Bridge technique for hemifacial spasm with vertebral artery involvement

Background To assess efficacy and safety of a newly developed decompression technique in microvascular decompression for hemifacial spasm (HFS) with vertebral artery (VA) involvement. Methods A rigid Teflon (Bard® PTFE Felt Pledget, USA) with the ends placed between the lower pons and the flocculus creates a free space over the root exit zone (REZ) of the facial nerve (bridge technique). The bridge technique and the conventional sling technique for VA-related neurovascular compression were compared retrospectively in 60 patients. Elapsed time for decompression, number of Teflon pieces used during the procedure, and incidences of intraoperative manipulation to the lower cranial nerves were investigated. Postoperative outcomes and complications were retrospectively compared in both techniques. Results The time from recognition of the REZ to completion of the decompression maneuvers was significantly shorter, and fewer Teflon pieces were required in the bridge technique than in the sling technique. Lower cranial nerve manipulations were performed less in the bridge technique. Although statistical analyses revealed no significant differences in surgical outcomes except spasm-free at postoperative 1 month, the bridge technique is confirmed to provide spasm-free outcomes in the long-term without notable complications. Conclusions The bridge technique is a safe and effective decompression method for VA-involved HFS.

Computational hemodynamic analysis of the offending vertebral artery at the site of neurovascular contact in a case of hemifacial spasm associated with subclavian steal syndrome: illustrative case

BACKGROUND Hemifacial spasm (HFS) is caused by neurovascular contact along the facial nerve’s root exit zone (REZ). The authors report a rare HFS case that was associated with ipsilateral subclavian steal syndrome (SSS). OBSERVATIONS A 42-year-old man with right-sided aortic arch presented with progressing left HFS, which was associated with ipsilateral SSS due to severe stenosis of the left brachiocephalic trunk. Magnetic resonance imaging showed contact between the left REZ and vertebral artery (VA), which had shifted to the left. The authors speculated that the severe stenosis at the left brachiocephalic trunk resulted in the left VA’s deviation, which was the underlying cause of the HFS. The authors performed percutaneous angioplasty (PTA) to dilate the left brachiocephalic trunk. Ischemic symptoms of the left arm improved after PTA, but the HFS remained unchanged. A computational fluid dynamics study showed that the high wall shear stress (WSS) around the site of neurovascular contact decreased after PTA. In contrast, pressure at the point of neurovascular contact increased after PTA. LESSONS SSS is rarely associated with HFS. Endovascular treatment for SSS reduced WSS of the neurovascular contact but increased theoretical pressure of the neurovascular contact. Physical release of the neurovascular contact is the best treatment option for HFS.

Long-Term Retrospective Analysis of Re-do Microvascular Decompression in Patients With Hemifacial Spasm

Objective: To explore the clinical characteristics of patients with persistent or recurrent hemifacial spasm (HFS) and the experience of microvascular decompression (MVD) in the treatment of such patients to accumulate additional clinical evidence for optimal treatment protocols.Methods: We retrospectively analyzed the clinical data, surgical methods and treatment efficacies of 176 patients with persistent or recurrent HFS from January 2009 to January 2018.Results: Missing compression zones was the main reason for symptom persistence (87.50%) or recurrence (71.50%) after MVD treatment of HFS. We divided the surgical area into three zones. Most persistent or recurrent cases had decompression only in the root exit zone (REZ) (Zone 1) but missed the ventrolateral pons-involved area (Zone 2) or the bulbopontine sulcus-involved area (Zone 3) in the first MVD. Too much use of Teflon (12.50%), arachnoid adhesions (5.60%) and Teflon granulomas (10.40%) can also cause a recurrence. The difference between preoperative and postoperative Cohen scores was statistically significant in persistent or recurrent HFS patients (p<0.05). The postoperative follow-up time ranged from 36 to 108 months (71.75 ± 22.77).Conclusions: MVD should be performed in the compression site, which is mostly located at the brainstem/facial REZ. Intraoperative exploration should be conducted in accordance with the abovementioned zones to effectively avoid missing offending vessels. Re-do MVD is effective in patients with persistent or recurrent HFS.

