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BACKGROUND AND PURPOSE:Imaging CBF is important for managing pediatric moyamoya. Traditional arterial spin-labeling MR imaging detects delayed transit thorough diseased arteries but is inaccurate for measuring perfusion because of these delays. Velocity-selective arterial spin-labeling is insensitive to transit delay and well-suited for imaging Moyamoya perfusion. This study assesses the accuracy of a combined velocity-selective arterial spin-labeling and traditional pulsed arterial spin-labeling CBF approach in pediatric moyamoya, with comparison to blood flow patterns on conventional angiography. MATERIALS AND METHODS:Twenty-two neurologically stable pediatric patients with moyamoya and 5 asymptomatic siblings without frank moyamoya were imaged with velocity-selective arterial spin-labeling, pulsed arterial spin-labeling, and DSA (patients). Qualitative comparison was performed, followed by a systematic comparison using ASPECTS-based scoring. Quantitative pulsed arterial spin-labeling CBF and velocity-selective arterial spin-labeling CBF for the middle cerebral artery, anterior cerebral artery, and posterior cerebral artery territories were also compared. RESULTS:Qualitatively, velocity-selective arterial spin-labeling perfusion maps reflect the DSA parenchymal phase, regardless of postinjection timing. Conversely, pulsed arterial spin-labeling maps reflect the DSA appearance at postinjection times closer to the arterial spin-labeling postlabeling delay, regardless of vascular phase. ASPECTS comparison showed excellent agreement (88%, κ = 0.77, P < .001) between arterial spin-labeling and DSA, suggesting velocity-selective arterial spin-labeling and pulsed arterial spin-labeling capture key perfusion and transit delay information, respectively. CBF coefficient of variation, a marker of perfusion variability, was similar for velocity-selective arterial spin-labeling in patient regions of delayed-but-preserved perfusion compared to healthy asymptomatic sibling regions (coefficient of variation = 0.30 versus 0.26, respectively, Δcoefficient of variation = 0.04), but it was significantly different for pulsed arterial spin-labeling (coefficient of variation = 0.64 versus 0.34, Δcoefficient of variation = 0.30, P < .001). CONCLUSIONS:Velocity-selective arterial spin-labeling offers a powerful approach to image perfusion in pediatric moyamoya due to transit delay insensitivity. Coupled with pulsed arterial spin-labeling for transit delay information, a volumetric MR imaging approach capturing key DSA information is introduced.

Pediatric cerebrovascular diseases have distinct clinical presentations, pathophysiology, and management compared to the adult counterparts. This introductory article discusses the imaging techniques and neurovascular conditions unique to each age group from the fetal stages through childhood, including vascular malformations, arteriopathy, and strokes. The article also underscores the importance of genetic factors and the need for a multidisciplinary approach in the diagnosis and treatment of pediatric neurovascular disorders., Competing Interests: Disclosure The authors declare no conflicts of interest related to the content of this article., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: To assess whether white matter injuries differ in symptomatic vs asymptomatic moyamoya-affected hemispheres using diffusion magnetic resonance imaging since there is controversy regarding when or if to revascularize children with asymptomatic moyamoya., Study Design: We conducted a cross-sectional study of children with moyamoya who underwent diffusion magnetic resonance imaging before revascularization surgery as well as controls without moyamoya. We measured the fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity of white matter tracts in the watershed regions. Moyamoya-affected hemispheres were included if they did not have any visible stroke or infarct. Moyamoya-affected hemispheres were labeled "symptomatic" if transient ischemic attack, seizure, or movement disorder were localizable to that hemisphere, or if the child experienced headaches. Moyamoya-affected hemispheres were "asymptomatic" if the child did not have symptoms attributable to that hemisphere. Asymptomatic and symptomatic hemispheres were compared with each other and control children using ANOVA., Results: We included 17 children with moyamoya with 26 moyamoya-affected hemispheres and 27 control children. Compared with controls, mean diffusivity, radial diffusivity, and axial diffusivity were greater in both symptomatic and asymptomatic moyamoya-affected hemispheres but were not significantly different from each other., Conclusions: Children with moyamoya without stroke or silent infarct have unrecognized white matter injury that is similar in both symptomatic and asymptomatic moyamoya-affected hemispheres, suggesting that symptoms do not accurately reflect moyamoya severity., Competing Interests: Declaration of Competing Interest This work was supported by a Boston Children's Hospital Office of Faculty Development/Basic & Clinical Translational Research Executive Committees Faculty Career Development Fellowship (L.L.), Thrasher Early Investigator Award (J.S.). The authors declare no conflicts of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background and Purpose: Vein of Galen malformation (VOGM) is the most common congenital cerebrovascular malformation, and many patients have high mortality rates and poor cognitive outcomes. Quantitative diagnostic tools are needed to improve clinical outcomes, and the purpose of this study was to characterize intracranial blood flow in VOGM using quantitative 4D flow MRI., Materials and Methods: A prospective study of children with VOGM was conducted by acquiring 4D flow MRI to quantify total blood inflow to the brain, flow in the pathologic falcine sinus, and flow in the superior sagittal sinus. Linear regression was used to test the relationships between these flows and age, clinical status, and the mediolateral diameter of the outflow tract of the lesion through the falcine or straight sinus diameter, which is a known morphologic prognostic metric., Results: In all 11 subjects (mean age, 22 [SD,17 ] weeks), total blood flow to the brain always exceeded normal levels (mean, 1063 [SD, 403] mL/minute). Significant correlations were observed between falcine sinus flow and the mediolateral diameter of the straight or falcine sinus, the posterior cerebral artery/MCA flow ratio and age at scanning, and superior sagittal sinus flow proximal to malformation inflow and age at scanning., Conclusions: Using 4D flow MRI, we established the hemodynamic underpinnings of the mediolateral diameter of the straight or falcine sinus and investigated metrics representing parenchymal venous drainage that could be used to monitor the normalization of hemodynamics during embolization therapy., (© 2024 by American Journal of Neuroradiology.)

Four distinct vascular anomalies can be seen to affect the brain on fetal imaging: vein of Galen malformations, nongalenic arteriovenous pial fistulas, dural sinus malformations, and intracranial venous malformations. These congenital disorders affect the arteries and veins of the developing brain and are rarely seen beyond the neonatal stage. The 4 fetal cerebrovascular anomalies are associated with quite disparate natural histories and prognoses. MRI plays a pivotal role in the evaluation of fetuses with these conditions because of its ability to definitively establish the diagnosis, to detect subtle parenchymal injuries, to delineate the course of abnormal vessels in detail and to some extent the nature of vascular flow, and to identify ischemic, thrombotic, and hemorrhagic complications. Recently, an investigational transuterine embolization procedure targeted at treating fetuses with vein of Galen malformations who are at high risk for neonatal decompensation has emerged as a promising alternative to expectant management and postnatal embolization, with imaging being used to identify suitable patients for the intervention and in preprocedural planning. This manuscript reviews the essential imaging and clinical features of these 4 fetal neurovascular anomalies and underscores the practical aspects related to counseling, prognosis, and the multidisciplinary management of these entities., (© 2025 by American Journal of Neuroradiology.)

