Delayed isolated sixth nerve palsy recovered spontaneously without any medical or surgical treatment after 8 weeks, while delayed hearing loss did not improve.

Conclusion

Delayed cranial nerve (VI, VII, and VIII) palsies can occur following uncomplicated MVD for HFS. DFP is not an unusual complication after MVD, and prognosis is fairly good. Delayed sixth nerve palsy and delayed hearing loss are extremely rare complications after MVD for HFS. We should consider the possibility of development of these complications during the follow up for MVD.     

Blefarospasmo y espasmo hemifacial: tratamiento a largo plazo con toxina botulínica

Introduction

Our purpose is to describe the demographic, clinical and therapeutic characteristics of patients with blepharospasm (BS) and hemifacial spasm (HFS) in treatment with botulinum toxin type A (BtA).

Patients and methods

Retrospective analysis of patients diagnosed with BS or HFS and treated with BtA in the Neurology Department at Complejo Asistencial de Segovia between March 1991 and December 2009.

Results

Different variables were collected from 34 patients with BS and 55 with HFS, of whom 44.1% and 32.7% respectively had been undergoing treatment with BtA for more than 10 years. Elapsed time from symptom onset to the first visit was 24 months in the BS group and 59.7 months in the HFS group. Diagnosis was given on the first visit for 76.5% of the BS patients and 90.7% of the HFS patients. Patients were referred by their primary care centres in 34.6% of the cases with BS and in 77.6% of the cases with HFS. The most commonly used BtA preparation was BOTOX^® in both groups, and there were no cases of primary or secondary resistance. The median dose of BtA was raised gradually in both groups, and the increase was statistically significant during the early years of treatment. The most common side effect was ptosis (47.1% in BS, 32.5% in HFS).

Conclusions

BS and HFS are the most common facial movement disorders. The demographic and clinical characteristics and therapeutic findings from this study show that treatment with BtA is both effective and safe over the long term.     

Prognostic Factors of Hemifacial Spasm after Microvascular Decompression

Objective

The factors that influence the prognosis of patients with hemifacial spasm (HFS) treated by microvascular decompression (MVD) have not been definitely established. We report a prospective study evaluating the prognostic factors in patients undergoing MVD for HFS.

Methods

From January 2004 to September 2006, the authors prospectively studied a series of 293 patients who underwent MVD for HFS. We prospectively analyzed a number of variables in order to evaluate the predictive value of independent variables for the prognosis of patients undergoing MVD. The patients were followed-up at regular intervals and divided into as cured and unsatisfactory groups based on symptom relief. Uni- and multivariate analyses were performed using logistic regression models.

Results

A total 273 of 293 (94.2%) patients achieved symptom relief within one year after the operation. Intraoperatively, the indentation of the root exit zone was observed in 259 (88.5%) patients. Uni- and multivariate analyses revealed that the symptoms at postoperative 3 months (p<0.001) and indentation of the root exit zone (p=0.036) were associated with good outcomes.

Conclusion

The intraoperative finding of root exit zone indentation will help physicians determine the prognosis in patients with HFS. To predict the prognosis of HFS, a regular follow-up period of at least 3 months following MVD should be required.     

The Efficacy and Safety of Microvascular Decompression for Hemifacial Spasm in Elderly Patients

Objective

The purpose of this study was to examine the efficacy and safety of microvascular decompression (MVD) for hemifacial spasm (HFS) in elderly patients.

Methods

Between 1997 and June 2008, 1,174 patients had undergone MVD for HFS at our institute. Among these, 53 patients were older than 65 years. We retrospectively reviewed and compared the complication and the cure rates of these patients with those of younger patients.

Results

There were 38 females and 15 males. The mean duration of symptoms of HFS of these patients was 94.6 months (range, 12-360 months), compared with 67.2 months (range, 3-360 months) in the younger group. The overall cure rate in elderly patients who underwent MVD for HFS during this period was 96.2%. Permanent cranial nerve dysfunctions, such as hearing loss and facial palsy, were seen in 2 patients (3.8%, 2/53) in the elderly group and 19 patients (1.7%, 19/1121) in the younger group. The difference in permanent cranial nerve dysfunction between the two groups was not statistically significant. There was no operative mortality in either group.

