To be thorough or tailored: influence of the arachnoid dissection range on the surgical outcomes of microvascular decompression for hemifacial spasm.

BACKGROUND: As one of the most fundamental elements in exposure and decompression, the dissection of arachnoid has been rarely correlated with the surgical results in studies on Microvascular decompression (MVD) procedures for Hemifacial spasm (HFS). MATERIALS AND METHODS: Patients' records of the HFS cases treated with MVD from January 2016 to December 2021 in our center was retrospectively reviewed. The video of the procedures was inspected thoroughly to evaluate the range of dissection of arachnoid. Four areas were defined in order to facilitate the evaluation of the dissection range. The correlation between the arachnoid dissection and the surgical outcomes were analyzed. RESULTS: The arachnoid structures between the nineth cranial nerve and the seventh, eighth cranial nerves were dissected in all cases, other areas were entered based on different consideration. The rate of neurological complications of the extended dissection pattern group was higher than that of the standard pattern group (P < 0.05). The procedures in which the arachnoid structure above the vestibulocochlear nerve was dissected, led to more neurological complications (P < 0.05). CONCLUSION: Thorough dissection as an initial aim for all cases was not recommended in MVD for HFS, arachnoid dissection should be tailored to achieving safety and effectiveness during the procedure.

White matter structural changes before and after microvascular decompression for hemifacial spasm.

Hemifacial spasm (HFS) is a syndrome characterized by involuntary contractions of the facial muscles innervated by the ipsilateral facial nerve. Currently, microvascular decompression (MVD) is an effective treatment for HFS. Diffusion weighted imaging (DWI) is a non-invasive advanced magnetic resonance technique that allows us to reconstruct white matter (WM) virtually based on water diffusion direction. This enables us to model the human brain as a complex network using graph theory. In our study, we recruited 32 patients with HFS and 32 healthy controls to analyze and compare the topological organization of whole-brain white matter networks between the groups. We also explored the potential relationships between altered topological properties and clinical outcomes. Compared to the HC group, the white matter network was disrupted in both preoperative and postoperative groups of HFS patients, mainly located in the somatomotor network, limbic network, and default network (All P < 0.05, FDR corrected). There was no significant difference between the preoperative and postoperative groups (P > 0.05, FDR corrected). There was a correlation between the altered topological properties and clinical outcomes in the postoperative group of patients (All P < 0.05, FDR corrected). Our findings indicate that in HFS, the white matter structural network was disrupted before and after MVD, and that these alterations in the postoperative group were correlated with the clinical outcomes. White matter alteration here described may subserve as potential biomarkers for HFS and may help us identify patients with HFS who can benefit from MVD and thus can help us make a proper surgical patient selection.

Comparison of Radiofrequency Ablation and Craniotomy Microvascular Decompression for Treatment of Hemifacial Spasm.