Anterior transpetrosal resection of the lower ventral pontine cavernous malformation: A technical case report with operative video

Background: Surgical treatment of pontine cavernous malformations (CMs) is challenging due to the anatomical difficulties and potential risks involved. We successfully applied an anterior transpetrosal approach (ATPA) to remove a lower ventral pontine CM, and herein we discuss the outline of our procedure accompanied by a surgical video. Case Description: A 50-year-old woman presenting with progressively worsening diplopia was urgently admitted to our hospital. Preoperative images showed a lower ventral pontine CM compressing the corticospinal tract posteriorly. Considering the location of the CM, we determined that an ATPA was the appropriate approach to achieve a more anterolateral trajectory. We performed extradural anteromedial petrosectomy and penetrated the brainstem from the point just below the anterior inferior cerebellar artery and above the root exit zone of the abducens nerve, which might be located in the somewhat lowest border of actual maneuverability in the ATPA. Maneuverability through this corridor was sufficient without hindering and darkening the high magnification microscopic view, as demonstrated in our surgical video. Conclusion: This report demonstrates surgical treatment of a lower ventral pontine CM using the ATPA. The surgical video we present provides information that is useful for understanding this technique’s maneuverability and working window.

Treatment for Hemifacial Spasm Associated with a Dissecting Vertebral Artery Aneurysm Requiring Microvascular Decompression in Addition to Endovascular Trapping: A Case Report with Literature Review

Background The treatment protocol for hemifacial spasm (HFS) associated with dissecting vertebral artery aneurysm (DVAA) has not been established. Case Description A-42-year-old man with left HFS underwent endovascular trapping for a DVAA that was identified on brain imaging. Although the dissecting segment was treated successfully, the HFS persisted for 3 months, and subsequently microvascular decompression (MVD) was needed. The posteroinferior cerebellar artery (PICA) was found to be interposed between the root exit zone of the facial nerve and DVAA during surgery. After pulling out the PICA, the HFS ceased immediately. Conclusion HFS associated with DVAA should be considered carefully before formulating a treatment strategy. Moreover, the cause of pulsatile compression may not be visible on brain imaging, and MVD surgery may be indicated in such cases.

Hemifacial Spam: Endoscopic Assistance in Facial Nerve Decompression With Lateral Spread Response Corroboration: 2-Dimensional Operative Video

This video depicts the case of a 48-yr-old female with 3 yr of progressive left hemifacial spasm (HFS) refractory to medication. Magnetic resonance imaging showed a large anterior inferior cerebellar artery (AICA) and also a labyrinthine artery loop around the facial nerve (FN) root exit zone. A large bony eminence was also noted in the superior and lateral aspects of the porous acousticus (PA). She preferred surgery if “cure” was possible in lieu of Botox injections. A left retro sigmoid craniotomy was performed with brainstem auditory evoked responses (BAERs) and FN monitoring along with lateral spread response (LSR) assessment. The large bony prominence was drilled in its lateral aspect. Despite this, visualization was still limited and therefore we utilized a 30-degree-angled endoscope to observe the vessels caudal and cranial to the FN. This view prompted us to then drill further at the PA to decompress the FN as well as mobilize the labyrinthine artery away from the nerve. The LSR showed a dramatic improvement when FN decompression was accomplished, and then a further improvement with arterial mobilization and Teflon pledget placement. The BAERS remained at baseline throughout. FN function and hearing were intact on postoperative clinical assessment. Her symptomatic improvement was recorded at 12 mo after surgery. This video illustrates a more complex case of microvascular decompression with skull base concepts and techniques. The patient provided consent for the procedure and use of her images and operative video for publication.

Clinical Research on Delayed Cure after Microvascular Decompression for Hemifacial Spasm

Objective The clinical data of patients with hemifacial spasm (HFS) were analyzed statistically to identify factors leading to delayed cure after microvascular decompression (MVD). Methods A retrospective analysis of the clinical data of 600 patients with HFS subjected to MVD from March 2016 to May 2018 was performed. Student t test, chi-square test, logistic regression analysis, and multivariate analysis of variance were used to analyze the correlation between delayed cure and its related factors. Results Among the 600 patients enrolled, 117 had delayed cure after MVD. The shortest duration of delayed cure was 4 days, and the longest was 540 days, with an average of 108 days. The frequency of delayed improvement in these patients was not associated with sex, age, or offending vessel type (p > 0.05); however, delayed cure was positively correlated with the course of the disease, grade of HFS severity, and disappearance of abnormal muscle responses during the operation (p < 0.05). Moreover, a longer disease course was associated with more severe related symptoms and a longer duration of postoperative delayed cure. Conclusion MVD is an effective treatment for HFS. Given that postoperative delayed cure was unavoidable, even with accurate identification of the offending vessel and sufficient decompression of the root exit zone, delayed cure should be considered in patients undergoing reoperation due to lack of remission or relapse after the operation. Additionally, the timing of efficacy assessments should be delayed.

