Hypertension of neurogenic origin: effect of microvascular decompression of the CN IX-X root entry/exit zone and ventrolateral medulla on blood pressure in a prospective series of 48 patients with hemifacial spasm associated with essential hypertension

Determining prognostic factors in the treatment of primary hemifacial spasm: Clinical outcomes and complications. A literature review

Objective

Primary Hemifacial Spasm (PHFS) significantly impacts quality of life, necessitating effective treatment like microvascular decompression of the facial nerve. This study aims to identify prognostic factors related to surgical treatment to enhance outcomes and minimize complications. A systematic review of literature from the past five years was conducted.

Methods

Following PRISMA guidelines, we systematically searched databases like PubMed, Embase, Scopus, Ovid, EBSCO, and Cochrane using keywords such as 'Hemifacial spasm,' 'Microvascular decompression,' 'Neurovascular conflict,' and 'Surgical techniques.' The search spanned January 2018 to November 2023. The 'Rayyan' program facilitated data compilation. Each author reviewed abstracts, applying inclusion criteria like systematic reviews, clinical trials, observational studies, and case series, while excluding theoretical or non-English articles.

Results

Of 26 selected articles, those solely addressing PHFS treatment with botulinum toxin and lacking surgical procedure data were excluded. Thus, our analysis focused on 16 articles, including meta-analyses, systematic reviews, clinical trials, and observational studies.

Discussion

Microvascular decompression at the cerebellar pontine angle is the mainstay treatment for hemifacial spasm. Despite limited statistically significant prognostic factors in the literature, overarching recommendations aim to improve outcomes, minimize complications, and prevent recurrences. Key considerations include surgeon expertise, precise techniques, thorough nerve exploration, identifying the conflict's cause, and intraoperative monitoring.

Conclusions

PHFS significantly impacts patients' lives, necessitating timely surgical intervention if initial treatments fail. While statistically significant prognostic factors may be lacking, this study highlights crucial considerations for successful treatment.

Ventrolateral medullary compression by vascular contact in primary hemifacial spasm: a radiological analysis

BACKGROUND

The neurovascular conflict (NVC) causing hemifacial spasm (HFS) can also cause compression of ventrolateral medulla (VLM) which contains the central sympathetic neurons. VLM compression has been associated with hypertension. Whether the VLM compression in HFS patients is associated with hypertension is not clear.

OBJECTIVE

To determine the frequency, severity of VLM compression and its association with hypertension in HFS patients.

METHODS

A cross-sectional, hospital-based, case control study and recruited 120 study subjects (50 cases of primary HFS, 30 hypertensive and 40 normotensive age-, sex- matched controls). The VLM compression was assessed in magnetic resonance imaging Constructive Interference in Steady State (CISS) 3D sequences.

RESULTS

Hypertension was present in 30 cases (60%). Six patients with HFS (20%) were detected to be hypertensive after the onset of HFS. VLM compression was seen in 24 cases (48%), 7 hypertensive controls (23.3%) and 5 normotensive controls (10%) (p = 0.03). Twenty-four patients with hypertension had VLM compression and remaining 6 patients with hypertension did not have VLM compression (80% vs 20%; p = 0.02). Normotensive patients did not have VLM compression. Vertebral artery was the most common artery causing VLM compression (22 patients; 7 hypertensive and 5 normotensive controls).

CONCLUSION

VLM compression is more common in HFS patients as compared to hypertensive and normotensive controls. It is more common in hypertensive HFS patients in comparison with normotensive HFS patients. Microvascular decompression is an option in hypertensive HFS patients with VLM compression if the hypertension is medically refractory.

The effect of microvascular decompression of the CN IX-X root entry/exit zone and the ventrolateral medulla in neurogenic hypertension involving the vertebral/basilar artery

Introduction

Neurogenic hypertension (HTN) is a type of HTN characterized by increased activity of the sympathetic nervous system. Vascular compression is one of the pathogenic mechanisms of neurogenic HTN. Despite Jannetta's solid anatomical and physiological arguments in favor of neurogenic HTN in the 1970's, the treatment for essential HTN by microvascular decompression (MVD) still lacks established selection criteria. Therefore, the subjects selected for our center were limited to patients with primary trigeminal neuralgia (TN) and primary hemifacial spasm (HFS) of the vertebral/basilar artery (VA/BA) responsible vessel type coexisting with neurogenic HTN who underwent MVD of the brainstem to further explore possible indications for MVD in the treatment of neurogenic HTN.

