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.

[Early results of intraoperative neurophysiological monitoring in surgical treatment of hemifacial spasm]. / Analiz blizhaishikh rezul'tatov intraoperatsionnogo neirofiziologicheskogo monitoringa pri khirurgicheskom lechenii gemifatsial'nogo spazma.

BACKGROUND: Neurophysiological monitoring in surgery for hemifacial spasm has been used since the 1990s, when Moller et al. demonstrated the effectiveness of intraoperative assessment of lateral spread response (LSR) regarding postoperative outcomes. Currently, there are conflicting data on effectiveness and feasibility of this technique. Widespread hemifacial spasm determines the relevance of neurophysiological monitoring in surgical treatment of these patients. OBJECTIVE: To evaluate the effectiveness of various methods of intraoperative neurophysiological monitoring in surgical treatment of hemifacial spasm regarding early postoperative outcomes. MATERIAL AND METHODS: The study group included 43 patients (8 men and 35 women) aged 26-68 years. We assessed severity of hemifacial spasm using the SMC Grading Scale. All patients underwent vascular decompression of the facial nerve under neurophysiological control: monitoring of transcranial motor evoked potentials from facial muscles (m. orbicularis oculi, m. orbicularis oris, m. mentalis) and recording unilateral LSR. The control group included 23 patients (4 men and 19 women) aged 29-83 years. In this group, facial nerve decompression was performed without neurophysiological control. The effect of neurophysiological monitoring on postoperative outcomes (in-hospital period and 3 postoperative months) after vascular decompression of the facial nerve was assessed using the SMC Grading Scale. We considered severity and incidence of spasms. RESULTS: Thirty-one (72%) patients in the main group had no spasms of mimic muscles at discharge. In the control group, there were no spasms in 15 patients (65%). At the same time, there were fewer Grade I patients in the control group (12%) compared to the main group (26%). Moreover, 27 (66%) and 12 (52%) patients were free from episodes of hemifacial spasm in both groups, respectively. Patients with hemifacial spasm grade I-II comprised 29% in the main group and 34% in the control group. The number of relapses within three months increased in the control group (13%). CONCLUSION: Intraoperative monitoring of transcranial motor evoked potentials from the facial muscles and LSR during vascular decompression of the facial nerve increases the efficiency of surgery for hemifacial spasm in early postoperative period. Less number of relapses and lower intensity of hemifacial spasm necessitate neurophysiological monitoring in neurosurgical treatment of these patients.

New Technology: Compound Abnormal Muscle Response During Microvascular Decompression for Hemifacial Spasm.

OBJECTIVE: To discuss effect of intraoperative compound abnormal muscle response (AMR) in patients undergoing microvascular decompression (MVD) for hemifacial spasm (HFS). METHODS: Eighty-six HFS patients were underwent single or compound AMR monitoring during MVD. Single AMR recording was from the frontal muscle by stimulation of the marginal mandibular branch. Compound AMR recordings were obtained from the orbicularis oris and mentalis muscles by electrical stimulation of the temporal branch of the facial nerve, and from the frontal and orbicularis oculi muscles by stimulation of the marginal mandibular branch. Clinical outcome was compared with compound AMR results at the completion of MVD. RESULTS: Forty-two of 45 patients' AMR were recorded by compound AMR monitoring and 34 of 41 patients' AMR were recorded by single AMR monitoring during MVD. Hemifacial spasm resolved completely in 41 patients whose compound AMR was recorded and in 26 patients whose single AMR was recorded. Compound AMR gained a sensitivity of 96.3% and a specificity of 97.2%. Correspondingly, single AMR gained a sensitivity of 97.1% and a specificity of 86.3%. CONCLUSIONS: Our results suggest that compound AMR is more suitable than single AMR in MVD for HFS.

[Higher efficacy of botulinum toxin therapy for hemifacial spasm recurrence after vascular decompression. Case report and literature review]. / Uvelichenie effektivnosti botulinoterapii pri vozvrate simptomov gemifatsial'nogo spazma posle vaskulyarnoi dekompressii. Klinicheskii sluchai i obzor literatury.

