Feasibility, safety, and efficacy of endovascular treatment of anterior cranial fossa dural arteriovenous fistulas: a systematic review and meta-analysis with a subanalysis for Onyx.

Dural Arteriovenous Fistulas (dAVFs) of the anterior cranial fossa (ACF) are uncommon but carry a high risk of hemorrhage and pose substantial treatment challenges. Recent advancements in endovascular treatment (EVT), including the introduction of novel liquid embolic agents, have markedly bolstered EVT's role in managing ACF-dAVFs, with notable series published in the last five years. We aimed to assess the feasibility, safety, and efficacy of EVT for ACF-dAVFs. We searched Medline, Scopus, Web of Science, and Cochrane Library databases following PRISMA guidelines. Eligible studies included those with ≥ 5 patients undergoing embolization of ACF-dAVFs, detailing both angiographic and clinical outcomes. We used single proportion analysis with 95% confidence intervals under a random-effects model, I2 to assess heterogeneity, and Baujat and sensitivity analysis to address high heterogeneity. Publication bias was assessed by funnel-plot analysis and Egger's test. Outcomes included complete occlusion following embolization, unsuccessful endovascular embolization attempts, incomplete occlusion following embolization, symptom resolution or clinical improvement following embolization, recurrence; procedure-related complications, morbidity, and mortality. Additionally, a subanalysis for studies exclusively utilizing Onyx™ embolic system was done. Eighteen studies comprising 231 ACF-dAVF were included. Unsuccessful endovascular embolization attempts rate was 2%. Complete occlusion rate was 85%, with 4% of complications. Incomplete occlusion rate was 10%. Successfully embolized patients experienced either symptom resolution or clinical improvement in 94% of cases. Morbidity and mortality rates were 1% and 0%, respectively. Onyx subanalyses showed an overall rate of 0% for unsuccessful attempts, 95% for complete occlusion, and 5% for incomplete occlusion. Symptom resolution or clinical improvement was 98% and recurrence rate was 0%. EVT for ACF-dAVF is highly feasible, effective, and safe, with a low rate of complications, morbidity, and mortality. The subanalyses focusing on Onyx embolizations revealed superior efficacy and safety outcomes compared to the findings of the primary analyses involving all included studies.

Middle Meningeal Artery Embolization in the Management of Chronic Subdural Hematoma: a Comprehensive Review of Current Literature.

PURPOSE OF REVIEW: Chronic subdural hematoma (cSDH) is a common intracranial hemorrhagic disorder with a high incidence rate among the elderly. While small, asymptomatic cSDH may resolve spontaneously, surgical intervention has been the treatment of choice for larger, symptomatic cases. Surgical evacuation of cSDH may be associated with high rates of recurrence, and even asymptomatic cSDH cases tend to progress. Over the last few years, middle meningeal artery (MMA) embolization has proven to be a safe non-invasive treatment of choice with favorable outcomes and a low recurrence rate. The ensuing paper discusses current treatment modalities for cSDH and reviews existing literature on the anatomy of MMA and its embolization as a treatment option for cSDH. RECENT FINDINGS: Recent studies show that traumatic head injury leading to subdural hemorrhage can induce neovascularization that may initiate a cycle of recurrent subdural hematoma. Distal branches of MMA supply blood to the dural layers. Several studies have revealed that embolization of the MMA can stop the neovascularization process and blood flow. In addition, patients who underwent MMA embolization had a significantly quicker brain re-expansion and lower recurrence rate. Although the management of cSDH is still very much a dilemma, recent research findings bring MMA embolization to light as a promising treatment alternative and adjunctive therapy.

Mechanical Revascularization in the Era of the Field Assessment Stroke Triage for Emergency Destination (FAST-ED): A Retrospective Cohort Assessment in a Community Stroke Practice.

