Cortical Arteriovenous Malformations Research Articles

Crisis Averted: Clinical T1b Renal Mass with Concurrent Arteriovenous Malformation and Renal Vein Thrombus

Arteriovenous malformations (AVMs) secondary to renal-cell carcinoma (RCC) are well-described in the literature. Independently, renal vein and inferior vena cava tumor thrombi can be detected in locally-advanced RCC. A 67-year-old gentleman presented with a cT1b renal mass detected on workup for elevated creatinine. Multiphase CT imaging obtained for partial nephrectomy surgical-planning revealed an initially-missed renal cortical AVM. This drastically changed the plan for intervention, including use of an open approach with AVM embolization by interventional radiology prior and avoidance of a nephron-sparing approach. Final pathology confirmed the AVM and a subclinical renal vein thrombus masked by arterial flow on CT imaging, making this the first concurrent case described in the literature. Herein, we describe avoidance of catastrophic intraoperative hemorrhage by careful review of preoperative imaging and provide a literature review of imaging modalities for both renal surgical-planning and detection of tumor thrombi in RCC.

Factors associated with seizures at initial presentation in pediatric patients with cerebral arteriovenous malformations.

Children with cerebral arteriovenous malformations (AVMs) can present with seizures, potentially increasing morbidity and impacting clinical management. However, the factors that lead to seizures as a presenting sign are not well defined. While AVM-related seizures have been described in case series, most studies have focused on adults and have included patients who developed seizures after an AVM rupture. To address this, the authors sought to analyze demographic and morphological characteristics of AVMs in a large cohort of children. The demographic, clinical, and AVM morphological characteristics of 189 pediatric patients from a single-center database were studied. Univariate and multivariate logistic regression models were used to test the effect of these characteristics on seizures as an initial presenting symptom in patients with unruptured brain AVMs. Overall, 28 of 189 patients initially presented with seizures (14.8%). By univariate comparison, frontal lobe location (p = 0.02), larger AVM size (p = 0.003), older patient age (p = 0.04), and the Supplemented Spetzler-Martin (Supp-SM) grade (0.0006) were associated with seizure presentation. Multivariate analysis confirmed an independent effect of frontal lobe AVM location and higher Supp-SM grade. All patients presenting with seizures had AVMs in the cortex or subcortical white matter. While children and adults share some risk factors for seizure presentation, their risk factor profiles do not entirely overlap. Pediatric patients with cortical AVMs in the frontal lobe were more likely to present with seizures. Additionally, the Supp-SM grade was highly associated with seizure presentation. Future clinical research should focus on the effect of therapeutic interventions targeting AVMs on seizure control in these patients.

Interest of awake surgery for ruptured cerebral arteriovenous malformations close to speech areas – Surgical note

BackgroundCerebral arteriovenous malformations (AVMs) are rare, with incidence of 1.12–1.42 cases per 100,000 person-years (Ozpinar et al., 2017). Few studies report applications of awake surgery. The goal of this report was to assess the interest of awake surgery in complete resection of cortical AVMs located close to eloquent speech areas, enabling detection of real functional cortical reorganization due to the AVM and parenchymal hematoma. Case reportA 38-year-old right-handed patient was admitted to the University Hospital of Besançon for dysphasia due to a ruptured left temporal arteriovenous malformation. The patient underwent asleep-awake-asleep surgery. Intraoperative cortical mapping revealed the presence of functional language areas in uncommon locations compared to known neuro-functional anatomy. DiscussionIn this patient, speech areas were redistributed, probably due to neuroplasticity after cerebral hemorrhage, leading to a new cortical architecture, which would have been unrecognized based on preoperative radiological imaging alone. ConclusionWe report the interest of awake surgery to achieve complete safe resection of ruptured AVMs located close to eloquent speech areas, using intraoperative cortical mapping.