Background: Mechanical thrombectomy (MT) is a well-established treatment modality for large vessel occlusion (LVO) in adults, but there are limited data in the pediatric population. The rarity of the condition makes prospective trial design difficult, and therefore evaluation of MT devices and outcomes is sparse. In pediatric LVO cases, some newer devices may be appropriate for use in revascularization procedures. Furthermore, illustrative specific device-access combinations have rarely been presented in young patients under the age of 5 years., Methods: This was a single institution experience in intracranial MT procedures for pediatric acute ischemic stroke (AIS). A given procedure was included if there was an attempt at MT between 2015 and 2023., Results: Sixteen endovascular procedures were performed in 15 patients with AIS, with a mean age of 7.4 years; eight patients were <5 years of age. MT was attempted in 15/16 (93.7%) procedures, including 11 (73.3%) in the anterior circulation and four (26.7%) in the posterior circulation; one case recanalized after medical treatment. The most common MT techniques were combined aspiration with a stentriever (n=10, 66.7%) and aspiration alone (n=3, 20%). Traditional stentrievers (4-6 mm) were used in seven cases and low-profile stentrievers in four cases. Improved reperfusion was achieved in all low-profile stentriever cases. Reperfusion of modified Thrombolysis in Cerebral Infaction ≥2b was obtained in 73.3% of cases, including 72.7% of those in which a stentriever was used., Conclusions: Low-profile thrombectomy devices may achieve similar revascularization results to other approaches in challenging clinical scenarios observed in younger children., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Infantile-type dural arteriovenous shunts (IDAVS) are rare and heterogeneous vascular lesions, complicating their classification and management. The current tripartite classification of pediatric dural arteriovenous shunts (DAVS) into dural sinus malformation, infantile-type, and adult-type, does not stand up to scrutiny, given the variable presentations of the latter two types in children. We estimate the prevalence of IDAVS and evaluate the long term outcomes after endovascular treatment (EVT)., Methods: A retrospective review of a pediatric cerebrovascular database between 2006 and 2023 was conducted. Clinical and radiographic data were analyzed to evaluate the presentation and long term outcomes of IDAVS., Results: IDAVS were identified in 8 (0.5%) of 1463 patients, with mean age at diagnosis of 34.7 months; male infants comprised 62.5%. The most common clinical presentations included macrocephaly (37.5%), seizures (25%), and dilated scalp veins (25%). EVT was performed in 87.5% of cases, averaging 5.8 procedures per patient. Radiographic obliteration was observed in 28.6%. Good clinical outcomes (modified Rankin Scale score of ≤2) were achieved in 85.7%. Our findings showcased discrepancies and limitations in the current classification of pediatric DAVS, prompting a re-evaluation., Conclusion: IDAVS accounted for a small proportion of pediatric cerebrovascular pathologies, with markedly heterogeneous presentations. Stepwise selective embolization was associated with favorable outcomes, and is recommended over an aggressive approach with the goal of complete angiographic obliteration. Our proposed revised classification system bifurcates pediatric DAVS into dural sinus malformations and all other DAVS that are manifest in children, thereby enhancing diagnostic clarity and therapeutic approaches., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: To describe a surgical technique for posterior cerebral revascularization in pediatric patients with moyamoya arteriopathy. Here, we describe the clinical characteristics, surgical indications, operative techniques, and clinical and radiographic outcomes in a series of pediatric patients with moyamoya disease affecting the posterior cerebral artery (PCA) territory., Methods: A retrospective single-center series of all pediatric patients with moyamoya disease who presented to our institute between July 2009 through August 2019 were reviewed. The clinical characteristics, surgical indications, operative techniques, and long-term clinical and radiographic outcomes of pediatric moyamoya patients with PCA territory ischemia were collected and analyzed., Results: A total of 10 PCA revascularization procedures were performed in 9 patients, 5 female, ages 1 to 11.1 years (average 5.2 years). Complications included 1 stroke, with no infections, hemorrhages, seizures, or deaths. One patient had less than 1 year of radiographic and clinical follow-up. In 8 of 9 patients with at least 1 year of radiographic follow-up, there was engraftment of surgical vessels present in all cases. No new strokes were identified on long-term follow-up despite the radiographic progression of the disease. In the 8 cases available for analysis, the average follow-up was 50.8 months with a range of 12 to 117 months., Conclusions: PCA territory ischemia in patients with progressive moyamoya disease can be surgically treated with indirect revascularization. Here, we describe our experience with PCA revascularization procedures for moyamoya disease, including pial pericranial dural (PiPeD) revascularization and pial synangiosis utilizing the occipital artery. These surgical options may be useful for decreasing the risk of stroke in pediatric moyamoya patients with severe posterior circulation disease., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: Optimal choroid plexus tumor (CPT) treatment involves gross total resection; however, intraoperative hemorrhage risk remains significant given tumor vascularity. This study describes pediatric CPT management and identifies patients most likely to benefit from preoperative embolization., Methods: CPTs resected from 1997 to 2021 were included. The characteristics of embolized patients were compared to nonembolized patients; nonembolized patients were further stratified based on open vascular control-pedicle feeder ligation versus no pedicle ligation prior to tumor debulking. Statistical analyses identified factors associated with estimated blood loss (EBL), transfusion, length of stay, and complications., Results: Among the 46 CPT cases identified, 98% achieved gross total resection, and 15% received embolization. Embolized patients were younger, smaller, and had larger tumors compared to nonembolized patients (median: 0.8 vs. 2.1 years; 9.3 vs. 14.4 kg; 91.08 vs. 5.5 cm 3 ). Transfused patients were similarly younger and smaller (P < 0.05) than nontransfused patients. Among nonembolized patients, open vascular control was achieved in smaller tumors (<13 cm 3 ) with significantly lower EBL (P = 0.002). Higher EBL was observed in patients with larger tumors, hydrocephalus, transependymal edema, vomiting, lethargy, and developmental regression (all P < 0.05). Patients with lethargy had longer hospital stays and a higher likelihood of postoperative complications (P < 0.05). There were no significant differences in complication rates between the embolization and nonembolization groups., Conclusions: Despite higher surgical risk profiles, embolized patients had similar complication rates and postoperative hydrocephalus management as nonembolized patients. Embolization was particularly beneficial in patients at high risk for surgical morbidity, such as those <2 years, weighing <10 kg, and with a tumor volume >15 cm 3 ., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Vein of Galen malformation (VOGM) is a rare, life-threatening vascular malformation in neonates and is treated with embolization. However, even at the most experienced centers, patients face high mortality and morbidity. In utero treatment options have been limited by lack of animal models or simulations., Objective: To create a novel ultrasound phantom simulator for a preclinical feasibility study of in utero fetal intervention for VOGM., Methods: Novel phantoms were designed and built in two configurations of spherical and windsock shape from cryogel material to mimic the salient vasculature of the fetal VOGM, based on real-patient fetal MR imaging dimensions. Critical anatomy was realistically mimicked within this model and transtorcular ultrasound-guided coil deployment was simulated. Each phantom model was assessed before and after treatment to evaluate coil mass deposition within the target., Results: The two phantoms underwent pretreatment T2-weighted MR imaging assessment, ultrasound-guided embolization, post-treatment MR and fluoroscopic imaging, and visual inspection of the sliced phantoms for target embolization verification. Postoperative MR scans confirmed realistic compact deposition of the coil masses within the central cavity. Phantom embolization results were submitted as part of the institutional review board and US Food and Drug Administration investigative device exemption approval for a first-in-humans clinical trial of fetal intervention for VOGM., Conclusions: A phantom simulator for fetal intervention of VOGM produces lifelike results during trial interventions, removing obstacles to feasibility and safety evaluations, typically precluded by non-availability of appropriate animal models. The study provides a proof of concept for potentially wider applications of medical simulation to enable novel procedural advancements in neurointerventions., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Importance: Vein of Galen malformations (VOGMs) are complex arteriovenous malformations in neonates and young children. Recent advances in endovascular interventions have drastically improved treatment and clinical outcomes in what was previously high-morbidity, high-mortality disease. The high-flow shunt pathophysiology in VOGMs can lead to dynamic changes in the malformation angioarchitecture, and over time patients can develop jugular bulb stenosis. In the setting of inaccessible transvenous access to the malformation for endovascular embolization in cases where transarterial embolization is inadequate, a combined surgical and endovascular technique must be used. We present the first successful modern-day application of direct puncture through transverse sinus for transvenous embolization of a VOGM., Clinical Presentation: We present 2 unique cases of complex VOGM malformations in patients who had previously undergone staged endovascular embolization for reduction of flow within the malformation. On follow-up, in both cases, there was development of severe sigmoid sinus and jugular bulb stenosis, increasing intracranial venous congestion and causing marked clinical deterioration. The stenosis prevented traditional transvenous access and treatment. We describe a direct puncture transverse sinus access using a burr hole approach for endovascular transvenous embolization in both cases with successful clinical outcomes., Conclusion: Direct access using burr hole craniotomy to the transverse sinus for transvenous endovascular embolization is a safe approach in the setting of severe jugular bulb stenosis for treatment of VOGMs. This technique can be done efficiently to achieve complete flow elimination in the malformation, in cases where that is called for, without significant risks or complications related to the approach., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