BACKGROUND: Endovascular mechanical revascularization has become the mainstay acute stroke management secondary to emergent large vessel occlusions. In patients who can benefit from mechanical revascularization, the ability to intervene in a timely manner directly correlates with improved outcomes. The field assessment for stroke triage (FAST-ED) prehospital triage tool, is one of many stroke severity scales designed to decrease time to diagnosis in the field and optimize patient triage to comprehensive stroke centers. It is however unclear what impact if any, this tool has on time to activation of hospital stroke intervention teams. We set out to assess the impact of the implementation of the FAST-ED triage tool on the activation of the stroke intervention team in a community stroke treatment practice. METHODS: We retrospectively reviewed institutional records for consecutive admissions with reported stroke alerts between March 2017 and September 2018, and selected patients who presented via Emergency Medical Services (EMS). The association between FAST-ED scores and impact on time to revascularization as well as the association between FAST-ED scores and the presence of emergent large vessel occlusion were analyzed. RESULTS: There was a statistically significant improvement in interventional team activation times in favor of the FAST-ED cohort, (P < .05). CONCLUSIONS: FAST-ED implementation demonstrates a statistically significant improvement on stroke team activation times for patients who are candidates for mechanical revascularization. Larger cohort analysis is needed to fully evaluate the magnitude of this effect.

Endovascular aspiration of a symptomatic free-floating common carotid artery thrombus.

Free-floating thrombi of the common carotid artery (CCA) are a very rare cause of ischemic stroke. To date, only a few reports have been described in the academic literature. Revascularization is indicated due to the risk of thromboembolic disease and hemodynamic-related stroke syndromes. Medical treatment typically includes anticoagulation and, in some circumstances, open surgical thrombectomy is an additional option. Although rarely described in the literature, endovascular thrombectomy is a viable treatment alternative in these patients.

Diagnosis of Normal-Pressure Hydrocephalus: Use of Traditional Measures in the Era of Volumetric MR Imaging.

Purpose To assess the diagnostic performance of the callosal angle (CA) and Evans index (EI) measures and to determine their role versus automated volumetric methods in clinical radiology. Materials and Methods Magnetic resonance (MR) examinations performed before surgery (within 1-5 months of the MR examination) in 36 shunt-responsive patients with normal-pressure hydrocephalus (NPH; mean age, 75 years; age range, 58-87 years; 26 men, 10 women) and MR examinations of age- and sex-matched patients with Alzheimer disease (n = 34) and healthy control volunteers (n = 36) were studied. Three blinded observers independently measured EI and CA for each patient. Volumetric segmentation of global gray matter, white matter, ventricles, and hippocampi was performed by using software. These measures were tested by using multivariable logistic regression models to determine which combination of metrics is most accurate in diagnosis. Results The model that used CA and EI demonstrated 89.6%-93.4% accuracy and average area under the curve of 0.96 in differentiating patients with NPH from patients without NPH (ie, Alzheimer disease and healthy control). The regression model that used volumetric predictors of gray matter and white matter was 94.3% accurate. Conclusion CA and EI may serve as a screening tool to help the radiologist differentiate patients with NPH from patients without NPH, which would allow for designation of patients for further volumetric assessment. © RSNA, 2017.

Clopidogrel versus newer P2Y12 inhibitors in the dual antiplatelet therapy for stent-assisted coil embolization of intracranial aneurysms: A meta-analysis.

INTRODUCTION: Stent-assisted coil embolization (SACE) for cerebral aneurysms requires dual antiplatelet therapy (DAPT), commonly clopidogrel plus aspirin is preferable to ticagrelor or prasugrel plus aspirin. However, there are few studies assessing the safety of the association of ticagrelor or prasugrel plus aspirin. OBJECTIVES: Compare the safety of newer P2Y12 inhibitors with clopidogrel in patients that underwent a SACE for cerebral aneurysms. METHODS: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, we searched PubMed and Embase for studies comparing newer P2Y12 inhibitors with clopidogrel in patients undergoing DAPT for SACE. Outcomes were total number of complications, number of hemorrhagic complications, and number of thromboembolic complications both intraoperative and follow-up. A random effects model was used to calculate odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: We included 1026 patients from six studies. Newer P2Y12 inhibitors were used in 562 (54,77%) patients. There were no significant differences between groups in total number of complications (OR 0.80; 95% CI 0.32, 1.99; p < 0.01; I2 = 78%), in intraoperative hemorrhagic complications (OR 0.66; 95% CI 0.09, 4.71; p = 0.68; I2 = 0%), follow-up hemorrhagic complications (OR 1.23; 95% CI 0.70, 2.15; p = 0.49; I2 = 0%), intraoperative thromboembolic complications (OR 0.43; 95% CI 0.14, 1.35; p = 0.25; I2 = 24%), and in follow-up thromboembolic complications (OR 0.89; 95% CI 0.33, 2.39; p = 0.03; I2 = 59%). CONCLUSION: In patients who underwent a SACE, newer P2Y12 inhibitors showed no differences in intraoperative and follow-up complications compared with clopidogrel.