Hemifacial spasm (HFS) is an involuntary synchronous tonic and/or clonic contraction of mimic muscles following ipsilateral facial nerve dysfunction. The last one is a result of neurovascular conflict between the facial nerve and vessel. Currently, vascular decompression is a pathogenetic treatment modality for primary HFS. Various authors describe postoperative recurrence of HFS, and botulinum toxin therapy remains the only option for these patients. We aimed to describe the efficacy of botulinum toxin therapy in patients with HFS recurrence after surgical vascular decompression. The article presents a female patient with a long-term history of HFS and botulinum toxin therapy (with different formulations). Efficacy of therapy gradually decreased (progressive reduction of intervals between injections). MRI revealed a close relationship between posterior inferior cerebellar artery and roots of acoustic-facial nerves near the brainstem. The patient underwent vascular decompression of the left facial nerve root under intraoperative monitoring with positive postoperative outcome. However, HFS symptoms recurred in 3 days after surgery. Botulinum toxin type A (BTA) injections were resumed with significant positive effect that can be explained by reduction of one of the factors involved into HFS. Thus, patients with HFS recurrence after vascular decompression may benefit from BTA therapy.

A successful treatment of hemifacial spasm due to anterior inferior cerebellar artery aneurysm in adolescent: a case report and literature review.

OBJECTIVE: Hemifacial spasm (HFS) is usually caused by compression of the facial nerve at the root exit zone (REZ), and is extremely rare in adolescents and even rarer in aneurysm compression. CASE REPORT: We describe symptomatic hemifacial spasm caused by a saccular aneurysm of the anterior inferior cerebellar artery (AICA) that was treated by clipping. A 17-year-old adolescent developed left hemifacial spasm that had gradually worsened over a period of 1 year before admission to our department. During the course of MVD (microvascular decompression), saccular aneurysm of AICA was accidentally found to compress the facial nerve. The cause of the facial spasm was considered to be compression of the left facial nerve by the aneurysm. Clipping the aneurysm was performed. The hemifacial spasm disappeared immediately. CONCLUSION: Our report indicates that HFS caused by saccular aneurysm of AICA can be treated by clipping, and that aneurysms should be considered in the treatment of adolescent HFS, especially those difficult to identify on imaging examination.

How I do it: minimizing muscle damage in microvascular decompression for hemifacial spasm.

BACKGROUND: Key hole surgery was recruited for MVD surgery since the maneuver is through the small space between the cerebellum and temporal/occipital bone. However, even small wounds can cause severe postoperative pain if there is significant tissue damage. Attention has been given to the size of the craniotomy rather than to the skin incision or soft tissues such as muscles. METHOD: Suboccipital muscle dissection focusing on splitting the splenius capitis muscle was presented. The dura was reapproximated without additional dissection to harvest a fascia graft. CONCLUSION: Muscle injury should be minimized to alleviate postoperative pain.

A pacemaker-assisted microvascular decompression for a patient with left primary facial spasm and arrhythmia: a case report.

BACKGROUND: Primary facial spasm accompanied by arrhythmia is a rare clinical phenomenon and has not been reported before. We describe this phenomenon and discuss its mechanism and treatment. CASE PRESENTATION: We herein present a rare case of a patient with left primary facial spasm and a third-degree atrioventricular block (III degree AVB), who was implanted with a temporary cardiac pacemaker to receive microvascular decompression (MVD) because of refusal of a permanent cardiac pacemaker. The symptoms of facial spasm disappeared after MVD. The temporary cardiac pacemaker was removed on the second day after surgery. Her ECG still showed the third-degree atrioventricular block after a follow-up period of 5 months. CONCLUSIONS: We are the first to report a patient with facial spasm and arrhythmia who was implanted with a temporary cardiac pacemaker to receive MVD. This case report demonstrated that the concomitant presence of a III degree AVB maybe not a contraindication for MVD, and the etiology of this facial spasm was the actual vascular compression of the facial nerve entry zone that was not related to the atrioventricular block.