To elucidate the pathogenesis of vein of Galen malformations (VOGMs), the most common and most severe of congenital brain arteriovenous malformations, we performed an integrated analysis of 310 VOGM proband-family exomes and 336,326 human cerebrovasculature single-cell transcriptomes. We found the Ras suppressor p120 RasGAP (RASA1) harbored a genome-wide significant burden of loss-of-function de novo variants (2042.5-fold, p = 4.79 x 10 -7 ). Rare, damaging transmitted variants were enriched in Ephrin receptor-B4 (EPHB4) (17.5-fold, p = 1.22 x 10 -5 ), which cooperates with p120 RasGAP to regulate vascular development. Additional probands had damaging variants in ACVRL1, NOTCH1, ITGB1, and PTPN11. ACVRL1 variants were also identified in a multi-generational VOGM pedigree. Integrative genomic analysis defined developing endothelial cells as a likely spatio-temporal locus of VOGM pathophysiology. Mice expressing a VOGM-specific EPHB4 kinase-domain missense variant (Phe867Leu) exhibited disrupted developmental angiogenesis and impaired hierarchical development of arterial-capillary-venous networks, but only in the presence of a "second-hit" allele. These results illuminate human arterio-venous development and VOGM pathobiology and have implications for patients and their families., (© 2023. The Author(s).)

Objective: To assess the extent and resolution of pulmonary hypertension (PH), cardiovascular factors, and echocardiographic findings associated with mortality in infants and children with vein of Galen malformation (VOGM)., Study Design: We performed a retrospective review of 49 consecutive children with VOGM admitted to Boston Children's Hospital from 2007 to 2020. Patient characteristics, echocardiographic data, and hospital course were analyzed for 2 cohorts based on age at presentation to Boston Children's Hospital: group 1 (age ≤60 days) or group 2 (age >60 days)., Results: Overall hospital survival was 35 of 49 (71.4%); 13 of 26 (50%) in group 1 and 22 of 23 (96%) in group 2 (P < .001). High-output PH (P = .01), cardiomegaly (P = .011), intubation (P = .019), and dopamine use (P = .01) were significantly more common in group 1 than group 2. Among patients in group 1, congestive heart failure (P = .015), intubation (P < .001), use of inhaled nitric oxide (P = .015) or prostaglandin E1 (P = .030), suprasystemic PH (P = .003), and right-sided dilation were significantly associated with mortality; in contrast, left ventricular volume and function, structural congenital heart disease, and supraventricular tachycardia were not associated. Inhaled nitric oxide achieved no clinical benefit in 9 of 11 treated patients. Resolution of PH was associated with overall survival (P < .001)., Conclusions: VOGM remains associated with substantial mortality among infants presenting at ≤60 days of life owing to factors associated with high output PH. Resolution of PH is an indicator associated with survival and a surrogate end point for benchmarking outcomes., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Competing Interests: Competing interests: None declared.

Background: Digital subtraction angiography (DSA) assesses revascularization in pediatric moyamoya patients after surgery, but MRI and angiography (MRI/A) may provide comparable data., Objective: To evaluate DSA and MRI/A with respect to clinical utility in postoperative follow-up, complication profile, and relative cost at 1 year., Methods: All pediatric moyamoya patients who received bilateral indirect revascularization between 2011 and 2020 were retrospectively reviewed at 1 institution. Patients who underwent MRI/A-only, DSA-only, or both after 1 year were compared., Results: Eighty-two patients were included. At 1 year, patients who underwent either MRI/A (n = 29) or DSA (n = 40) had no significant differences in detection rate of new at-risk hypovascular territories (6.9% vs 2.5%, P = .568) or need for subsequent revascularization beyond the mean 40 ± 24-month follow-up period (3.4% vs 5.0%, P > .9). Among patients who underwent both MRI/A and DSA (n = 13), both studies identified the same at-risk territories. No patients experienced MRI/A-related complications, compared with 3 minor DSA-related complications. The use of MRI/A yielded a 6.5-fold reduction in cost per study vs DSA at 1 year., Conclusion: Using DSA to follow moyamoya patients after indirect revascularization is generally safe but associated with a low rate of minor complications and a 6.5-fold greater financial cost relative to MRI/A. These data support changing practice to eliminate the use of DSA when following routine bilateral moyamoya cases in the absence of clinical symptoms or specific concerns. Using MRI/A as the primary postoperative follow-up modality in this select population provides noninferior care and greater patient access, while reducing cost and potentially decreasing risk., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Introduction: Computational fluid dynamics (CFD) assess biological systems based on specific boundary conditions. We propose modeling more advanced hemodynamic metrics, such as core line length (CL) and critical points which characterize complexity of flow in the context of cerebral vasculature, and specifically cerebral veins during the physiologically evolving early neonatal state of vein of Galen malformations (VOGM). CFD has not been applied to the study of arteriovenous shunting in Vein of Galen Malformations but could help illustrate the pathophysiology of this malformation. Methods: Three neonatal patients with VOGM at Boston Children's Hospital met inclusion criteria for this study. Structural MRI data was segmented to generate a mesh of the VOGM and venous outflow. Boundary condition flow velocity was derived from PC-MR sequences with arterial and venous dual velocity encoding. The mesh and boundary conditions were applied to model the cerebral venous flow. We computed flow variables including mean wall shear stress (WSSmean), mean OSI, CL, and the mean number of critical points (nCrPointsmean) for each patient specific model. A critical point is defined as the location where the shear stress vector field is zero (stationary point) and can be used to describe complexity of flow. Results: The division of flow into the left and right venous outflow was comparable between PC-MR and CFD modeling. A high complexity recirculating flow pattern observed on PC-MR was also identified on CFD modeling. Regions of similar WSSmean and OSImean (<1.3 fold) in the left and right venous outflow channels of a single patient have several-fold magnitude difference in higher order hemodynamic metrics (> 3.3 fold CL, > 1.7 fold nCrPointsmean). Specifically, the side which developed JBS in each model had greater nCrPointsmean compared to the jugular bulb with no stenosis (VOGM1: 4.49 vs. 2.53, VOGM2: 1.94 vs. 0, VOGM3: 1 vs. 0). Biologically, these regions had subsequently divergent development, with increased complexity of flow associating with venous stenosis. Discussion: Advanced metrics of flow complexity identified in computational models may reflect observed flow phenomena not fully characterized by primary or secondary hemodynamic parameters. These advanced metrics may indicate physiological states that impact development of jugular bulb stenosis in VOGM., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Hadad, Rangwala, Stout, Mut, Orbach, Cebral and See.)

