Trigeminal neuralgia in a patient with a dural arteriovenous fistula in Meckel's cave: case report

Dural arteriovenous fistula presenting as trigeminal neuralgia: Case report and literature review

Background

Trigeminal neuralgia (TN) secondary to a dural arteriovenous fistula (DAVF) is quite rare, and the goal of treatment is to resolve both the fistula and the pain.

Case presentation

We herein report a case of TN secondary to a DAVF in a 64-year-old woman with a 1-year history of right-sided TN. Brain magnetic resonance imaging and digital subtraction angiography showed a right tentorial DAVF. Interventional embolization was performed, but the pain was not relieved after the operation. Six months later, we performed microvascular decompression of the trigeminal nerve. During the operation, we electrocoagulated the tortuous and dilated malformed vein, which was compressing the trigeminal nerve, to reduce its diameter and mitigate the compression on the cisternal segment of the trigeminal nerve. That patient's pain was relieved postoperatively. In addition, we reviewed the literature of TN caused by DAVF and found a total of 30 cases, 22 of which were treated by interventional embolization. Of these 22 cases, the interventional embolization healed the fistula with pain relief in 14 cases and healed the fistula without pain relief in 8 cases. We found that the venous drainage methods of the 8 cases were all classified into the posterior mesencephalic group.

Conclusions

We believe that this drainage pattern contributes to the more common occurrence of unrelieved pain. For such patients, microvascular decompression can be performed with intraoperative coagulation to narrow the dilated veins until the cisternal segment of the trigeminal nerve is no longer compressed. Satisfactory curative effects can be obtained using this technique.

Investigating the Effects of Trigeminal Impression and Internal Acoustic Opening Morphology Differences for Possible Surgical Applications

PURPOSE

The exhaustive information regarding the types of trigeminal pore (TP) or trigeminal impression (TI), internal acoustic opening (IAO), and related surgical approaches is lacking in the literature. Therefore, this study is performed to further elucidate the types of TP or TI, IAO, and the relationships with critical surgical landmarks in the skull base.

METHODS

Trigeminal impression (TI) and internal acoustic opening (IAO) found in 11 dry skulls, 24 right temporal bones, and 25 left temporal bones were examined on both sides to define their relationship to each other and nearby structures. The age and sex of these bones were not identified. Besides these, 77 skulls were examined by radiologic imaging methods. These skulls were identified by gender.

RESULTS

According to test results, there was a significant difference between the left and right internal acoustic opening in the case of horizontal dimension (HD). The left HD-IAO is bigger than the right one. In addition, right HD-IAO, vertical dimension (VD) of right internal acoustic opening, left HD-IAO, and left VD-IAO values differed significantly in male and female patients.

CONCLUSIONS

Investigating the relationship of TI and IAO with relevant structures suggests that surgical approaches involving the TP and IAO indicated that surgical approaches considering the TI and IAO variations may be used in the development of surgical processes and primary surgical interventions.

Trigeminal neuralgia associated with dural arteriovenous fistula: a case report and literature reviews

Trigeminal neuralgia is a paroxysmal, intense electric shock-like, or knife-like, recurrent pain that affects one or more sense areas of the unilateral facial trigeminal nerve. It can be classified into two groups from an etiological standpoint: primary and secondary. The pain episodes brought on by such vascular compression are still categorized as primary trigeminal neuralgia, despite the fact that microvascular compression of the trigeminal nerve root has now been demonstrated to be the primary cause. A rare and complicated condition known as a dural arteriovenous fistula (DAVF) can irritate the Gasserian ganglion or compress the trigeminal nerve's root entry zone (REZ), leading to secondary trigeminal neuralgia (TN). At present, the treatment of DAVF-induced trigeminal neuralgia is not conclusive. This article reports a case of DAVF-induced trigeminal neuralgia cured by MVD and reviews the relevant literature.