Seizure Presentation in Patients With Brain Arteriovenous Malformations Treated With Stereotactic Radiosurgery: A Multicenter Study

Abstract INTRODUCTION Seizures are the second most common clinical presentation in patients with brain arteriovenous malformations (AVMs), and they are the most common presentation of unruptured AVMs. The aim of this multicenter, retrospective cohort study was to identify predictors of seizure presentation in AVM patients treated with stereotactic radiosurgery (SRS). METHODS We performed a retrospective review of AVM patients treated with SRS at 8 participating International Radiosurgery Research Foundation sites. Patient and AVM characteristics were compared between those with versus without a seizure presentation in univariable and multivariable models. Subgroup analysis of patients with cortical AVMs was performed. RESULTS The study cohort comprised 2333 AVM patients, including 419 (18%) with and 1914 (82%) without a seizure presentation. Prior AVM resection (OR = 7.65, P = .001), lack of prior AVM hemorrhage (OR = 0.004, P < .001), cortical AVM location (OR = 1559.42, P < .001), lower Spetzler-Martin (SM) grade (OR = 0.51, P = .007), and higher Virginia Radiosurgery AVM Score (VRAS; OR = 1.46, P = .008) were independent predictors of seizure presentation. The rate of seizure presentation in patients with cortical AVMs was 27%. Prior AVM resection (OR = 8.36, P < .001), lack of prior AVM hemorrhage (OR = 0.004, P < .001), and temporal AVM location (OR = 4.15, P < .001) were independent predictors of seizure presentation for cortical AVMs. CONCLUSION We identified multiple factors associated with seizure presentation in AVM patients selected to undergo SRS. Prior AVM resection, cortical AVM location, and lack of prior AVM hemorrhage were the strongest predictors of pre-SRS seizures. SM grade and VRAS may have a role in seizure risk stratification. Among cortical AVMs, temporal lobe localization was predictive of seizure presentation.

Treatment Strategy of a Patient With a Brain Arteriovenous Malformation and Cranial Dural Fistula: 2-Dimensional Operative Video.

We present the case of a 56-yr-old right-handed male, after informed consent was obtained, who presented with acute confusion and agitation, on the background of a remote history of an uncomplicated resection of a left parietal grade 2 glioma. Imaging revealed a large, acute right temporal intracerebral hemorrhage (ICH). Standard vascular workup for the cause of the ICH included catheter angiography. No direct cause of the hemorrhage was revealed; however, a high grade parasagittal dural arteriovenous fistula (DAVF) with cortical venous reflux was noted close to the prior craniotomy site. The venous reflux was towards the left hemisphere, but it was hypothesized that similar reflux on the right side may have been present and was not presently evident due to thrombosis. The DAVF was embolized by endovascular means, followed by evacuation of the hematoma. Follow-up angiogram 7 mo later revealed a high-flow, right superior temporal cortical arteriovenous malformation (AVM). The DAVF unfortunately had also progressed. Endovascular occlusion of both lesions was attempted but was not successful. Subsequently, microsurgical resection for both the vascular malformations was performed with careful pre- and intraoperative planning to obtain a successful clinical and angiographic result. In this video, we summarize diagnostic and therapeutic nuances that have broad implications for the workup of ICH and the strategic management of a unique scenario involving a brain AVM and high-grade cranial dural fistula in the same patient. Prior to each procedure, informed consent was obtained from the patient, which includes consent for publication.

Seizure Presentation in Patients with Brain Arteriovenous Malformations Treated with Stereotactic Radiosurgery: A Multicenter Study

