The neurovascular triad: mixed cavernous, capillary, and venous malformations of the brainstem

Coexistence of brain capillary telangiectasia and venous angioma: A case report and literature review

While Cerebral vascular malformations exhibit distinct clinical and radiographical features, rare instances of coexisting lesions occur. This case report sheds light on the rare coexistence of brain capillary telangiectasia and venous angioma in a patient presenting with a seizure attributed to frontal lobe bleeding. Though often silent, brain capillary telangiectasia can manifest with serious life-threatening intracranial bleeding. Therefore, in cases of spontaneous intracranial bleeding, an MRI of the head is crucial to rule out such cerebral vascular malformations.

Developmental venous anomaly associated with dural arteriovenous fistula: Etiopathogenesis and hemorrhagic risk

Introduction

Developmental venous anomalies (DVAs) have traditionally been defined as non-pathological congenital lesions. Compared to isolated DVAs, the association of DVAs with arteriovenous shunts seems to have a more adverse clinical connotation. In this review, we describe the association between DVA and dAVF and discuss the hemorrhagic risk. We also advance a hypothesis about the potential de novo formation of a DVA and challenge the dogma about their "developmental" or "congenital" nature.

Methods

A systematic review of the literature on the association of DVA and dAVF was performed in accordance with the PRISMA-P (Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols) guidelines.

Results

A number of 678 papers was initially identified, but only 9 studies were included in the final qualitative analysis. Most of the patients presented with bleeding (56%), with a median GCS of 14 (range 10-15). In 56% of the cases the DVA had a supratentorial location. Supratentorial DVAs mostly drained in the superior sagittal sinus (80%), while all of infratentorial/combined DVAs drained in deep ependymal veins of the 4th ventricle. All the supratentorial dAVFs drained into the superior sagittal sinus, while the infratentorial/combined dAVFs mostly drained in the jugular bulb, Vein of Rosenthal, or transverse-sigmoid sinuses (75%). Most of the dAVFs were classified as Cognard type IIa + b (67%), while in a smaller number of cases type I (22%) and type V (11%). The dAVF was the target of treatment in each case and most patients underwent endovascular treatment (78%). The dAVF was completely occluded in 78% of cases and no periprocedural complications were reported.

Conclusion

The clinical presentation, radiological findings, and treatment outcomes of DVAs and associated dAVFs have been discussed. Despite the general opinion that DVAs are benign congenital lesions, increasing epidemiological and radiological evidence supports a potential acquired origin, and the venous system seem to play a pivotal role in their post-natal genesis and development.

[Capillary telangiectasia]

Brain capillary telangiectasia is usually a small collection of dilated capillary-like vessels. In most cases it is a harmless incidental finding with no clinical significance. They are most commonly located in the pons. In terms of image morphology, they show brush-like signal extinction in T2*/SWI (susceptibility-weighted imaging) sequences and contrast enhancement in T1-weighted images. Other sequences are usually unremarkable unless they involve unusually large capillary telangiectasias. Angiographically they usually remain silent. Sometimes they are associated with venous abnormalities and/or cavernomas. Their distinctive radiographic features usually allow for a reliable diagnosis. Differential diagnostic considerations, such as differentiation from a tumorous or inflammatory process, are sometimes necessary.

Brain capillary telangiectasias: from normal variants to disease

BACKGROUND

Brain capillary telangiectasias (BCTs) are small, dilated capillary networks in the brain that are most commonly asymptomatic. Though rare, symptomatic cases of BCTs have been reported, and it is therefore important to understand the nature of these lesions in order to facilitate proper recognition. Relative to other intracranial vascular malformations, updated information on the various epidemiologic, radiographic, and pathologic features of BCTs within the published literature may be inadequate.

METHODS

We searched the PubMed database for prior reports of symptomatically-manifested BCTs. Moreover, Google Scholar and PubMed were searched in order to review current epidemiologic, radiographic, pathologic, and pathogenetic features of BCTs.

