Faculty Bibliography

Background and aims: Intracranial arterial calcification (IAC) has been identified as an independent risk factor for ischemic stroke. The predictive value of calcification severity for the underlying pathophysiological mechanism of an ischemic stroke remains undetermined. We aimed to assess the degree of intracranial artery calcification in patients with ischemic stroke and evaluate its correlation with intracranial artery atherosclerotic disease as the underlying mechanism.
Method(s): Two hundred and eleven patients with strokes attributed to large vessel atherosclerotic disease from the NYU Ischemic Stroke Database, determined by two independent vascular neurologists, were enrolled. Patients with tandem lesions or competing pathophysiologic mechanisms were excluded. Head CT scans for each patient were reviewed. The degree of calcification of each vertebral and basilar artery was determined by two physicians using the Woodcock Score (interrater reliability score of kappa = 0.88).
Result(s): The highest prevalence of calcification was seen in the left vertebral artery (47%), and less commonly in the basilar artery (15%). There was a trend towards higher prevalence of moderate-severe IAC in patients with stroke due to intracranial atherosclerosis than patients with stroke due to extracranial atherosclerosis (40% vs. 28%, P = 0.073). The most common risk factors were hypertension (42 vs. 26%, p = 0.890), dyslipidemia (25 vs. 19%, p = 0.496), and type 2 diabetes (21 vs. 13%, p = 0.415), in patients with stroke due to intracranial atherosclerosis vs extracranial atherosclerosis, respectively.
Conclusion(s): There may be a positive correlation between the severity of vertebrobasilar atherosclerotic disease as determined by the Woodcock score and the likelihood that the underlying pathophysiological mechanism of an ischemic stroke is intracranial atherosclerotic disease.
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BACKGROUND AND PURPOSE/OBJECTIVE:delays in patients with large vessel occlusion evaluated between 6 and 16 hours from last known normal. METHODS:6 or 10 s volume-baseline core volume). We stratified the cohort into 4 categories based on treatment modality and Thrombolysis in Cerebral Infarction (TICI score; untreated, TICI 0-2a, TICI 2b, and TICI3) and calculated penumbral consumption rates in each category. RESULTS:=0.92). CONCLUSIONS:>6-s mismatch volume may remain viable in untreated patients at 24 hours.

INTRODUCTION/BACKGROUND:Flow diverters such as the pipeline embolization device (PED) cause hemodynamic changes of the treated vessel segment. In posterior communicating artery (PcomA), aneurysms' unique anatomic consideration have to be taken in account due to the connection between the anterior and posterior circulation. We hypothesize that in conjunction with PcomA remodeling, there will also be remodeling of the ipsilateral P1 segment of the posterior cerebral artery (PCA) after PED treatment for PcomA aneurysms. METHODS:We retrospectively collected radiological as well as clinical data of PcomA aneurysm patients treated with PED including PcomA and P1 vessel diameters before and after treatment as well as patient and aneurysm characteristics. RESULTS:= 0.042). There were no neurologic complications on LFU. CONCLUSION/CONCLUSIONS:In the treatment of PcomA aneurysms with PED, the P1 segment of the PCA increases in diameter while the PcomA diameter decreases. Our results suggest that this remodeling effect is associated with aneurysm occlusion and decrease of PcomA is hemodynamically compensated for by an increase in the ipsilateral P1 diameter.

Venous variants and pathologic abnormalities are the most common causes of pulsatile tinnitus. These conditions include causes of turbulence within normally located veins and sinuses, and abnormally enlarged or abnormally located veins in close transmissive proximity to the conductive auditory pathway. Such disorders include pathologic abnormalities of the lateral sinus (transverse sinus stenosis and sigmoid sinus wall anomalies), abnormalities and variants of the emissary veins, and anomalies of the jugular bulb and jugular vein. Despite being the most common causes for pulsatile tinnitus, venous variants and pathologic abnormalities are often overlooked in the workup of pulsatile tinnitus. Such oversights can result in delayed patient care and prolonged patient discomfort. Advances in both cerebrovascular imaging and endovascular techniques allow for improved diagnostic accuracy and an increasing range of endovascular therapeutic options to address pulsatile tinnitus. This review illustrates the venous causes of pulsatile tinnitus and demonstrates the associated endovascular treatment. © RSNA, 2021.

Lacunar stroke is a marker of cerebral small vessel disease and accounts for up to 25% of ischaemic stroke. In this narrative review, we provide an overview of potential lacunar stroke mechanisms and discuss therapeutic implications based on the underlying mechanism. For this paper, we reviewed the literature from important studies (randomised trials, exploratory comparative studies and case series) on lacunar stroke patients with a focus on more recent studies highlighting mechanisms and stroke prevention strategies in patients with lacunar stroke. These studies suggest that lacunar stroke is a heterogeneous disease with various mechanisms, including most commonly lipohyalinosis and less commonly atheromatous disease and cardioembolism, highlighting the importance of a careful review of brain and neurovascular imaging, a cardiac and systemic evaluation. A better understanding of pathomechanisms of neurological deterioration may lead to investigating the utility of novel treatment strategies and optimisation of short-term antithrombotic treatment strategies to reduce the risk of neurological deterioration and prevent long-term disability in patients with lacunar stroke.

