Demonstration of neurovascular compression in trigeminal neuralgia and hemifacial spasm with magnetic resonance imaging: Comparison with surgical findings in 60 consecutive cases

doi:10.1016/S0090-3019(02)00993-X

Surgical Neurology

Volume 59, Issue 2, February 2003, Pages 93-99

https://doi.org/10.1016/S0090-3019(02)00993-X Get rights and content

Abstract

Background

Until recently, it has been impossible to demonstrate vascular compression at the root entry or exit zone (REZ) of the trigeminal nerve and facial nerve in patients with trigeminal neuralgia (TN) and hemifacial spasm (HFS) preoperatively, although surgical findings have revealed apparent neurovascular compression and its correction has resulted in a good outcome in most cases. Revealing the anatomic correlation between nerves and vessels at the REZ preoperatively would be useful to predict operative findings.

Methods

To assess whether the vascular contact of the nerve at the REZ could be demonstrated preoperatively, high-resolution magnetic resonance tomographic angiography (MRTA) was performed in 21 patients with TN and 39 with HFS. Neuroradiological findings were compared with the operative findings in all patients. Contralateral asymptomatic nerves were evaluated as a control.

Results

MRTA correctly identified offending vessels in 14 (67%) of the 21 TN and 34 (87%) of the 39 HFS patients. Failure to identify neurovascular contact was noted in the cases with compression by veins or small arteries, thickened arachnoid, or distal compression. Neurovascular contact was also observed in 15% of the asymptomatic nerves. The deformity of the nerve seemed to be a more important factor for determining operative indication.

Conclusions

MRTA could demonstrate offending vessels in TN and HFS at a high rate and was useful to predict operative findings. MRTA gave supportive evidence of surgical indications in patients with TN and HFS, although attention should be paid to the fact that MRTA did not necessarily detect all of the offending vessels.

Section snippets

Magnetic resonance tomographic angiography

All patients underwent MRTA preoperatively using a 1.5-Tesla MR scanner (Philips Gyroscan ACS-NT Power Truk 1000 Advanced) to evaluate the neurovascular relationship as a routine examination. Scanning parameters were repetition time (TR) of 24 msec, echo time (TE) of 4.9 msec, and flip angle of 22°. This technique generates slices of 0.9-mm thickness and 0.45-mm slice gap (over contiguous slices). It displays vessels as hyperintense structures, cerebrospinal fluid (CSF) as hypointense, and

Offending vessels on MRTA

Excluding the cases of motion artifact, satisfactory images were obtained in all 60 cases and evaluated. In the cases of TN, neurovascular contact at the REZ was revealed in 15 (71%) of the 21 symptomatic cases. On MRTA, the single superior cerebellar artery (SCA) alone was responsible in 13 cases (Figure 1A). A duplicated SCA and anterior inferior cerebellar artery (AICA) were seen to compress the trigeminal nerve in the other 2 cases. Vessels in contact with the nerves were not found on MRTA

Discussion

Recently, it has been accepted that the cause of TN or HFS is neurovascular compression at the REZ and surgical decompression results in good relief from the symptoms. Vascular compression was noted at operation in about 80 to 90% of cases 9, 16, 30. Until now, it has been difficult to determine neurovascular relationships preoperatively on CT, conventional MRI, or cerebral angiography. The fact that neurovascular compression is not recognized until the operation raises the question of whether

Conclusions

In TN and HFS cases, MRTA could reveal a neurovascular relationship and be useful for operative planning. Although operative indications should be based on clinical symptoms, vascular contact at the REZ on the symptomatic side provides support for operation. The combination of neurovascular compression and deformity of the affected nerve is a more convincing finding. There is a possibility that improper operative indications could be applied especially in cases of atypical symptoms, when

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Cited by (102)

