Symptoms Do Not Predict White Matter Injury in the Watershed Regions in Children with Moyamoya.

OBJECTIVE: To assess if white matter injuries differ in symptomatic versus asymptomatic moyamoya-affected hemispheres using diffusion magnetic resonance imaging (dMRI) since there is controversy on when or if to revascularize children with asymptomatic moyamoya. STUDY DESIGN: We conducted a cross-sectional study of children with moyamoya who underwent dMRI prior to revascularization surgery as well as controls without moyamoya. We measured the fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) 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 (TIA), seizure, or movement disorder were localizable to that hemisphere, or if the child had 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 MD, RD, and AD were higher in both symptomatic and asymptomatic moyamoya-affected hemispheres but were not significantly different from each other. CONCLUSION: 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.

Characterizing Revascularization After Encephalo-Duro-Arterio-Synangiosis (EDAS) in Adult Patients With Moyamoya Disease Using the Orbital Grading System.

BACKGROUND: The Matsushima grade has traditionally been used to evaluate vessel ingrowth from the superficial temporal artery after encephalo-duro-arterio-synangiosis (EDAS) for Moyamoya disease (MMD) patients. However, this grading is subjective and prone to measurement variability. Herein, we propose the orbital grading system quantifying leptomeningeal and burr hole-related vessel-ingrowth from the superficial temporal artery and/or middle meningeal artery to the middle and anterior cerebral arteries post EDAS in MMD patients. METHODS: An anatomical classification was developed by reference to 2 parallel vertical lines from the bony landmarks of the orbit, categorized from Grade 0-3. Regression models were used to compare clinical and functional outcomes of our grading system with the Matsushima scale. RESULTS: Forty MMD patients, with median age of 48 years, mostly females (72.5%), underwent 56 EDAS procedures. Presentation included ischemic events (65.0%), hemorrhage (22.5%), and seizures (7.5%). Most patients were categorized as Suzuki ≥ IV (69.5%). Fifty EDAS (89.9%) had concurrent burr holes placed (parietal and frontal regions). At a median follow-up of 13.7 months, collateral growth was graded as follows: grade 0 (6; 10.8%), grade 1 (12; 21.4%), grade 2 (23; 41.1%), and grade 3 (15; 26.8%). Linear regression showed similarities in the distribution between the orbital grading system and Matsushima grading (r = 0.86; P < 0.01). Ischemic events were fewer in hemispheres categorized as grade 2-3 compared to grade 0-1 (P = 0.047) as well as in Matsushima grading A or B compared to C (P = 0.047). CONCLUSIONS: The orbital grading system demonstrated agreement in identifying postoperative ischemic events as the Matsushima grade and provides a more practical and objective evaluation of collateral vessel ingrowth after EDAS with and without burr holes.

The evolution and future directions of bypass surgery.

Cerebral bypass surgery is one of the most complex and elegant procedures in neurosurgery. It involves several meticulous steps that test the skills of even the most prepared neurosurgeons. This surgery has transcended its traditional role in arterial stenosis and atherosclerosis, expanding its applications to include flow preservation techniques for complex conditions such as aneurysms, tumors, and vascular malformations. The decreased number of procedures performed across many hospitals reflects the development of newer endovascular therapies but is also due to the results of the extracranial-intracranial bypass study, the Carotid Occlusion Surgery Study, and the Carotid and Middle Cerebral Artery Occlusion Surgery Study, which have raised questions about the efficacy of cerebral bypass surgery for individuals with carotid artery occlusion who are prone to ischemic stroke. Despite this, there is still a potential benefit of bypass surgery for patients with hemodynamic impairment refractory to medical management. Also, revascularization in moyamoya vasculopathy is an effective strategy for preventing ischemic and hemorrhagic events in both children and adults. Additionally, innovations in the technique, such as the flow-regulated bypass and intraoperative flow assessment, aim to minimize perioperative morbidity. Despite bypass surgery being less performed in this current era, the teaching and development of these skills are still encouraged for future neurosurgeons, as a role for bypass will exist for the foreseeable future.