Seizures are the second most common clinical presentation in patients with brain arteriovenous malformations (AVMs) and the most common presentation of unruptured AVMs. The aim of the present multicenter, retrospective cohort study was to identify the predictors of seizure presentation in patients with AVM who had undergone stereotactic radiosurgery (SRS). We performed a retrospective review of patients with AVM who had been treated with SRS at 8 participating International Radiosurgery Research Foundation sites. The patient and AVM characteristics were compared between those with and without seizure presentation in univariable and multivariable models. A subgroup analysis of patients with cortical AVMs was performed. The study cohort included 2333 patients with AVM, including 419 (18%) with and 1914 (82%) without a seizure presentation. Previous AVM resection (odds ratio [OR], 7.65; P= 0.001), a lack of previous AVM hemorrhage (OR, 0.004; P < 0.001), a cortical AVM location (OR, 1559.42; P < 0.001), a lower Spetzler-Martin grade (OR, 0.51; P= 0.007), and a higher Virginia radiosurgery AVM score (OR, 1.46; P= 0.008) were independent predictors of seizure presentation. The rate of seizure presentation in patients with cortical AVMs was 27%. Previous AVM resection (OR, 8.36; P < 0.001), a lack of previous AVM hemorrhage (OR, 0.004; P < 0.001), and temporal AVM location (OR, 4.15; P<0.001) were independent predictors of seizure presentation for cortical AVMs. We identified multiple factors associated with seizure presentation in patients with AVM to undergo SRS. Previous AVM resection, a cortical AVM location, and a lack of previous AVM hemorrhage were the strongest predictors of pre-SRS seizures. The Spetzler-Martin grade and Virginia radiosurgery AVM score might have a role in seizure risk stratification. For cortical AVMs, a temporal lobe location was predictive of seizure presentation.

Characteristics and Long-Term Outcome of 127 Children With Cerebral Arteriovenous Malformations

Population-based long-term data on pediatric patients with cerebral arteriovenous malformations (AVMs) are limited. To clarify the characteristics and long-term outcome of pediatric patients with AVM. A retrospective analysis was performed on 805 consecutive brain AVM patients admitted to a single center between 1942 and 2014. The patients were defined as children if they were under 18 yr at admission. Children were compared to an adult cohort. Changing patterns of presentation were also analyzed by decades of admission. The patients comprised 127 children with a mean age of 12 yr. The mean follow-up time was 21 yr (range 0-62). Children presented more often with intracerebral hemorrhage (ICH) but less often with epilepsy than adults. Basal ganglia, cerebellar, and posterior paracallosal AVMs were more common in pediatric than in adult patients. Frontal and temporal AVMs, in contrast, were more common in adult than in pediatric patients. As the number of incidentally and epilepsy-diagnosed AVMs increased, ICH rates dropped in both cohorts. In total, 22 (82%) pediatric and 108 (39%) adult deaths were assessed as AVM related. After multivariate analysis, small AVM size and surgical treatment correlated with a favorable long-term outcome. Hemorrhagic presentation was more common in children than in adults. This was also reflected as lower prevalence of epileptic presentation in the pediatric cohort. Lobar and cortical AVM locations were less frequent, whereas deep and cerebellar AVMs were more common in children. Hemorrhagic presentation correlated negatively with incidentally and epilepsy-diagnosed AVMs. In children, AVM was a major cause of death, but in adults, other factors contributed more commonly to mortality.

Operative nuances of surgery for cortical arteriovenous malformations: A safe solution and permanent cure.

Operative nuances of surgery for cortical arteriovenous malformations: A safe solution and permanent cure.

Preoperative Functional Findings and Surgical Outcomes in Patients with Motor Cortical Arteriovenous Malformation

The relationship between preoperative functional findings, derived from functional magnetic resonance imaging and diffusion tensor imaging, and surgical outcomes in patients with motor cortical arteriovenous malformations (AVMs) has not been determined. The aim of this study was to determine the relationship between preoperative functional findings and surgical outcomes in patients with motor cortical AVM. Fifteen patients with AVM involving the precentral knob and/or paracentral lobule were reviewed. Each motor function involved was examined as an independent object. Preoperative functional findings included cortical reorganization, activation around the nidus, corticospinal tract (CST) reorganization, nidus involving the CST, and the level of the CST involved. The relationship between preoperative functional findings and surgical outcomes was analyzed statistically. A muscle strength of grade 3 or less was defined as a poor outcome after surgery, and a muscle strength of grade 4 or greater was defined as a good outcome. Eighteen objects were created and analyzed. Cortical reorganization (P = 1.000) was not correlated with surgical outcomes. However, nidus involving the CST was significantly associated with poor short-term outcomes (1 week after surgery) (P = 0.028) and permanent deficit in muscle strength (P = 0.042). Most of the objects had good outcomes (16/18, 88.9%) at 6 months after surgery (long-term outcomes). Only 1 patient with CST ruptured at the corona radiata level and 1 patient who had postoperative hemorrhage obtained poor long-term outcomes. Nidus involving the CST and the level of the CST involved, rather than cortical reorganization, may be associated with surgical outcomes in patients with motor cortical AVM.