Methods

A retrospective analysis of 63 patients who were diagnosed with neurogenic HTN had symptoms of HFS and TN cranial nerve disease. Patients were treated at our neurosurgery department from January 2018 to January 2023. A preoperative magnetic resonance examination of the patients revealed the presence of abnormally located vascular compression in the rostral ventrolateral medulla (RVLM) and the root entry zone (REZ) of the IX and X cranial nerves (CN IX- X).

Results

There was no significant difference between the two groups in terms of gender, age, course of HFS, course of TN, course of HTN, degree of HTN, or preoperative blood pressure. Based on the postoperative blood pressure levels, nine out of 63 patients were cured (14.28%), eight cases (12.70%) showed a marked effect, 16 cases (25.40%) were effective, and 30 cases were invalid (47.62%). The overall efficacy was 52.38%. However, 39 cases of combined cranial nerve disease were on the left side of the efficacy rate (66.67%) and 24 cases of combined cranial nerve disease were on the right side of the efficacy rate (29.16%).

Discussion

Over the last few decades, many scholars have made pioneering progress in the clinical retrospective study of MVD for neurogenic hypertension, and our study confirms the efficacy of MVD in treating vertebral/basilar artery-type neurogenic hypertension by relieving the vascular pressure of RVLM. In the future, with the development and deepening of pathological mechanisms and clinical observational studies, MVD may become an important treatment for neurogenic hypertension by strictly grasping the surgical indications.

Conclusion

MVD is an effective treatment for neurogenic HTN. Indications may include the following: left-sided TN or HFS combined with neurogenic HTN; VA/BA compression in the left RVLM and REZ areas on MRI; and blood pressure in these patients cannot be effectively controlled by drugs.

Clinical and Educational Aspects of Neuroimaging in Microsurgery of the Posterior Fossa: A Comprehensive Review

The clinical and educational value of modern high-resolution magnetic resonance imaging (MRI) and image processing in neurovascular diseases of the posterior fossa with regard to preoperative planning and intraoperative comparison with the actual anatomical situation was consecutively evaluated. Patients with trigeminal neuralgia (TN), hemifacial spasm (HFS), glossopharyngeal neuralgia (GN) and arterial hypertension (HTN) were analyzed. The high-resolution MRI data was segmented and visualized three-dimensionally using computer graphics methods. New anatomical insights were gained, such as the classification of neurovascular compression (NVC) in HFS and GN. It was also possible to visualize the pathognomonic cerebrospinal fluid signal in patients with TN for the first time. Using the new imaging methods, pregnant hypertensive patients were examined and the existence of NVC was confirmed for the first time, and the findings were compared to other studies dealing with NVC syndromes. This review gives an overview on the established methods of neuroimaging and image processing of neurovascular structures in the posterior fossa with the focus on clinical and educational aspects.

Lateral medullary vascular compression manifesting as paroxysmal hypertension

Neurovascular compression of the rostral ventrolateral medulla (RVLM) has been described as a possible cause of refractory essential hypertension. We present the case of a patient affected by episodes of severe paroxysmal hypertension, some episodes associated with vago-glossopharyngeal neuralgia. Classical secondary forms of hypertension were excluded. Imaging revealed a neurovascular conflict between the posterior inferior cerebellar artery (PICA) and the ventrolateral medulla at the level of the root entry zone of the ninth and tenth cranial nerves (CN IX-X REZ). A MVD of a conflict between the PICA and the RVLM and adjacent CN IX-X REZ was performed, resulting in reduction of the frequency and severity of the episodes. Brain MRI should be performed in cases of paroxysmal hypertension. MVD can be considered in selected patients.