Correlation between pain assessment scale and neurovascular compression distance to the root exit zone in trigeminal neuralgia analysis using 3D CISS MRI sequence

BACKGROUND Trigeminal neuralgia (TN) is primarily caused by neurovascular compression (NVC) at root exit zone (REZ) in cerebellopontine angle cistern. In some NVC cases, it was suspected that clinical symptoms may be correlated with the distance of trigeminal nerve root to vascular contact. Pain assessment scale (PAS) was the most common scale used to evaluate TN pain, therefore this study was conducted to analyze the correlation between PAS usingnumeric rating scale (NRS) and distance from the NVC to REZ location in patients with TN using 3D CISS MRI sequence. METHODS This cross-sectional study was conducted at the Department of Radiology, Faculty of Medicine, Universitas Indonesia, Cipto Mangunkusumo Hospital, Jakarta, using secondary data of 32 patients, collected from Picture Archiving and Communication System from January 2013 to January 2016. Statistical analysis was performed using SPSS, version 20.0. Spearman p-value of < 0.05 was considered significant. RESULTS A total of 32 patients met the inclusion criteria. The mean (SD) distances from the NVC to the REZ were 2.1 (2.1), 2.31 (2.25), and 3.22 (2.63) mm on the shortest, medial, and lateral sides, respectively. The correlation coefficients (r) between the PAS value and the NVC distance in relation to the trigeminal nerve REZ were −0.39 (p = 0.021), −0.57 (p < 0.01), and −0.57 (p = 0.294) on the shortest, lateral, and medial sides, respectively. CONCLUSIONS PAS using the NRS instrument exhibited an inverse correlation to NVC distance to the REZ of the trigeminal nerve. Shorter distance increased the PAS value.

Endoscopic-Assisted Microvascular Decompression of Ectatic Vertebral Artery for Hemifacial Spasm: Operative Video and Technical Nuances

In this operative video atlas manuscript, the authors demonstrate the operative nuances and surgical technique for endoscopic-assisted microvascular decompression of a large ectatic vertebral artery causing hemifacial spasm. A retrosigmoid approach was performed and a large ectatic vertebral artery was transposed away from the root exit zone of cranial nerve VII (Fig. 1). The lateral spread response disappeared, signifying adequate decompression of the facial nerve (Fig. 2). The use of endoscopic-assistance during the microsurgical decompression was very useful to confirm the origin and also the resolution of neurovascular conflict. Postoperatively, the patient experienced immediate resolution of hemifacial spasm with normal facial nerve and hearing function. Written consent was obtained from the patient to publish videos, photographs, and images from the surgery.The link to the video can be found at: https://youtu.be/RlMz44uCDCw.

Long-term Outcomes of Microvascular Decompression in the Treatment of Hemifacial Spasm Based on Different Offending Vessels

Objective To evaluate clinical features, outcomes, and complications in patients with hemifacial spasm (HFS) after microvascular decompression (MVD) of different offending vessels. Methods Clinical data were collected from 362 patients with HFS treated with MVD between January 2013 and January 2014. Patients were divided into five groups based on the offending vessel: A (anterior inferior cerebellar artery [AICA] compression), B (posterior inferior cerebellar artery [PICA] compression), C (AICA plus PICA compression), D (vertebral artery [VA] compression), and E (VA plus small vessel compression). Results The most common offending vessel was the AICA (51.38%). The most common compression site was the root exit zone. During the follow-up period, the effective rate was 95.48% in group A, 92.15% in group B, 93.10% in group C, 90.14% in group D, and 91.45% in group E. Twenty-nine patients exhibited delayed facial palsy, the most common complication. Conclusion No statistically significant differences were found in long-term outcomes or MVD-related complications among the study groups. The type of offending vessel was not a prognostic factor for MVD in patients with HFS.