Predictability of vascular conflict by MRI in trigeminal neuralgia
2019, Clinical Neurology and Neurosurgery
Citation Excerpt :
In our review, 6 of 69 patients were without conflict at the time of surgery, 3 of whom were accurately predicted by MRI (Table 1). As noted above, the absence of conflict at surgery in patients with classic TN and Type 1 TN is by no means rare and has been described in multiple other reports. [1,4,14,19–23] In the report by Maarbjerg et al, there was no vascular conflict identified in 15 patients (11%). [14]
Objective: Magnetic resonance imaging (MRI) has been investigated extensively in its success or failure to identify preoperative vascular compression in patients with trigeminal neuralgia (TN). To this end, we reviewed our case load to evaluate the concordance or discordance between preoperative MRI and intraoperative findings.
Patients and Methods: Sixty-nine patients with Type 1 TN and retrievable MRI images, operative reports, and intraoperative photographs were retrospectively reviewed.
Results: Our review shows that MRI predicted conflict (arterial or venous) in 58 cases that was confirmed at surgery in 55 cases. MRI predicted no conflict in 11 cases, whereas surgery revealed no conflict in a total of 6 cases. Thus, in predicting conflict at surgery, MRI had a sensitivity of 87%, and specificity of 50%, respectively. Conversely, MRI accurately predicted intraoperative conflict (positive predictive value) in 95% of cases, and the absence of conflict (negative predictive value) in 27%. These results reveal that MRI is more accurate in predicting conflict than the absence of conflict at surgery.
Conclusion: Our results support the reliance on the clinical diagnosis of Type 1 TN to recommend microvascular decompression (MVD). The presence of vascular compression by MRI should encourage the surgeon to persevere in search of the offending vessel when it proves elusive. MRI positive and negative predictive values for conflict are expected to increase with better resolution imaging. The absence of neurovascular conflict on high-resolution MRI should not negate MVD in the treatment of a patient with classic TN.
Veins of the Cerebellopontine Angle and Specific Complications of Sacrifice, with Special Emphasis on Microvascular Decompression Surgery. A Review
2018, World Neurosurgery
Good knowledge of the anatomy of veins is of crucial importance for the functional surgery of cranial nerve (CN) disorders, especially microvascular decompression for trigeminal neuralgia (TN), hemifacial spasm (HFS), and vagoglossopharyngeal neuralgia (VGPN). Although controversial, veins may be involved in neurovascular conflicts and may constitute dangerous obstacles to access to the CNs.
With the aim of estimating the implications of veins in those diseases and evaluating the linked surgical difficulties, we carried out a review of the literature from 2000 to the end of February 2018. For this review, articles found on PubMed that gave enough precision about veins were retained (39 articles on TN, 38 on HFS, 8 on VGPN, and 26 on complications related to venous sacrifices).
Before this review, we described a simplified anatomic classification of veins, amenable to easing the surgical approach to CNs. Access to the trigeminal nerve, via the infratentorial-supracerebellar route, is almost always affected by the superficial superior petrosal venous system, whereas access to the facial and cochleovestibular complex as well as to the lower CNs, through the infrafloccular trajectory, is almost always exempt of important venous obstacles.
Respective incidences of venous compression at the origin of hyperactive CN syndromes are given. The percentages of a venous conflict alone were calculated at 10.8% for TN, 0.1% for HFS, and 2.9% for VGPN. We review the complications considered in relation with venous sacrifices. Precautions to minimize these complications are given.
Imaging of hemifacial spasm
2018, Neurochirurgie
Almost all primary hemifacial spasms are associated with one or more neurovascular conflicts, most often at the root exit zone in the immediate vicinity of the brainstem. Imaging has first to exclude a secondary hemifacial spasm and secondly to search for and characterize the responsible neurovascular conflict(s). Magnetic resonance imaging should include high-resolution anatomical hyper T2-weighted sequences and magnetic resonance angiography by using 1.5 or even better 3 Tesla magnets. The most frequent vascular compressions are from the anterior-inferior cerebellar artery, the posterior-inferior cerebellar artery and the vertebrobasilar artery; venous conflicts are very rare. Conflicts are often multiple; also, the same vessel may compress the facial nerve in two places. Also, conflicts may be aided by particular anatomical circumstances, including arterial dolichoectasia, posterior fossa with a small volume or bony malformations.
Multimodal Image-Based Virtual Reality Presurgical Simulation and Evaluation for Trigeminal Neuralgia and Hemifacial Spasm
2018, World Neurosurgery
Citation Excerpt :
Therefore, a precise preoperative evaluation of the characteristics of NVC is not only crucial to the surgical planning and outcome of MVD surgery but also makes possible a shorter operation time. Although magnetic resonance imaging (MRI)-based evaluation methods have been routine for diagnosing TN and HFS, there are still various deficiencies of the relative tools or strategies reported in previous studies.9-18 For example, conventional two-dimensional structural MRI is insufficient to depict the neurovascular relationship in the CPA because of its poor resolution.19,20
To address the feasibility and predictive value of multimodal image-based virtual reality in detecting and assessing features of neurovascular confliction (NVC), particularly regarding the detection of offending vessels, degree of compression exerted on the nerve root, in patients who underwent microvascular decompression for nonlesional trigeminal neuralgia and hemifacial spasm (HFS).