Comparing surgical clipping with endovascular treatment for unruptured middle cerebral artery aneurysms: a systematic review and updated meta-analysis.

OBJECTIVE: Unruptured middle cerebral artery aneurysm (uMCAA) has traditionally been treated with open surgical clipping (SC). Endovascular treatments (EVTs) were designed to reduce surgical risks in these cases. Nevertheless, despite its potential benefits, many surgeons favor SC for uMCAA. This updated meta-analysis aimed to compare the safety, efficacy, and clinical outcomes of SC and EVT for uMCAA. METHODS: The authors searched the Medline, Embase, and Cochrane Library databases according to the Cochrane and PRISMA guidelines. Eligible studies included those with ≥ 4 patients with uMCAA reporting comparative data of SC and EVT. The endpoints were the complete occlusion rate (Raymond class I and II), good clinical outcomes (modified Rankin Scale score ≤ 2 or Glasgow Outcome Scale score ≥ 4), procedure-related complications (further divided into major and minor), and mortality. The authors pooled OR with 95% CI values with a random-effects model. I2 statistics were used to assess heterogeneity, and sensitivity analysis was conducted to address high heterogeneity. Publication bias was assessed with funnel plot analysis and the Egger's test. RESULTS: The analysis included data from 10 studies. Regarding the complete occlusion assessment, the comparative analysis revealed OR 0.17 (95% CI 0.08-0.40, p < 0.01), favoring SC. In terms of achieving good clinical outcomes, OR 0.44 (95% CI 0.20-0.97, p < 0.05) was determined, favoring SC. No differences regarding total procedure-related complications, major complications, or mortality were identified. However, a higher likelihood of minor complications was identified for EVT, with OR 4.68 (95% CI 2.01-10.92, p < 0.01). CONCLUSIONS: This systematic review and meta-analysis identified a lower likelihood of complete occlusion at last follow-up and lower likelihood of good clinical outcomes in patients treated with EVT when compared with SC. Furthermore, a higher likelihood of minor complications was identified in patients who underwent EVT when compared with SC. The findings reinforce that, based on the currently available data, SC should be considered the primary approach for treating uMCAA. However, EVT is an evolving approach, and this study's findings represent a synthesis of observational studies. Randomized trials are warranted to elucidate which approach should be the mainstay for uMCAA and to identify the nuances that determine whether SC or EVT is more or less indicated for addressing uMCAA with consideration of the individuality of each patient and aneurysm.

A GluR1-cGKII interaction regulates AMPA receptor trafficking.

Trafficking of AMPA receptors (AMPARs) is regulated by specific interactions of the subunit intracellular C-terminal domains (CTDs) with other proteins, but the mechanisms involved in this process are still unclear. We have found that the GluR1 CTD binds to cGMP-dependent protein kinase II (cGKII) adjacent to the kinase catalytic site. Binding of GluR1 is increased when cGKII is activated by cGMP. cGKII and GluR1 form a complex in the brain, and cGKII in this complex phosphorylates GluR1 at S845, a site also phosphorylated by PKA. Activation of cGKII by cGMP increases the surface expression of AMPARs at extrasynaptic sites. Inhibition of cGKII activity blocks the surface increase of GluR1 during chemLTP and reduces LTP in the hippocampal slice. This work identifies a pathway, downstream from the NMDA receptor (NMDAR) and nitric oxide (NO), which stimulates GluR1 accumulation in the plasma membrane and plays an important role in synaptic plasticity.

Use of quantitative magnetic resonance angiography in patients with symptomatic intracranial arterial stenosis who undergo stenting: Presentation of three cases.