Angioarchitectural features of brain arteriovenous malformations associated with seizures: a single Center retrospective series

Epileptic seizures account for 24-40% of all clinical onsets in patients with brain arteriovenous malformations (AVMs). We retrospectively reviewed the angioarchitectural features of AVMs associated with seizures in 168 patients admitted to our Department from 1997 to 2012. Patients were dichotomized according to demographic characteristics, type of treatment, bleeding occurrence, and morphological and topographic features. Clinical status at admission and discharge was also recorded. The association of each one of these variables with seizures occurrence was statistically tested. Continuous variables and outcome were compared with Student's t-test, whereas categorical ones were compared using Fisher's exact test. The independent contribution of some seizures predictors was assessed with a logistic regression model. Associations were considered significant for P < 0.05. About 29% patients showed seizures and 47% bleeding. No significant difference in age and sex was observed between patients with and without seizures. AVMs > 4 cm (P = 0.001) and those fed by dilated arterial feeders (P = 0.02) were associated with increased risk of seizures. A higher risk of seizures occurrence was also observed in cortical AVMs compared with deeper ones (75.5% vs. 55.4%; P = 0.01), and in AVMs fed by middle and posterior cerebral arteries branches compared with the other vessels (81.6% vs. 45.3%; P < 0.001 and 48.9% vs. 23.5%; P = 0.002, respectively). No lobar predisposition was observed. A nidus > 4 cm also appeared as an independent risk factor of seizures occurrence (OR 2.82; 95% CI, 1.26-6.31; P = 0.009) at logistic regression analysis. AVM morphology, especially nidus dimension, appeared to more significantly influence seizures occurrence than their topography.

A case of ruptured renal cortical arteriovenous malformation of the right testicular vein in hemorrhagic fever with renal syndrome

Hemorrhagic fever with renal syndrome (HFRS) is an acute viral disease characterized by fever, hemorrhage, and renal failure. Among the various hemorrhagic complications of HFRS, the spontaneous rupture of an arteriovenous malformation of the testicular vessels with a retroperitoneal hematoma is a rare finding. Here, we report a case of HFRS complicated by a massive retroperitoneal hematoma that was treated with transcatheter arterial embolization.

Intra-Arterial Intraoperative Computed Tomography Angiography Guided Navigation

Precise intraoperative surgical localization of small distal aneurysms, arteriovenous malformations (AVMs), and cranial base dural arteriovenous fistulae may be challenging. Current neuronavigational techniques are based on imaging techniques with limited sensitivity to detect vascular lesions that are small. We introduce the technique of intraoperative computed tomography angiography (iCTA) with an intra-arterial injection for surgical navigation. To determine whether iCTA integrated with a navigation platform is accurate and useful for precise localization of small vascular lesions that are challenging to treat. This study included 8 patients: 2 with aneurysms, 3 with small cortical AVMs, and 3 with cranial base dural arteriovenous fistulae. iCTA with intra-arterial contrast injection was performed in all patients for precise localization of the small vascular lesion to facilitate craniotomy planning and microsurgical approach. All operative reports, inpatient and outpatient records, and radiographic studies available were reviewed retrospectively. : The iCTA was used to target 2 aneurysms, 3 small subcortical AVMs, and 3 dural arteriovenous fistulae. This technique was most helpful to localize the 3 AVMs and the distal M4 aneurysm precisely. Craniotomy planning was accurate in all instances; no complications related to the technique were noted, and all patients had uneventful postoperative recoveries. iCTA is an effective and accurate novel technique that can enhance the safety of surgical treatment for small intra-axial vascular pathology. AVM, arteriovenous malformationCTA, computed tomography angiographyDAVF, dural arteriovenous fistulaDSA, digital subtraction angiographyiCTA, intraoperative computed tomography angiographyMCA, middle cerebral arteryMSCT, multislice computed tomographyMRA, magnetic resonance angiography.

