Trigeminal neuralgia caused by microarteriovenous malformations of the trigeminal nerve root entry zone: symptomatic relief following complete excision of the lesion with nerve root preservation

Trigeminal neuralgia secondary to arteriovenous malformation in the brainstem: a case report and a brief review

Trigeminal neuralgia, a condition characterized by high intensity, paroxysmal and unilateral pain, can be characterized as secondary when associated with conditions such as multiple sclerosis and tumors. However, among these secondary cases, there are also arteriovenous malformations, characterized by a nidus mass of vessels separated by parts of sclerotic tissues, responsible for a small portion of the neuralgias of the trigeminal nerve. The case report described is of a 54-year-old male patient who has a brainstem AVM and refers to lancing and paroxysmal pain in the right hemiface in the territories of V2 and V3 after feeding and brushing the teeth. The treatment of this patient was done from the insertion of a balloon from the foramen ovale, accessed by the Meckel fossa and the trigeminal ganglion. The literature review demonstrated, from the analysis of gender, age, vascularization, localization and treatments of reports of TGN secondary to brainstem AVM, the reduced number of cases described.

Arteriovenous malformation of the trigeminal nerve root presented with venous congestive edema of the medulla oblongata and upper cervical cord: illustrative case

BACKGROUND

Arteriovenous malformation (AVM) of the trigeminal nerve root (TNR) is a rare subtype of the lateral pontine AVM. Most of them are diagnosed when they bleed or exert trigeminal neuralgia. Venous congestive edema is a rare phenomenon caused by TNR AVMs.

OBSERVATIONS

An 82-year-old man was admitted with progressive limb weakness and dysphasia. Magnetic resonance imaging (MRI) revealed extensive edema of the medulla oblongata and the upper cervical cord with signal flow void at the C3 anterior spinal cord. Vertebral angiography revealed a small nidus fed mainly by the pontine perforating arteries (PPAs). The anterior pontomesencephalic vein (AMPV) was dilated, functioning as the main drainage route. This suggests that venous hypertension triggered the brainstem and upper cervical cord edema. MRI with gadolinium enhancement showed that the nidus was located around the right TNR. Because the nidus sat extrinsically on the pial surface of the right TNR’s base, microsurgical obliteration with minimum parenchymal injury was achieved. Postoperative MRI showed disappearance of the brainstem and cervical cord edema with improved clinical symptoms.

LESSONS

TNR AVM is rarely associated with brainstem and upper cervical cord edema caused by venous hypertension of the congestive drainage system.

Trigeminal Neuralgia from an Arteriovenous Malformation of the Trigeminal Root Entry Zone with a Flow-Related Feeding Artery Aneurysm: The Role of a Combined Endovascular and "Tailored" Surgical Treatment

Idiopathic trigeminal neuralgia (TN) due to an embedded arteriovenous malformation (AVM) on the trigeminal root entry zone (REZ) is rare but a potentially challenging condition to manage. Herein, we report such a case with an additional unruptured aneurysm on the feeding artery and highlight the role of a multimodality approach to their management. A 50-year-old female presented with drug-resistant right-sided trigeminal neuralgia for one year. The magnetic resonance imaging (MRI) suggested a possibility of AVM, the angiographic study showed an AVM nidus with feeders from the right anterior inferior cerebellar artery (AICA) and a dilated right intrinsic pontine artery, the latter showing a flow-related aneurysm towards its brainstem end. The flow-related aneurysm, as well as the dilated intrinsic pontine artery feeder, was embolized at first. During surgery, the AVM was found embedded inside the root entry zone. Parts of the AVM and its draining vein were partially coagulated followed by microvascular decompression of the AICA loop as well as a feeder emanating from it following which the patient recovered completely. She subsequently received gamma knife surgery (GKS) for the residual AVM and remained asymptomatic after 3.5 years of GKS. AVM-related TN are rare, and the additional presence of a feeding artery aneurysm increases the management complexity. Endovascular management of the aneurysm followed by microvascular decompression (MVD) and tailored AVM coagulation represent a prompt and effective means of pain control. Subsequent GKS is necessary to obliterate the AVM nidus.