Objective: Neurosurgical outcomes are not well defined in the management of pediatric patients with cerebral venous sinus thrombosis (CVST) following acute mastoiditis. Specific notable sequelae are otogenic (otitic) hydrocephalus and CVST management. Correspondingly, the aim of this study was to integrate the currently published metadata to summarize these outcomes., Methods: Electronic searches were performed using the Ovid Embase, PubMed, Scopus, and Cochrane databases from inception to November 2022 following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Cohort-level data were then abstracted for analysis for appropriate pediatric patients. Outcomes were pooled by random-effects meta-analyses of proportions where possible., Results: Twenty-three study cohorts describing 312 pediatric patients with otogenic CVST were included. At a cohort level, the median patient age was 6 years among 181 boys (58%) and 131 girls (42%). Modeling indicated papilledema at presentation in 46% of cases (95% CI 30%-62%). Regarding management, antibiotics were applied universally in all cases, mastoidectomy or other otologic surgery was performed in 91% (95% CI 82%-98%), and prophylactic anticoagulation was administered in 86% (95% CI 75%-95%). There was only 1 case (0.3%) of postprocedural intracranial hemorrhage, and there were no deaths reported among all studies. Although diagnostic lumbar puncture was performed in 14% (95% CI 3%-28%) at presentation, clinical otogenic hydrocephalus was ultimately suspected in 31% (95% CI 14%-49%), and acetazolamide was given in 65% (95% CI 35%-91%) overall. There were 10 cases (3%) that proceeded to permanent CSF diversion in the form of ventricular shunting. At a median follow-up of 8 months among all studies, the venous sinus was completely recanalized in 67% (95% CI 53%-79%)., Conclusions: Most CVSTs following acute mastoiditis will recanalize with the standard use of antibiotics, otologic surgery, and anticoagulation, with minimal symptomatic hemorrhage risk. However, an appreciable proportion of these patients will develop symptomatic otogenic hydrocephalus, and it is imperative that the appropriate surveillance and workup is performed to fully optimize patient outcomes long-term. The possible need for permanent CSF diversion should be recognized.

Background: Vascular access in neonates is limited by the small size of the femoral artery and the risk of complications, including thrombosis and limb ischemia. Although umbilical artery access has been described, previous reports detail exchange of the umbilical artery catheter (UAC) for a conventional arterial sheath, which can be difficult and cumbersome. We aim to describe direct use of the UAC as the sheath and guide catheter in neonatal patients requiring endovascular treatment for life-threatening intracranial arteriovenous shunts., Methods: We reviewed all cases between 2016 and 2021 of neonatal intervention using a direct UAC approach. We describe our technique of utilizing UACs for cerebral angiography and neurointerventions in newborns without catheter exchange, allowing for repeated, straightforward endovascular access in neonates across multiple interventions., Results: Seven consecutive neonates underwent endovascular neurointerventional procedures for the treatment of life-threatening, high-flow arteriovenous shunts using a direct UAC access technique without procedural morbidity. Five of seven patients underwent more than one procedure in the neonatal period, between day 1 and day 10 of life., Conclusions: Use of the UAC itself as a diagnostic catheter for cerebral angiography or as a guide catheter for neurointerventions greatly facilitates endovascular interventions in newborns and is ideal for patients requiring multiple interventions in the neonatal period. This technique helps to mitigate the risk of neonatal femoral artery access and its complications, including thrombosis, dissection, spasm, stenosis, and limb ischemia., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Pediatric neurointervention is challenged by the appropriateness of adult catheters and devices. This multicenter report on the smallest groin access sheaths offers technical notes and clinical outcomes in the pediatric neurointerventional population., Methods: All pediatric neurointerventional cases from 2019 to 2021 were reviewed for use of a 3.3F Pediavascular or a 4F Merit Prelude Ideal low profile sheath. Hospital records were reviewed for complications and technical notes and compared with arterial groin access with the 4F Terumo Pinnacle in infants less than 1 year old, before the low profile sheaths at one author's institution were introduced., Results: From January 1, 2019 to March 31, 2021 there were 347 procedures performed at Boston Children's Hospital and University of Wisconsin. Forty-four procedures in 26 patients were identified in which a 3.3F (38 cases, 20 patients) or 4F (6 cases, 6 patients) sheath was used. The average age was 2.2 years (1.5 days to 18 years). Retinoblastoma intra-arterial chemotherapy infusion (18 of 44) was the most common indication. The remaining procedures comprised vein of Galen embolization (12), diagnostic cerebral angiography (13), and one preoperative tumor embolization. Morbidity included a groin hematoma and decreased pulses (4.5%). No major groin complications occurred. There was no statistically significant difference compared with the historical cohort (132 procedures), which had seven instances of decreased pulses (5.3%, p>0.05)., Conclusion: The 3.3F Pediavascular and 4F Merit Prelude Ideal sheaths are easily incorporated into the pediatric neurointerventionalist's armamentarium for infants and readily accommodate various microcatheters for distal embolization and catheterization., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Purpose: Brain injury in fetuses with vein of Galen malformations and nongalenic AVFs is a rare complication whose appearance, course, and prognosis are poorly studied. We sought to characterize the MR imaging features and examine associations with postnatal outcome., Materials and Methods: This was a retrospective analysis of fetal MRIs of subjects with vein of Galen malformation and nongalenic arteriovenous fistulas. Two pediatric neuroradiologists independently reviewed examinations to determine the presence of abnormalities on structural imaging (T1 volumetric interpolated breath-hold examination and T2-HASTE), DWI, and T2*-weighted images; discrepancies were adjudicated by a third reviewer. Radiologic progression of injury was determined by additional fetal or neonatal MRIs. A simple composite score evaluating poor neonatal clinical outcome as either intubation or death by postnatal day 2 was also queried. A body fetal imager evaluated the presence of systemic findings of right heart strain., Results: Forty-nine fetal MR imaging examinations corresponding to 31 subjects (27 vein of Galen malformations and 4 nongalenic AVF cases) were analyzed. Injury was observed in 8 subjects (26%) with 14 fetal examinations; the mean gestational age at identification of injury was 32.2 (SD 4.9) weeks. Structural abnormalities were present in all subjects with injury; restricted diffusion, in 5/7 subjects with available data; and T2* abnormalities, in all subjects with available data ( n = 7). Radiologic progression was documented in all cases with follow-up imaging ( n = 7). All subjects with fetal brain injury had a poor neonatal clinical outcome., Conclusions: Brain injury in fetuses with vein of Galen malformation and nongalenic AVFs shows a combination of structural abnormalities, restricted diffusion, and blooming on T2* images. Injury appears to portend a poor prognosis, with relentless progression and a likely association with adverse neonatal outcomes., (© 2022 by American Journal of Neuroradiology.)