This prospective study includes 42 consecutive patients who underwent microvascular decompression for classic primary trigeminal neuralgia or HFS. All patients underwent preoperative 1.5-T magnetic resonance imaging (MRI) with T2-weighted three-dimensional (3D) sampling perfection with application-optimized contrasts by using different flip angle evolutions, 3D time-of-flight magnetic resonance angiography, and 3D T1-weighted gadolinium-enhanced sequences in combination, whereas 2 patients underwent extra experimental preoperative 7.0-T MRI scans with the same imaging protocol. Multimodal MRIs were then coregistered with open-source software 3D Slicer, followed by 3D image reconstruction to generate virtual reality (VR) images for detection of possible NVC in the cerebellopontine angle. Evaluations were performed by 2 reviewers and compared with the intraoperative findings.
For detection of NVC, multimodal image-based VR sensitivity was 97.6% (40/41) and specificity was 100% (1/1). Compared with the intraoperative findings, the κ coefficients for predicting the offending vessel and the degree of compression were >0.75 (P < 0.001). The 7.0-T scans have a clearer view of vessels in the cerebellopontine angle, which may have significant impact on detection of small-caliber offending vessels with relatively slow flow speed in cases of HFS.
Multimodal image-based VR using 3D sampling perfection with application-optimized contrasts by using different flip angle evolutions in combination with 3D time-of-flight magnetic resonance angiography sequences proved to be reliable in detecting NVC and in predicting the degree of root compression. The VR image-based simulation correlated well with the real surgical view.
Microvascular decompression for hemifacial spasm: Outcome on spasm and complications. A review
2018, Neurochirurgie
Over the last decades microvascular decompression (MVD) has been established as the curative treatment of the primary Hemifacial Spasm (HFS), proven to be linked in almost all cases to a neurovascular compression of the facial nerve. Because the disease is not life-threatening and MVD not totally innocuous, efficacy and safety have to be weighted before decision taken of indicating surgery. The authors have been charged by the French Speaking Society of Neurosurgery to conduct a detailed evaluation of the probability of relief of the spasm that MVD is able to obtain, together with its potential complications. For the review, the authors have gone through the reports available from the Pubmed system. Eighty-two publications have been read and analysed, totalizing more than 10,000 operated cases. In most series, the percentage of patients with total relief ranged between 85% and 90%. Relief was obtained after a certain delay in as many as in 33% ± 8% of the patients in many series. For those, delay lasted around one year in 12% of them. When effect of MVD was considered achieved, relief remained permanent in all but 1%–2% of the long-term followed patients. As regards to complications, risk of permanent cranial nerve deficit was evaluated at 1%–2% for facial palsy, 2%–3% for non-functional hearing loss, 0.5%–1% for lower cranial nerve dysfunction. Risk of stroke was at 0.1% and mortality at 0.1%. CSF leakage and related complications could be reduced at less than 2% in most series provided careful closing techniques be applied. Complications were at a higher rate in repeated MVD. MVD is an effective curative method for almost all the patients affected with primary HFS. Because MVD for HFS is functional surgery, scrupulous consideration of its potential risks, together with the ways to avoid complications are of paramount importance. When MVD is estimated to have failed, it is wise to wait one year before considering to repeat surgery, as number of patients may benefit from delayed effect. This is the more so as important as repeated surgery entails a higher rate of complications.
Improved Microvascular Decompression in Treating Trigeminal Neuralgia: Application of Nest-Shaped Teflon Fibers
2018, World Neurosurgery
Citation Excerpt :
Patients meeting the following inclusion criteria were included: a definite TN diagnosis made according to the American Academy of Neurology and the European Federation of Neurological Societies guidelines.7 Magnetic resonance imaging and 3-dimensional time-of-flight magnetic resonance angiography examination were conducted to exclude TN secondary to cyst or tumor and to detect the possible offending vessel(s).8 The present study was approved by the Ethics Committee of the People's Hospital of Rizhao.
To develop an improved technique for microvascular decompression (MVD) surgery using nest-shaped Teflon fibers.
Eighteen consecutive patients with trigeminal neuralgia (TN) who underwent MVD using nest-shaped Teflon fibers between January 2012 and December 2013 were included in this investigation. During the surgery, the Teflon prosthesis was formed into a nest shape by gently pushing it from the center toward the periphery. Immediate postoperative outcomes were evaluated using a numerical rating scale score, and patients were followed up for recurrence.
Immediately after the surgery, pain was completely relieved in 16 patients (88.9%) and partially relieved in 2 patients (11.1%). Seven patients (38.9%) developed postoperative complications. All complications were successfully mitigated before discharge. The patients were followed up for 2.0–3.4 years. During follow-up, recurrence was observed in 2 patients (11.1%). No Teflon adhesion or Teflon-induced granuloma was found.
The nest-shaped Teflon fibers in MVD surgery for TN is safe and applicable. The long-term outcomes and the comparison between hollow nest-shaped implants and the standard cigar-shaped implants should be assessed in future investigations with larger sample sizes.