BACKGROUND:Over the past 2 decades, a growing number of large-scale clinical trials have helped expand the toolkit for emergency management of acute ischemic stroke. This article is intended to be an up-to-date resource to aid nonstroke specialist neurology providers and ophthalmologists in identifying situations and patient populations in which urgent stroke evaluation should be completed with options for emergent reperfusion therapy considered. EVIDENCE ACQUISITION/METHODS:The literature forming the foundation of the guidelines for early management of patients with acute ischemic stroke was reviewed, annotated, and summarized. RESULTS:Data from both initial and follow-up trials investigating the benefits and indications for use of intravenous thrombolysis and endovascular intervention for stroke are reviewed systematically, with an emphasis on new updates to qualifying patient populations and time periods for treatment. CONCLUSIONS:Recent studies underscore the conclusion that timely reperfusion in acute ischemic stroke is the most effective available treatment and that there are a growing number of new scenarios and patients for which interventions maybe applied.

Central retinal artery occlusion (CRAO) is a form of acute ischemic stroke which affects the retina. Intravenous thrombolysis is emerging as a compelling therapeutic approach. However, it is not known which patients may benefit from this therapy because there are no imaging modalities that adequately distinguish viable retina from irreversibly infarcted retina. The inner retina receives arterial supply from the central retinal artery and there is robust collateralization between this circulation and the outer retinal circulation, provided by the posterior ciliary circulation. Fundus photography can show canonical changes associated with CRAO including a cherry-red spot, arteriolar boxcarring and retinal pallor. Fluorescein angiography provides 2-dimensional imaging of the retinal circulation and can distinguish a complete from a partial CRAO as well as central versus peripheral retinal non-perfusion. Transorbital ultrasonography may assay flow through the central retinal artery and is useful in the exclusion of other orbital pathology that can mimic CRAO. Optical coherence tomography provides structural information on the different layers of the retina and exploratory work has described its utility in determining the time since onset of ischemia. Two experimental techniques are discussed. 1) Retinal functional imaging permits generation of capillary perfusion maps and can assay retinal oxygenation and blood flow velocity. 2) Photoacoustic imaging combines the principles of optical excitation and ultrasonic detection and - in animal studies - has been used to determine the retinal oxygen metabolic rate. Future techniques to determine retinal viability in clinical practice will require rapid, easily used, and reproducible methods that can be deployed in the emergency setting.

BACKGROUND:Comaneci (Rapid Medical) is a compliant, adjustable mesh that provides temporary scaffolding during coiling of wide-necked intracranial aneurysms (WNAs) that preserves antegrade flow. We report our early multi-institutional experience with the Comaneci device in the USA. METHOD/METHODS:We reviewed all patients with WNAs that were treated using the Comaneci device for coil remodeling of ruptured and unruptured aneurysms at 4 institutions between July 2019 and May 2020. Clinical characteristics, angiographic variables, and endovascular results were assessed. RESULTS:A total of 26 patients were included (18 women). The mean age was 62.7 years (range 44-81). Fifteen patients presented with ruptured aneurysms and 11 with unruptured aneurysms. The mean aneurysm neck width was 3.91 mm (range 1.9-6.5) with a mean dome-to-neck ratio of 1.57 (range 0.59-3.39). The mean maximum width was 5.80 mm (range 3.0-9.9) and the mean maximum height was 5.61 mm (range 2.0-11.8). Successful aneurysm occlusion was achieved in 25 of 26 patients. Complete occlusion was achieved in 16 patients, near-complete occlusion was observed in 9 patients, and 1 patient demonstrated residual filling. The mean time of device exposure was 24 min (range 8-76). No vasospasm was observed at the device location. Clot formation on the device was noted in 2 separate cases, but there were no clinical sequelae. There was 1 intraprocedural complication in a case that involved the simultaneous use of 2 Comaneci devices. CONCLUSIONS:Our initial experience shows that the Comaneci device is a promising and reliable tool that can safely support coil remodeling of WNAs.

BACKGROUND:The pterygovaginal artery (PtVA), a recurrent branch of the internal maxillary artery (IMA), can be a feeder of skull base tumors. Preoperative embolization can help endoscopic resection of hypervascular lesions, which is performed under a narrow surgical space with restricted instrumental maneuverability. METHODS:We performed preoperative embolization in five cases with hypervascular skull base lesions supplied by the PtVA, four of which were resected via endoscopic endonasal approach. In two cases, selective PtVA embolization through the distal IMA was successfully conducted. RESULTS:In all the cases, intraoperative bleeding during endoscopic resection was easily controlled. The medial and lateral origins of the PtVA from the IMA were demonstrated by cone-beam CT images reconstructed from three-dimensional rotational angiography, and anastomoses around the eustachian tube and soft palate were visualized by superselective angiography. CONCLUSIONS:The PtVA embolization can be an effective strategy before endoscopic skull base tumor resection. When embolizing through the PtVA, clinicians should be aware of its anatomical variations and dangerous anastomoses. Understanding the surrounding angioarchitecture by angiographic techniques helps ensure safe embolization.