Introduction: Although endovascular techniques have improved outcomes in vein of Galen malformations (VOGM), there is still a high rate of morbidity and mortality, particularly among cases with decompensation in the neonatal period. The dimension of the draining venous sinus on fetal imaging correlates with the risk of neonatal decompensation. In fetuses within this high-risk group who do not have end-organ injury, there is a theoretical therapeutic opportunity to reduce the arteriovenous shunt before the normal physiological changes of birth precipitate decompensation. This study investigates the safety and potential benefit of treating a VOGM in utero, which has not been previously studied., Methods and Analysis: This study aims to enroll 20 subjects: pregnant women with a fetus harbouring a high-risk VOGM (defined on MRI by a narrowest medial-lateral width greater than 8 mm in the draining venous sinus). Unfortunately, the subset of fetuses with in utero end-organ injury is ineligible, because the late stage of pathology is not amenable to recovery from a cerebrovascular intervention, likely not even in utero. This study aims to alter the physiology before such developments accrue.At or after 23 weeks of gestation, a transuterine transposterior fontanelle needle puncture to the torcular allows ultrasound-guided deployment of coils to embolise the draining venous malformation.This study has 97.5% power to detect major safety events at 30% or greater, and 80% power to detect a reduction in the rate of neonatal intervention from 80% to 30%. In the staged study design, an interval evaluation after 11 patients invokes study termination if safety events occur above the allowed threshold., Ethics and Dissemination: The institutional review boards at Mass General Brigham and Boston Children's Hospital (BCH) reviewed and approved this protocol. The BCH Department of Radiology and a patient family philanthropic donation fund this study. The trial results will be published in peer-reviewed journals and presented at scientific conferences., Trial Registration Number: NCT04434729., Competing Interests: Competing interests: APS is on the scientific advisory board for Microbot Medical with CSF diverting implants. CSF diversion represents a rare intervention in infants with vein of Galen malformations, but every effort is made to avoid CSF diversion in the VOGM population, and this is not a component of the intervention studied or reported here., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: Clinical manifestations of blue rubber bleb nevus syndrome (BRBNS) and multifocal venous malformation (MVM) vary depending on the location of the lesions. The aim of this study was to assess the risk of developing CSF leaks in patients with epidural venous malformations (VMs)., Methods: The authors retrospectively investigated the relationship between the development of a CSF leak and the presence of epidural VMs., Results: Nine patients (5 females) had epidural VMs and presentation that was confirmatory or suggestive of a CSF leak: 4 had BRBNS, 4 had MVMs, and 1 had a solitary VM. Of 66 patients with BRBNS, clinical and imaging features of CSF leak were noted in 3 (4.5%) with epidural VMs at the age of 11-44 years. A fourth patient had suggestive symptoms without imaging confirmation. An epidural blood patch was ineffective in 2 patients, both with more than one source of leakage, requiring surgical repair or decompression. Symptomatic downward displacement of the cerebellar tonsils was noted in 3 patients with MVM and 1 with a solitary VM; 3 required surgical decompression., Conclusions: These findings suggest an increased risk of CSF leak in patients with epidural VM, including BRBNS, MVMs, and solitary VMs. Awareness of the association between epidural VM and CSF leakage may facilitate earlier diagnosis and therapeutic intervention.

Objective: Ivy sign is a radiographic finding on FLAIR MRI sequences and is associated with slow cortical blood flow in moyamoya. Limited data exist on the utility of the ivy sign as a diagnostic and prognostic tool in pediatric patients, particularly outside of Asian populations. The authors aimed to investigate a modified grading scale with which to characterize the prevalence and extent of the ivy sign in children with moyamoya and evaluate its efficacy as a biomarker in predicting postoperative outcomes, including stroke risk., Methods: Pre- and postoperative clinical and radiographic data of all pediatric patients (21 years of age or younger) who underwent surgery for moyamoya disease or moyamoya syndrome at two major tertiary referral centers in the US and Israel, between July 2009 and August 2019, were retrospectively reviewed. Ivy sign scores were correlated to Suzuki stage, Matsushima grade, and postoperative stroke rate to quantify the diagnostic and prognostic utility of ivy sign., Results: A total of 171 hemispheres in 107 patients were included. The median age at the time of surgery was 9 years (range 3 months-21 years). The ivy sign was most frequently encountered in association with Suzuki stage III or IV disease in all vascular territories, including the anterior cerebral artery (53.7%), middle cerebral artery (56.3%), and posterior cerebral artery (47.5%) territories. Following surgical revascularization, 85% of hemispheres with Matsushima grade A demonstrated a concomitant, statistically significant reduction in ivy sign scores (OR 5.3, 95% CI 1.4-20.0; p = 0.013). Postoperatively, revascularized hemispheres that exhibited ivy sign score decreases had significantly lower rates of postoperative stroke (3.4%) compared with hemispheres that demonstrated no reversal of the ivy sign (16.1%) (OR 5.5, 95% CI 1.5-21.0; p = 0.008)., Conclusions: This is the largest study to date that focuses on the role of the ivy sign in pediatric moyamoya. These data demonstrate that the ivy sign was present in approximately half the pediatric patients with moyamoya with Suzuki stage III or IV disease, when blood flow was most unstable. The authors found that reversal of the ivy sign provided both radiographic and clinical utility as a prognostic biomarker postoperatively, given the statistically significant association with both better Matsushima grades and a fivefold reduction in postoperative stroke rates. These findings can help inform clinical decision-making, and they have particular value in the pediatric population, as the ability to minimize additional radiographic evaluations and tailor radiographic surveillance is requisite.