Effect of Microvascular Decompression of the Vagus Root Entry/Exit Zone on Blood Pressure in Patients with Hemifacial Spasm Associated with Essential Hypertension: A Retrospective Clinical Analysis

Background  This study aimed to evaluate blood pressure alterations after microvascular decompression (MVD) surgery in patients with hemifacial spasm (HFS) with coexisting hypertension (HTN). Methods  A total of 56 patients with HFS with concurrent HTN who underwent MVD surgery in our center between 2015 and 2019 were retrospectively analyzed. Patients were divided into control and experimental groups: patients who received MVD treatment for only the facial nerve and those who received MVD for the affected facial nerve, ipsilateral vagus nerve, and adjacent ventrolateral medulla, respectively. Preoperative (3 days) and postoperative (7 days and 6 months) blood pressure measurements were analyzed. Results  No statistically significant differences were observed in gender, age, HFS course, HTN course, HTN grade, and preoperative blood pressure between the two groups. No significant difference was observed between pre- and postoperative blood pressure in the control group. In the experimental group, systolic blood pressure significantly differed between 3 preoperative days and 7 postoperative days ( p  < 0.05), as did diastolic blood pressure ( p  < 0.05). Measurement at 6 postoperative months also showed significant differences for both systolic blood pressure and diastolic blood pressure compared with that at 3 preoperative days ( p  < 0.05). HTN grade according to the World Health Organization classification criteria significantly differed between preoperative and postoperative measurements ( p  < 0.05). Conclusion  Vascular decompression of the ipsilateral vagus nerve roots may improve blood pressure management in patients with HFS with coexisting HTN who undergo MVD. Laterality of involvement (left vs. right) did not significantly differ.

The Distance Between the Cranial Nerve IX-X Root Entry/Exit Zone and the Pontomedullary Sulcus: MR Imaging Study in Patients With Hemifacial Spasm

Subject

To quantitatively describe the distance between the cranial nerve (CN) IX-X root entry/exit zone (REZ) and the pontomedullary sulcus in patients with hemifacial spasm (HFS).

Methods

A total of 215 outpatients with HFS were recruited. Finally, 108 patients who yielded high-quality images were enrolled in the study. MRIs were reconstructed to measure the distance between the bilateral CN IX-X REZs and the corresponding pontomedullary sulcus.

Results

Among the 108 patients, the ratio of males to females was 39/69, and the mean age was 57.9 ± 6.5 years. The ratio of left to right HFS involvement was 47/61. The average height was 1.62 ± 0.07 m, and the average body mass index (BMI) was 24.65 ± 2.97 kg/m². The distance between the cephalic end of the CN IX-X REZ and the pontomedullary sulcus was 2.7 ± 0.9 mm. The distance between the caudal end of the CN IX-X REZ and the pontomedullary sulcus was 7.6 ± 1.1 mm. No monotonic relationship was found between distance and height or BMI in the scatter diagrams.

Conclusions

The CN IX-X REZ is closely related to the pontomedullary sulcus in patients with HFS, and there is no difference between the left and right sides. The distances were not correlated with height or BMI in patients with HFS.

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.

Neurovascular Compression in Arterial Hypertension: Correlation of Clinical Data to 3D-Visualizations of MRI-Findings

Aims:

In this study, we attempted to identify clinical parameters predicting the absence or presence of Neurovascular Compression (NVC) at the Ventrolateral Medulla (VLM) in arterial hypertension (HTN) in MRI findings.

Background:

Cardiovascular and pulmonary afferences are transmitted through the left vagus and glossopharyngeal nerve to the brain stem and vasoactive centers. Evidence supports the association between HTN and NVC at the left VLM. Several independent studies indicate a reduction of HTN after Microvascular Decompression (MVD) of the left. Several independent studies indicate a reduction of HTN after Microvascular Decompression (MVD) of the left VLM. Image processing of MRI provides comprehensible detection of NVC. HTN affects hemodynamic parameters and organs.

Objective:

This study analyzes and correlates clinical data and MRI findings in patients with and without NVC at the VLM in treatment resistant HTN to obtain possible selection criteria for neurogenic hypertension.

