Venous angioma adjacent to the root entry zone of the trigeminal nerve: implications for management of trigeminal neuralgia

Somatosensory and trigeminal pathway abnormalities in Chinese patients with trigeminal neuralgia

This study aimed to evaluate somatosensory function in Chinese patients with trigeminal neuralgia (TN) using a standard quantitative sensory testing (QST) battery and electrophysiological tests consisting of contact heat-evoked potentials (CHEPs) and blink reflex (BR). Twenty patients with TN and 20 sex- and age-matched healthy controls were recruited for this study. A standard QST protocol recommended by the German Research Network on Neuropathic Pain was carried out on the patients' painful and contralateral faces, the controls' right faces, and all participants' right hands. The CHEPs and BR were recorded at the Cz electrode and bilateral lower bellies of the orbicularis oculi, respectively, with thermal stimuli applied to both sides of the patient's face and the control's right face. The cold detection threshold, heat pain threshold, and mechanical pain threshold on the painful face were lower than those of healthy controls (P < 0.05), whereas the cold pain threshold and mechanical detection threshold were higher (P < 0.05) on the painful faces than those of the contralateral faces from patients or healthy controls. Mechanical pain sensitivity was higher in both test sites than in healthy controls (P < 0.05). Significantly longer N latencies (P < 0.05) and lower N-P amplitudes (P < 0.01) were detected in the patients' painful sites than in the contralateral sites and those of healthy controls. Comprehensive somatosensory abnormalities were found in painful facial sites in patients with TN, suggesting disturbances in the processing of somatosensory stimuli. Deficiencies in electrophysiological tests further revealed unilaterally impaired function of the trigeminal pathway in TN patients.

Hemifacial spasm caused by the brainstem developmental venous anomaly: A case report and review of the literature

Background:

Hemifacial spasm (HFS) is usually caused by vascular compression of the root exit zone (REZ) of the facial nerve. Dual compression of the REZ by veins and arteries is also associated with HFS, but venous origin alone is rarely reported. We present a rare case of HFS caused by the brainstem developmental venous anomaly (DVA) treated with microvascular decompression (MVD).

Case Description:

A 30-year-old women presented with the left-sided HFS since the age of 18 years. The brainstem DVA was diagnosed by magnetic resonance imaging (MRI) and followed by two attempts of MVD at some other clinics without any improvement. At our hospital, MVD was performed through a left retromastoid craniotomy. Intraoperatively, after detaching the strong adhesions between the cerebellar hemisphere, petrosal dura and lower cranial nerves, and removing the Teflon sponge inserted during the previous operations, the compressing large vein was found, separated from facial nerve REZ and MVD was completed. The postoperative computed tomography angiography and MRI showed the thrombosis of the main trunk of DVA and decompression of the facial nerve REZ. Complete cessation of HFS with hearing preservation was observed with only slight weakness of mimic muscles which disappeared within 3 months after surgery.

Conclusion:

HFS associated with brainstem DVA is a very rare condition. MVD of the facial nerve REZ with transposition of the large draining vein should be considered as an effective treatment option.

3-dimensional computer graphics model elucidating involvement of intraparenchymal venous malformation in trigeminal nucleus of brachium pontis with intractable trigeminal neuralgia

Venous malformation (VM) in the posterior cranial fossa occasionally cause trigeminal neuralgia (TN), which were treated with microvascular decompression of its drainer, whereas it was effective only in the limited cases, and its pathological mechanism causing TN is controversial. A 72-year-old man had a 20-year history of typical but severe TN in his left face. Without radiographic evidence of vascular compression on the root entry zone (REZ) of the trigeminal nerve, he underwent stereotactic radiosurgery in previous hospital, resulting in only temporary improvement. On T1-wighted magnetic resonance image with enhancement, the left trigeminal nerve was focally enhanced, which was typical finding after high dose irradiation for TN. Simultaneously, it disclosed small "caput medusa" within the pontine tegmentum, indicated existence of VM in brachium pontis. A 3-dimensional computer graphics model created by fusion of magnetic resonance angiography, diffusion tensor tractography, and fast imaging employing steady-state acquisition elucidated VM was located in the trigeminal nucleus of brachium pontis, which will be very useful for understanding the anatomic correlation of VM and pontine trigeminal nucleus. Since there was no vascular compression at the REZ of the trigeminal nerve, microvascular decompression was not indicated. With minimum dose of gabapentine and carbamazepin, his facial pain completely disappeared and controlled for more than 5 years.

Cerebral Venous Malformations in a Chinese Population: Clinical Manifestations, Radiological Characteristics, and Long-Term Prognosis

OBJECTIVE

We elucidated the clinical and radiological characteristics and analyzed the risk factors for hemorrhage and poor outcomes of cerebral venous malformations (CVMs) in a northern Chinese population.