Conclusion

Microvascular decompression is the most effective surgical modality available for the treatment of HFS. Results of this study indicate that such technique can be performed in the elderly without higher rates of morbidity or mortality. Any patient with HFS, whose general health is acceptable for undergoing general anesthesia, should be considered as a candidate for MVD.     

Time Course of Symptom Disappearance after Microvascular Decompression for Hemifacial Spasm

Objective

This study is to investigate time course of symptom disappearance in patients whose spasm relieved completely after microvascular decompression (MVD).

Methods

Of 115 patients with hemifacial spasm (HFS) who underwent MVD from April 2003 to December 2006, 89 patients who had no facial paralysis after operation and showed no spasm at last follow-up more than 1.5 years after operation were selected. Symptom disappearance with time after MVD was classified into type 1 (symptom disappearance right after operation), type 2 (delayed symptom disappearance) and type 3 (unusual symptom disappearance). Type 2 was classified into type 2a (with postoperative silent period) and type 2b (without silent period).

Results

Type 1, type 2a, type 2b and type 3 were 38.2%, 48.37%, 12.4% and 1.1%, respectively. Delayed disappearance group (type 2) was 60.7%. Post-operative symptom duration in all cases ranged from 0 to 900 days, average was 74.6 days and median was 14 days. In case of type 2, average post-operative symptom duration was 115.1 days and median was 42 days. Five and 3 patients required more than 1 year and 2 years, respectively, until complete disappearance of spasm. In type 2a, postoperative silent period ranged from 1 to 10 days, with an average of 2.4 days.

Conclusion

Surgeons should be aware that delayed symptom disappearance after MVD for HFS is more common than it has been reported, silent period can be as long as 10 days and time course of symptom disappearance is various as well as unpredictable.     

Efficacy of the Disappearance of Lateral Spread Response before and after Microvascular Decompression for Predicting the Long-Term Results of Hemifacial Spasm Over Two Years

Objective

The purpose of this large prospective study is to assess the association between the disappearance of the lateral spread response (LSR) before and after microvascular decompression (MVD) and clinical long term results over two years following hemifacial spasm (HFS) treatment.

Methods

Continuous intra-operative monitoring during MVD was performed in 244 consecutive patients with HFS. Patients with persistent LSR after decompression (n=22, 9.0%), without LSR from the start of the surgery (n=4, 1.7%), and with re-operation (n=15, 6.1%) and follow-up loss (n=4, 1.7%) were excluded. For the statistical analysis, patients were categorized into two groups according to the disappearance of their LSR before or after MVD.

Results

Intra-operatively, the LSR was checked during facial electromyogram monitoring in 199 (81.5%) of the 244 patients. The mean follow-up duration was 40.9±6.9 months (range 25-51 months) in all the patients. Among them, the LSR disappeared after the decompression (Group A) in 128 (64.3%) patients; but in the remaining 71 (35.6%) patients, the LSR disappeared before the decompression (Group B). In the post-operative follow-up visits over more than one year, there were significant differences between the clinical outcomes of the two groups (p<0.05).

Conclusion

It was observed that the long-term clinical outcomes of the intra-operative LSR disappearance before and after MVD were correlated. Thus, this factor may be considered a prognostic factor of HFS after MVD.     

3D-TOF-MRA成像对微血管减压术术前诊断的价值

目的观察三维时间飞越法磁共振血管成像(3D-TOF-MRA)结合MR重建技术对微血管减压手术(MVD)的价值。方法对11例三叉神经痛,17例面肌痉挛,1例复发性舌咽神经痛,1例三叉神经痛合并面肌痉挛患者采用MVD治疗。术前应用3D-TOF-MRA结合MR重建技术进行检查,寻找和判别责任血管,以指导临床手术。结果术前3D-TOF-MRA检查30例中,28例证实有明显的责任血管,并在术中得到证实;2例三叉神经痛患者3D-TOF-MRA检查、未发现责任血管,其中1例术中发现为三叉神经出脑干区腹侧受到基底动脉明显压迫,另外1例术中可见小脑上动脉有多支细小动脉攀附于三叉神经出脑干区,给予MVD+选择性三叉神经感觉根切断术后症状完全缓解。30例患者中,术后完全缓解26例,明显缓解4例。结论 3D-TOF-MRA结合MR重建技术对于微血管减压术术前责任血管的判定及手术设计具有重要的应用价值。     

A new method for monitoring abnormal muscle response in hemifacial spasm: A prospective study

Objective

To examine a new abnormal muscle response (AMR) monitoring method during microvascular decompression (MVD) for hemifacial spasm.