BACKGROUND: Hemifacial spasm (HFS) is distinguished by sudden and involuntary spasms of the facial muscles, predominantly on one side of the face. Microvascular decompression (MVD) is an efficacious surgical technique for treating HFS; however, MVD may occasionally lead to noteworthy postoperative complications. Previously, we reported the successful utilization of an innovative awake computed tomography-guided percutaneous puncture of the stylomastoid foramen for administering radiofrequency ablation (RFA) therapy in the treatment of HFS. STUDY DESIGN: Prospective clinical research study. SETTING: Department of Anesthesiology and Pain Medical Center, Ningbo, China. OBJECTIVES: The aim of this study was to compare and contrast the clinical outcomes and adverse reactions associated with attempts to use RFA and MVD to manage primary HFS. METHODS: Three hundred patients received either RFA or MVD treatment (Group R and Group M). We tracked and recorded each patient's cure rate, remission rate, intraoperative and postoperative complications, short-term and long-term therapeutic outcomes, hospitalization duration, hospitalization expenses, and operation time. RESULTS: One hundred and fifty-eight patients were placed in the R group, and 142 patients were sorted into the M group. In the R group, 87.34% of patients showed improvement, 9.49% experienced relief, and 3.16% experienced treatment failure. Similarly, in the M group, 85.92% of patients showed improvement, 10.56% experienced relief, and 3.52% experienced treatment failure. The difference in therapeutic efficacy between the 2 groups was not significant. However, the M group had significantly lower recurrence rates at 3 months, 6 months, and one year post-operation than the R group did. Notably, the M group also experienced a higher rate of postoperative complications. Among the complications reported in the M group were 25 cases of dizziness or headache (17.6%) following the operation, 22 cases of hearing damage, including one case of complete hearing loss on the side involved, and 28 cases of peripheral nerve injury with abnormal skin sensation. Postoperative facial paralysis occurred in 15 patients, including 10 cases of moderate to severe facial paralysis that were relieved to grade II after one year. In comparison, the R group had 40 cases of grade II and 53 cases of grade III, and no cases of more severe facial paralysis were found. There were also 13 cases of peripheral nerve injury, such as local skin numbness and tenderness. Importantly, there were no cases of facial hematoma, intracranial hemorrhage, infection, or any other complications in either group, and no fatalities occurred during the study period. LIMITATIONS: The limitations of this study are the exclusion of transient postoperative complications, the lack of in-person follow-up with patients, and the potential underestimation of certain complications. CONCLUSION: The short-term outcome was found to be comparable between the 2 treatment modalities. Notably, RFA demonstrates both safety and efficacy as a method for managing primary HFS; however, the procedure may lead to mild facial paralysis. In situations during which surgery is contraindicated, especially among elderly or high-risk surgical patients, percutaneous facial nerve RFA at the stylomastoid foramen may be considered as an alternative therapeutic approach.

Letter to the editor: fully endoscopic microvascular decompression for hemifacial spasm: a clinical study and analysis.

This article presents a comprehensive analysis of microvascular decompression (MVD) surgery as a treatment option for hemifacial spasm (HFS). Beginning with a thorough literature review, it explores the historical context, prevalence, and underlying mechanisms of HFS, laying a robust foundation for discussing MVD. Various surgical techniques, from traditional microscopic to fully endoscopic approaches, are described, along with their procedural nuances and advantages. Clinical data, including patient demographics and surgical success rates, substantiate the efficacy of MVD in alleviating HFS symptoms. The discussion of postoperative complications provides valuable insights into practical challenges. However, limitations such as single-center design, lack of robust statistical analysis, and absence of comparative data between endoscopic and microscopic approaches diminish the article's potential impact. Recommendations for multicenter collaborations, enhanced statistical analyses, comparative studies, and discussions on surgical training could significantly enhance the article's contribution to neurosurgery practice.

Microvascular decompression for hemifacial spasm after Bell's palsy: a retrospective clinical study.

OBJECTIVE: This study aimed to investigate the clinical characteristics of hemifacial spasm (HFS) after Bell's palsy and to evaluate the therapeutic efficacy of microvascular decompression (MVD). METHODS: A retrospective analysis was conducted on 18 patients who underwent MVD for HFS after Bell's palsy at our institution between January 1, 2017, and December 31, 2021. Clinical presentations, intraoperative findings, postoperative outcomes, and complications were comprehensively assessed. RESULTS: Neurovascular compression (NVC) was identified in all the 18 patients. The offending vessels included anterior inferior cerebellar artery (AICA) in 6 patients (33.3%), posterior inferior cerebellar artery (PICA) in 7 patients (38.9%), vertebral artery (VA) combined with AICA in 3 patients (16.7%), and VA alongside PICA in 2 patients (11.1%). Notably, marked arachnoid membrane adhesion was evident in 11 patients (61.1%). 15(83.3%) patients were cured immediately after MVD, delayed relief was found in 3 (16.7%) patients. During the follow-up period, recurrence was not documented. Surgical complications were limited to facial paralysis in 3 patients and auditory impairment in 1 patient. No additional surgical complications were recorded. CONCLUSIONS: In patients manifesting HFS after Bell's palsy, NVC predominantly underlies the etiology. MVD is a reliably safe and efficacious therapeutic intervention.

Fully endoscopic microvascular decompression for hemifacial spasm: a clinical study and analysis.