Multimodal management of ruptured cerebral micro-arteriovenous malformations: A retrospective series of 19 cases and a review of the literature

BACKGROUND

Micro-arteriovenous malformations (micro-AVMs) are defined as AVMs just visible on angiography with a nidus size between 0.5 and 1cm. Their principal manifestation is intracranial hemorrhage and their diagnosis and therapeutic management are still unclear.

METHODS

The aim of our work was to show the clinical presentation, treatment and outcome of ruptured cerebral micro-AVMs in a retrospective cohort study of 19 patients and a systematic review of the literature.

RESULTS

We obtained a total of 20 micro-AVMs in 19 patients. The mean age was 47.3 years. Clinical presentation was acute bleeding. The mean volume of hematoma was 12.9 mm³ (0 - 60.4), with topographic distribution as follows: 64% cortical with supratentorial bleeding, 26% deep, and 10% in the posterior fossa. Among the 20 micro-AVMs of the series, 11 (55%) had endovascular management, 6 (30%) had surgical treatment and 3 (15%) had GK radiosurgery alone. All of our patients have been cured at the end of the follow up without re-permeabilization. In our series, clinical outcome showed good recovery with a mean score of 4.6 on Glasgow Outcome Scale (GOS). In the literature, 88% of patients had a GOS of 4 or 5.

DISCUSSION

Intracerebral hematoma (ICH) was the main clinical manifestation. In the case of negative initial angiographic assessment, patients must have supraselective angiographic exploration. In the case of conservative treatment of hematoma, endovascular obliteration and microsurgical exclusion seems to be reasonable therapeutic options, according to our observations.

P2X receptors and trigeminal neuralgia

There is currently no effective cure for trigeminal neuralgia (TN) - a relatively common disease that causes long-term pain in patients. Previous research has shown that ionotropic ATP signaling through excitatory and calcium-permeable P2X receptor channels plays a critical role in pathological pain generation and maintenance. In this paper, we review several hypotheses on the pathogenic mechanisms underlying TN. We further discuss pathways or agents that can target P2X expression in TN, thereby affecting pain induction and maintenance.

Right Retrosigmoid Approach for In Situ Occlusion of Brainstem Arteriovenous Malformation Surrounding the Trigeminal Nerve: 3-Dimensional Operative Video

Arteriovenous malformations (AVMs) of the trigeminal root entry zone are rare and can be associated with neurovascular compression syndromes as well as intracranial hemorrhage.1 They generally have a small nidus located on and around the pial surface of the brainstem; thus, they are feasible for surgery. Nevertheless, they represent a challenge given the vicinity and involvement of cranial nerves and brainstem perforators.2-4This video demonstrates the case of a 57-yr-old man with new onset of a severe headache without neurological deficit associated with MRI evidence of a vascular malformation around the cisternal right trigeminal nerve. The nerve showed an altered signal on the MRI. Angiography revealed a Spetzler-Martin grade II AVM with a 16-mm nidus supplied by basilar artery perforators, right anterior inferior cerebellar artery, and the superior cerebellar artery (SCA), with drainage into the superior petrosal vein and sigmoid sinus. After an unsuccessful attempted embolization, the patient was referred for and elected microsurgical treatment. With the patient in a lateral position, a right retrosigmoid approach was performed. After cisternal dissection and identification of the nidus, the feeders were occluded by alternating cauterization and clipping to avoid damage to the critical surrounding structures. The AVM in-situ occlusion was carried on without resection, given the involvement of the trigeminal nerve. The intraoperative indocyanine green angiography allowed recognition of the venous drainage and helped to localize and differentiate the feeders from normal perforators. In the immediate postoperative course, the patient suffered from mild numbness with a V2-V3 distribution that progressively improved. Angiography showed no residual AVM.