Endovascular treatment of trigeminal neuralgia with cranial autonomic symptoms due to a right-sided petrous ridge dAVF

Dural arteriovenous fistula represents a rare cause of secondary Trigeminal Neuralgia. To date, there have been 18 reported cases of successful treatment of trigeminal neuralgia with endovascular embolization. Here we describe a unique case of a 51-year-old man with right-sided petrous ridge dural arteriovenous fistula causing ipsilateral V1 pain and cranial autonomic dysfunction. Cerebral angiography confirmed a Cognard type 3 right-sided tentorial dAVF supplied by an enlarged meningo-hypophpyseal vessel from the extradural ICA and by the middle meningeal artery. The fistula drains towards the midline via deep cerebral veins, the internal cerebral vein and the straight sinus with likely variceal compression of the right trigeminal nerve root entry zone. Transarterial Onyx embolization resulted in complete obliteration of the dural arteriovenous fistula with immediate resolution of facial pain and autonomic symptoms. After 24 months, the patient remains symptom-free and has no radiographic or clinical evidence of fistula recurrence. To date, there have been no other cases reported of trigeminal neuralgia with cranial autonomic symptoms or SUNCT syndrome due to a dural arteriovenous fistula. The presence of cranial autonomic symptoms with trigeminal neuralgia or a diagnosis of SUNCT should not deter endovascular treatments of dural arteriovenous fistulas or treatment of other compressive vascular lesions.

Trigeminal Neuralgia Caused by Dural Arteriovenous Fistula of the Transverse-Sigmoid Sinus without Vessel Compression at Root Entry Zone

Objective

The vessel compression at the root entry zone (REZ) of trigeminal nerve is a common cause of trigeminal neuralgia (TN). We report a rare case of TN caused by dural arteriovenous fistula (DAVF) of the transverse-sigmoid sinus without vessel compression at REZ.

Case Presentation

A 45-year-old woman presented with right side tinnitus and was diagnosed as a DAVF of the right transverse-sigmoid sinus (Borden Type I). After that, the facial pain in the right maxillary nerve area appeared and was getting worse. DSA revealed an enlargement of the artery of foramen rotundum (AFR) as one of the feeding arteries. MRI revealed no evidence of vascular compression at REZ. The patient was treated with transarterial embolization (TAE) with Onyx via the branches of the middle meningeal artery (MMA) and occipital artery (OA). The AFR decreased in size and the facial pain was improved. However, the DAVF and the facial pain were recurred. Finally, the DAVF was completely embolized with transvenous embolization (TVE). During 1-year follow-up period, the patient remained free of pain without recurrence.

Conclusion

The compression of the maxillary nerve by the AFR might result in TN, because the pain diminished after shrinkage of the AFR by the endovascular treatment.

Reappraisal of the types of trigeminal porus and importance in surgical applications

OBJECTIVE

The detailed information regarding the types of trigeminal porus (TP) and related surgical approach is lacking in the literature. Therefore, we performed this study to elucidate further the types of TP and the relationships with critical surgical landmarks in the skull base.

METHODS

The study was performed on 19 formalin-fixed cadavers of the cranial base (52.6% male, n = 10; 47.4% female, n = 9) on both sides. Calculations were made of the vertical dimension (VD), horizontal dimension (HD), and types of TP, the thickness of the TP, the HD and VD of the internal acoustic meatus, the distance between the TP-IAM, the thickness of the ossifying tissue that forms the TP, the trigeminal nerve (CN V) in both types and the distance between the CN V-VI.

RESULTS

The elliptical (42.1% left, 36.8% right), oval (52.6% left, 36.8% right) and slit-like (5.3% right) types of TP were detected (X² = 11.722). The HD of the TP was, on average, 8.02 mm (female) and 9.2 mm (male) on the right side, and 8.26 mm (female) and 8.81 mm (male) on the left side. The VD of the TP was, on average, 1.99 mm (female) and 2.65 mm (male) on the right side, and 2.42 mm (female) and 2.94 mm (male) on the left side.

