A Case of Metastatic CNS Melanoma of Unknown Primary Presenting with Seizures

Seizures are a common occurrence. The goal of evaluating a seizure is to identify the etiology and to determine the likelihood of recurrence as well as guide management. We present a unique presentation of a 47-year-old female that presented with late onset seizures admitted due to status epilepticus. Brain magnetic resonance indicated diffuse supratentorial hemorrhagic lesions. Neurological workup including brain vessel imaging, CT chest, abdomen, and pelvis as well as CSF and serological workup for vasculitis failed to demonstrate the cause of her brain lesions. Ultimately, a brain biopsy showed metastatic melanoma of unknown primary origin.

Refining the mandibular osteoradionecrosis rat model by in vivo longitudinal µCT analysis

Osteoradionecrosis (ORN) is one of the most feared side effects of radiotherapy following cancers of the upper aero-digestive tract and leading to severe functional defects in patients. Today, our lack of knowledge about the physiopathology restricts the development of new treatments. In this study, we refined the ORN rat model and quantitatively studied the progression of the disease. We tested the impact of radiation doses from 20 to 40 Gy, delivered with incident 4MV X-ray beams on the left mandible of the inbred Lewis Rat. We used micro-computed tomography (µCT) to obtain in vivo images for longitudinal bone imaging and ex vivo images after animal perfusion with barium sulphate contrast agent for vessel imaging. We compared quantification methods by analyzing 3D images and 2D measurements to determine the most appropriate and precise method according to the degree of damage. We defined 25 Gy as the minimum irradiation dose combined with the median molar extraction necessary to develop non-regenerative bone necrosis. µCT image analyses were correlated with clinical and histological analyses. This refined model and accurate methods for bone and vessel quantification will improve our knowledge of the progression of ORN pathology and allow us to test the efficacy of new regenerative medicine procedures.

Non-contrast head CT alone for thrombectomy in acute ischemic stroke: analysis of the ANGEL-ACT registry

BackgroudThe goal of this study was to determine if the choice of imaging paradigm performed in the emergency department influences the procedural or clinical outcomes after mechanical thrombectomy (MT).MethodsThis is a retrospective comparative outcome study which was conducted from the ANGEL-ACT registry. Comparisons were made between baseline characteristics and clinical outcomes of patients with acute ischemic stroke undergoing MT with non-contrast head computed tomography (NCHCT) alone versus patients undergoing NCHCT plus non-invasive vessel imaging (NVI) (including CT angiography (with or without CT perfusion) and magnetic resonance angiography). The primary outcome was the modified Rankin Scale (mRS) score at 90 days. Secondary outcomes included change in mRS score from baseline to 90 days, the proportions of mRS 0–1, 0–2, and 0–3, and dramatic clinical improvement at 24 hours. The safety outcomes were any intracranial hemorrhage (ICH), symptomatic ICH, and mortality within 90 days.ResultsA total of 894 patients met the inclusion criteria; 476 (53%) underwent NCHCT alone and 418 (47%) underwent NCHCT + NVI. In the NCHCT alone group, the door-to-reperfusion time was shorter by 47 min compared with the NCHCT + NVI group (219 vs 266 min, P<0.001). Patients in the NCHCT alone group showed a smaller increase in baseline mRS score at 90 days (median 3 vs 2 points; P=0.004) after adjustment. There were no significant differences between groups in the remaining clinical outcomes.ConclusionsIn patients selected for MT using NCHCT alone versus NCHCT + NVI, there were improved procedural outcomes and smaller increases in baseline mRS scores at 90 days.