Trigeminal neuralgia caused by a dilated superior cerebellar artery and a draining vein of cerebellar arteriovenous malformations: a case report and review of the literature

Trigeminal neuralgia (TN) secondary to arterivenous malformations (AVMs) is relatively rare. We here report on a case of TN caused by cerebellar AVMs that was successfully treated by total AVMs resection in conjunction with microvasecular decompression (MVD) in one stage. In addition, we perform a review of the literature about the treatment of TN caused by cerebellar AVMs.

Embolization of ruptured arteriovenous malformations in the cerebellopontine angle cistern

Among brainstem arteriovenous malformations (AVMs), there exist small AVMs predominantly located in the cerebellopontine angle cistern (CPAC) with minimal extension into the pial surface of the brainstem. However, previous studies of CPAC AVMs did not particularly discuss the role of embolization in the treatment of these lesions. This study was conducted to clarify the effectiveness and validity of embolization in the treatment of CPAC AVMs. We retrospectively reviewed five patients with CPAC AVMs who underwent endovascular treatment. These patients were treated with embolization followed by open surgery or gamma knife (GK) radiosurgery. Radiological findings and clinical course for these patients were then assessed. All five patients presented with a hemorrhage. Angiography revealed that the main feeder contained a dilated pontine perforating artery in all cases. Embolization through the dilated pontine perforating artery effectively reduced shunt flow within the nidus or obliterated associated aneurysms. Magnetic resonance imaging showed infarction on the lateral pons in four patients, one of which developed transient mild dizziness and mild ataxia of the right side. Subsequent open surgery was performed in three patients, and GK radiosurgery was performed in two patients without complications. At the end of the follow-up period, all patients demonstrated favorable outcomes. Postoperative rebleeding did not occur in any of the patients. Disappearance of the AVM was confirmed in four patients, except in the one patient treated with GK. Although ischemic complications should be noted, embolization of CPAC AVMs may be an appropriate treatment option to reduce the risk of subsequent surgery or radiosurgery.

Trigeminal Neuralgia Due to Red Vein Draining a Supratentorial Arteriovenous Malformation: Case Report

Trigeminal neuralgia (TGN) is rarely caused by arteriovenous malformation (AVM). The AVMs causing TGN are reported mostly in the ipsilateral posterior fossa. The culprit vessels are dilated feeding artery or nidus itself. We present a rare case of TGN caused by dilated draining veins from a supratentorial AVM. The patient suffered from TGN with an incidentally found large AVM, which had been left untreated. The neuralgia was successfully relieved by microvascular decompression. Dilated red veins compressed the nerve at the root entry zone and distant cisternal portion of the nerve. Technically, transposition is not practical for fragile, dilated red veins with high pressure. Interposition is safer method in this case.

Trigeminal neuralgia caused by brain arteriovenous malformations: A case report and literature review

Few cases of trigeminal neuralgia (TGN) induced by brain arteriovenous malformations (bAVMs) have previously been reported. The present case report described one case of TGN caused by bAVMs in a 32-year-old male patient who suffered from recurrent pain in his right cheek for a period of two years, for whom the seizure frequency and duration of pain increased for 6 months. Magnetic resonance imaging was performed, which demonstrated flow-void signals in the abnormal vessels in the right cerebellopontine angle. Subsequent digital subtraction angiography confirmed the diagnosis of bAVMs, and showed the nidus was fed by the right superior cerebellar and the right anterior inferior cerebellar, and drained into the adjacent venous sinuses on the same side. The patient underwent an interventional embolization treatment. TGN was completely relieved following embolization of the majority of the bAVMs. Pain relief may be associated with blocking of the pulsatile compression of the feeding arteries of the bAVMs, the arterialized draining veins or the malformed niduses following embolization, which is similar to the effects induced by microvascular decompression surgery of the trigeminal nerve. In the present case study and review, the underlying mechanism and treatment strategy of TGN caused by bAVMs were discussed in the context of present case, and a literature review was carried out.