METHODS

We included 60 consecutive patients with CVM patients in Beijing Tiantan Hospital from January 2011 to February 2018. The clinical manifestations, radiological characteristics, management, and outcomes were elucidated and analyzed. The patients were followed up for 5-64 months (median, 26). Poor outcomes included repeat bleeding, secondary infarction, severe disability (modified Rankin scale score ≥3), and death.

RESULTS

Infratentorial CVMs were more prone to intracranial hemorrhage (75% vs. 28.6%; P < 0.001), dizziness (37.5% vs. 10.7%; P = 0.017), and focal neurological deficits (65.6% vs. 25%; P = 0.002) than were supratentorial CVMs. Supratentorial CVMs were more prone to seizure (32.1% vs. 0%; P = 0.001) than were infratentorial CVMs. Multivariate logistic regression revealed that the major risk factors for intracranial hemorrhage in CVMs were infratentorial lesions (P = 0.003) and complicated cavernous angiomas (P = 0.016). Compared with conservative treatment, resection of hematoma or cavernous angiomas with CVM preservation did not increase the risk of poor outcomes (P = 0.646). However, CVM resection significantly increased that risk (odds ratio, 44.0; P = 0.003).

CONCLUSIONS

Our results have shown that conservative treatment of CVMs results in a relatively good prognosis. For those complicated by hemorrhage or cavernous angiomas requiring surgical interventions, the integrity of the CVM should be preserved, irrespective of the treatment. In exceptional cases, before CVM resection, the CVM drainage should be comprehensively evaluated.

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.

Gamma Knife Stereotactic Radiosurgery for Trigeminal Neuralgia Caused by a Developmental Venous Anomaly

Background: Trigeminal neuralgia (TN) is mostly caused by vascular compression of the nerve's root entry zone due to an ectatic artery. Rarer causes include compression from tumors, vascular malformations or multiple sclerosis plaques. Developmental venous anomalies (DVAs) are benign, aberrantly appearing venous structures that drain normal cerebral tissue. DVAs are a rare etiology of TN. The management of TN caused by a DVA is controversial as disruption of the DVA can be catastrophic. Methods: We report a case of a young man with severe medically refractory TN related to a brachium pontis DVA who was successfully treated by gamma knife stereotactic radiosurgery (GKSR) to the trigeminal nerve. Results: Within 2 weeks of GKSR, the patient reported experiencing 60% pain relief; 5 years postoperatively, he remains completely pain free with some mild sensory loss in the V2 and V3 areas. Conclusions: GKSR has an established role in the management of TN. This is the first reported case of using GKSR to treat TN caused by a DVA. In the setting of a DVA, GKSR should be an initial consideration for TN therapy after medical failure because of the high surgical risk related to disrupting the DVA. © 2015 S. Karger AG, Basel.

Trigeminal neuralgia caused by venous angioma: case report

A 34-year-old female presented with trigeminal neuralgia caused by a venous malformation in the right cerebello-pontine region. Computed tomography and magnetic resonance imaging demonstrated the abnormal draining veins from the venous malformation. The dilated vessels extended around the trigeminal nerve and compressed the root entry zone. Microvascular decompression (MVD) was performed, and her trigeminal neuralgia was completely relieved without neurological deficits. The offending vessel in most cases of trigeminal neuralgia is an arterial branch. Veins may also be associated with trigeminal neuralgia. The present rare case shows that MVD may be useful for the treatment of trigeminal neuralgia associated with venous malformation. Good outcome depends on decompression of the root entry zone without injury to the vessel. Surgical injury in this region can cause severe neurological deficits. Several treatment options should be prepared for the surgery, such as MVD or rhizotomy.

Cerebral developmental venous anomalies

INTRODUCTION

Cerebral developmental venous anomalies (DVAs) are the most frequently encountered cerebral vascular malformation. As such, they are often observed incidentally during routine CT and MRI studies. Yet, what DVAs represent from a clinical perspective is frequently not common knowledge and DVAs, therefore, still generate uncertainty and concern amongst physicians. This article reviews our current understanding of developmental venous anomalies.

RESULTS

In the majority of cases, DVAs follow a benign clinical course. On rare occasions, DVAs become symptomatic generally due to an underlying associated vascular malformation such as cavernous malformations or thrombosis of the collecting vein. Rare forms of DVAs include arterialized DVAs and DVAs involved in the drainage of sinus pericranii, which warrant additional investigation by digital subtraction angiography. Cerebral abnormalities such as atrophy, white matter lesions and calcifications within the drainage territory of asymptomatic DVAs, are often identified on CT or MR imaging studies and likely represent secondary changes due to venous hypertension. There is increasing evidence that DVAs have a propensity for developing venous hypertension, which is thought to be the cause of associated cavernous malformations and parenchymal abnormalities.