Fully endoscopic microvascular decompression (MVD) of the facial nerve is the main surgical treatment for hemifacial spasm. However, the technique presents distinct surgical challenges. We retrospectively analyzed prior cases to consolidate surgical insights and assess clinical outcomes. Clinical data from 16 patients with facial nerve spasms treated at the Department of Neurosurgery in the First Affiliated Hospital of Bengbu Medical College, between August 2020 and July 2023, were retrospectively examined. Preoperatively, all patients underwent magnetic resonance angiography to detect any offending blood vessels; ascertain the relationship between offending vessels, facial nerves, and the brainstem; and detect any cerebellopontine angle lesions. Surgery involved endoscopic MVD of the facial nerve using a mini Sigmoid sinus posterior approach. Various operative nuances were summarized and analyzed, and clinical efficacy, including postoperative complications and the extent of relief from facial paralysis, was evaluated. Fully endoscopic MVD was completed in all patients, with the offending vessels identified and adequately padded during surgery. The offending vessels were anterior inferior cerebellar artery in 12 cases (75%), vertebral artery in 3 cases (18.75%), and posterior inferior cerebellar artery in 1 case (6.25%). Intraoperative electrophysiological monitoring revealed that the lateral spread response of the facial nerve vanished in 15 cases and remained unchanged in 1 case. Postoperative facial spasms were promptly alleviated in 15 cases (93.75%) and delayed in 1 case (6.25%). Two cases of postoperative complications were recorded-one intracranial infection and one case of tinnitus-both were resolved or mitigated with treatment. All patients were subject to follow-up, with no instances of recurrence or mortality. Fully endoscopic MVD of the facial nerve is safe and effective. Proficiency in endoscopy and surgical skills are vital for performing this procedure.

Role of a Tortuous Vertebrobasilar Artery and Anchoring Perforators in the Etiology of Hemifacial Spasm.

BACKGROUND: In >70% of patients with hemifacial spasm (HFS), the offending artery is either the anterior inferior cerebellar artery (AICA) or posterior inferior cerebellar artery (PICA), without a tortuous vertebrobasilar artery (VBA). We hypothesized that anchoring perforators around the root exit zone (REZ) of the AICA or PICA might induce vascular deviation and compression. We investigated the occurrence of these perforators from the AICA or PICA and the extent of VBA tortuosity to reveal the pathology of vascular compression. METHODS: This retrospective review included 110 patients after excluding those with vertebral artery (VA) compression alone. The occurrence of perforators was determined according to operative findings within 5 mm of the REZ, and VBA tortuosity was evaluated using MATLAB. We analyzed the association between perforators, VBA tortuosity, and the surgical implications. RESULTS: The occurrence of perforators from the offending AICA or PICA around the REZ was significantly higher in the group without VA compression (Group A) than in the group with VA compression (Group B). VBA tortuosity was significantly lower in Group A. VBA tortuosity was inversely correlated with the presence of AICA or PICA perforators in all 110 patients. Operative results were similar between the groups, although patients with low VBA tortuosity tended to require interposition in decompression procedures. CONCLUSIONS: Anchoring perforators around the REZ play a crucial role in vascular compression for patients with less tortuous VBAs. Moreover, surgeons should be prepared to deal with multiple perforators in a more complicated surgery in cases of less tortuous VBA.

Experience in treating children with ocular dyskinesia and hemifacial spasm secondary to pontine tumours adjacent to the fourth ventricle and systematic review.

OBJECTIVE: To investigate the treatment plan and prognosis of children with ocular dyskinesia and hemifacial spasm secondary to pontine tumours adjacent to the fourth ventricle. METHODS: In this retrospective study, the clinical information of 10 consecutively collected children with ocular dyskinesia and hemifacial spasm secondary to pontine tumours adjacent to the fourth ventricle was analyzed. All 10 children underwent pontine tumour resection through a trans-cerebellomedullary fissure approach; 4 children underwent preoperative diffusion tensor imaging scans to determine the relationship between the tumour and facial nerve nucleus, and the other 6 children underwent intraoperative deep electroencephalography (EEG) tumour monitoring, in which the tumour electrical discharge activity of the tumour was recorded. A voxel distribution map was established to describe the distribution of the tumour location, and patient prognosis was evaluated through clinical and imaging follow-up. RESULTS: All 10 children achieved total tumour resection; 9 tumours were pathologically suggested to be ganglioglioma (WHO grade I), and 1 was a hamartoma. The symptoms of the original ocular dyskinesia and hemifacial spasm disappeared immediately after the operation. The children were followed up for 4-75 months, and none of the symptoms recurred; four cases with preoperative diffusion tensor imaging showed that the tumour was close to the facial nerve. Four in six intraoperative electrophysiological monitoring showed that the tumour had electrical discharge behaviour, and the tumour distribution map indicates a high density of tumour presence in the facial nerve nucleus and the nucleus of the abducens nerve. CONCLUSIONS: In paediatric patients, the facial symptoms are related to the location and abnormal electrical discharge of the tumour. There is no significant correlation between ocular dyskinesia and the location of the tumour. Conventional antiepileptic therapy for this disease is ineffective, and early surgical intervention for total tumour resection can achieve a clinical curative effect.