Clinical characteristics of arteriovenous malformations in the cerebellopontine angle cistern

OBJECTIVE Arteriovenous malformations (AVMs) in the cerebellopontine angle cistern (CPAC) are specific lesions that can cause neurovascular compression syndromes as well as intracranial hemorrhage. Although case reports describing the CPAC AVMs, especially those presenting with trigeminal neuralgia (TN), have been accumulating by degrees, the pathophysiology of CPAC AVMs remains obscure. The authors' purpose in the present study was to evaluate the clinical and radiographic features of CPAC AVMs as well as the treatment options. METHODS This study defined a CPAC AVM as a small AVM predominantly located in the CPAC with minimal extension into the pial surface of the brainstem and closely associated with cranial nerves. All patients with CPAC AVMs treated in the authors' affiliated hospitals over a 16-year period were retrospectively identified. Clinical charts, imaging studies, and treatment options were evaluated. RESULTS Ten patients (6 men and 4 women), ranging in age from 56 to 77 years (mean 65.6 years), were diagnosed with CPAC AVMs according to the authors' definition. Six patients presented with hemorrhage, 3 with TN, and the remaining patient developed a hemorrhage subsequent to TN. Seven AVMs were associated with the trigeminal nerve (Group V), and 3 with the facial-vestibulocochlear nerve complex (Group VII-VIII). All patients in Group VII-VIII presented with the hemorrhage instead of hemifacial spasm. Regarding angioarchitecture, the intrinsic pontine arteries provided the blood supply for all CPAC AVMs in Group V. In addition, 5 of 7 AVMs with hemorrhagic episodes accompanied flow-related aneurysms, although no aneurysm was detected in patients with TN alone. With respect to treatment, all patients with hemorrhagic presentation underwent Gamma Knife surgery (GKS), resulting in favorable outcomes except for 1 patient who experienced rebleeding after GKS, which was caused by the repeated rupture of a feeder aneurysm. The AVMs causing TN were managed with surgery, GKS, or a combination, according to the nidus-nerve relationship. All patients eventually obtained pain relief. CONCLUSIONS Clinical symptoms caused by CPAC AVMs occur at an older age compared with AVMs in other locations; CPAC AVMs also have distinctive angioarchitectures according to their location in the CPAC. Although GKS is likely to be an effective treatment option for the CPAC AVMs with hemorrhagic presentations, it seems ideal to obliterate the flow-related aneurysms before performing GKS, although this is frequently challenging. For CPAC AVMs with TN, it is important to evaluate the nidus-nerve relationship before treatment, and GKS is especially useful for patients who do not require urgent pain relief.

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.

Arteriovenous malformation of the vestibulocochlear nerve

We describe a rare case of an arteriovenous malformation (AVM) embedded in the vestibulocochlear nerve presenting with subarachnoid hemorrhage (SAH) treated by microsurgical elimination of the main feeding artery and partial nidus volume reduction with no permanent deficits. This 70-year-old woman was incidentally diagnosed 4 years previously with two small unruptured tandem aneurysms (ANs) on the right anterior inferior cerebral artery feeding a small right cerebellopontine angle AVM. The patient was followed conservatively until she developed sudden headache, nausea and vomiting and presented to our outpatient clinic after several days. Magnetic resonance imaging demonstrated findings suggestive of early subacute SAH in the quadrigeminal cistern. A microsurgical flow reduction technique via clipping between the two ANs and partial electrocoagulation of the nidus buried within the eighth cranial nerve provided radiographical devascularization of the ANs with residual AVM shunt flow and no major deficits during the 2.5 year follow-up. This is only the second report of an auditory nerve AVM. In the event of recurrence, reoperation or application of alternative therapies may be considered.

