Arteriovenous malformation in the trigeminal nerve. Case report

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.

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.

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 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.

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.

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.

Venous haemangioma of the mandibular division of the trigeminal nerve

OBJECTIVES

To present a rare cause of facial pain, and the differential diagnosis of a lesion of the mandibular division of the trigeminal nerve.

CASE REPORT

A 19-year-old woman presented to a tertiary referral skull base centre with right periorbital pain and a progressive, right-sided deficit of the mandibular division of the trigeminal nerve. Clinical examination revealed right-sided hypoaesthesia in the mandibular division of the trigeminal nerve dermatome, mild trismus and some wasting of the right masseter muscle. Computed tomography and magnetic resonance imaging scans revealed a small area of mildly enhancing soft tissue centred within the foramen ovale, with concentric enlargement. Surgery was undertaken via an infratemporal fossa (Fisch) type D approach. A vascular lesion was found filling the foramen ovale, with no obvious nerve separate from the lesion. The lesion was removed en bloc. Histopathological analysis demonstrated a venous haemangioma within the nerve.

CONCLUSION

Facial pain is common, and may be wrongly attributed to trigeminal neuralgia. A thorough clinical examination must be performed to identify subtle neurological abnormalities, and appropriate imaging undertaken to exclude rare causes, such as this venous haemangioma of the mandibular division of the trigeminal nerve.

Cervical spine dural arteriovenous fistula presenting with congestive myelopathy of the conus

Spinal dural arteriovenous fistulas (DAVFs) are the spinal vascular malformations that are encountered most often, and they are usually encountered in the lower thoracic region. Cervical spine DAVFs are exceedingly rare and may be difficult to differentiate from radicular arteriovenous malformations, epidural arteriovenous shunts, or perimedullary AVFs. Typical angiographic findings in spinal DAVFs include a slow-flow shunt with converging feeding vessels from radiculomeningeal arteries draining via a radicular vein centripetally into perimedullary veins. The MR imaging findings such as spinal cord edema and perimedullary dilated vessels may be used to direct the spinal angiography that is needed to localize and classify the shunt. When the shunt is distant from the pathological imaging findings, the diagnosis may be difficult to establish, especially when the shunt is present at an atypical location such as the cervical spine. The authors present the case of a 51-year-old man presenting with lower thoracic and conus medullaris congestive edema due to a cervical spine DAVF that was located at the C-5 level. Transarterial embolization with N-butyl cyanoacrylate closed the proximal vein and completely obliterated the fistula. Clinical and imaging follow-up confirmed occlusion of the fistula, with improvement in clinical symptoms.

Retrograde venonidal microsurgical obliteration of brain stem AVM: a clinical feasibility study

PURPOSE

The highly eloquent surroundings of brainstem arteriovenous malformations (AVMs) present particular surgical challenges. In the present pilot study we tried to examine whether to occlude the draining vein after control of major feeding arteries and then to coagulate the nidus retrogradely might be a viable concept for brainstem AVMs instead of the traditional perinidal dissection.

METHODS

A total of five patients harbouring pontine or mesencephalic AVMs were treated at our institution between February 2007 and August 2008. Three of them presented after haemorrhage. In two instances, partial endovascular obliteration was performed prior to surgery. Following exposure and control of major feeders, the principal draining vein was clamped to test tolerance. In none of the cases was major stasis and bleeding from the nidus seen. The draining vein was subsequently coagulated and then stepwise shrinking by retrograde coagulation of the nidus was done. The coagulated nidus was left in place.

RESULTS

The procedure was technically successful in all cases and no major postoperative complication related to the procedure was seen. Control angiography confirmed complete occlusion in all cases.

CONCLUSIONS

Due to the usually small size of brainstem AVMs, retrograde coagulation of the nidus without additional resection can be a feasible approach in order to avoid additional damage by circumferential dissection.

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.

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.