Delayed complete remission of hemifacial spasms following microvascular decompression and the implications for optimal time of revision surgery.

BACKGROUND: Microvascular decompression (MVD) is an effective method for directly treating hemifacial spasms (HFS). The timing for the consideration of failed MVD and reoperation has been paradoxical. OBJECTIVE: This study aimed to investigate the delayed complete remission of HFS in terms of prevalence rate, duration between surgery and delayed complete remission, and predictive factors. METHODS: A hundred patients with HFS who underwent MVD from 2012-2021 were enrolled in the study. All HFS occurred as a result of compression of the facial nerve by adjacent blood vessels. Clinical information, intraoperative findings, and surgical outcomes were incorporated for data analysis. RESULTS: In the first week after MVD, 67 of 100 patients achieved complete remission of HFS, while the remaining 33 had incomplete remission. In long-term follow-up, 26 individuals gradually developed delayed complete remission with a median duration of 9.1 months. Finally, 86 of 100 patients achieved complete long-term remission. Recurrent HFS and incomplete remission were found in 7 and 7 patients, respectively. Factors associated with postoperative complete remission in the first week were a severe degree of facial nerve compression (p = 0.047, OR 2.75, 95% CI 1.01-7.40), with long-term complete remission was left-sided HFS (p = 0.012, OR 5.73, 95% CI 1.47-22.36), and with the appearance of delayed complete remission was the prolonged duration of HFS at least 3 years before MVD (p = 0.046, OR 3.75, 95% CI 1.03-13.76). Transient facial paresis was found in 11% of the patients. Of them, facial nerve function recovered completely in all cases. CONCLUSIONS: A delayed complete remission of HFS could be expected in long-term follow-up after MVD and is probably related to a longer duration of HFS before surgery. Unnecessary reoperation should be avoided in the early years following the first surgery.

A nomogram based on clinical multivariate factors predicts delayed cure after microvascular decompression for hemifacial spasm.

BACKGROUND: The course of disease after microvascular decompression (MVD) in patients with hemifacial spasm (HFS) is variable. The purpose of this study was to develop and validate a nomogram to predict the probability of delayed cure after microvascular decompression in patients with hemifacial spasms based on clinical multivariate factors. METHODS: A retrospective data collection was performed on 290 patients with HFS undergoing MVD at our center from January 2017 to January 2022. The patients were randomly assigned to the training cohort (n = 232) and validation cohort (n = 58) at a ratio of 8:2. Retrospective analysis was performed of information on clinical, radiological, and intraoperative findings and clinical outcomes. Univariate and multivariate analyses were performed in the training cohort, and a nomogram was constructed using a stepwise logistic regression approach. The receiver operating characteristic (ROC) was calculated to evaluate the reliability of the nomogram model. Decision curve analysis (DCA) was used to assess the clinical application value of the nomogram model. RESULTS: In the training cohorts, 73 patients (73/232) had a delayed cure. In the validation cohorts, 18 patients (18/58) had a delayed cure. We developed a novel nomogram model to predict the risk of delayed cure after MVD in HFS patients based on the presence of vertebral artery compression, venous compression, absence of LSR, degree of facial nerve indentation, degree of neurovascular compression, and internal auditory canal vascular looThe area under the curve (AUC) of the nomogram model was 0.9483 in the training cohort and 0.9382 in the validation cohort. The calibration curve showed good correspondence between the predicted and actual probabilities in the training and validation groups. The decision curve showed that the nomogram model had good performance in clinical applications. CONCLUSIONS: We developed and validated a preoperative and intraoperative multivariate factors nomogram to predict the possibility of delayed cure after MVD in HFS patients, which may help clinicians in the comprehensive management of HFS.