Methods:

In 44 patients with treatment resistant HTN, we compared MRI findings of neurovascular imaging to demographic, clinical and lifestyle data, office and 24-hour ambulatory Blood Pressure (BP), and cardiovascular imaging and parameters.

Results:

Twenty-nine (66%) patients had evidence of NVC at the VLM in MRI. Sixteen patients (36%) had unilateral NVC on the left side, 7 (16%) unilateral right and 6 (14%) bilateral NVC. Fifteen (34%) had no evidence of NVC at the VLM. Patients with left sided NVC were significantly younger, than those without NVC (p=0.034). They showed a statistically significant variance in daytime (p=0.020) and nighttime diastolic BP (p<0.001) as the mean arterial pressure (p=0.020). Other measured parameters did not show significant differences between the two groups.

Conclusion:

We suggest to examine young adults with treatment resistant HTN for the presence of NVC at VLM, before signs of permanent organ damage appear. Clinical and hemodynamic parameters did not emerge as selection criteria to predict NVC. MVD as a surgical treatment of NVC in HTN is not routine yet as a surgical treatment of NVC in HTN is not routine yet. Detection of NVC by imaging and image processing remains the only criteria to suggest MVD, which should be indicated on an individual decision.

Sympathetic hyperactivity, hypertension, and tachycardia induced by stimulation of the ponto-medullary junction in humans

OBJECTIVE

The purpose of this study is to investigate changes in autonomic activities and systemic circulation generated by surgical manipulation or electrical stimulation to the human brain stem.

METHODS

We constructed a system that simultaneously recorded microsurgical field videos and heart rate variability (HRV) that represent autonomic activities. In 20 brain stem surgeries recorded, HRV features and sites of surgical manipulation were analyzed in 19 hypertensive epochs, defined as the periods with transient increases in the blood pressure. We analyzed the period during electrical stimulation to the ponto-medullary junction, performed for the purpose of monitoring a cranial nerve function.

RESULTS

In the hypertensive epoch, HRV analysis showed that sympathetic activity predominated over the parasympathetic activity. The hypertensive epoch was more associated with surgical manipulation of the area in the caudal pons or the rostral medulla oblongata compared to controls. During the period of electrical stimulation, there were significant increases in blood pressures and heart rates, accompanied by sympathetic overdrive.

CONCLUSIONS

Our results provide physiological evidence that there is an important autonomic center located adjacent to the ponto-medullary junction.

SIGNIFICANCE

A large study would reveal a candidate target of neuromodulation for disorders with autonomic imbalances such as drug-resistant hypertension.

Is MVD the effective treatment for poorly controlled hypertension?

BACKGROUND

Studies have shown that microvascular decompression (MVD) surgery could improve the clinical symptoms of hemifacial spasm (HFS) and decrease the blood pressure (BP) in patients with refractory hypertension. More positive long-term results are required to establish MVD as a treatment option for high blood pressure (HBP) and to refine the patient selection criteria.

METHODS

From October 2015 to September 2018, based on patient selection for cases with both HFS and poorly controlled HBP of nervous origin, MVD surgeries were performed on 12 patients aiming for better BP control. The patients were followed-up for at least 2 years. The surgical outcomes and associated factors were analyzed.

RESULTS

With respect to neurovascular compression (NVC) of facial nerve, the intra-operative findings concurred with pre-operative radiological findings except that in one case. Intra-operatively ipsilateral cranial nerve (CN) IX-X root exit zone (REZ) and rostral ventrolateral medulla (RVLM) NVCs were confirmed and concordant with pre-operative radiological findings in all 12 cases. 9 Of the 12 cases were completely free of facial spasm after surgery. 2 patients achieved partial relief. 1 patient still suffered from frequent facial spasm. 10 out of 12 patients achieved BP lowering after surgery. The BP of those 10 patients stayed at a relatively stable scale over the follow-up period. Although statistical significance was not obtained, for patients who are operated on the left side and those who have only 1 offensive artery, the surgery might lead to better BP control.