Microvascular Decompression for Familial Hemifacial Spasm : Single Institute Experience

Objective

The purpose of this study was to evaluate the characteristics and surgical outcomes of familial hemifacial spasm (HFS) and to discuss the role of genetic susceptibility.

Methods

Between 2001 and 2011, 20 familial HFS patients with ten different pedigrees visited our hospital. The data from comprehensive evaluation of these patients, including clinical, radiological and electrophysiological data and surgical outcomes were reviewed to characterize familial HFS and to compare the characteristics between familial HFS and sporadic HFS.

Results

According to the family tree, the inheritance pattern was difficult to define clearly using these data. Radiologic findings suggested that the vertebral artery (VA) was a more frequent offender in familial HFS than in sporadic cases (35.0% vs. 10.0%, p<0.001). Chi-square test showed that there were no correlation between VA tortuosity and underlying morbidity such as diabetes or hypertension (p=0.391). Eighteen out of 19 patients who underwent microvascular decompression showed no residual spasm. Other features of familial HFS overlap with sporadic cases. These findings suggest that certain genetic susceptibilities rather than hypertension or diabetes may influence vascular tortuosity and HFS development.

Conclusion

In this study, familial HFS seems not so different from sporadic cases. Authors thought familial HFS could have heterogeneous etiology. Further study of familial HFS including clinical, anatomic, genetic, and molecular information may help identify a gene or trait that can provide insight into the mechanisms of sporadic and familial HFS.     

Clinical outcome of posterior fixation of the C1 lateral mass and C2 pedicle by polyaxial screw and rod

Objective

Because of atlantoaxial complex has a unique and complicated anatomy and instability of this complex is very dangerous. We investigated the clinical results of posterior C1–C2 fixation with a polyaxial screw–rod system.

Methods

Between July 2001 and December 2007, the authors treated 17 patients suffering from atlantoaxial deformity and instability. Atlantoaxial fusion was employed in 9 patients with upper cervical fracture and dislocation, in 6 patients with atlantoaxial subluxation, in 1 patient with pure transverse ligament injury, and in 1 patient with basilar invagination. The mean age at the time of surgery was 40.4 years (range, 15–68 years).

Results

Operative times ranged from 165 to 420 min (average 306 min), and the postoperative mean VAS score was 2.4. The mean follow-up period was 26 months. Solid fusion was achieved in 15 patients at the last follow up; no injury of the vertebral artery or spinal cord and no operative mortality occurred in these cases.

Conclusions

We suggest that posterior atlantoaxial fixation using the polyaxial screw–rod system is an effective and relatively safe technique. The navigation guidance system employed during the surgical procedure was helpful methods. Future studies of the feasibility of navigation system-guided surgical procedures will be required.     

Combined Hyperactive Dysfunction Syndrome of the Cranial Nerves

Objective

Combined hyperative dysfunction syndrome (HDS) defined as the combination of HDSs such as trigeminal neuralgia (TN), hemifacial spasm (HFS) and glossopharyngeal neuralgia (GPN), which may or may not occur simultaneously on one or both sides. We reviewed patients with combined HDS and demonstrated their demographic characteristics by comparing them with those of patients with a single HDS.

Methods

Between October 1994 and February 2006, we retrospectively studied a series of 1,720 patients who suffered from HDS and found 51 patients with combined HDSs. We analyzed several independent variables in order to evaluate the prevalence and etiologic factors of combined HDS.

Results

The combined HDS group accounted for 51 of 1,720 (2.97%) patients with HDS; 27 cases of bilateral HFS, 10 cases of bilateral TN and 14 cases of HFS with TN. Their mean age was 52.1 years (range, 26-79 years). There were 5 men and 46 women. Seven patients had synchronous and 44 patients metachronous onset of HDSs. By comparison of combined and single HDS groups, we found that age and hypertension were closely associated with the prevalence of combined HDS (p < 0.05).

Conclusion

This study revealed that combined HDS was very rare. Hypertension and age might be the most important causative factors to evoke combined HDS.     