Intracranial atherosclerotic disease (ICAD) is an important cause of ischemic stroke. The etiology of stroke in patients with ICAD could be due to several mechanisms including hypoperfusion, artery-to-artery embolism, and plaque extension over small penetrating artery ostia. Management of symptomatic ICAD includes medical and endovascular management. Quantitative magnetic resonance angiography (MRA) is a technique that allows for non-invasive measurement of large vessel blood flow in the head and neck. Here, we describe procedural and clinical outcomes on three patients who presented with symptomatic ICAD and were treated with angioplasty and stenting. Quantitative MRA was used pre- and post- procedurally to assess the effects of stenting on the intracranial blood flow. Quantitative measures of intracranial blood flow may serve as an additional triage tool in the evaluation of patients with symptomatic ICAD.

Middle Meningeal Artery Embolization and the Treatment of a Chronic Subdural Hematoma.

Chronic subdural hematoma (cSDH) is a common pathology that typically affects the elderly. It is believed to occur due to injury to the dural border cells, which creates an inflammation/proliferation reaction. Ineffective repair leads to the formation of a new external layer of cells and fragile capillaries, which damage easily and can worsen the condition. Conventionally, asymptomatic cSDH is managed by observation, and symptomatic cases are treated by surgical evacuation. Unfortunately, recurrence rates of the SDH following surgical evacuation can be high. One treatment option for SDH involves embolization of the middle meningeal artery (MMA). The MMA provides blood supply to the dura mater and feeds the membrane capillaries covering the SDH. MMA embolization blocks the blood flow to this system and can promote hematoma resolution. In this paper, we review the existing literature on MMA embolization and discuss the underlying pathophysiology of cSDH.

Fusiform superior cerebellar artery aneurysm treated with flow diversion: A case report.

BACKGROUND: Fusiform aneurysms of the distal superior cerebellar artery are rare and challenging to treat. Due to the rarity of these lesions, there is little consensus regarding their management. Treatment options have traditionally included parent artery sacrifice with either an endovascular approach or microsurgical clipping. Given the small diameter of the superior cerebellar artery, flow diversion has not been typically considered as a viable treatment option for these aneurysms. CASE DESCRIPTION: A 67-year-old female presented complaining of severe sudden onset headache. Noncontrast head CT demonstrated no intracranial hemorrhage. Head CT angiogram demonstrated a 4.2 mm fusiform aneurysm in the distal right superior cerebellar artery. The patient underwent treatment with the Pipeline embolization device which was deployed in the right superior cerebellar artery covering the aneurysm. Six-month posttreatment follow-up angiogram demonstrated resolution of the aneurysm with patency of the parent vessel. CONCLUSION: To the best of our knowledge, this is the first report of a distal superior cerebellar artery aneurysm treated with the Pipeline embolization device. The use of a Pipeline stent to create flow diversion should be considered in a case of a fusiform aneurysm of the right superior cerebellar artery. Treatment with flow diversion may allow for the treatment of the aneurysm while preserving patency of the parent vessel.

A Roadmap to Reopening a Neurosurgical Practice in the Age of COVID-19.

BACKGROUND: The Coronavirus disease 2019 (COVID-19) outbreak has left a lasting mark on medicine globally. METHODS: Here we outline the steps that the Lenox Hill Hospital/Northwell Health Neurosurgery Department-located within the epicenter of the pandemic in New York City-is currently taking to recover our neurosurgical efforts in the age of COVID-19. RESULTS: We outline measurable milestones to identify the transition to the recovery period and hope these recommendations may serve as a framework for an effective path forward. CONCLUSIONS: We believe that recovery following the COVID-19 pandemic offers unique opportunities to disrupt and rebuild the historical patient and office experience as we evolve with modern medicine in a post-COVID-19 world.