Improving recovery after microvascular decompression surgery for hemifacial spasm: experience from 530 cases with enhanced recovery after surgery (ERAS) protocol.

OBJECTIVE: To assess the efficacy of microvascular decompression (MVD) for hemifacial spasm with an enhanced recovery after surgery (ERAS) protocol. METHODS: 984 hemifacial spasm patients who underwent MVD from Jan 2017 to Dec 2017 were analyzed. They were divided into the conventional treatment group (control; n = 453) and the later ERAS group (n = 531). The multimodal ERAS protocol consists of 23 perioperative elements. Time to feeding, mobilization, and urinary catheter removal, wound pain, postoperative nausea and vomiting (PONV), and total, preoperative, and perioperative hospital length of stay (LOS), along with outcomes and complications, were analyzed. RESULTS: The patients in both groups had similar clinical characteristics. Patients in the ERAS group had significantly higher rates of early feeding (469 [88.5%], ERAS, vs. 183 [40.6%], control; p < 0.05), early mobilization (497 [93.7%], ERAS, vs. 215 [47.7%], control; p < 0.05), and early removal of urinary catheter (458 [86.4%], ERAS, vs. 175 [38.8%], control; p < 0.05). The ERAS group also had a significantly lower incidence of wound pain (135 [25.5%], ERAS, vs. 348 [77.2%], control) and PONV (173 [32.6%], ERAS, vs. 251 (55.7%), control) (p < 0.05) and significantly shorter preoperative (0.9 ± 0.3 d, ERAS, vs. 2.3 ± 0.6 d, control), postoperative (4.1 ± 0.4 d, ERAS, vs. 5.8 ± 0.7 d, control), and total LOS (5.2 ± 0.3 d, ERAS, vs. 8.8 ± 0.6 d, control) (p < 0.05). There was no significant difference in outcomes or surgical complication rates between two groups. CONCLUSIONS: Implementation of the ERAS protocol for patients undergoing MVD procedures for the treatment of HFS improved the quality of perioperative care without an increase in adverse events.

Predictive values of maximum changes of brainstem auditory evoked potentials during microvascular decompression for hemifacial spasm.

BACKGROUND: Brainstem auditory evoked potentials (BAEPs) have been widely monitored to prevent hearing loss (HL) during microvascular decompression (MVD) for hemifacial spasm (HFS); however, their predictive value is still unclear. The aim of this study is to investigate the predictive values of the maximum changes in BAEPs and define the best warning indicator and a cutoff value (CV) during HFS-MVD. METHODS: The clinical data of 93 HFS-MVD patients were retrospectively analysed. The maximum change rates of the latency and amplitude of waves I, III, and V and the interpeak latencies (IPLs) I-III, I-V, and III-V, when BAEPs change most during MVD, were defined. Pure tone audiometry was performed to evaluate hearing loss (HL). Logistic regression, propensity score, receiver operating curve (ROC), and area under the curve (AUC) were used to identify the predictive value of relevant indexes and to determine the CV (with the largest Youden index) of the best index at different levels of HL. RESULTS: The AUCs of BAEPs for predicting HL were 0.98, 0.92, and 0.84 for 50 dB, 30 dB, and 10 dB, respectively. The amplitude of wave V (AwV) was the best single predictive index at all three HL levels. The CV of AwV was 55% (50 dB), 46% (30 dB), and 34% (10 dB). At 50 dB HL, the predictive value of IPLs I-V (AUC 0.89 with CV 0.6 ms) was better than that of LwV (AUC 0.82 with CV 1 ms). CONCLUSION: BAEPs can predict HL well. AwV is the best single predictive index of all BAEPs. The reduction of AwV by 34% (watching), 46% (reporting), and 55% (warning) can be used as a sliding-scale warning sign. In addition, IPLs I-V (> 0.6 ms) and LwV (> 1 ms) should also be observed and reported during MVD.

How I do it: 3D exoscopic endoscope-assisted microvascular decompression.