Is hemifacial spasm affected by changes in the heart rate? A study using heart rate variability analysis

Objective

Hemifacial spasm (HFS) is caused by arterial conflict at the root exit zone of the facial nerve. As the offending artery is pulsatile in nature, this study investigated the association of heart rate fluctuation with HFS.

Collagen-only biomatrix as dural substitute: What happened after a 5-year observational follow-up study

Objectives

To assess long-term efficacy of the collagen-only biomatrix as a dural substitute in a large case series.

Patients and methods

We reviewed a prospectively acquired database of patients who underwent neurosurgical surgeries in whom the dural substitute was used and who were the subject of two previous studied with shorter follow-ups.

Results

The present study was conducted on 111 subjects of the original 209 patients. No late complications, nor local or systemic toxicity were observed during the observational period. As a matter of facts, 5 patients (4.5%) underwent reoperation for different reasons and 2 out of 5 experienced subcutaneous fluid collections; another case (0.9%), already reported in our previous studies, developed a CSF leak after an endoscopic endonasal operation for an intra-suprasellar arachnoid cyst.

Conclusions

Our data further confirm that the collagen-only biomatrix derived from horse equine tendon is a safe and effective dural substitute for routine neurosurgical procedures.     

What is the best treatment of drug-resistant trigeminal neuralgia in patients affected by multiple sclerosis? A literature analysis of surgical procedures

Objective

Drug-resistant trigeminal neuralgia (TN) can complicate the clinical course of patients affected by multiple sclerosis (MS). Various surgical procedures have been reported for the treatment of this condition, but there is no agreement on the best management of these patients. To our knowledge, there is no critical literature analysis focusing on this particular topic. The aim of this study was to evaluate the clinical outcome of different surgical procedures utilized for drug-resistant TN in MS patients.

Methods

We reviewed the literature about the studies reporting on surgical treatment of drug-resistant TN in MS patients. Case reports and case series less than 4 patients were excluded from the analysis. Nineteen studies were selected for the statistical analysis. To reduce the variability of the data, the selected studies were evaluated for the following outcome parameters: acute pain relief rate (APR), rate of recurrence (RR), pain free at follow-up rate (PF at FU) and complication rate (CR). For the statistical analysis, chi-square statistic, using the Fisher's exact test was utilized.

Results

There was no procedure statistically superior in terms of APR rate in MS patients following the surgical treatment of TN. The highest RR was observed for percutaneous balloon compression (PBC) (60.2 ± 14.4%). This result was statistically significant when compared to gamma knife surgery (GKS) (p = 0.0129) and microvascular decompression (MVD) (p = 0.0281). MVD together with percutaneous radiofrequency rhizothomy (PRR) was associated with a statistically better PF at FU rate (56.5 ± 16.8% and 73.5 ± 14.2%, respectively). However PBC and MVD showed statistical significant minor CR compared to other techniques (no complications and 18.7 ± 17.4%, respectively).

Conclusion

Our study shows no differences in the short term results among different procedures for TN in MS patients. Each technique demonstrate advantages and limits in terms of long term pain, recurrence rate and complication rate. Each patient should be accurately informed on pros and cons of each procedure in order to be involved in the most appropriate choice.     

The critical warning sign of real-time brainstem auditory evoked potentials during microvascular decompression for hemifacial spasm

Objective

The aim of this study was to define the critical warning sign of real-time brainstem auditory evoked potential (BAEP) for predicting hearing loss (HL) after microvascular decompression (MVD) for hemifacial spasm (HFS).

神经内镜在三叉神经痛和面肌痉挛手术中的应用

目的 探讨神经内镜在三叉神经痛和而肌痉挛手术中的辅助作用。方法 在显微血管减压术中使用神经内镜，观察神经根进出脑干部位及局部血管的分布和走行情况，确认压迫血管；在实施减压后观察神经根松解情况、垫棉的位置和压迫血管移位后的状态。结果 60例三叉神经痛病例中，56例术后疼痛消失，4例疼痛减轻；40例面肌痉挛病例中，37例术后痉挛消失，3例减轻。平均随访3．2年无一例复发。结论 显微血管减压术中辅助使用神经内镜，能提高手术治疗效果，减少并发症发生。