Trigeminal neuralgia from an Arteriovenous malformation: An intra-operative diagnosis

We report the case of a 72-year-old lady with a magnetic resonance imaging (MRI) occult arteriovenous malformation (AVM) causing trigeminal neuralgia (TN). The possibility of an AVM when managing patients with TN should be borne in mind. Where possible, decompression of the trigeminal nerve should be attempted, as first-line therapy.

Trigeminal neuralgia caused by nerve compression by dilated superior cerebellar artery associated with cerebellar arteriovenous malformation: case report

Intracranial arteriovenous malformation (AVM) is a rare cause of trigeminal neuralgia (TGN). In this presented case, successful resolution of AVM-related TGN following embolization and gamma knife radiosurgery (GKRS) was obtained. A patient suffered from TGN on the left side, which was thought to be caused by root entry zone compression by dilated superior cerebellar artery (SCA) associated with cerebellar AVM. The cerebellar vermis AVM was embolized in endovascular surgery. The AVM was reduced in size and TGN was partially relieved. The patient subsequently underwent GKRS for the residual nidus. TGN was completely resolved within one year and a half. GKRS following embolization of the nidus improved the flow-related dilation of the SCA and completely relieved TGN.

Intrinsic arteriovenous malformation embedded in the trigeminal nerve of a patient with trigeminal neuralgia

A 66-year-old man presented with typical right trigeminal neuralgia. Neuroimaging showed a small arteriovenous malformation (AVM) in the right cerebellopontine angle. Suboccipital craniotomy verified that the AVM was almost completely embedded in the root entry zone of the trigeminal nerve and the nerve axis was tilted infero-posteriorly. The patient obtained complete pain relief without sequelae after surgery by transposition of the superior cerebellar artery and correction of the tilted nerve axis. The nidus of the unresected AVM was obliterated by gamma knife radiosurgery.

Aetiology and pathogenesis of trigeminal neuralgia: a comprehensive review

Objectives

The aim of present paper was to discuss issues related to trigeminal neuralgia with strong emphasis on the aetiology and pathogenesis of this problem.

Material and Methods

An electronic search of 5 databases (1965 - Oct 2012) and a hand search of peer-reviewed journals for relevant articles were performed. In addition, experience acquired from treating 3263 patients in the Department of Maxillofacial Surgery, Lithuanian University of Health Sciences, were also summarized.

Results

Generally, aetiological factors can be classified into 3 most popular theories that were based on: 1) Related to other disease, 2) Direct injury to the trigeminal nerve, and 3) Propagates the polyetiologic origin of the disease. In addition, two pathogenesis mechanisms of trigeminal neuralgia were proposed. First: the peripheral pathogenetic mechanism that is often induced by progressive dystrophy around the peripheral branches of the trigeminal nerve. Second, central pathogenetic mechanism which often triggered by peripheral pathogen that causes long-lasting afferent impulsation and the formation of a stable pathologic paroxysmal type irritation focus on the central nerve system (CNS).

Conclusions

Patients with susceptive trigeminal neuralgia should be examined carefully by specialists who have expertise in assessing and diagnosing of possible pathological processes and be able to eliminate the contributing factors so the trigeminal neuralgia can be properly managed.

Arteriovenous micromalformation of the trigeminal root: intraoperative diagnosis with indocyanine green videoangiography: case report

BACKGROUND AND IMPORTANCE

To report on a single case of arteriovenous micromalformation (micro-AVM) of the trigeminal root that was diagnosed during microvascular decompression for trigeminal neuralgia with the use of indocyanine green (ICG) videoangiography.