BACKGROUND: Microvascular decompression (MVD) is an effective treatment for drug-resistant trigeminal neuralgia and hemifacial spasm. However, failure of symptomatic improvement can arise from difficulties in identifying and/or decompressing the offending vessel. Microscopic and endoscopic techniques have been used to improve visualisation and safety of the procedure but there are limitations to each technique. METHOD: A 3D exoscopic endoscope-assisted MVD technique is described, including advice on potential pitfalls. CONCLUSION: Compared with the standard microscope-assisted techniques, the 3D exoscopic endoscope-assisted MVD offers an improved visualisation without compromising the field of view within and outside the surgical field.

Wedge-technique for transposition of the vertebral artery in microvascular decompression for hemifacial spasm: technical nuances and surgical outcomes.

BACKGROUND: Transposition of the vertebral artery (VA) for microvascular decompression for hemifacial spasm (HFS) is often challenging. Various procedures have been proposed to transpose the immobile tortuous VA that cannot be decompressed satisfactorily in the usual manner. METHODS: A Teflon piece that is cut into a wedge shape was used for transposition of the VA as an offending artery in HFS. One or more wedge-shaped Teflon pieces were simply inserted into a small space between the VA and the brainstem or cerebellar hemisphere without any contact with the entry into the root exit zone (REZ) of the facial nerve. A minimal space can be created by slight mobilization of the VA through rostral or caudal, or in between to the lower cranial nerves (LCNs). In cases of a hypertrophic VA that is hard to mobilize, two or more rigid wedge-shaped Teflon pieces that are coated by fibrin glue can be applied to obtain adequate mobilization of the VA. Moreover, a much harder Teflon bar, which is bent into a V shape, can be used in cases of an immobile VA. Once the VA is transposed to an appropriate position, the Teflon, VA, and contacted surface of the brainstem are fixed together by drops of fibrin glue. RESULTS: The offending arteries were VA-posterior inferior cerebellar artery (PICA) in eight cases, VA in four cases, PICA in four cases, VA-anterior inferior cerebellar artery (AICA) in one case, and AICA in one case. Eighteen cases of HFS were successfully treated using the "Wedge technique." Symptoms disappeared within 2 weeks in all patients. Transient facial nerve palsy developed in one case, and transient hoarseness developed in one case. CONCLUSIONS: The wedge technique is a simple straight-line maneuver that facilitates sufficient transposition of the VA without any related complications. This technique is also useful for other large offending vessels, such as the anterior or posterior inferior cerebellar arteries, which are hard to mobilize due to the torque of the vessels.

A Rare Potential Compression Can Be Avoided by Lateral Spread Response Recordings During Microvascular Decompression for Hemifacial Spasm.

The authors report a 34-year-old female with hemifacial spasm who was identified as a candidate for microvascular decompression. Lateral spread response (LSR) was not recorded at first because of anatomical shift of neurovascular relationship after drainage of cerebrospinal fluid, but they reappeared only after a piece of shredded gelatin sponge was placed near the posteroinferior cerebellar artery to expand surgical field. As the authors removed the gelatin sponge, the LSRs disappeared instantly. Subsequently, the authors put some soft shredded Teflon between the offending vessel and brainstem. Since then the authors did not find LSRs anymore. Clinical follow-up had been carried out with a questionnaire from 1 week to 3 months postoperatively, and the patient was cured with no complications. This report presented that the gelatin sponge placed in an inappropriate position resulting in compression potentially leading to the opposite effect of treatment. Such kind of excessive operation could be avoided by electrophysiological monitoring.

How I do it: endoscopic microvascular decompression for hemifacial spasm associated with the vertebral artery.

BACKGROUND: Microvascular decompression (MVD) of hemifacial spasm (HFS) associated with the vertebral artery (VA) shows higher rates of incomplete cure and complications compared to non-VA-related HFS. METHOD: Purely endoscopic MVD for VA-associated HFS via a retrosigmoid keyhole was performed. Neurovascular conflicts by a directly offending artery and VA around the root exit zone of the facial nerve were clearly demonstrated under 30° endoscopic view without significant cerebellar retraction. The VA and directly offending artery were safely transposed with preservation of perforators under excellent view. CONCLUSION: Endoscopic MVD offers reliable decompression for VA-associated HFS with minimal invasiveness.