RESULTS

Forty-eight published studies were included for a total of 99 individual cases of BCTs with symptomatic manifestations. Thirty-three symptomatic BCTs were hemorrhagic in nature, while 66 were non-hemorrhagic. The mean age at presentation of hemorrhagic lesions was 25.5 years, and the most common location was the supratentorial CNS (54.5%) with motor disturbance representing the most commonly encountered presenting symptom (26.1%). 15.2% of hemorrhagic lesions were treated with surgical removal. In non-hemorrhagic lesions, the mean age at presentation was 39.8 years with the pons being the most common lesion location (78.5%) and headache being the most common presenting symptom (22.2%). 12.1% of patients with non-hemorrhagic lesions were treated with surgical removal.

CONCLUSIONS

Despite their rarity, symptomatic BCTs, both hemorrhagic and non-hemorrhagic, can cause devastating neurological sequelae, potentially through multiple mechanisms. The large majority of these lesions do not require intervention, though surgical removal has been achieved with good outcome in select cases. Further documentation of symptomatic manifestations with or without surgical intervention is vital in order to further understand the clinical, surgical, and pathogenic implications of these less-appreciated vascular malformations.

Hemorrhage owing to cerebral cavernous malformation: imaging, clinical, and histopathological considerations

Cavernous malformation (CM) is the second most common cerebral vascular malformation and is often found incidentally. Their natural history is usually benign, however, patients with CM who present with symptomatic hemorrhage may later follow a serious clinical course if left untreated. The risk of hemorrhage is associated with previous hemorrhage, lesion location (infratentorial and deep), and the presence of associated developmental venous anomaly (DVA). Histopathological specimens also indicate that coexistence of DVA and other vascular malformations may be associated with hemorrhage owing to CMs. Diagnosing CMs is difficult, even in patients who initially present with symptomatic hemorrhage. Computed tomography scans typically reveal a hemorrhagic CM as a nonspecific heterogenous mass of high density, which may not be misdiagnosed as a solitary hematoma, especially when located in the infratentorial region. Magnetic resonance imaging demonstrates internal loculation with mixed-signal intensities typical for CMs, although this may be partially or completely masked by acute hemorrhage. Susceptibility-weighted imaging (SWI) reveals a significant "blooming" effect of hemosiderin deposition. Three-dimensional postcontrast T1-weighted imaging is essential to identify associated DVAs, and this is important for both diagnosis and planning of surgical treatment. Contrast-enhanced MRI should be performed to diagnose hemorrhagic CMs and differentiate them from spontaneous solitary hematoma or hemorrhagic tumors.

Symptomatic large or giant capillary telangiectasias: management and outcome in 5 cases

Brain capillary telangiectasias (BCTs) are usually small and benign with a predilection in the pons and basal ganglion. Reports of large and symptomatic BCTs are rare. Large BCTs have a much higher risk of causing uncontrolled bleeding and severe neurological defects, and they can be fatal if left untreated. Therefore, large BCTs should be managed with special caution. Because of the lack of reports, diagnosis of large BCTs has been difficult. Strategies of management are undefined for large or giant BCTs.

The current study presents 5 cases of giant and large BCTs. To the authors’ knowledge, this is the largest series of this disease ever reported. Radiological findings, histopathological characteristics, clinical presentations, and surgical management were analyzed in 5 symptomatic, unusually large BCTs (mean diameter 5.06 cm, range 1.8–8 cm).

Four patients presented with focal or generalized seizures, and 1 patient presented with transient vision loss attributed to the lesions. Gross-total resection of the lesion was achieved in all patients. After surgery, the 4 patients with seizures were symptom free for follow-up periods varying from more than 1 to 5 years with no additional neurological deficits.

The unique location, radiological characteristics, and clinical course suggest that giant BCTs could be a different entity from small BCTs. Surgery might be a good option for treatment of patients with intractable neurological symptoms, especially in those with surgically accessible locations. Complete removal would be anticipated to provide relief of the symptoms without causing new neurological deficits.