Coronavirus Neurosurgical/Head and Neck Drape to Prevent Aerosolization of Coronavirus Disease 2019 (COVID-19): The Lenox Hill Hospital/Northwell Health Solution.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has infected more than 13 million people on a global scale and claimed more than half million deaths across 213 countries and territories. While the focus is currently on recovery from the pandemic, the disease has significantly changed the way we practice medicine and neurosurgery in New York City and the United States. Apart from the emergency cases, several health systems across the country have similarly started to perform elective surgeries. Although COVID-19 screening and testing guidelines have been proposed and adopted by many hospitals, these may not adequately protect the operating room personnel who are in proximity to the patient for prolonged periods. There are concerning reports of especially high transmission rates of COVID-19 in transmucosal head and neck procedures conducted by otolaryngologists and neurosurgeons, despite attempts at wearing what constitutes appropriate personal protective equipment. METHODS: Here, we describe a simple technique of additional draping that can be used for all cranial, endonasal, spinal, and neurointerventional cases to limit the transmission of coronavirus. RESULTS: The proposed technique offers a simple, commonly available, cost-effective alternative that avoids the use of additional retractor systems. Moreover, this technique can be used in all neurosurgical procedures. CONCLUSIONS: With the rising concerns regarding airborne spread of the virus, we expect that these precautions will prove highly useful as we enter the recovery phase of this pandemic and hospitals attempt to prevent a return to widespread infection. In addition, its availability and cost effectiveness make this technique especially attractive to practical use in centers with limited resources.

MRI myelography for diagnosis and targeted blood patching of multilevel thoracic spine CSF leaks: Report of 2 cases.

In patients with occult cerebrospinal fluid (CSF) leaks or CSF leak syndrome, orthostatic headaches are a common presenting symptom. Although computed tomography (CT) myelography has historically been the gold standard for diagnosis with radioisotope cisternography as a diagnostic alternative, magnetic resonance imaging (MRI) myelography using intrathecal gadolinium has reported sensitivity of 80%-87%. Two patients with spontaneous orthostatic headaches lasting for several days were diagnosed with CSF leaks at multiple thoracic segments using MRI myelogram with intrathecal gadolinium (Gadavist, Bayer, Whippany, NJ). This allowed for subsequent targeted treatment with CT fluoroscopy guidance, resulting in therapeutic responses within 1-2 treatment with targeted blood patching. Although intrathecal gadolinium is an off-label use, the superior contrast resolution and lack of radiation exposure makes MRI myelography an excellent imaging modality for diagnosing CSF leak, targeting treatment, and monitoring outcomes compared to CT myelography and radioisotope cisternography.

Use of Pipeline Flex is associated with reduced fluoroscopy time, procedure time, and technical failure compared with the first-generation Pipeline embolization device.

BACKGROUND: Flow diversion with the Pipeline embolization device is a well-established method of intracranial aneurysm treatment. However, deployment of the first-generation device (Pipeline Classic) can be technically challenging. The Pipeline Flex contains the same flow-diverting stent with a modified delivery system. OBJECTIVE: To compare procedural outcomes between the first-generation device (Pipeline Classic) and the Pipeline Flex. METHODS: Thirty-eight of the first 40 consecutive patients who underwent intracranial aneurysm treatment with the Pipeline Flex and 58 of the most recent 60 consecutive patients who underwent treatment with the Pipeline Classic at our institution were evaluated. Patient demographics, aneurysm characteristics, technical procedural details, and early outcomes were analyzed. RESULTS: The two groups were comparable for age, gender, and location of target aneurysms. Use of Pipeline Flex decreased procedure time by 44.2 min (p≤0.001) and fluoroscopy time by 22.0 min (p=0.001) compared with the Pipeline Classic. Similarly, radiation exposure was less in the Flex group with a mean difference of 3473.5 Gy cm2 (p=0.002), while contrast usage was decreased with a mean difference of 22.3 mL (p=0.007). These differences remained significant in multivariate regression analysis. Finally, the rate of device deployment failure was lower in the Flex group (7.1%) than in the Classic group (23.9%) (p=0.034). CONCLUSIONS: Use of Pipeline Flex significantly reduces the total procedure and fluoroscopy time, contrast usage, patient radiation exposure, and proportion of recaptured devices in comparison with the Pipeline Classic, probably owing to an enhanced delivery system that allows for more reliable and controlled deployment.

Stent retrieval thrombectomy in acute stoke is facilitated by the concurrent use of intracranial aspiration catheters.