[A Case of Coexistent Glossopharyngeal Neuralgia and Hemifacial Spasm Successfully Treated with Transposition of the Vertebral Artery].

A case of coexistent glossopharyngeal neuralgia and hemifacial spasm was treated by transposition of the vertebral artery. A 60-year-old man was referred to our hospital due to pain in the left posterior part of the tongue that was difficult to control with oral medication at a local hospital. The diagnosis was left glossopharyngeal neuralgia based on the symptoms, imaging findings, and lidocaine test results. Moreover, the patient had left hemifacial spasm. Microvascular decompression was performed, which confirmed that the vertebral artery was compressing the lower cranial nerve and the posterior inferior cerebellar artery was compressing the root exit zone of the facial nerve. The vertebral artery and posterior inferior cerebellar artery were transposed using TachoSil®. After the surgery, both glossopharyngeal neuralgia and hemifacial spasm disappeared, and the patient was discharged.

Teflon Might Be a Factor Accounting for a Failed Microvascular Decompression in Hemifacial Spasm: A Technical Note.

BACKGROUND: Although Teflon is widely adopted for microvascular decompression (MVD) surgery, it has never been addressed for failure analysis. This study analyzed the reasons for failed MVDs with emphasis on the Teflon sponge. METHODS: Among the 685 hemifacial spasm cases between 2010 and 2014, 31 were reoperated on within a week because of unsatisfactory outcome, which was focused on in this study. Intraoperative findings regarding Teflon inserts of these repeat MVDs were reviewed. RESULTS: Among the 38 without satisfactory outcomes, 31 underwent repeat MVDs, and they were all spasm free afterwards. Eventually, the final cure rate was 99.2%. It was found in the repeat MVDs that the failure was attributable to the Teflon insert in most of the cases (74.2%) directly or indirectly. It was caused by improper placement (47.8%), inappropriate size (34.8%) and unsuitable shape (17.4%) of the Teflon sponge. CONCLUSION: Although it is not difficult for an experienced neurosurgeon to discover a neurovascular conflict during the MVD process, the size, shape and location of the Teflon sponge should not be ignored. Basically, the Teflon insert is used to keep the offending artery away from the facial nerve root rather than to isolate it. Therefore, the ideal Teflon sponge should be just small enough to produce a neurovascular separation.

Benefits of microvascular decompression on social anxiety disorder and health-related quality of life in patients with hemifacial spasm.

BACKGROUND: Hemifacial spasm (HFS), an involuntary movement disorder characterized by unilateral spasms of the muscles innervated by the facial nerve, is likely to cause social anxiety disorder due to its significant facial disfigurement and may have a significant influence on a patient's health-related quality of life (HRQoL). The goal of this study was to investigate the influence of microvascular decompression (MVD) on the severity of social anxiety symptoms and HRQoL in patients with HFS. METHODS: Patients who underwent MVD from January to May 2015 were included in this study. Demographic data were collected before surgery. Clinical data, including the standardized measures of anxiety and depression (Hospital Anxiety Depression Scale, HADS), social anxiety (Liebowitz Social Anxiety Scale, LSAS), and the severity of HFS were assessed before surgery and 6 months after surgery. HRQoL data were also collected before surgery and 6 months after surgery using the Korean version of the short form 36 (SF-36). RESULTS: Six patients (21.4 %) scored 60 or greater on the preoperative LSAS and were considered to have generalized social anxiety disorder (high-LSAS group). The duration of symptom was significantly higher in the high-LSAS group than in the low-LSAS group (7.8 ± 2.2 vs. 4.1 ± 2.6; p = 0.011). The high-LSAS group was more likely to have psychological comorbidities and had a more impaired quality of life than the low-LSAS group at preoperative evaluation. Six months after MVD, a significant improvement, compared to preoperative scores, was observed for the total LSAS score (p = 0.007) and anxiety subscale score of HADS (p = 0.012) in the high-LSAS group. Other significant improvements were also observed in role-emotional (p = 0.039) and mental component summary (p = 0.024) of the SF-36 in the high-LSAS group compared to the low-LSAS group. CONCLUSIONS: This study shows that HFS patients seem to gain benefits from MVD not only for their facial disfigurement but also for social anxiety symptoms that may be associated with mental health improvements in their quality of life.