Importance: Moyamoya disease (MMD), a progressive vasculopathy leading to narrowing and ultimate occlusion of the intracranial internal carotid arteries, is a cause of childhood stroke. The cause of MMD is poorly understood, but genetic factors play a role. Several familial forms of MMD have been identified, but the cause of most cases remains elusive, especially among non-East Asian individuals., Objective: To assess whether ultrarare de novo and rare, damaging transmitted variants with large effect sizes are associated with MMD risk., Design, Setting, and Participants: A genetic association study was conducted using whole-exome sequencing case-parent MMD trios in a small discovery cohort collected over 3.5 years (2016-2019); data were analyzed in 2020. Medical records from US hospitals spanning a range of 1 month to 1.5 years were reviewed for phenotyping. Exomes from a larger validation cohort were analyzed to identify additional rare, large-effect variants in the top candidate gene. Participants included patients with MMD and, when available, their parents. All participants who met criteria and were presented with the option to join the study agreed to do so; none were excluded. Twenty-four probands (22 trios and 2 singletons) composed the discovery cohort, and 84 probands (29 trios and 55 singletons) composed the validation cohort., Main Outcomes and Measures: Gene variants were identified and filtered using stringent criteria. Enrichment and case-control tests assessed gene-level variant burden. In silico modeling estimated the probability of variant association with protein structure. Integrative genomics assessed expression patterns of MMD risk genes derived from single-cell RNA sequencing data of human and mouse brain tissue., Results: Of the 24 patients in the discovery cohort, 14 (58.3%) were men and 18 (75.0%) were of European ancestry. Three of 24 discovery cohort probands contained 2 do novo (1-tailed Poisson P = 1.1 × 10-6) and 1 rare, transmitted damaging variant (12.5% of cases) in DIAPH1 (mammalian diaphanous-1), a key regulator of actin remodeling in vascular cells and platelets. Four additional ultrarare damaging heterozygous DIAPH1 variants (3 unphased) were identified in 3 other patients in an 84-proband validation cohort (73.8% female, 77.4% European). All 6 patients were non-East Asian. Compound heterozygous variants were identified in ena/vasodilator-stimulated phosphoproteinlike protein EVL, a mammalian diaphanous-1 interactor that regulates actin polymerization. DIAPH1 and EVL mutant probands had severe, bilateral MMD associated with transfusion-dependent thrombocytopenia. DIAPH1 and other MMD risk genes are enriched in mural cells of midgestational human brain. The DIAPH1 coexpression network converges in vascular cell actin cytoskeleton regulatory pathways., Conclusions and Relevance: These findings provide the largest collection to date of non-East Asian individuals with sporadic MMD harboring pathogenic variants in the same gene. The results suggest that DIAPH1 is a novel MMD risk gene and impaired vascular cell actin remodeling in MMD pathogenesis, with diagnostic and therapeutic ramifications.

Competing Interests: Competing interests: None declared.

Objective: Isolated anterior cerebral artery (ACA) territory ischemia in pediatric moyamoya disease (MMD) is rare but has been increasingly recognized, particularly in children manifesting progression of disease in a delayed fashion after middle cerebral artery revascularization surgery. Surgical treatment is complicated by limited graft choices, with the small number of case series largely focused on complex, higher-risk operations (omental flap transfers, large interhemispheric rotational grafts); direct bypass (often untenable in children due to vessel size); or, alternatively, the technically simpler method of multiple burr holes (of limited efficacy outside of infants). Faced with the problem of a growing cohort of pediatric patients with MMD that could benefit from anterior cerebral revascularization, the authors sought to develop a solution that was specifically designed for children and that would be lower risk than the more complex approaches adapted from adult populations but more effective than simple burr holes. In this study, the authors aimed to describe the long-term clinical and radiographic outcomes of a novel approach of pial pericranial dural (PiPeD) revascularization, building on the principles of pial synangiosis but unique in using the pericranium and the dura mater as the primary vascular supply, and employing a larger craniotomy with arachnoid dissection to provide robust full-territory revascularization in all ages with reduced risk relative to more complex procedures., Methods: The medical records of all pediatric patients with MMD who presented at a single center between July 2009 and August 2019 were retrospectively reviewed to identify patients with MMD with anterior cerebral territory ischemia. Clinical characteristics, surgical indications, operative techniques, and long-term clinical and radiographic follow-up data were collected and analyzed., Results: A total of 25 operations (5.6% of total procedures) were performed in 21 patients (mean age 9.4 years [range 1-16.5 years]; 12 female and 9 male). Almost one-third of the patients had syndromic associations, with no familial cases. Complications included 1 patient (4.7%) with a superficial infection, with no postoperative strokes, hemorrhage, seizures, or deaths. Long-term follow-up was available in 18 of 21 patients (mean 24.9 months [range 4-60 months]). Radiographic engraftment was present in 90.9% (20/22 hemispheres), and no new strokes were evident on MRI on long-term follow-up, despite radiographic progression of the disease., Conclusions: The use of the pericranium and the dura mater for indirect revascularization provided robust vascularized graft with great flexibility in location and high potential for engraftment, which may obviate more complex and higher-risk operations for ACA territory ischemia. Long-term follow-up demonstrated that PiPeD revascularization conferred durable, long-term radiographic and clinical protection from stroke in pediatric patients with MMD. Based on the results of the current study, the PiPeD technique can be considered an additional tool to the armamentarium of indirect revascularization procedures in select pediatric patients with MMD.

Introduction: A major difficulty in treating moyamoya disease is the lack of effective methods to detect novel or progressive disease prior to the onset of disabling stroke. More importantly, a tool to better stratify operative candidates and quantify response to therapy could substantively complement existing methods. Here, we present proof-of-principle data supporting the use of urinary biomarkers as diagnostic adjuncts in pediatric moyamoya patients. Methods: Urine and cerebrospinal fluid specimens were collected from pediatric patients with moyamoya disease and a cohort of age and sex-matched control patients. Clinical and radiographic data were paired with measurements of a previously validated panel of angiogenic proteins quantified by ELISA. Results were compared to age and sex-matched controls and subjected to statistical analyses. Results: Evaluation of a specific panel of urinary and cerebrospinal fluid biomarkers by ELISA demonstrated significant elevations of angiogenic proteins in samples from moyamoya patients compared to matched controls. ROC curves for individual urinary biomarkers, including MMP-2, MMP-9, MMP-9/NGAL, and VEGF, showed excellent discrimination. The optimal urinary biomarker was MMP-2, providing a sensitivity of 88%, specificity of 100%, and overall accuracy of 91%. Biomarker levels changed in response to therapy and correlated with radiographic evidence of revascularization. Conclusions: We report, for the first time, identification of a panel of urinary biomarkers that predicts the presence of moyamoya disease. These biomarkers correlate with presence of disease and can be tracked from the central nervous system to urine. These data support the hypothesis that urinary proteins are useful predictors of the presence of moyamoya disease and may provide a basis for a novel, non-invasive method to identify new disease and monitor known patients following treatment., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Sesen, Driscoll, Moses-Gardner, Orbach, Zurakowski and Smith.)