CLINICAL PRESENTATION

A 52-year-old woman with drug-resistant trigeminal neuralgia underwent a key hole suboccipital cerebellopontine angle exploration after the usual magnetic resonance imaging (MRI) screening had raised the suspicion of a vascular compression. In surgery, the petrosal vein was found to be bigger than usual and arterialized; the trigeminal root was embedded in a tangle of abnormal arterialized vessels. Intraoperative ICG videoangiography showed that the direction of flow in the arterialized petrosal vein was anterograde, thus allowing for the differential diagnosis between micro-AVM and tentorial dural fistula. It was possible to achieve only a partial nerve decompression because of the intimate relationship between the trigeminal root and the pathological vessels. Postoperative angiography and MRI with contrast administration confirmed the intraoperative diagnosis of micro-AVM. The patient was discharged neurologically intact on postoperative day 4. One month after surgery, she remains pain-free despite a 50% reduction in antiepileptic drugs.

CONCLUSION

Surgeons performing microvascular decompression should be aware that a diagnosis of vascular compression based on MRI without contrast administration could not exclude the presence of a pontine micro-AVM. ICG videoangiography provides an elegant means of showing the flow dynamics of these pathological vessels. An MRI protocol that is suitable to avoid this kind of intraoperative drawback should be defined and systematically used in the preoperative evaluation of all such surgical candidates.

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.

Quadruple vessel involvement at root entry zone in trigeminal neuralgia

The author describes a rare case of trigeminal neuralgia where four major named vessels of the posterior circulation were detected to be in close approximation to the trigeminal nerve. The quadruple vessel compression included a tortuous dilated basilar trunk, ipsilateral anterior inferior cerebellar artery, a superior cerebellar artery and superior petrosal vein. All vessels were related to the root entry zone of the nerve. Significance of such a multiple vessel neuovascular conflict at the root entry zone is discussed, highlighting technical implications during surgical management and its prognostic relevance.

Trigeminal neuralgia secondary to arteriovenous malformations of the posterior fossa

BACKGROUND

Trigeminal neuralgia secondary to a posterior fossa AVM has been seldom reported in the literature. Most of the cases have been published on a case report basis, and there is not a general agreement about the best way of treatment.

METHODS

In this work, we analyze our experience with 5 cases of TN secondary to a posterior fossa AVM, treated at the Division of Neurosurgery from the National Institute of Neurology and Neurosurgery, "Manuel Velasco Suarez," Mexico City, Mexico, from January 1985 to December 2004.

RESULTS

Trigeminal neuralgia associated with an AVM occurred in 1.3% of 375 brain AVMs and 9.8% of 37 posterior fossa AVMs. All had received drug therapy unsuccessfully, and 2 of them underwent a percutaneous thermocoagulation without solving the neuralgia. In 4 patients, a microvascular decompression was completed with excellent results.

CONCLUSIONS

Even when different ways of treatment have been reported, it seems that percutaneous procedures (glycerol injection, thermocoagulation, or microcompression of the gasserian ganglia) give variable clinical results. The reported experience and our own results support the microvascular decompression of the trigeminal nerve as the best treatment whenever the total excision of the AVM cannot be accomplished.

Ruptured Arteriovenous Malformation in the Auditory Nerve: Technical Case Report

OBJECTIVE AND IMPORTANCE:

Arteriovenous malformations in the cranial nerves are very rare, and only one case has been reported in the literature. To our knowledge, this is the first case report of an arteriovenous malformation in the auditory nerve.

CLINICAL PRESENTATION:

A 30-year-old woman presented with a subarachnoid hemorrhage resulting from rupture of an arteriovenous malformation in the auditory nerve.

INTERVENTION:

During the operation, the auditory nerve bundle was found to be severely damaged and a nidus was identified inside the bundle.

CONCLUSION:

Although arteriovenous malformations are thought to arise in the 4th to 8th weeks of gestation, this case might indicate a more specific time of emergence based on embryogenesis of the cranial nerves.

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.

Intrinsic Arteriovenous Malformation of the Trigeminal Nerve in a Patient with Trigeminal Neuralgia: Case Report

OBJECTIVE AND IMPORTANCE:

Intrinsic arteriovenous malformation (AVM) of the trigeminal nerve is extremely uncommon and may be associated with trigeminal neuralgia.