Optic Nerve Edema in Pediatric Middle Cranial Fossa Arachnoid Cysts: Report of 51 Patients From a Single Institution.

BACKGROUND: Middle fossa arachnoid cysts (MFACs) are rare, congenital lesions that may rupture and cause symptoms of elevated intracranial pressure. We sought to describe the presence of and factors associated with optic nerve edema in MFACs, focusing on the utility of ophthalmologic evaluations for guiding cyst management. METHODS: We reviewed clinical and radiographic information for all patients with MFACs with ophthalmologic evaluations at our institution. Headache, cranial nerve palsy, emesis, altered mental status, fatigue, and seizures were considered MFAC-related symptoms. Univariate and multivariable analyses evaluated factors associated with optic edema. RESULTS: Fifty-one patients between 2003 and 2022 were included. Cysts were a median volume of 169.9 cm3 (interquartile range: 70.5, 647.7). Evidence of rupture with subdural hematoma/hygroma occurred in 19 (37.3%) patients. Eighteen (35.3%) patients underwent surgery for their cyst and/or rupture-associated intracranial bleed. Eleven (21.6%) patients had optic edema; all were symptomatic and experienced cyst rupture. Ten of these patients received surgery. Postoperatively, optic edema resolved in 80% of cases. Cyst volume and symptoms were not associated with optic edema; however, patients with ruptured cysts, particularly those with traumatic rupture, were more likely to have optic edema and receive surgery (P < 0.001). CONCLUSIONS: We found optic edema in 21.6% of evaluated MFACs, and this comprised of 57.9% of ruptured cases. Optic edema was not found in unruptured cysts. Cyst fenestration improved optic edema and patient symptoms. In conjunction with clinical history and neuroimaging, optic edema may help guide MFAC management, particularly in patients with cyst rupture.

Evaluation of the safety, accuracy, and helpfulness of the GPT-4.0 Large Language Model in neurosurgery.

BACKGROUND: Although prior work demonstrated the surprising accuracy of Large Language Models (LLMs) on neurosurgery board-style questions, their use in day-to-day clinical situations warrants further investigation. This study assessed GPT-4.0's responses to common clinical questions across various subspecialties of neurosurgery. METHODS: A panel of attending neurosurgeons formulated 35 general neurosurgical questions spanning neuro-oncology, spine, vascular, functional, pediatrics, and trauma. All questions were input into GPT-4.0 with a prespecified, standard prompt. Responses were evaluated by two attending neurosurgeons, each on a standardized scale for accuracy, safety, and helpfulness. Citations were indexed and evaluated against identifiable database references. RESULTS: GPT-4.0 responses were consistent with current medical guidelines and accounted for recent advances in the field 92.8 % and 78.6 % of the time respectively. Neurosurgeons reported GPT-4.0 responses providing unrealistic information or potentially risky information 14.3 % and 7.1 % of the time respectively. Assessed on 5-point scales, responses suggested that GPT-4.0 was clinically useful (4.0 ± 0.6), relevant (4.7 ± 0.3), and coherent (4.9 ± 0.2). The depth of clinical responses varied (3.7 ± 0.6), and "red flag" symptoms were missed 7.1 % of the time. Moreover, GPT-4.0 cited 86 references (2.46 citations per answer), of which only 50 % were deemed valid, and 77.1 % of responses contained at least one inappropriate citation. CONCLUSION: Current general LLM technology can offer generally accurate, safe, and helpful neurosurgical information, but may not fully evaluate medical literature or recent field advances. Citation generation and usage remains unreliable. As this technology becomes more ubiquitous, clinicians will need to exercise caution when dealing with it in practice.

Endovascular Applications for the Management of High-Grade Gliomas in the Modern Era.