Developmental venous anomaly responsible for hemifacial spasm

Hemifacial spasm (HFS) is a facial movement disorder characterized by involuntary, unilateral and intermittent contractions of the facial muscles. It is one of the syndromes related to neurovascular conflict, first described by Jannetta et al. in 1979. Typically, HFS is due to pulsatile compression by the anterior inferior cerebellar artery. We describe a rare case of left developmental venous anomaly in a 59-year-old man referred to us with a six-month history of left-sided HFS. We performed an MR study of the brain and cerebellopontine angles, which demonstrated a compression of the ipsilateral facial nerve by the developmental venous anomaly.

Brainstem cavernomas: a surgical challenge

OBJECTIVE

The authors show their experience with brainstem cavernomas, comparing their data with the ones of a literature review.

METHODS

From 1998 to 2009, 13 patients harboring brainstem cavernomas underwent surgical resection. All plain films, medical records and images were reviewed in order to sample the most important data regarding epidemiology, clinical picture, radiological findings and surgical outcomes, as well as main complications.

RESULTS

The mean age was 42.4 years (ranging from 19 to 70). No predominant gender: male-to-female ratio, 6:7. Pontine cases were more frequent. Magnetic resonance imaging was used as the imaging method to diagnose cavernomas in all cases. The mean follow-up was 71.3 months (range of 1 to 138 months). Clinical presentation was a single cranial nerve deficit, VIII paresis, tinnitus and hearing loss (69.2%). All 13 patients underwent resection of the symptomatic brainstem cavernoma. Complete removal was accomplished in 11 patients. Morbidity and mortality were 15.3 and 7.6%, respectively.

CONCLUSIONS

Cavernomas can be resected safely with optimal surgical approach (feasible entry zone) and microsurgical techniques, and the goal is to remove all lesions with no cranial nerves impairment.

A new strategic neurosurgical planning tool for brainstem cavernous malformations using interactive computer graphics with multimodal fusion images

OBJECT

In this study, the authors used preoperative simulation employing 3D computer graphics (interactive computer graphics) to fuse all imaging data for brainstem cavernous malformations. The authors evaluated whether interactive computer graphics or 2D imaging correlated better with the actual operative field, particularly in identifying a developmental venous anomaly (DVA).

METHODS

The study population consisted of 10 patients scheduled for surgical treatment of brainstem cavernous malformations. Data from preoperative imaging (MRI, CT, and 3D rotational angiography) were automatically fused using a normalized mutual information method, and then reconstructed by a hybrid method combining surface rendering and volume rendering methods. With surface rendering, multimodality and multithreshold techniques for 1 tissue were applied. The completed interactive computer graphics were used for simulation of surgical approaches and assumed surgical fields. Preoperative diagnostic rates for a DVA associated with brainstem cavernous malformation were compared between conventional 2D imaging and interactive computer graphics employing receiver operating characteristic (ROC) analysis.

RESULTS

The time required for reconstruction of 3D images was 3-6 hours for interactive computer graphics. Observation in interactive mode required approximately 15 minutes. Detailed anatomical information for operative procedures, from the craniotomy to microsurgical operations, could be visualized and simulated three-dimensionally as 1 computer graphic using interactive computer graphics. Virtual surgical views were consistent with actual operative views. This technique was very useful for examining various surgical approaches. Mean (±SEM) area under the ROC curve for rate of DVA diagnosis was significantly better for interactive computer graphics (1.000±0.000) than for 2D imaging (0.766±0.091; p<0.001, Mann-Whitney U-test).

CONCLUSIONS

The authors report a new method for automatic registration of preoperative imaging data from CT, MRI, and 3D rotational angiography for reconstruction into 1 computer graphic. The diagnostic rate of DVA associated with brainstem cavernous malformation was significantly better using interactive computer graphics than with 2D images. Interactive computer graphics was also useful in helping to plan the surgical access corridor.

Susceptibility-weighted MR imaging for diagnosis of capillary telangiectasia of the brain

BACKGROUND AND PURPOSE

BCT is a benign entity, whose appearance on conventional MR imaging makes its differentiation from neoplastic, inflammatory, or subacute ischemic disease challenging. SWI is sensitive to susceptibility effects from deoxyhemoglobin with excellent spatial resolution. Only scarce case reports have described the utility of SWI in cases of BCT. Our aim was to show the diagnostic value of SWI applied to a larger series of cases.