CLINICAL PRESENTATION:

A 55-year-old man experienced severe lightning pain in the second and third divisions of the left trigeminal nerve territory. Vertebral angiography demonstrated an AVM fed by the superior cerebellar artery. Magnetic resonance imaging with three-dimensional spoiled gradient recalled acquisition at steady state revealed an AVM intrinsic to the left trigeminal nerve and a small arterial loop causing compression at the root entry zone of the trigeminal nerve.

INTERVENTION:

Intraoperative inspection revealed an indentation of the root entry zone caused by a small arterial loop but not by the AVM. The offending artery was displaced to decompress the root entry zone using a prosthesis without resection of the AVM. The patient was relieved of the neuralgia immediately after surgery without further neurological deficit. He has been free of trigeminal neuralgia during a follow-up period of 2 years and is scheduled to undergo stereotactic radiosurgery for the treatment of the AVM.

CONCLUSION:

Intrinsic AVM of the trigeminal nerve may cause trigeminal neuralgia. However, as in the present case, a coexistent vascular lesion rather than the intrinsic AVM could be a cause of the neuralgia.

Arteriovenous malformation surrounding the trigeminal nerve--case report

A 57-year-old man presented with subarachnoid hemorrhage due to the rupture of an arteriovenous malformation (AVM) located at the base of the root of the right trigeminal nerve. In contrast to previous similar cases, his history included no evidence of trigeminal neuralgia or sensory loss. Right vertebral artery angiography revealed a doubled superior cerebellar artery feeding the angioma nidus. The patient refused radiotherapy and preferred surgical treatment. Intraoperatively, a close relationship between arterial feeders and rootlets of the trigeminal nerve was observed. Complete removal of the malformation was achieved and confirmed angiographically. The postoperative course was complicated by subdural hygroma that required repeated drainage and eventually a shunting procedure. This case demonstrates that microsurgical treatment of a trigeminal AVM is feasible. However, stereotactic radiosurgery may be the preferred treatment option considering the potential for postoperative complications.

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

OBJECTIVE AND IMPORTANCE

Trigeminal neuralgia is often the result of vascular compression at the root entry zone of the trigeminal nerve. We report a case of trigeminal neuralgia in a patient with a dural arteriovenous fistula in Meckel's cave. Endovascular closure of the fistula resulted in elimination of the patient's pain at the gasserian ganglion level.

CLINICAL PRESENTATION

A 77-year-old woman was referred for treatment of trigeminal neuralgia after failed conservative treatment, including multiple gasserian ganglion blocks. Magnetic resonance imaging of the brain suggested a vascular lesion, and cerebral angiography demonstrated a dural arteriovenous fistula in Meckel's cave.

INTERVENTION

Endovascular coil embolization was performed, with obliteration of the dural arteriovenous fistula and resolution of facial pain but with decreased sensation in the face.

CONCLUSION

Trigeminal neuralgia may be associated with complex vascular lesions around the base of the brain and along the course of the trigeminal nerve. The evaluation of patients with trigeminal neuralgia should include high-quality, thin-section, magnetic resonance imaging scans, to exclude the possibility of vascular lesions and other structural lesions. In particular, patients who are being evaluated for surgical treatment of trigeminal neuralgia should undergo magnetic resonance imaging, with a focus on the course of the trigeminal nerve.

Arteriovenous malformation in the trigeminal nerve. Case report

The authors report on an arteriovenous malformation (AVM) within the trigeminal nerve in an otherwise healthy 76-year-old man who presented with the sudden onset of headache and ataxia. The AVM was totally resected via a lateral suboccipital approach to the cerebellopontine angle. Dural arteriovenous fistulas and AVMs of the dorsal root entry zone and adjacent brainstem that compress the trigeminal nerve have been previously described. To the authors' knowledge, this is the first reported case of an angiographically, surgically, and pathologically proven AVM arising from within the trigeminal nerve itself.