[Historical Review of Hemifacial Spasm].

Facial spasm is a disorder characterized by mostly unilateral(hemifacial)involuntary facial muscle contractions, usually caused by vascular compression of the facial nerve. It has been known since ancient times and we can currently find both old medical and artistic presentations. Charles Bell has described at least one definite case(No. IV)with hemifacial spasm in his textbook published in 1830 as did the following physicians like Romberg, Hammond, Gowers, and Brissaud. Babinski coined the name hemispasme facial in 1905 and its English term "hemifacial spasm" appeared in the article by Ehni et al. in 1945. Neurovascular or microvascular decompression surgery was applied to treat this disease in the 1960s and remains a curative therapeutic procedure. Therapy with botulinum toxin appeared as a less invasive procedure in the 1980s and is currently the preferred treatment because of its high safety and efficacy. Secondary facial spasms may occur as a consequence of facial paresis or space-occupying lesion along the facial nerve pathway.

[Prevalences of Trigeminal Neuralgia and Hemifacial Spasm].

Neurosurgeons must have knowledge about the epidemiology of trigeminal neuralgia and facial spasm. The annual incidence of trigeminal neuralgia is 4.3-28.9 per 100,000 persons, with a prevalence of 76.8 per 100,000 persons, increasing with age. It is more common in women and on the right side, with SCA being the most common causative vessel. The long-term efficacy of MVD for trigeminal neuralgia is 80% with complete resolution of pain and 5.2% with complications, which is safe and highly effective when performed by an expert surgeon. Hemifacial spasm has an annual incidence of 0.78/100,000 with a prevalence of approximately 10 per 100,000, increasing with age. It is more common in women and on the left side. AICA alone is the most common causative vessel. The long-term efficacy of MVD for facial spasms is 87.1% with complete resolution of facial spasms and 3.0% with complications. As with trigeminal neuralgia, safe and highly effective treatment can be expected when treated by an expert surgeon.

[Botulinum Toxin Treatment for Hemifacial Spasm:Based on the Practical Clinical Experience in the Neurology Outpatient Clinic].

Botulinum toxin(BTX)treatment is the first-line neurological treatment for hemifacial spasm(HFS). In my neurology clinic, Clinique Kita Neurologique(CKN), I have provided a cumulative total of approximately 400 BTX treatments for approximately 50 HFS patients for 23 years. Based on my own practical clinical experience, I have demonstrated the efficacy of BTX treatment. In compressive HFS, BTX treatment is indicated in patients who are not indicated or unwilling to undergo neurodecompression surgery. This is also indicated in the case of a long waiting period before surgery. In postparetic HFS, BTX treatment is indicated in patients with spasm and synkinesia. The amount of each BTX injection in postparetic HFS should be less than that in compressive HFS because of latent facial paresis. Although BTX injections can be easily administered in neurology outpatient clinics, it is important to perform the procedure safely and promptly.

[Image Diagnosis for Hemifacial Spasm].

Cisternography using heavy T2-weighted images from 3-Tesla magnetic resonance imaging(MRI)and three-dimensional time-of-flight MR angiography(3D TOF MRA)is useful for identifying conflicting vessels in primary hemifacial spasm(HFS). Cisternography provides high-signal images of the cerebrospinal fluid and low-signal images of the cranial nerves and cerebral blood vessels, whereas 3D TOF MRA provides high-signal images with only vascular information. The combination of these two methods increases the identification rate of conflicting vessels. The neurovascular conflict(NVC)site in HFS is where the facial nerve exits the brainstem. However, on MRI, the true NVC site is often more proximal than the facial nerve attachment to the brainstem. On preoperative MRI, it is important to not miss the blood vessels surrounding the proximal portion of the facial nerve. If multiple compression vessels or deep vessels are located in the supraolivary fossette, they may be missed. Coronal section imaging and multiplanar reconstruction(MPR)minimize the chances of missing a compression vessel. Preoperative MRI and CT can also provide various other information, such as volume of the cerebellum, presence of emissary veins, shape of the petrosal bone, and size of the flocculus.