CONCLUSIONS

In our study, ellipse and slit-like types of TP are taken into account in order to plan the surgical approaches to remove or prevent the extension of tumors. A combined surgical technique is recommended to reach the TP easily without damaging the nearby surgical structures during surgery. The oval type of TP allows a wide range of movements, so it is more advantageous in skull base surgery.

Three Cases of Trigeminal Neuralgia with Radiographic Absence of Meckel's Cave

Trigeminal neuralgia (TN) is a debilitating but treatable disease. Classic TN has referable vascular compression of the trigeminal nerve, but rarely secondary sources of anatomic compression will present, including vascular malformations, aneurysms, or tumors. Understanding the etiology of the patients' symptoms leads to targeted treatment. Three patients presented with symptoms consistent with TN: shooting, paroxysmal pains in the distribution of the trigeminal nerve. However, imaging revealed no vascular conflict at the root entry zone of the trigeminal nerve. Instead, on the affected side Meckel's cave was absent. No other compressive mass lesion was identified. In all three cases, patients were offered both Gamma Knife Radiosurgery and surgical decompression of Meckel's cave. All 3 patients elected to proceed with stereotactic radiation and reported improvement in pain. Many cases of classic TN can be explained by neurovascular conflict at the trigeminal root entry zone, but secondary sources of compression or restriction along the nerve can result in similar symptomology. In this case series, an absent or hypoplastic ipsilateral Meckel's cave may have produced symptoms consistent with TN. Imaging with fine cuts through Meckel's cave is an important diagnostic tool.

Ossification of the roof of the porus trigeminus with duplicated abducens nerve

Ossification of parts of the intracranial dura mater is common and is generally accepted as an age-related finding. Additionally, duplication of the abducens nerve along its course to the lateral rectus muscle is a known, although uncommon anatomical variant. During routine cadaveric dissection, an ossified portion of dura mater traveling over the trigeminal nerve's entrance (porus trigeminus) into the middle cranial fossa was observed unilaterally. Ipsilaterally, a duplicated abducens nerve was also observed, with a unique foramen superolateral to the entrance of Dorello's canal. To our knowledge, there has been no existing report of a simultaneous ossified roof of the porus trigeminus with an ipsilateral duplicated abducens nerve. Herein, we discuss this case and the potential clinical and surgical applications. We believe this case report will be informative for the skull base surgeon in the diagnosis of neuralgic pain in the frontomaxillary, andibular, orbital, and external and middle ear regions.

Rare Cervical Intramedullary Cavernous Angioma with Trigeminal Neuralgia and Cervical Itch: Case Report and Review of the Literature

INTRODUCTION

Intramedullary cavernous angioma (ICA) is a rare lesion of the spinal cord, representing only 3% - 5% of central nervous system lesions. The coexistence of trigeminal neuralgia and refractory itch is very rarely encountered in clinical practice. To our knowledge, a report of an ICA with trigeminal neuralgia and local neuropathic itch has never been published to date. Thus, we present a very interesting case of a C2 ICA.

CASE PRESENTATION

A 61-year-old female presented with right facial pain for three years, which was exacerbated by accompanying cervical pain and itch for one month. The patient's symptoms were relieved after surgery, and there was no recurrence of lesions one year later.

CONCLUSIONS

ICA with trigeminal neuralgia and local neuropathic itch is very rarely encountered in clinical practice. As it is not always diagnosed at first, some patients miss the best treatment period. Therefore, we call for emphasis to be placed on early diagnosis and timely surgical treatment.

Role of endovascular embolization for trigeminal neuralgia related to cerebral vascular malformation

OBJECTIVE

The objective of this article is to describe the trigeminal neuralgia related to cerebral vascular malformation that is rarely reported and the experience referring to endovascular treatment.

PATIENTS AND METHODS

A total of 10 patients who had cerebral vascular malformation (AVM and dAVF) in a single center presented with trigeminal neuralgia. Clinical and angiographic presentations as well as their clinical outcomes after embolization were reviewed.