High-grade gliomas (HGGs) have a poor prognosis and are difficult to treat. This review examines the evolving landscape of endovascular therapies for HGGs. Recent advances in endovascular catheter technology and delivery methods allow for super-selective intra-arterial cerebral infusion (SSIACI) with increasing precision. This treatment modality may offer the ability to deliver anti-tumoral therapies directly to tumor regions while minimizing systemic toxicity. However, challenges persist, including blood-brain barrier (BBB) penetration, hemodynamic complexities, and drug-tumor residence time. Innovative adjunct techniques, such as focused ultrasound (FUS) and hyperosmotic disruption, may facilitate BBB disruption and enhance drug penetration. However, hemodynamic factors that limit drug residence time remain a limitation. Expanding therapeutic options beyond chemotherapy, including radiotherapy and immunobiologics, may motivate future investigations. While preclinical and clinical studies demonstrate moderate efficacy, larger randomized trials are needed to validate the clinical benefits. Additionally, future directions may involve endovascular sampling for peri-tumoral surveillance; changes in drug formulations to prolong residence time; and the exploration of non-pharmaceutical therapies, like radioembolization and photodynamic therapy. Endovascular strategies hold immense potential in reshaping HGG treatment paradigms, offering targeted and minimally invasive approaches. However, overcoming technical challenges and validating clinical efficacy remain paramount for translating these advancements into clinical care.

Yield of genetic evaluation in non-syndromic pediatric moyamoya patients.

PURPOSE: Few guidelines exist for genetic testing of patients with moyamoya arteriopathy. This study aims to characterize the yield of genetic testing of non-syndromic moyamoya patients given the current pre-test probability. METHODS: All pediatric moyamoya patients who received revascularization surgery at one institution between 2018 and 2022 were retrospectively reviewed. Patients with previously diagnosed moyamoya syndromes or therapeutic cranial radiation were excluded. RESULTS: Of 117 patients with moyamoya, 74 non-syndromic patients (44 females, 59%) were eligible. The median age at surgery was 8.1 years. Neurosurgeons referred 18 (24%) patients for neurogenetic evaluation. Eleven (61%) patients subsequently underwent genetic testing. Eight (73%) patients had available testing results. Five (62.5%) of these patients had developmental delay compared to 16 (22%) of the entire cohort. Six (75%) patients who underwent genetic testing were found to have at least one genetic variant. These results led to diagnosis of a new genetic disorder for 1 (12.5%) patient and screening recommendations for 2 (25%) patients. An RNF213 variant in one patient led to recommendations for family member screening and pulmonary hypertension screening. Another patient was diagnosed with CBL disorder and referred for cancer screening. The median age at surgery in patients with clinically actionable findings was 4.6 years compared to 9.2 years in those who were referred for genetic testing. All 3 patients who had an actionable finding had developmental delay. CONCLUSION: It may be beneficial to refer moyamoya patients under 5 for genetic screening given the high likelihood of discovering actionable mutations.

Management of Choroid Plexus Tumors and the Benefit of Preoperative Embolization in Pediatric Patients: Report of 46 Cases from a Single Institution.

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 cm3). 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 cm3) 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 cm3.

Posterior cerebral territory ischemia in pediatric moyamoya: Surgical techniques and long-term clinical and radiographic outcomes.

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.

Prevention of postoperative stroke in pediatric moyamoya patients: a standardized perioperative care protocol.