The Common Carotid Artery Thrombus and Embolic Stroke in the Setting of COVID-19 Infection

Since the outbreak of the COVID-19 in Wuhan, China in 2019, there have been increasing reports of large vessel thrombosis and associated embolic stroke in patients with COVID-19 infection. The pathogenesis is thought to be multifactorial, including angiotensin-converting enzyme 2 receptor-mediated endothelial damage, rupture of atherosclerotic plaques, cytokine-storm induced-inflammation, and hypercoagulability. Here, we present a case of an otherwise-healthy COVID-19 patient who developed a right common carotid artery thrombus and embolic stroke with left sided numbness and weakness. Blood tests were significant for elevated levels of inflammatory biomarkers and di-dimer. Vessel imaging showed no evidence of underlying atherosclerosis or arterial dissection. Cardiac workup was unremarkable. The etiology of the carotid artery thrombus was likely COVID-19 related inflammation and hypercoagulability. He was started on apixaban 5mg twice daily for secondary stroke prevention. After 3 months, he was transitioned from apixaban to aspirin 81mg daily. At 4-month follow-up, he improved with only residual left arm numbness. Our case study suggests that in patients with large vessel thrombosis in the setting of Covid-19 infection, oral anticoagulation for 3 months followed by daily aspirin may be a reasonable treatment option for secondary stroke prevention.

POS0803 TRENDS IN THE INCIDENCE OF GIANT CELL ARTERITIS ACROSS SEVEN DECADES AND CHANGES IN DIAGNOSTIC MODALITIES: A POPULATION-BASED STUDY

Background:Diagnostic methods for giant cell arteritis (GCA) have evolved over recent decades, and large vessel imaging plays an increasing role in disease detection.Objectives:This study aims to estimate the incidence of GCA over the past 10 years in a population and compare it to preceding incidence estimates. It also explores trends in the diagnostic modalities used to identify GCA.Methods:A pre-existing population-based cohort of patients diagnosed with GCA between 1950 and 2009 was extended with incident cases from 2010 to 2019. The diagnosis of GCA was confirmed by review of medical records of patients with ICD9/10 codes for GCA between 1/1/2010 and 12/31/2019. Incident cases that met either one of the following sets of inclusion criteria were added to the cohort: one, American College of Rheumatology 1990 GCA classification criteria; or two, patients aged ≥50 years with elevation of erythrocyte sedimentation rate or C-reactive protein and radiographic evidence of large vessel vasculitis attributed to GCA. Incident cases were classified into one of three groups: group 1, temporal artery biopsy (TAB) positive; group 2, TAB negative or not done with positive large-vessel imaging; or group 3, clinical diagnosis of GCA.Results:The study cohort included 305 patients diagnosed with GCA from 1950 until 2019. Fifty-five incident cases were diagnosed between 2010 and 2019; 37 females (67%) and 18 males (33%). The age and sex adjusted incidence rates (95% CI) per 100,000 between 2010 and 2019 for females, males, and the total population were 13.0 (8.8, 17.3), 8.6 (4.6, 12.7), and 10.8 (8.0, 13.7), respectively. The corresponding incidence rates from 2000-2009 were 28.0 (21.0, 35.1), 10.2 (5.0, 15.5), and 20.5 (15.9, 25.1), respectively. This represents a significant decline in the incidence rates in females (p<0.001) and the total group (p<0.001) between the 2000-2009 and 2010-2019 cohorts but no change in males (p=0.64). Of the 55 patients diagnosed between 2010 and 2019, there were 37 (67%) in group 1, 10 (18%) in group 2, and 8 (15%) in group 3. In contrast, of the 250 patients diagnosed between 1950 and 2009 there were 209 (84%) in group 1, 4 (2%) in group 2, and 37 (15%) in group 3. There was a significant difference between the 1950-2009 and 2010-2019 cohorts in the composition of these groups (p<0.001).Conclusion:In this population-based cohort of patients with GCA diagnosed over a 70-year period, the incidence of GCA has declined in recent years. The total decline is driven by a decline in females but not in males. The reasons for this are unclear but should be followed over time and investigated in other population-based cohorts. There has also been a shift in the diagnostic modalities for GCA. In recent years, there are fewer TAB positive patients, and more patients diagnosed with large vessel imaging. This is the first population-based incidence cohort demonstrating a trend towards increased use of large vessel imaging for the diagnosis of GCA.References:[1]Chandran AK, et al. Incidence of Giant Cell Arteritis in Olmsted County, Minnesota, over a 60-year period 1950-2009. Scand J Rheumatol. 2015;44(3):215-218.[2]Gonzalez-Gay MA, et al. Giant cell arteritis: is the clinical spectrum of the disease changing? BMC Geriatr. 2019; Jul 29;19(1):200.[3]Rubenstein E, et al. Sensitivity of temporal artery biopsy in the diagnosis of giant cell arteritis: a systemic literature review and meta-analysis. Rheumatology (Oxford). 2020 May 1:59(5):1011-1020.Figure 1.Trends in the incidence of GCA in Olmsted County by sex (1950-2019).Acknowledgements:This study was made possible using the resources of the Rochester Epidemiology Project, which is supported by the National Institute on Aging of the National Institutes of Health (NIH) under Award Number R01 AG034676, and CTSA Grant Number UL1 TR000135 from the National Center for Advancing Translational Sciences (NCATS), a component of the NIH. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.Disclosure of Interests:Thomas Garvey: None declared, Cynthia S. Crowson: None declared, Matthew Koster: None declared, Kenneth J Warrington Grant/research support from: Clinical research support from Eli Lilly and Kiniksa