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EndovascularDemonstration of neurovascular compression in trigeminal neuralgia and hemifacial spasm with magnetic resonance imaging: Comparison with surgical findings in 60 consecutive cases

Abstract

Background

Methods

Results

Conclusions

Section snippets

Magnetic resonance tomographic angiography

Offending vessels on MRTA

Discussion

Conclusions

Am J Surg

Surg Neurol

Hemifacial spasmevaluation by magnetic resonance imaging and magnetic resonance tomographic angiography

Ann Neurol

Long-term outcome after operation for trigeminal neuralgia in patients with posterior fossa tumors

J Neurosurg

Hemifacial spasm resulting from facial nerve compression near the internal acoustic meatus

Neurol Med Chir (Tokyo)

MRI of intracranial neurovascular compression

J Comput Assist Tomogr

Response of trigeminal neuralgia to “decompression” of sensory rootdiscussion of cause of trigeminal neuralgia

JAMA

Trigeminal neuralgia in patients with multiple sclerosislesion localization with magnetic resonance imaging

Neurology

Microvascular relations of the trigeminal nerve

J Neurosurg

Neurovascular compression in trigeminal neuralgiaa clinical and anatomical study

J Neurosurg

Microsurgical relationships of the superior cerebellar artery and trigeminal nerve

J Neurosurg

Three-dimensional-MRI of neurovascular compression in patients with hemifacial spasm

Neuroradiology

Trigeminal neuralgia (tic douloureux)MR imaging assessment

Radiology

Microsurgical management of trigeminal neuralgia

Arch Neurol

Posterior fossa neurovascular compression syndromes other than neuralgias

Endovascular
Demonstration of neurovascular compression in trigeminal neuralgia and hemifacial spasm with magnetic resonance imaging: Comparison with surgical findings in 60 consecutive cases