RESULTS

Of the 10 cases, seven dAVFs and three AVMs were detected. In contrast to the dilated feeding arteries, an ectasia of the draining vein that is adjacent to the root entry zone of the trigeminal nerve such as the petrosal vein and lateral mesencephalic vein has the major role in causing the trigeminal neuralgia. All of these patients had relief of facial pain after endovascular embolization during follow-up (mean 57.3 months, range 5 to 100 months). There were no permanent neurological deficits.

CONCLUSIONS

Endovascular embolization is an effective method in treating trigeminal neuralgia related to cerebral vascular malformation.

Sacrificing the superior petrosal vein during microvascular decompression. Is it safe? Learning the hard way. Case report and review of literature

BACKGROUND

Venous infarction as a complication of microvascular decompression (MVD) is a recognized but extremely rare occurrence in an otherwise standard neurosurgical procedure. Sacrificing one or more veins is considered safe by majority of experienced surgeons and authors. However, in the recent years, there has been growing debate about the management of venous trigeminal compression and/or superior petrosal complex (separation vs. coagulation and cutting of the vein), with few papers describing mild to severe complications related to venous sacrifice.

CASE DESCRIPTION

We report our dramatic experience during re-exploration for MVD on a male who developed massive cerebellar, brainstem, and brain infarction. Extensive analysis of surgical planning and literature debate about this topic is also reported.

CONCLUSION

Despite rare, venous infarction after venous sacrifice in MVD is possible and can have catastrophic consequences. We would advise: (1) To try preserving the vein anytime this is possible, especially if it is large in size; (2) if it is decided to sacrifice the vein temporary occlusion while observing changed in the neurophysiology might be safer; (3) when planning an MVD for suspected venous compression, possible alternative forms of treatment should also be considered.

Cavernous Malformation in the Trigeminal Distribution: A Case Report of Aggressive Presentation and Management

BACKGROUND

Cavernous malformation (CM) is a vascular malformation found in the encephalic parenchyma, spinal cord, nerve roots, and extraneural tissue. CM in the trigeminal distribution is exquisitely uncommon and its biological behavior not completely understood. The clinical picture might be diverse, depending on the affected sector of the trigeminal architecture, and literature debating its pathobiology is scarce.

CASE DESCRIPTION

We describe a case of 56-year-old woman who presented with left trigeminal neuralgia and a rapidly growing cavernous malformation of the entire distribution of the fifth nerve. The clinical picture evolved to a progressive gait ataxia and follow-up neuroimaging showed a large intracranial mass leading to a brainstem compression. After microsurgical resection, the mass proved to be a typical CM of the trigeminal root.

CONCLUSION

We present an uncommonly aggressive progression of a CM of the trigeminal root, Gasserian ganglion, and cavernous sinus evolving to severe brainstem compression. The documentation of this unique case as well as its management is presented is discussed.

Remission of neurovascular conflicts in the cerebellopontine angle in interventional neuroradiology

Background and purpose

To investigate the efficacy of endovascular treatment (EVT) for neurovascular conflicts (NVCs) in the cerebellopontine angle (CPA) caused by intracranial aneurysms (IAs) and intracranial arteriovenous malformations (AVMs), including trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia.

Materials and methods

From January 2010 to January 2014, 14 consecutive patients presenting with three NVCs caused by IAs or intracranial AVMs were admitted to our department. The clinical outcomes of these NVCs after EVT were retrospectively analyzed.