A precision medicine framework for personalized simulation of hemodynamics in cerebrovascular disease

Background Cerebrovascular disease, in particular stroke, is a major public health challenge. An important biomarker is cerebral hemodynamics. To measure and quantify cerebral hemodynamics, however, only invasive, potentially harmful or time-to-treatment prolonging methods are available. Results We present a simulation-based approach which allows calculation of cerebral hemodynamics based on the patient-individual vessel configuration derived from structural vessel imaging. For this, we implemented a framework allowing segmentation and annotation of brain vessels from structural imaging followed by 0-dimensional lumped simulation modeling of cerebral hemodynamics. For annotation, a 3D-graphical user interface was implemented. For 0D-simulation, we used a modified nodal analysis, which was adapted for easy implementation by code. The simulation enables identification of areas vulnerable to stroke and simulation of changes due to different systemic blood pressures. Moreover, sensitivity analysis was implemented allowing the live simulation of changes to simulate procedures and disease progression. Beyond presentation of the framework, we demonstrated in an exploratory analysis in 67 patients that the simulation has a high specificity and low-to-moderate sensitivity to detect perfusion changes in classic perfusion imaging. Conclusions The presented precision medicine approach using novel biomarkers has the potential to make the application of harmful and complex perfusion methods obsolete.

Abstract 56: Incidence of Large Vessel Occlusions in Children Who Present Within Extended Thrombectomy Treatment Window

Introduction: Mechanical thrombectomy (MT) should be considered in children with persistent deficits with large vessel occlusion (LVO), although the recognition and diagnosis of stroke is often delayed. With the recent extension of treatment windows to 24 hours in adult studies, more children may now be MT candidates. The aim of this project was to examine LVO incidence in childhood strokes that present within 24 hours of symptom onset. Methods: Patients with clinical and radiographic confirmed stroke from 1995-2018 were identified via internal database search. Patients with last known normal < 24 hours and imaging within the MT time window (24 hours) were included for analysis. A pediatric neuroradiologist independently reviewed imaging to confirm presence/absence of LVO. Results: Of 165 patients with childhood stroke, 60 (36.3%) had last known normal <24 hours and vessel imaging within the MT timeframe (table). Fourteen patients (8.5%) had an LVO; nine with internal carotid or M1 and five with M2 occlusions. Median time from symptom onset to imaging was 6.47 hours in LVO patients. Most common stroke etiologies with LVO were unilateral focal cerebral arteriopathy of childhood (5) and other (5). One of the LVO patients underwent MT. Conclusions: At our institution, over 1/3 rd of patients presented within 24 hour of symptom onset with vascular imaging, and nearly 1/4 of those children (8.5% overall) had an LVO amenable to potential MT. While not all children with LVO will be MT candidates, this study shows that significant numbers of children present with LVO within the adult MT treatment window.