[Trigeminal Neuralgia and Hemifacial Spasm: What to Do If It Does Not Cure?]

Although microvascular decompression(MVD)is a highly effective treatment, there is little pathological evidence and some aspects of its mechanism remain unclear. Therefore, when symptoms appear after surgery, it is difficult to determine the pathological condition and select the treatment method. Therefore, we recommend dividing these factors into three categories. The first is "prolonged cure." Compressed nerves may take time to regenerate; therefore, it is necessary to wait at least one year to see if they recover naturally, especially in facial spasms. The second is "uncured." Intraoperative video and postoperative imaging findings should be reviewed. If a compressed blood vessel is overlooked or inappropriately decompressed, additional surgery should be performed. The third is "true recurrence," which is the loss of fixation of compressed blood vessels and granulomatization of the Teflon. Nerve bending that occurs again due to the retraction of the trigeminal nerve is corrected by reoperation. The therapeutic effects of reoperation are particularly strong in trigeminal neuralgia. Owing to the risk of nerve damage due to adhesion dissection, it is important to carefully consider and establish good communication with patients before surgery.

[Surgical Techniques for Microvascular Decompression in Hemifacial Spasm].

This study discusses the key microvascular decompression(MVD)techniques for the treatment of hemifacial spasm(HFS). The author's experience is based on their institution's cases, highlighting three critical techniques. (1)Vertebral artery(VA)repositioning: Repositioning the VA is essential in challenging cases. This article focuses on the relocation of the proximal portion of the VA and the importance of careful dissection. (2)Relocating vessels compressing the peripheral branches of the facial nerve: HFS can result from nerve compression at various locations, including the cisternal portion. This study addressed cisternal compression and considered the nearby nerves. (3)Considering the perforating branches during repositioning, cases may involve complex branching of the perforating arteries. This paper describes an approach that carefully repositions the vessels without damaging the perforating branches. The results from 100 VA-involved cases showed excellent outcomes, with 91.2% of patients experiencing T0(excellent)results. This study emphasized the need to adapt the surgical approach to each unique case to ensure the safety and effectiveness of MVD. This study provides insights into the critical MVD techniques for HFS, emphasizing the importance of continuous experience and knowledge accumulation. These techniques can be learned by other neurosurgeons, thereby expanding the availability of safe and successful MVD procedures for HFS.

[Pure Endoscopic Microvascular Decompression for Trigeminal Neuralgia and Hemifacial Spasm].

The panoramic view offered by endoscopy has been used to observe neurovascular compression in endoscope-assisted microsurgery to compensate for the blind spots in microvascular decompression(MVD)for trigeminal neuralgia and hemifacial spasm. In recent years, purely endoscopic MVD has been performed as a minimally invasive surgery and has become a new surgical technique for MVD. Endoscopic MVD has gained acceptance, and further developments are expected. Here, we present endoscopic MVD, including the setup, equipment, surgical procedures, and decompression techniques by transposition, as well as representative cases, and discuss the future prospects and possibilities of endoscopic MVD.

[Intraoperative Monitoring During Microvascular Decompression].

During microvascular decompression(MVD)for hemifacial spasm(HFS), trigeminal neuralgia(TN), and glossopharyngeal neuralgia(GPN), brainstem auditory-evoked potential monitoring is widely used to preserve hearing function. In MVD for HFS, abnormal muscle response monitoring is useful for identifying the offending vessels compressing the facial nerve and confirming the completion of decompression intraoperatively. The amplitude of facial motor-evoked potential by transcranial electrical stimulation in the orbicularis oculi muscle is reported to decrease after completing MVD. The Z-L response(ZLR)probably confirms the true offending vessels by stimulating the culprit vessels; then, the ZLR could disappear after decompressing the offending vessels away from the compression sites. Spontaneous electromyographic activities obtained from the mentalis muscles by injection of saline into the facial nerve reportedly decreased after MVD compared with those before MVD. In MVD for the GPN, glossopharyngeal motor-evoked potential by transcranial electrical stimulation is used to preserve swallowing function and not to assess the completion of MVD. Because MVD for both the TN and GPN can result in normalization of the hyperactivity of the sensory nerve, it may be difficult to develop any monitoring to confirm the completion of MVD during surgery.