CONCLUSIONS

DVAs represent variations of the normal cerebral venous angioarchitecture and by enlargement follow an uneventful clinical course. Complications can, however, occur and their management requires a thorough understanding of the nature of DVAs, including their frequent coexistence with other types of vascular malformation, and the existence of more complex but rare forms of presentation, such as the arterialized DVAs.

DEVELOPMENTAL VENOUS ANOMALIES

DEVELOPMENTAL VENOUS ANOMALIES (DVAs), formerly known as venous angiomas, have become the most frequently diagnosed intracranial vascular malformation. DVAs are currently considered congenital cerebrovascular anomalies with mature venous walls that lack arterial or capillary elements. They are composed of radially arranged medullary veins, which converge in an enlarged transcortical or subependymal collector vein, and have characteristic appearances (caput medusae) on magnetic resonance imaging and angiography. DVAs were once thought to be rare lesions with substantial potential for intracerebral hemorrhage and considerable morbidity. The prevalence of incidental and asymptomatic DVAs has been more apparent since the advent of magnetic resonance imaging; recent cohort studies have challenged the once-held view of isolated DVAs as the cause of major neurological complications. The previously reported high incidence of intracerebral hemorrhage associated with DVAs is currently attributed to coexistent, angiographically occult cavernous malformations. Some patients may still have noteworthy neurological morbidity or die as a result of acute infarction or hemorrhage directly attributed to DVA thrombosis. DVAs can coexist with cavernous malformations and arteriovenous malformations. Such combination or transitional forms of malformations might suggest common pathways in pathogenesis. Recent data support a key role for DVAs in the pathogenesis of mixed vascular malformations.

Developmental venous anomaly of petrous veins: intraoperative findings and indocyanine green video angiographic study

OBJECTIVE

We describe the intraoperative findings and results of an indocyanine green (ICG) video angiographic study in a patient with a developmental venous anomaly of the petrous veins.

CLINICAL PRESENTATION

A 56-year-old man sought treatment after experiencing lacerating facial pain on the right side for almost 2 years. His neurological examination results were normal. A magnetic resonance imaging scan revealed the presence of a venous angioma in close relationship with the trigeminal nerve and the intrapontine tract of its fibers. The patient underwent a retrosigmoid craniotomy to explore the cerebellopontine angle. Near-infrared ICG video angiography was used to study the venous pattern of circulation. The venous angioma did not appear to be the source of any compression and was left untouched. At the entry zone of the nerve root, the trigeminal nerve was found to be compressed by a loop of the superior cerebellar artery, which was moved and repositioned away from the nerve.

RESULTS

Near-infrared ICG video angiography disclosed an unexpected difference in filling time between developmental venous anomaly drainage veins and normal veins. The patient's pain resolved after microvascular decompression.

CONCLUSION

Near-infrared ICG video angiography was particularly accurate and useful in the study of the venous dynamic of circulation. Further studies are required to confirm the supposed capability of ICG video angiography to differentiate developmental venous anomaly drainage veins and normal veins. Although magnetic resonance imaging supported the involvement of the venous angioma in the etiopathogenesis of this patient's trigeminal pain, surgical exploration disclosed a different cause.

Parenchymal abnormalities associated with developmental venous anomalies

INTRODUCTION

To report a retrospective series of 84 cerebral developmental venous anomalies (DVAs), focusing on associated parenchymal abnormalities within the drainage territory of the DVA.

METHODS

DVAs were identified during routine diagnostic radiological work-up based on magnetic resonance imaging (MRI) (60 cases), computed tomography (CT) (62 cases) or both (36 cases). Regional parenchymal modifications within the drainage territory of the DVA, such as cortical or subcortical atrophy, white matter density or signal alterations, dystrophic calcifications, presence of haemorrhage or a cavernous-like vascular malformation (CVM), were noted. A stenosis of the collecting vein of the DVA was also sought for.

RESULTS

Brain abnormalities within the drainage territory of a DVA were encountered in 65.4% of the cases. Locoregional brain atrophy occurred in 29.7% of the cases, followed by white matter lesions in 28.3% of MRI investigations and 19.3% of CT investigations, CVMs in 13.3% of MRI investigations and dystrophic calcification in 9.6% of CT investigations. An intracranial haemorrhage possibly related to a DVA occurred in 2.4% cases, and a stenosis on the collecting vein was documented in 13.1% of cases. Parenchymal abnormalities were identified for all DVA sizes.

CONCLUSION

Brain parenchymal abnormalities were associated with DVAs in close to two thirds of the cases evaluated. These abnormalities are thought to occur secondarily, likely during post-natal life, as a result of chronic venous hypertension. Outflow obstruction, progressive thickening of the walls of the DVA and their morphological organization into a venous convergence zone are thought to contribute to the development of venous hypertension in DVA.

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.

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.