Importance: Vascular anomalies of the head and neck are relatively rare lesions. Management is challenging because of the high likelihood of involvement of functionally critical structures. Multiple modalities of treatment exist for vascular anomalies of the head and neck, including medical therapies, sclerotherapy and embolization procedures, and surgery. This review focuses on the accurate diagnosis and the relative roles of the various therapeutic options., Observations: Vascular anomalies are classified by the International Society for the Study of Vascular Anomalies into 2 major groups: vascular tumors and vascular malformations. Vascular tumors encompass proliferative lesions ranging from infantile and congenital hemangiomas to kaposiform hemangioendothelioma. Alternatively, vascular malformations are embryologic errors in vasculogenesis. This article focuses on the management of vascular malformations. The 3 primary vascular malformation subclassifications are lymphatic, venous, and arteriovenous. The burden of disease, diagnosis, and current management options are discussed in detail for each subtype., Conclusions and Relevance: Most vascular malformations of the head and neck require a multidisciplinary approach. Available medical, interventional radiologic, and surgical interventions are constantly evolving. Optimization of function and cosmesis must be balanced with minimization of treatment-associated morbidity. Otolaryngologists-head and neck surgeons must remain up to date regarding options for diagnosis and management of these lesions.

Background: Significant advances have been reported recently in the genetic and mechanistic characterization of extracranial venous malformations. However, intracranial purely venous malformations (icVM) analogous to those outside the CNS have not been systematically described., Purpose: We sought to ascertain whether such an entity as icVM could in fact be identified, distinct from previously described CNS venous anomalies and analogous to extracranial venous malformations., Methods: Our prospectively collected pediatric cerebrovascular database was reviewed to identify patients with icVM; 1458 consecutive angiograms and/or angiographic interventions performed on 706 children at our institution from October, 2006 through May, 2019 were evaluated, in addition to outside imaging studies on 192 additional patients sent to our Vascular Anomalies Center for cerebrovascular review during the same time period. Thus, the cohort consisted of 898 children., Results: Nineteen of 898 patients (2.1%) were found to harbor icVM, including 9 (47.3%) with sinus pericranii, 15 (78.9%) with associated large, complex extracranial venous malformations, and 3 (15.7%) with neurocognitive delay. There was no intracranial hemorrhage or venous hypertension seen in the cohort. Asymptomatic venous thrombosis in the superior sagittal sinus was seen in three patients., Conclusion: Venous malformations, both extracranial and icVM, share many characteristics that are distinct from developmental venous anomalies. icVM were not associated with venous hypertension. The underlying genetic mutations involved in the development of icVM, germ-line or somatic, remain to be elucidated, but may very well involve shared mechanisms and pathways with extracranial venous malformations.

Objective: To describe the clinical, radiologic, and histopathologic features of "congenital disseminated pyogenic granuloma" involving various organs with high morbidity related to cerebral hemorrhagic involvement., Study Design: We searched the database of the Vascular Anomalies Center at Boston Children's Hospital from 1999 to 2019 for patients diagnosed as having multiple vascular lesions, visceral vascular tumors, congenital hemangiomatosis, multiple pyogenic granulomas, or multiple vascular lesions without a definite diagnosis. A retrospective review of the medical records, photographs, histopathologic, and imaging studies was performed. Only patients with imaging studies and histopathologic diagnosis of pyogenic granuloma were included., Results: Eight children (5 male, 3 female) had congenital multifocal cutaneous vascular tumors. Lesions also were found in the brain (n = 7), liver (n = 4), spleen (n = 3), muscles (n = 4), bone (n = 3), retroperitoneum (n = 3), and intestine/mesentery (n = 2). Less commonly affected were the spinal cord, lungs, kidneys, pancreas, and adrenal gland (n = 1 each). The mean follow-up period was 21.8 months. The cerebral and visceral lesions were hemorrhagic with severe neurologic sequelae. The histopathologic diagnosis was pyogenic granuloma with prominent areas of hemorrhage and necrosis. The endothelial cells had enlarged nuclei, pale cytoplasm and were immunopositive for CD31 and negative for D2-40 and glucose transporter 1., Conclusions: Congenital disseminated pyogenic granuloma is a distinct multisystemic aggressive disorder that primarily affects the skin, brain, visceral organs, and musculoskeletal system. Differentiation of this entity from other multiple cutaneous vascular lesions is critical because of possible cerebral hemorrhagic involvement., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: This survey was focused on the provision of neurointerventional services, the current practices of managing patients under COVID-19 conditions, and the expectations for the future., Methods: Invitations for this survey were sent out as a collaborative effort of the European Society of Minimally Invasive Neurological Therapy (ESMINT), the Society of NeuroInterventional Surgery (SNIS), the Sociedad Iberolatinoamericana de Neuroradiologia Diagnostica y Terapeutica (SILAN), the Society of Vascular and Interventional Neurology (SVIN), and the World Federation of Interventional and Therapeutic Neuroradiology (WFITN)., Results: Overall, 475 participants from 61 countries responded (six from Africa (1%), 81 from Asia (17%), 156 from Europe (33%), 53 from Latin America (11%), and 172 from North America (11%)). The majority of participants (96%) reported being able to provide emergency services, though 26% of these reported limited resources. A decrease in emergency procedures was reported by 69% of participants (52% in ischemic and hemorrhagic stroke, 11% ischemic, and 6% hemorrhagic stroke alone). Only 4% reported an increase in emergency cases. The emerging need for social distancing and the rapid adoption of remote communication was reflected in the interest in establishing case discussion forums (43%), general online forums (37%), and access to angio video streaming for live mentoring and support (33%)., Conclusion: Neurointerventional emergency services are available in almost all centers, while the number of emergency patients is markedly decreased. Half of the participants have abandoned neurointerventions in non-emergent situations. There are considerable variations in the management of neurointerventions and in the expectations for the future., Competing Interests: Competing interests: Consultancy: Acandis, Bayer, Boehringer Ingelheim, Cerenovus, Medtronic, Microvention, Stryker, CD: Proctor Medtronic. DL: Consultant to Cerenovus, Genentech, Stryker, Medtronic as Imaging Core Lab. WJ: Consultancy: Rebound Therapeutics, Integra, Viseon, Imperative Care, Medtronic, Q’Apel, Stream Biomedical, Spartan Micro; Investor: Cerebrotech, Endostream, Viseon, Rebound, and Spartan Micro, JMM: Disclosures are: Penumbra: speaker’s bureau, Stryker: Consultant., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Purpose: Neonates with vein of Galen malformations are split into 2 cohorts: one needing urgent neonatal embolization, with relatively high mortality and morbidity even with expert care, and a cohort in which embolization can be deferred until infancy, with far better prognosis. We aimed to identify brain MR imaging characteristics obtained from fetal and early neonatal scans that can predict the clinical presentation., Materials and Methods: Patients with vein of Galen malformations were stratified into a neonatal at-risk cohort if the patient needed urgent neonatal intervention or if neonatal death occurred; or an infantile treatment cohort if they were stable enough not to require treatment until >1 month of age. Twelve vascular MR imaging parameters, measured by 2 independent observers, were systematically correlated with the need for early neonatal intervention and/or neonatal mortality., Results: A total of 32 neonatal patients (21 patients in the neonatal at-risk cohort, 11 in the infantile treatment cohort) were identified. Maximal mediolateral diameter (area under the curve  = 0.866, P  < .001) and cross-sectional area (area under the curve = 0.836, P  = .002 ) at the narrowest point of the straight or falcine sinus were most predictive of clinical evolution into the neonatal at-risk cohort. There were 15 patients who had fetal MRIs (10 in the neonatal at-risk cohort and 5 in the infantile treatment cohort). Here too, maximal mediolateral diameter (area under the curve = 0.980, P  = .003) and cross-sectional area (area under the curve  = 0.941, P  = .007) at the narrowest point of the straight or falcine sinus were highly predictive of the neonatal at-risk cohort., Conclusions: Early neonatal and fetal MR imaging can be readily used for accurate early risk stratification, assisting in directing resources, timing treatment decisions, and identifying appropriate cohorts for novel interventions., (© 2020 by American Journal of Neuroradiology.)