CONCLUSIONS

MVD is a safe and effective treatment for hypertension due to central nervous system (CNS) NVC in patients with both HBP and HFS. Further studies are required to examine long-term outcomes and establish criteria for patient selection.

3D-Visualization of Neurovascular Compression at the Ventrolateral Medulla in Patients with Arterial Hypertension

Purpose

Controversy exists on the association of arterial hypertension (HTN) and neurovascular compression (NVC) at the ventrolateral medulla (VLM). No standardized and reproducible technique has been introduced yet for detection of NVC in HTN. This study aimed to generate, analyze and compare different results of exact reproducible anatomical 3D-representations of the VLM in patients with HTN, based on magnetic resonance imaging (MRI).

Methods

A 3T scanner provided MRI (T2-constructive interference in steady state (CISS) high resolution imaging and three-dimensional Time-of-flight (3D-TOF) angiography) from the posterior fossa of 44 patients with clinical treatment-resistant HTN. Image processing consists of segmentation of the CISS data, registration and fusion of the CISS and TOF data and visualization. For each patient two 3D-visualizations (before and after fusion) were obtained. The reproduction quality of the vessels, flow-related signal variability and pulsation artifacts were analyzed and compared, using a ranking score.

Results

Integrating vascular information from TOF into CISS data reduced artifacts in 3D-visualizations of exclusively processed CISS data. The quality of 3D-visualization of the vessels near the brain stem was significantly improved (p = 0.004). The results were reproducible and reliable. The quality of the 3D-presentations of neurovascular relationships at the VLM improved significantly (p < 0.001).

Conclusion

The 3D-visualization of fused image data provides an excellent overview of the relationship between cranial nerves and vessels at the VLM and simplifies the detection of NVC in HTN. It provides a powerful tool for future clinical and scientific research. Although microvascular decompression (MVD) in treatment resistant HTN is not a standard procedure, it can be discussed in selected patients with intractable severe HTN.

Efficacy of microvascular decompression on the vascular compression type of neurogenic hypertension: A meta-analysis

OBJECTIVE

Neurogenic hypertension is a type of hypertension characterized by increased sympathetic activity. Vascular compression is one of the pathogenic mechanisms of neurogenic hypertension. The sample sizes of currently available studies on MVD in the treatment of hypertension are small, and the results are considerably different. Therefore, we conducted a meta-analysis of the previous literature to obtain the most realistic efficiency and analyzed the current situation of MVD as a treatment option of the vascular compression type of neurogenic hypertension.

METHOD

We systematically searched and identified relevant studies published before July 2019 from PubMed and Embase. Six studies involving 162 participants were included into our final analysis.

RESULT

The data showed that the effective rate of MVD was 70.1% (95% CI: 0.602-0.801). The most common offending vessel was PICA (29.9%), followed by VA/BA (23.9%) and VA/BA plus PICA (12.7%). Complications were mostly related to the VII, VIII, IX, and/or X cranial nerve dysfunction.

CONCLUSION

MVD as a treatment option of the vascular compression type of neurogenic hypertension is effective and safe. In spite of this conclusion, more prospective studies are needed to confirm it. On the other hand, a diagnostic method with higher sensitivity and specificity is necessary.

Microvascular decompression for the treatment of neurogenic hypertension with trigeminal neuralgia

Background

To evaluate the efficacy of microvascular decompression (MVD) in reducing hypertension (HTN) in hypertensive patients with trigeminal neuralgia (TN).

Methods

The clinical data of 58 cases of neurogenic HTN with TN treated in our hospital were retrospectively reviewed. Preoperative MR revealed abnormal blood pressure in the left rostral ventrolateral medulla (RVLM) and the posterior cranial nerve root entry zone (REZ). The patients were divided into control group: only trigeminal nerve was treated with MVD; experimental group: trigeminal nerve, RVLM and REZ were treated with MVD at the same time. The patients were followed up for 6 months to 1 year to observe the changes of blood pressure.