BACKGROUND: New device technology has changed the techniques used for revascularization of emergent large vessel occlusion in acute stroke. We report technical results using stent retrievers (SRs) for thrombectomy alone versus SRs used in conjunction with a new group of devices, intracranial aspiration catheters (IACs). Our aim is to demonstrate differences in procedural time and thrombectomy attempts between these two groups. METHODS: A retrospective evaluation was performed of a prospectively maintained database of 97 patients treated at a single institution for anterior circulation stroke with SRs. Patients were divided into two groups, a combination group defined as the SR/IAC group and the SR alone group defined as the SR group. RESULTS: Patients in the SR/IAC group had a mean age of 66 years vs 59 years in the SR group (p=0.008). Mean presenting National Institutes of Health Stroke Scale (NIHSS) scores in the SR/IAC and control groups were 18.7 and 18.2, respectively (p=0.50). Recanalization rates (Thrombolysis In Cerebral Infarction (TICI) 2b or 3) in the SR/IAC and SR groups were 85% (58/68) and 90% (26/29), respectively (p=0.41). Mean time from groin arteriotomy to recanalization was 50±3.6 min (range 19-136) in the SR/IAC group (n=59) and 61±6.6 min (range 28-140) in the SR group (n=27) (p=0.049). The total number of thrombectomy attempts in the SR/IAC and SR groups were 1.9±0.1 (range 1-4) and 2.5±0.6 (range 1-6), respectively (p=0.009). Post-procedural subarachnoid hemorrhage was seen in 15% (10/68) and 10% (3/29) of cases in the SR/IAC and SR groups, respectively (p=0.41). CONCLUSION: When using SRs for intracranial stroke thrombectomy, the concurrent use of IACs is associated with a decrease in procedural time and thrombectomy attempts compared with use of SRs alone.

Arterial Abnormalities Leading to Tinnitus.

Tinnitus is a common symptom that usually originates in the middle ear. Vascular causes of pulsatile tinnitus are categorized by the location of the source of the noise within the cerebral-cervical vasculature: arterial, arteriovenous, and venous. Arterial stenosis secondary to atherosclerotic disease or dissection, arterial anatomic variants at the skull base, and vascular skull base tumors are some of the more common causes of arterial and arteriovenous pulsatile tinnitus. Noninvasive imaging is indicated to evaluate for possible causes of pulsatile tinnitus, and should be followed by catheter angiography if there is a strong clinical suspicion for a dural arteriovenous fistula.

Dural Arteriovenous Fistulae: Imaging and Management.

Intracranial dural arteriovenous fistulae (DAVF) are pathologic arteriovenous shunts between meningeal arteries and dural venous sinuses or veins. They account for approximately 10% to 15% of all intracranial vascular malformations and are most common in middle-aged patients. DAVF are the most common vascular cause of pulsatile tinnitus. Digital subtraction angiography remains the gold standard for diagnosing these lesions. The pattern of venous drainage determines the type of DAVF and their risk for hemorrhage. Endovascular treatment has become a first-line option for their management. This article describes the natural history, clinical presentation, classification, imaging features, and management options of intracranial DAVF.

Varicella-Zoster Virus Vasculopathy: A Case Report Demonstrating Vasculitis using Black-Blood MRI.

Infections are rare but important causes of stroke. Among these, varicella zoster virus has been known to cause ischemic stroke. During an attack of herpes zoster ophthalmicus, it has been hypothesized that the virus replicates in the trigeminal ganglion and travels via the trigeminal nerve centrally to cause cerebral vasculopathy. Here we present a case of a 69 year-old Caucasian immunocompromised woman who suffered recurrent ischemic infarcts within the same vascular distribution following an episode of zoster ophthalmicus three months prior. An imaging technique termed black-blood magnetic resonance imaging was utilized to aid in the diagnosis of cerebral vasculitis. The case is used to provide a literature review of the pathogenesis, diagnosis, and treatment of cerebral varicella zoster vasculopathy. In situations where an isolated unilateral cerebral vasculopathy is identified, neurologists are urged to consider varicella zoster as a treatable etiologic agent, as untreated vasculopathy can lead to further strokes.