Characteristics of Brain Arteriovenous Malformations Presenting with Seizures without Acute or Remote Hemorrhage

We report on the predictors of seizure presention in unruptured brain arteriovenous malformations (AVMs). Between 1999 and 2008, 302 consecutive patients with AVMs were referred to our institution for endovascular treatment. Seventy-four patients (24.5%) experienced seizures without hemorrhage before treatment. We tested for statistical associations between angioarchitectural characteristics and seizure presentation. When we compared the 74 patients with seizures without hemorrhage with the 228 patients who did not experience seizures initially (total of 302 patients), male sex, cortical AVM location, AVM size of more than 3 cm, superficial venous drainage and presence of varices in the venous drainage were statistically associated with seizures (P=0.016, P=0.002, P=0.022, P=0.005, and P=0.022, respectively). Posterior fossa and deep locations and coexisting aneurysms were statistically associated with no seizures. The angioarchitectural characteristics of AVM associated with seizure presentation include male sex, cortical AVM location, AVM size of more than 3 cm, superficial venous drainage and presence of varices in the venous drainage.

Limiting the Current Density During Localization of the Primary Motor Cortex by Using a Tangential-Radial Cortical Somatosensory Evoked Potentials Model, Direct Electrical Cortical Stimulation, and Electrocorticography

Traditionally, the dual-radial model, which requires high cortical stimulation intensities and may evoke intraoperative seizures, is used for mapping during resection of lesions within or near the central sulcus. To examine the potential utility of using the multimodal tangential-radial triphasic model, which may increase the accuracy and reliability of cortical mapping at lower stimulation intensities. We performed a retrospective review of intracranial neuromonitoring cases at the University of Virginia. The tangential-radial triphasic model used direct electrical cortical stimulation (DECS), electrocorticography, and somatosensory evoked potentials with an additional P25 peak for waveform interpretation, instead of the older dual-radial model with N20 and P30 peaks alone. The central sulcus and sensory cortex were localized by generating multiple sensory maps. DECS with 50-Hz frequency was applied. Electrocorticography was used for detection of afterdischarges. Fifteen consecutive intracranial cases were identified. The patients consisted of 8 males and 7 females ranging in age from 12 to 74 years (median, 53 years). Fourteen patients had an intra-axial cortical mass, and 1 patient had a cortical arteriovenous malformation. The DECS thresholds ranged from 3.7 to 12 mA (median, 6.2 mA). Localization of motor and sensory cortices was accurately performed at low thresholds with bipolar DECS in all patients. Intraoperative seizures occurred in 1 patient (7%), and new permanent postoperative functional deficits occurred in 1 patient (7%). Our mapping technique appears safe and reliable for resection near the central sulcus. The tangential-radial triphasic model allows for lower stimulation intensities, reducing the risk of intraoperative seizures.

Unruptured arteriovenous malformation in a patient presenting with obstructive hydrocephalus

The authors report on a patient harboring an unruptured cortical arteriovenous malformation (AVM), who had presented with obstructive hydrocephalus due to compression of the cerebral aqueduct by a large venous varix. Although patients with ruptured AVMs are known to either present with or later suffer from obstructive hydrocephalus, those with unruptured AVMs who present in this manner are quite rare. Moreover, hydrocephalus caused by a venous varix draining an AVM, to our knowledge, has never been previously reported in the literature. This report serves to illustrate two primary points, namely, that tortuous venous varices draining AVMs can result in obstructive hydrocephalus and that this unusual circumstance can be fostered in the setting of venous outflow obstruction.

An Atypical Presentation of Visual Hallucinatory Experiences Following Prolonged Blindness*

We report a patient with long-standing blindness experiencing both simple and complex visual hallucinations secondary to a cortical arteriovenous malformation (AVM). The hallucinations were located in the right visual field corresponding to the contra-lateral site of cortical damage. This case contributes to our understanding of neurophysiological mechanisms underlying visual hallucinations and ongoing research investigating the phenomenology of hallucinations with respect to the cause and localization of neural damage.