Results

For four patients with IAs, angiographic follow-up confirmed total occlusion of the lesion in all, and the clinical outcomes of NVC were as follows: gradual relief in two (50%), transient partial relief but recurrence in one (25%), and no palliative effect in one (25%). For the 10 patients with intracranial AVMs, one (10%) experienced transient relief of NVC after angiogram examination (no EVT was performed). Of the other nine patients who received EVT, angiographic follow-up was obtained in seven (70%), demonstrating total obliteration of the lesion in three (30%), subtotal obliteration in two (20%), and partial obliteration in two (20%). Clinical outcomes included immediate relief of NVCs after single EVT in two cases (20%), gradual relief after single EVT in five (50%, one of them experienced transient aggravation), and complete relief after two sessions of EVT in two (20%). Complications of transient cranial nerve paresis related to EVT occurred in two cases (20%) with intracranial AVMs. In all, complete lasting relief of the NVCs was obtained finally in 11 cases (78.6%).

Conclusions

EVT is a feasible and less invasive approach for relief of NVCs in the CPA caused by IA or intracranial AVM and could be considered as a therapeutic option in these situations.

Tentorial dural arteriovenous fistula manifesting as contralateral trigeminal neuralgia: resolution after transarterial Onyx embolization

Tentorial dural arteriovenous fistula (DAVF) as a cause of trigeminal neuralgia is extremely rare. Although less than 10 cases have been reported in the literature, all cases presented with ipsilateral trigeminal neuralgia. Here we report a unique case of tentorial DAVF manifesting as contralateral trigeminal neuralgia. A 58-year-old man presented with right-sided trigeminal neuralgia. Cerebral angiography revealed a left tentorial DAVF and the MR imaging demonstrated a variceal venous dilatation occupying the left lateral pontine cistern and multiple venous flow voids adjacent to the right trigeminal nerve root entry zone. Transarterial Onyx embolization resulted in near complete obliteration of the fistula with immediate resolution of facial pain. The patient remains symptom free and without evidence of recurrence during 9 months of follow-up. Transarterial Onyx embolization may be an effective treatment modality for such an usual case.

Trigeminal Neuralgia Due to a Small Meckel's Cave Epidermoid Tumor: Surgery Using an Extradural Corridor

Tumors at the petrous apex are associated with a variety of symptoms, which most often involve the trigeminal nerve. The authors present a rare case of a small epidermoid tumor in Meckel's cave that caused medically refractory trigeminal neuralgia. The surgical challenge associated with approaches to such lesions is discussed. The skull base tumor was excised completely through a small temporal craniotomy. The practicality of neuronavigation in reaching the petrous apex using a small extradural window is presented.

Resolution of Trigeminal Neuralgia Following Cerebellar AVM Embolization With Onyx

Intracranial arteriovenous malformation (AVM) is a rare cause of trigeminal neuralgia (TN). Successful resolution of AVM-related TN following embolization surgery using Onyx has not been reported. In this case report, a posterior fossa AVM was embolized in two separate, staged endovascular surgeries using Onyx. The AVM was reduced in size, and the TN resolved. The patient subsequently underwent radiosurgery for the small, residual AVM, and he has maintained an uneventful follow-up. A thorough literature review was also performed for AVM-associated TN. Fifty-nine reports of AVM-related TN have been described to date, of which only three were treated with embosurgery. None of the prior two embosurgical reports utilized Onyx, and no AVM was obliterated with embosurgery alone. TN secondary to AVM can be resolved with embosurgery utilizing Onyx; however, complete elimination of the underlying AVM requires adjuvant surgery.

Complications related to percutaneous transarterial embolization of intracranial dural arteriovenous fistulas in 40 patients

BACKGROUND AND PURPOSE

An increasing number of intracranial dural arteriovenous fistulas (DAVFs) are amenable to endovascular treatment with Onyx. However, reports on complications caused by this technique have been limited. We present the initial Beijing Tiantan Hospital experience with adverse events related to transarterial Onyx embolization for DAVFs.

MATERIALS AND METHODS

Between September 2005 and February 2008, a total of 40 patients with DAVFs were treated at our institute with Onyx-18. There were 11 women and 29 men with a mean age of 43.15 years (age range, 23-60 years). We reviewed the clinical presentation, angiographic features, treatment, and outcome.