We investigated (1) EphrinB2 and EphB4 receptor expression in cerebral AVMs, (2) the impact of an altered EphrinB2:EphB4 ratio on brain endothelial cell function and (3) potential translational applications of these data. The following parameters were compared between AVM endothelial cells (AVMECs) and human brain microvascular endothelial cells (HBMVECs): quantified EphrinB2 and EphB4 expression, angiogenic potential, and responses to manipulation of the EphrinB2:EphB4 ratio via pharmacologic stimulation/inhibition. To investigate the clinical relevance of these in vitro data, Ephrin expression was assessed in AVM tissue (by immunohistochemistry) and urine (by ELISA) from pediatric patients with AVM (n = 30), other cerebrovascular disease (n = 14) and control patients (n = 29), and the data were subjected to univariate and multivariate statistical analyses. Compared to HBMVECs, AVMECs demonstrated increased invasion (p = 0.04) and migration (p = 0.08), impaired tube formation (p = 0.06) and increased EphrinB2:EphB4 ratios. Altering the EphrinB2:EphB4 ratio (by increasing EphrinB2 or blocking EphB4) in HBMVECs increased invasion (p = 0.03 and p < 0.05, respectively). EphrinB2 expression was increased in AVM tissue, which correlated with increased urinary EphrinB2 levels in AVM patients. Using the optimal urinary cutoff value (EphrinB2 > 25.7 pg/μg), AVMs were detected with high accuracy (80% vs. controls) and were distinguished from other cerebrovascular disease (75% accuracy). Post-treatment urinary EphrinB2 levels normalized in an index patient. In summary, AVMECs have an EphrinB2:EphB4 ratio that is increased compared to that of normal HBMVECs. Changing this ratio in HBMVECs induces AVMEC-like behavior. EphrinB2 is clinically relevant, and its levels are increased in AVM tissue and patient urine. This work suggests that dysregulation of the EphrinB2:EphB4 signaling cascade and increases in EphrinB2 may play a role in AVM development, with potential utility as a diagnostic and therapeutic target.

Purpose: Endovascular therapy benefits selected adults with acute stroke while data are lacking for children. The purpose of this study was to assess physician practice and institutional preparedness for endovascular therapy in pediatric stroke., Methods: A link to an anonymous online survey was sent to members of the International Pediatric Stroke Study (IPSS) group about physician experience with endovascular therapy, likelihood of treatment for provided clinical vignettes, and institutional readiness for the delivery of endovascular therapy to children., Results: Thirty-one pediatric physicians with a mean of 11 years (SD 7.1) of experience responded. All but two would consider endovascular therapy in a child, and 20 (64.5%) had recommended endovascular therapy for a child in the preceding year. Most (n = 19, 67.9%) did not commit to an age minimum for endovascular therapy. Sixteen (57.1%) would consider treatment up to 24 h after symptom onset with 19 (67.9%) respondents reporting that their practice changed after the 2018 American Heart Association guidelines extended the time window for endovascular therapy in adults. Seventeen (60.7%) preferred imaging that included perfusion in children presenting beyond 6 h. Nineteen (70.4%) had institutional endovascular therapy criteria. Physicians in larger pediatric groups had more "likely to treat" responses on the clinical vignettes than physicians working in smaller groups (11.7 vs. 6.1, p < 0.05)., Conclusion: Pediatric stroke physicians are largely willing to consider endovascular therapy with most changing their practice according to adult guidelines, though experience and selection criteria varied. These findings may help to inform consensus guidelines and clinical trial development.

The literature has long attempted distinct classifications of arteriovenous fistulae and arteriovenous malformations of the spine.1-3 It is worth noting that lesions can become more complex during recurrence and may not adhere to traditional definitions. In these cases, recognizing the principles of pathology and pathophysiology can guide management and treatment. We present the case of a spinal arteriovenous malformation with recurrence after prior treatment that is managed in the setting of a second opinion with a multidisciplinary approach. This case demonstrates (1) an evolution of recurrent arteriovenous shunting pathology observed both in the endovascular suite, and under direct microscopic visualization and (2) considerations in multimodal treatment with endovascular devices during microsurgical dissection and extirpation.  This manuscript was prepared with informed assent provided by the patient (a minor) and with informed consent by the parent of the patient, who is their legal representative and health-care proxy., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Background and Purpose: Imaging CBF is important for managing pediatric moyamoya. Traditional arterial spin-labeling MR imaging detects delayed transit thorough diseased arteries but is inaccurate for measuring perfusion because of these delays. Velocity-selective arterial spin-labeling is insensitive to transit delay and well-suited for imaging Moyamoya perfusion. This study assesses the accuracy of a combined velocity-selective arterial spin-labeling and traditional pulsed arterial spin-labeling CBF approach in pediatric moyamoya, with comparison to blood flow patterns on conventional angiography., Materials and Methods: Twenty-two neurologically stable pediatric patients with moyamoya and 5 asymptomatic siblings without frank moyamoya were imaged with velocity-selective arterial spin-labeling, pulsed arterial spin-labeling, and DSA (patients). Qualitative comparison was performed, followed by a systematic comparison using ASPECTS-based scoring. Quantitative pulsed arterial spin-labeling CBF and velocity-selective arterial spin-labeling CBF for the middle cerebral artery, anterior cerebral artery, and posterior cerebral artery territories were also compared., Results: Qualitatively, velocity-selective arterial spin-labeling perfusion maps reflect the DSA parenchymal phase, regardless of postinjection timing. Conversely, pulsed arterial spin-labeling maps reflect the DSA appearance at postinjection times closer to the arterial spin-labeling postlabeling delay, regardless of vascular phase. ASPECTS comparison showed excellent agreement (88%, κ = 0.77, P < .001) between arterial spin-labeling and DSA, suggesting velocity-selective arterial spin-labeling and pulsed arterial spin-labeling capture key perfusion and transit delay information, respectively. CBF coefficient of variation, a marker of perfusion variability, was similar for velocity-selective arterial spin-labeling in patient regions of delayed-but-preserved perfusion compared to healthy asymptomatic sibling regions (coefficient of variation = 0.30 versus 0.26, respectively, Δcoefficient of variation = 0.04), but it was significantly different for pulsed arterial spin-labeling (coefficient of variation = 0.64 versus 0.34, Δcoefficient of variation = 0.30, P < .001)., Conclusions: Velocity-selective arterial spin-labeling offers a powerful approach to image perfusion in pediatric moyamoya due to transit delay insensitivity. Coupled with pulsed arterial spin-labeling for transit delay information, a volumetric MR imaging approach capturing key DSA information is introduced., (© 2019 by American Journal of Neuroradiology.)