Microvascular decompression under neuroendoscopic view in hemifacial spasm: rostral-type compression and perforator-type compression.

We report microvascular decompression (MVD) under neuroendoscopic view in hemifacial spasm (HFS) patients with rostral- and perforator-type compression of the root exit zone (REZ) of the facial nerve. Using either a wireless iPad Mini as a monitor on the microscope or a high-resolution monitor, microscopic and endoscopic views enabled MVD for complete cure of HFS with rostral-type compression (the offender compressing the REZ on the opposite rostral side to the operative approach) or perforator-type compression (the offender tethered to the REZ by the perforator). MVD under neuroendoscopic view may offer more accurate MVD and complete resolution of HFS.

A successful treatment of coexistent hemifacial spasm and trigeminal neuralgia caused by a huge cerebral arteriovenous malformation: a case report.

Regardless hemifacial spasm (HFS) or trigeminal neuralgia (TN) is commonly caused by an offending artery, 36 cases caused by an arteriovenous malformation (AVM) have been reported in the literature. However, the concurrent HFS and TN caused by AVM have never been reported so far. We reported a case of coexistent HFS-TN associated with a huge AVM, and the symptoms of both spasm and pain relieved gradually after endovascular embolization of the nidus. The etiology and pathogenesis as well as the treatment of this disorder are discussed and reviewed in the article.

Adolescent-onset idiopathic hemifacial spasm.

AIMS: To study the clinical manifestations, illness-related factors and microsurgical management of adolescent-onset idiopathic hemifacial spasm. MATERIALS AND METHODS: Of the 1221 microvascular decompression procedures performed for idiopathic hemifacial spasm between March 2001 and July 2007, 16 (1.3%) were in adolescent age (≤18). RESULTS: Clinical manifestations in the adolescent-onset were typical, but milder when compared with late-onset. Gender, thickening and adhesion of the arachnoid membrane at the cerebellopontine angle and a small volume of posterior cranial fossa might be important illness-related factors for adolescent-onset idiopathic hemifacial spasm. Arterial compression was the main cause. Typical compression of offending arteries was observed in 14 patients. Compression of petrous bone crest was found in one patient. Immediate effective rate was 100%, and curative rate was 75%. The curative rate, effective rate and delayed resolution rate during the follow-up period (mean: 22.9 months) were 87.5%, 100% and 12.5%, respectively. There was no recurrence. The postoperative complications (2; 12.5%) included: One patient had transient moderate facial palsy and decreased hearing and one patient had transient decreased hearing and tinnitus. CONCLUSIONS: This suggests that microvascular decompression is effective in adolescent-onset idiopathic hemifacial spasm.

Hemifacial spasm caused by the cross-compression of the vertebral artery loop--a case-centered report of a stitched sling retraction technique.

Hemifacial spasm (HFS) is one of the neurovascular compression syndromes caused by the compression of the facial nerve outgoing from the brainstem by an artery, a vein or both. The treatment of choice of this disorder is a microvascular decompression (MVD). As initially described, MVD is a technique based on the application of the small prostheses that are placed between a cranial nerve and an imposing vessel. Neurovascular compression syndromes have relatively high rate of incidence. Therefore, many modifications of surgical technique have been described in order to minimize the risk of complications and increase the effectiveness and permanence of the vascular transposition as the success of the MVD most of all depends on the latter. The authors of this paper describe one of the aforementioned modifications that provides a complete and permanent vascular transposition together with its advantages and limitations in the treatment of the hemifacial spasm. Moreover, many aspects of different technical approaches are widely discussed and a case-centered stitched sling retraction technique is presented.