RESULTS

In 40 patients, total obliteration was achieved in 25 DAVFs (62.5%), with the remaining 15 patients not cured with residual shunts. Complications occurred in 9 patients, 5 DAVFs were located at tentorium, 2 were located at the transverse-sigmoid sinus, 1 was found at the inferior petrosal sinus, and 1 was found at the cavernous sinus, leading to permanent disability in 3 patients (morbidity, 7.5%). Complications included reflexive bradyarrhythmia in 3 (7.5%) patients, hemifacial hypoesthesia in 3 (7.5%) patients, hemifacial palsy in 2 (5%) patients, posterior fossa infarction in 2 (5%) patients, jaw pain in 1 (2.5%) patient, microcatheter gluing in 1 (2.5%) patient, hallucinations in 1 (2.5%) patient, and Onyx migration in 1 (2.5%) patient.

CONCLUSION

Although complete cure can be achieved by transarterial embolization with Onyx, the potential for serious complications exists with this procedure.

Results and complications of transarterial embolization of intracranial dural arteriovenous fistulas using Onyx-18

OBJECT

Use of the Onyx liquid embolic system has become an option for treating dural arteriovenous fistulas (DAVFs) because of its advantageous nonadhesive and cohesive properties. However, the complication rates associated with the use of this system have not been reported. The authors present their initial experience of the risks related to transarterial embolization using this system.

METHODS

Between February 2005 and February 2007, 31 patients with DAVFs were treated at Beijing Tiantan Hospital. Transarterial embolization using Onyx-18 was performed as a preoperative adjunct or as definitive therapy. The demographic characteristics, angiographic features, clinical presentation, treatment, and outcome of the patients were reviewed. Clinical follow-up status was supplemented by telephone interviews to determine Glasgow Outcome Scale scores.

RESULTS

In 19 patients (61.3%) there was complete angiographic evidence of elimination of the shunts and resolution of the symptoms. The remaining 12 patients were treated successfully but did not attain complete embolization and had residual shunting. Adverse events occurred in 5 of 31 patients, with 3 DAVFs located at the tentorium, 1 at the inferior petrosal sinus, and 1 at the cavernous sinus. Complications included trigeminocardiac reflex in 2 patients (6.5%), hemifacial hypesthesia in 3 patients (9.7%), hemifacial palsy in 2 patients (6.5%), jaw pain in 1 patient (3.2%), posterior fossa infarction in 1 patient (3.2%), and microcatheter gluing in 1 patient (3.2%). At the last follow-up examination, all patients had returned to an independent clinical status.

CONCLUSIONS

Although a complete resolution of symptoms can be achieved with transarterial embolization using the Onyx liquid embolic system, the potential for serious complications exists with this procedure, necessitating the participation of a skilled neurointerventionalist.

Dural arteriovenous fistula of the transverse-sigmoid sinus causing trigeminal neuralgia

The authors analysed an unusual case of dural arteriovenous fistula (DAVF) of the transverse-sigmoid sinus causing trigeminal neuralgia is presented. Although progression to almost continuous facial pain has been reported, symptoms may be indistinguishable from typical trigeminal neuralgia. The patient had a 6-year history of right-sided trigeminal neuralgia initially well controlled by medical management. He was referred for surgical management after 10 months of progressively worsening of symptoms. At the time of consultation, the patient complained of pulsatile tinnitus in the right ear. Computed tomography imaging and angiography demonstrated a DAVF involving the right transverse-sigmoid sinus junction with retrograde venous drainage. Surgical resection of the DAVF provided both angiographic cure and complete relief of all symptoms. The authors discuss the pathophysiology of trigeminal neuralgia in patients with a DAVF.