OBJECTIVE: Perioperative stroke is a major complication of revascularization surgery in patients with moyamoya. Vomiting is common after neurosurgical procedures and may result in acute changes in intracranial pressure and cerebral blood flow. The authors instituted a standardized perioperative nausea and vomiting protocol for children with moyamoya undergoing indirect bypass surgery at their institution and analyzed its association with perioperative stroke. They hypothesized that instituting a standardized perioperative nausea and vomiting protocol would be associated with reduction in the number of perioperative strokes in children with moyamoya undergoing indirect bypass surgery. METHODS: The authors retrospectively reviewed consecutive cases of children and young adults with moyamoya who underwent indirect bypass surgery before and after implementation of a new perioperative nausea and vomiting protocol at a single institution. They compared the rate of strokes in the perioperative period (postoperative days 0 and 1) in the 31 months following implementation to 31 months prior to implementation using Fisher's exact test. RESULTS: The median ages pre- and postimplementation were 8.5 (IQR 4-12) years and 8.3 (IQR 5-15) years, respectively. There were no significant differences between the cohorts in disease severity or other potentially confounding factors. In the 31 months prior to initiation of the perioperative nausea and vomiting protocol, there were 5 strokes in 137 surgically treated hemispheres (3.6%). After initiation of the protocol, there were no strokes in 114 surgically treated hemispheres (p = 0.065). CONCLUSIONS: Instituting a standardized perioperative nausea and vomiting protocol was associated with reduction in perioperative strokes in children with moyamoya treated with indirect bypass surgery.

Direct Transverse Sinus Puncture for Transvenous Coil Embolization of Vein of Galen Malformations: Innovating Existing Techniques.

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.

Middle meningeal artery embolization for refractory chronic subdural hematoma in a pediatric victim of nonaccidental trauma: illustrative case.

BACKGROUND: Chronic subdural hematoma (cSDH) in children is associated with several etiologies, one of which is nonaccidental trauma (NAT). Performed alone or as an adjunct to surgical intervention, middle meningeal artery (MMA) embolization may be effective in resolving and preventing the recurrence of cSDH in adult patients. However, MMA embolization for pediatric cSDH has not been adequately evaluated, and there exists no consensus on the appropriate selection of pediatric patients for this minimally invasive procedure. Appreciating the variable underlying pathophysiology of pediatric cSDH will enable the development of guidelines for patient selection. OBSERVATIONS: A 14-month-old female patient presented with depressed consciousness, seizure-like activity, and apneic episodes. She was diagnosed with bilateral subacute on chronic SDH associated with NAT, and imaging revealed diffuse brain atrophy. Despite undergoing burr hole drainage, she developed refractory cSDH and was treated with bilateral MMA embolization. At her 10-month follow-up, magnetic resonance imaging revealed a decrease in the size of the subdural collections, and she was tolerating feeds, at her neurological baseline, and seizure-free. LESSONS: Infants and young children with symptomatic cSDH secondary to NAT, whose tissue dynamics are reminiscent of cSDH in elderly patients with diffuse brain atrophy, may derive the most benefit from MMA embolization.

Evolution of clinical and translational advances in the management of pediatric arteriovenous malformations.

Arteriovenous malformations (AVMs) represent one of the most challenging diagnoses in pediatric neurosurgery. Until recently, the majority of AVMs was only identified after hemorrhage and primarily treated with surgery. However, recent advances in a wide range of fields-imaging, surgery, interventional radiology, radiation therapy, and molecular biology-have profoundly advanced the understanding and therapy of these complex lesions. Here we review the progress made in pediatric AVMs with a specific focus on innovations relevant to clinical care.

Focal drug-resistant temporal lobe epilepsy associated with an ipsilateral anterior choroidal artery aneurysm: illustrative case.

BACKGROUND: The occurrence of both an intracranial aneurysm and epilepsy, especially drug-resistant epilepsy (DRE), is rare. Although the overall incidence of aneurysms associated with DRE is unclear, it is thought to be particularly infrequent in the pediatric population. Surgical ligation of the offending aneurysm has been reported in conjunction with resolving seizure activity, although few cases have cited a combined approach of aneurysm ligation and resection of an epileptogenic focus. OBSERVATIONS: We present the case of a 14-year-old female patient with drug-resistant temporal lobe epilepsy and an ipsilateral supraclinoid internal carotid artery aneurysm. Seizure semiology, electroencephalography monitoring, and magnetic resonance imaging all indicated a left temporal epileptogenic focus, in addition to an incidental aneurysm. The authors recommended a combined surgery involving resection of the temporal lesion and surgical clip ligation of the aneurysm. Near-total resection and successful ligation were achieved, and the patient has remained seizure free since surgery at 1 year postoperatively. LESSONS: In patients with focal DRE and an adjacent intracranial aneurysm, a combined surgical approach involving both resection and surgical ligation can be used. Several surgical timing and neuroanesthetic considerations should be made to ensure the overall safety and efficacy of this procedure.