Treatment Strategy for Grade III Arteriovenous Malformations

The treatment of arteriovenous malformation (AVMs) depends on the efforts of a multidisciplinary team to provide better results than its natural course. Treatment options are reviewed based on our personal experience series of 208 grade III operated AVMs in a 10-year period. The Spetzler-Martin classification was modified to include subdivisions in the heterogeneous group of grade III AVMs as follows : IIIA(large cortical AVMs), IIIB(small limbic lobe AVMs) and IIIC(small insula lobe AVMs), to augment the surgical resection criteria. The treatment strategy was for most of the cases embolization plus surgery for grade IIIA, surgery for subdivision IIIB and radiosurgery for most and surgery for selected cases of IIIC. The surgical results (good outcome : IIIA 81%, IIIB 86% and IIIC 87%) showed that in spite of the higher surgical and anatomical complexity for the IIIC group in comparison with those IIIB and IIIA AVMs, there are selected cases that can be surgically approached with similar or even better surgical outcomes based on the subdivision proposed. Indeed, these data indicate that the treatment of AVMs can achieve better results when compared to its natural course if managed by a well-trained group of specialists led by an experienced neurosurgeon.

Epilepsia asociada a malformación arteriovenosa

To describe the characteristics of the patients with epilepsy, associated to arteriovenous malformation. We introduced 11 patients assisted in 1997, at University Cajuru Hospital, with arteriovenous malformation associated to refractory epileptic seizures. Six men and five women, with age between 12 and 40 years old (27 years in mean), were interned with epileptic crises, 4 generalized tonic-clonic, 3 partial simple secondarily generalized, one with complex partial and one with simple partial that the complex developed with secondary generalization. CT showed temporal lesion in 3 patients, parietal in 3 patient, ventricular in 3, parietal fose and temporoparietal on one patient, respectively. MRI was accomplished in 5 patients presenting temporal lesion in 3 and temporo-parietal in 2. It was possible to accomplish the EEG in 8 patients, all with epileptiform activity. The arteriography showed arteriovenous malformations in all the patients, 3 of the which died. Eight patients were guided for surgical treatment evidencing cavernous angioma in 6 patient and hemangioma in 2. We observed that cortical and not cortical arteriovenous malformation associates to epileptic seizures and in the cases in which it is possible, the surgical treatment favors the control of the seizures.

Lateral ventricular arteriovenous malformations: Natural history and surgical indications

The authors report 21 cases of lateral ventricular arteriovenous malformation (AVM) focusing on their natural history and surgical indications. Eighteen of 21 patients (86%) had bleedings prior to admission. We performed definitive surgery in 9 patients and conservative treatment in 12 patients. In 7 of 9 patients (78%) in the operative group and in 5 of 12 patients (42%) in the non-operative group, the nidus of the AVM was less than 4 cm in diameter. The other 2 AVMs in the operative group, more than 4 cm in diameter, were located in the temporal lobe and widely extended to the temporal horn of the lateral ventricle. The nidi of the AVMs were totally removed in all 9 cases in the operative group. All patients have been doing well except one who had a mental breakdown 6 years after surgery. In 10 patients in the non-operative group, AVMs were located in the left cerebral hemispheres. Three patients in the non-operative group had rebleeding of the AVM. Two of the 12 patients in the non-operative group (17%) died of the recurrent haemorrhages. The rate of bleeding of the lateral ventricular AVM seems to be higher than that of the cerebral cortical AVM, but the mortality due to recurrent bleeding might be similar between the two. The operative indications we made depended on the sizes and locations of the AVMs. For AVMs in the temporal horn, even though they were large, we performed total removals of the nidi and had good results. We did not perform any definitive surgery for AVMs more than 4 cm in diameter except for those in the temporal horn. The mortality and morbidity of the 21 cases were 10% and 14%, respectively. Patients with AVMs in the temporal horn and patients with small AVMs in the frontal horn were good candidates for definitive surgery. We undertook conservative treatment for patients with large AVMs, and the results were acceptable.