Dural arteriovenous malformation: an unusual cause of trigeminal neuralgia

Trigeminal neuralgia has been rarely reported in association with dural arteriovenous malformations (DAVMs). We describe a case of trigeminal neuralgia resulting from compression of the trigeminal nerve at its root entry zone by a large tentorial DAVM. Surgical interruption of the draining vein at its exit from the tentorium resulted in complete angiographic obliteration of the fistula with immediate resolution of the facial pain. We review the literature relevant to this topic and discuss the aetiology and pathophysiology of trigeminal neuralgia as well as the management of tentorial DAVMs.

Do leptomeningeal venous drainage and dysplastic venous dilation predict hemorrhage in dural arteriovenous fistula?

BACKGROUND

The objective of this study was to correlate the presence of leptomeningeal venous drainage and dysplastic venous dilation with the risk of intracranial hemorrhage in DAVFs.

METHODS

The subjects for this research were composed of 93 patients with DAVFs who were studied retrospectively with regard to therapeutic success and failure, who had undergone either neurosurgery or embolization or a combination of both methods, and whose disease was located in the cavernous sinus, the superior sagittal sinus, or the transverse-sigmoid sinus of the anterior fossa or of the tentorium. Also among these study subjects were patients who had had angiography done in at least 6 cranial vessels (external and internal carotid and vertebral arteries) before and after treatment and who had a minimum follow-up of 3 months. Cases of leptomeningeal venous drainage and dysplastic venous dilation and their associations with intracranial hemorrhage were ascertained for all the 93 case patients included in the study.

RESULTS

The presence of leptomeningeal drainage (P = .0002) and that of dysplastic venous dilation (P = .036) increased the risk of intracranial hemorrhage in case patients for DAVFs of the 5 regions.

CONCLUSION

There is a statistical significance between risk of intracranial hemorrhage in DAVFs and the presence of leptomeningeal drainage and dysplastic venous dilation.

Vertebrobasilar dolichoectasia as a cause of trigeminal neuralgia: the role of microvascular decompression. Case report

Our purpose is to report a case of trigeminal neuralgia caused by vertebrobasilar dolichoectasia treated with microvascular decompression. A 63-year-old man sought treatment for a recurrent lancinating left facial pain in V2 and V3 trigeminal territories. The computed tomography angiography revealed a mechanical compression of the left trigeminal nerve due to vertebrobasilar dolichoectasia. The patient was submitted to a left suboccipital craniotomy. Shredded Teflon® was introduced in the conflicting neurovascular area, achieving a satisfactory decompression. The patient’s pain resolved immediately. Vertebrobasilar dolichoectasia is a rare cause of trigeminal neuralgia and a successful outcome can be achieved with microvascular decompression.

Bony anomaly of Meckel's cave

This study describes the seemingly rare occurrence of bone formation within the proximal superior aspect of Meckel's cave thus forming a bony foramen for the proximal trigeminal nerve to traverse. The anatomy of Meckel's cave is reviewed and the clinical potential for nerve compression from this bony anomaly discussed.

Cavernous Malformation of the Trigeminal Nerve Manifesting with Trigeminal Neuralgia: Case Report

OBJECTIVE AND IMPORTANCE:

We describe a patient with a cavernous malformation within the trigeminal nerve at the nerve root entry zone who presented with trigeminal neuralgia.

CLINICAL PRESENTATION:

A 52-year-old woman sought treatment after experiencing dizziness and lancinating left facial pain for almost a year. Neurological examination revealed diminished sensation in the distribution of the trigeminal nerve on the left. Magnetic resonance imaging demonstrated a minimally enhancing lesion affecting the trigeminal nerve.

INTERVENTION:

The patient underwent a retrosigmoid craniotomy. At the nerve root entry zone, the trigeminal nerve was edematous with hemosiderin staining. The lesion, which was resected with microsurgical technique, had the appearance of a cavernous malformation on gross and histological examination. The patient's pain improved significantly after resection.

CONCLUSION:

Cavernous malformations can afflict the trigeminal nerve and cause trigeminal neuralgia. Microsurgical excision can be performed safely and is associated with improvement in symptoms.