Understanding development of jugular bulb stenosis in vein of galen malformations: identifying metrics of complex flow dynamics in the cerebral venous vasculature of infants.

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.

Diffusion-Weighted Magnetic Resonance Imaging Demonstrates White Matter Alterations in Watershed Regions in Children With Moyamoya Without Stroke or Silent Infarct.

BACKGROUND: Moyamoya is a disease with progressive cerebral arterial stenosis leading to stroke and silent infarct. Diffusion-weighted magnetic resonance imaging (dMRI) studies show that adults with moyamoya have significantly lower fractional anisotropy (FA) and higher mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) compared with controls, which raises concern for unrecognized white matter injury. Children with moyamoya have significantly lower FA and higher MD in their white matter compared with controls. However, it is unknown which white matter tracts are affected in children with moyamoya. METHODS: We present a cohort of 15 children with moyamoya with 24 affected hemispheres without stroke or silent infarct compared with 25 controls. We analyzed dMRI data using unscented Kalman filter tractography and extracted major white matter pathways with a fiber clustering method. We compared the FA, MD, AD, and RD in each segmented white matter tract and combined white matter tracts found within the watershed region using analysis of variance. RESULTS: Age and sex were not significantly different between children with moyamoya and controls. Specific white matter tracts affected included inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, superior longitudinal fasciculus, thalamofrontal, uncinate fasciculus, and arcuate fasciculus. Combined watershed region white matter tracts in children with moyamoya had significantly lower FA (-7.7% ± 3.2%, P = 0.02) and higher MD (4.8% ± 1.9%, P = 0.01) and RD (8.7% ± 2.8%, P = 0.002). CONCLUSIONS: Lower FA with higher MD and RD is concerning for unrecognized white matter injury. Affected tracts were located in watershed regions suggesting that the findings may be due to chronic hypoperfusion. These findings support the concern that children with moyamoya without overt stroke or silent infarction are sustaining ongoing injury to their white matter microstructure and provide practitioners with a noninvasive method of more accurately assessing disease burden in children with moyamoya.

Neurosurgical outcomes of pediatric cerebral venous sinus thrombosis following acute mastoiditis: a systematic review and meta-analysis.

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.

A persistent trigeminal artery demonstrates cerebrovascular embryologic development.

Background: Cerebrovascular embryologic development is characterized by the presence of four well-described carotid-vertebrobasilar (VB) anastomoses. As the fetal hindbrain matures and the VB system develops, these connections involute, yet some may persist into adulthood. The persistent primitive trigeminal artery (PPTA) is the most common of these anastomoses. In this report, we describe a unique variant of the PPTA and a four-way division of the VB circulation. Case Description: A female in her 70s presented with a Fisher Grade 4 subarachnoid hemorrhage. Catheter angiography revealed a fetal origin of the left posterior cerebral artery (PCA) giving rise to a left P2 aneurysm which was coiled. A PPTA arose from the left internal carotid artery and supplied the distal basilar artery (BA) including the superior cerebellar arteries bilaterally and the right but not left PCA. The mid-BA was atretic and the anterior inferior cerebellar artery-posterior inferior cerebellar artery complexes were fed solely from the right vertebral artery. Conclusion: Our patient's cerebrovascular anatomy represents a unique variant of the PPTA not well described in the literature. This demonstrates how hemodynamic capture of the distal VB territory by a PPTA is sufficient to prevent fusion of the BA.