MATERIALS AND METHODS

This was an observational retrospective study of 33 BCTs in 27 consecutive patients examined from August 2009 to January 2011 with MR imaging, including SWI. Morphology, signal intensity characteristics, and additional vascular malformations were analyzed. Preceding or follow-up examinations were available in 18 patients with a median time interval of 14.5 months (range, 2-115 months).

RESULTS

Twenty-five pontine and 8 supratentorial BCTs demonstrated distinct signal-intensity loss on SWI in combination with postcontrast enhancement. Mean lesion diameter was 4.9 mm (range, 1.5-17 mm). Thirty-nine percent showed slight signal-intensity changes on T1 and/or T2; the remainder were isointense to normal brain. In 30%, a prominent draining vessel was observed. Additional cerebral vascular malformations were found in 5 patients.

CONCLUSIONS

SWI represents a valuable tool for confirmation of presumed BCT. Demonstration of signal-intensity loss on SWI in an enhancing focal brain lesion, otherwise unremarkable on conventional MR images, is highly specific for BCT, thus excluding serious pathology and reassuring the patient and referring physician. This is particularly helpful for BCT in less typical locations.

Emerging clinical imaging techniques for cerebral cavernous malformations: a systematic review

Cerebral cavernous malformations (CCMs) are divided into sporadic and familial forms. For clinical imaging, T2-weighted gradient-echo sequences have been shown to be more sensitive than conventional sequences. Recently more advanced imaging techniques such as high-field and susceptibility-weighted MR imaging have been employed for the evaluation of CCMs. Furthermore, diffusion tensor imaging and functional MR imaging have been applied to the preoperative and intraoperative management of these lesions. In this paper, the authors attempt to provide a concise review of the emerging imaging methods used in the clinical diagnosis and treatment of CCMs.

De novo formation of orbital cavernous malformation 9 years after surgical management of dural arteriovenous fistula in the anterior middle fossa: case report

A 30-year-old man presented with recurrent dural arteriovenous fistula (dAVF) associated with de novo orbital cavernous malformation (CM), manifesting as progressive left visual disturbance. He had undergone transarterial embolization and subsequent surgical management for a left anterior middle fossa dAVF 9 years previously. External carotid angiography showed recurrence of the dAVF. Magnetic resonance imaging revealed a well delineated intraorbital mass lesion with hypointense signal rim by T(2)-weighted imaging, adjacent to the shunting point of the recurrent dAVF. Transcranial subtotal removal of the intraorbital mass lesion through the orbitopterional approach revealed continuity between the mass lesion and the draining vein of the recurrent dAVF. The histological diagnosis was CM. His symptom was relieved postoperatively, and no regrowth was seen during the follow-up period of one year. The coexistence of recurrent dAVF with newly formed orbital CM is extremely rare, but may indicate the underlying mechanism of the formation of CMs and recurrent dAVF.

Differential diagnosis of T2 hyperintense brainstem lesions: Part 1. Focal lesions

Brainstem lesions can be classified as focal or diffuse. Magnetic resonance imaging is the most suitable imaging modality for evaluating these lesions. As a rule, focal lesions are not large and have well-defined margins. Causes include tumors, vascular malformations, demyelinating diseases, brain abscesses, hypertrophic olivary degeneration, and dilated Virchow-Robin spaces. Differential diagnoses of these numerous entities mandates a review of magnetic resonance imaging findings in conjunction with epidemiologic aspects, clinical features, and other medical test results.

The putative role of the venous system in the genesis of vascular malformations

Recent clinical and experimental evidence has challenged the traditional concept of the venous system as a “passive” element in the genesis and evolution of intracranial vascular malformations. The authors review the clinical and experimental evidence linking the venous system and its anomalies to the genesis of various intracranial vascular malformations, including dural arteriovenous fistulas, cavernous malformations, parenchymal arteriovenous malformations, and capillary telangiectasia. They also describe the potential significance of different associations of these vascular anomalies.

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.