Results

There was no significant difference in gender, age, course of TN, course of HTN, grade of HTN and preoperative blood pressure between the two groups. After operation, the effective rate of HTN improvement with MVD was 32.1% in the control group. There was no significant difference in the preoperative and post operative blood pressure. (P△_SBP = 0.131; P△_BDP = 0.078). In the experimental group, the effective rate was 83.3%. The postoperative blood pressure was significantly lower than preoperative values. (P△_SBP < 0.001; P△_DBP < 0.001).

Conclusions

MVD is an effective treatment for neurogenic HTN. However, the criteria for selecting hypertensive patients who need MVD to control their HTN still needs to be further determined. Possible indications may include: left trigeminal neuralgia, neurogenic HTN; abnormal blood pressure compression in the left RVLM and REZ areas on MR; and blood pressure in these patients can not be effectively controlled by drugs.

Microvascular decompression in patients with hemifacial spasm

PURPOSE

To study blood pressure alterations after microvascular decompression (MVD) surgery in patients with hemifacial spasm (HFS).

METHODS

A retrospective study was performed to review HFS patients who received MVD surgery between January 2014 and December 2016. Vessels that were considered to be responsible for HFS were determined by reviewing the brain magnetic resonance imaging, magnetic resonance angiography, and surgical video. Blood pressure measurements were performed 1 day before (preoperative) and 7 days after (postoperative) the MVD surgery. Pre- and postoperative blood pressure measurements were compared.

RESULTS

A total of 374 patients were included in the study, with 118 (31.6%) male patients, age 53.8 ± 9.9 years old, and 141 (37.7%) patients with hypertension. Systolic blood pressure had statistically significant decrease in patients with (134.5 ± 8.2-132.6 ± 9.1 mmHg, p = .01) or without (125.6 ± 9.1-123.8 ± 10.0 mmHg, p = .01) hypertension. Diastolic blood pressure only had statistically significant decrease in patients with hypertension (83.0 ± 5.8-82.0 ± 6.5 mmHg, p = .04). Analyses in all the study patients and in the subgroup of patients with hypertension showed that more statistically significant blood pressure reductions were observed when left-side vessel or vertebrobasilar artery was involved.

CONCLUSION

In patients with HFS, MVD not only decreased blood pressure in patients with hypertension but also affected blood pressure in patients without hypertension. Blood pressure reductions were more prominent when left-side vessel or vertebrobasilar artery was involved.

Combined hyperactive dysfunction syndrome of the cranial nerves complicated by essential hypertension: A case report

RATIONALE

Combined hyperactive dysfunction syndrome (HDS) refers to a special type of HDS characterized by a combination of trigeminal neuralgia (TN), hemi facial spasm (HFS), and/or gloss pharyngeal neuralgia (GPN). Rostra ventrolateral medulla (RVLM) plays a crucial role in central cardiovascular regulation, and neurovascular compression of the RVLM has been identified as a contributor to essential hypertension.

PATIENT CONCERNS

A 65-year-old female with a facial tic and pain located in the root of the tongue and throat on the same side; the systolic and diastolic blood pressure was approximately 170 and 100 mmHg.

DIAGNOSIS

The patient was diagnosed with combined HDS (HFS-GPN) and essential hypertension. Brain magnetic resonance 3-dimensional time-of-flight imaging and digital subtraction angiography revealed vertebrobasilar artery compressed the left RVLM and contacted with the root entry zones of multiple cranial nerves.

INTERVENTIONS

The patient was treated with microvascular decompression surgery OUTCOMES:: The symptoms were completely relieved, and blood pressure was well-controlled.

LESSONS

The pathological association of hypertension and HDS should be highlighted, and microvascular decompression is an effective approach for relieving the hypertension.

New Onset Persistent Refractory Hypertension after Medulloblastoma Excision in Children-An Indicator of Poor Prognosis: A Case Series

Hypertension in the clinical setting of posterior fossa tumors is a known entity and occurs due to medullary compression by the tumor. Such hypertension usually responds to tumor excision. Postoperative hypertension occurring after posterior fossa tumor excision has been attributed to brain stem edema in a single report earlier, which resolved without any intervention. Here, we report two pediatric patients who developed new onset refractory, persistent postoperative hypertension after medulloblastoma excision, and discuss possible causes and the prognostic significance of this condition.